tag:theconversation.com,2011:/global/topics/mountains-3172/articlesMountains – The Conversation2024-03-01T13:33:37Ztag:theconversation.com,2011:article/2220572024-03-01T13:33:37Z2024-03-01T13:33:37ZAltitude sickness is typically mild but can sometimes turn very serious − a high-altitude medicine physician explains how to safely prepare<figure><img src="https://images.theconversation.com/files/577770/original/file-20240225-28-vk2tcl.jpg?ixlib=rb-1.1.0&rect=77%2C33%2C7271%2C4869&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Altitude sickness is rare at elevations of less than 8,200 feet but becomes much more common at higher altitudes.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/girls-having-fun-royalty-free-image/854544188?phrase=mountain+adventure+travel&adppopup=true">Maya Karkalicheva/Moment via Getty Images</a></span></figcaption></figure><p>Equipped with the latest gear and a thirst for adventure, mountaineers embrace the perils that come with conquering the world’s highest peaks. Yet, even those who tread more cautiously at high altitude are not immune from the health hazards waiting in the thin air above.</p>
<p>Altitude sickness, which most commonly refers to <a href="https://medlineplus.gov/ency/article/000133.htm">acute mountain sickness</a>, <a href="https://doi.org/10.1016/j.pcad.2010.02.003">presents a significant challenge</a> to those traveling to and adventuring in high-altitude destinations. Its symptoms can range from <a href="https://doi.org/10.1089/ham.2017.0164">mildly annoying to incapacitating</a> and, in some cases, may progress to more <a href="https://doi.org/10.1183/16000617.0096-2016">life-threatening illnesses</a>. </p>
<p>While <a href="https://doi.org/10.18111/9789284424023">interest in high-altitude tourism is rapidly growing</a>, general awareness and understanding about the hazards of visiting these locations <a href="https://doi.org/10.1089/ham.2022.0083">remains low</a>. The more travelers know, the better they can prepare for and enjoy their journey.</p>
<p>As an <a href="https://som.cuanschutz.edu/Profiles/Faculty/Profile/36740">emergency physician specializing in high-altitude illnesses</a>, I work to improve health care in remote and mountainous locations around the world. I’m invested in finding ways to allow people from all backgrounds to experience the magic of the mountains in an enjoyable and meaningful way.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Researcher wearing cold-weather gear stands in front of a health clinic in the Himalayas." src="https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/578372/original/file-20240227-24-3c22h9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The author in front of the Himalayan Rescue Association clinic in Nepal.</span>
<span class="attribution"><span class="source">Brian Strickland</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>The science behind altitude sickness</h2>
<p>Altitude sickness is rare in locations lower than 8,200 feet (2,500 meters); however, <a href="https://www.ncbi.nlm.nih.gov/books/NBK430716/">it becomes very common</a> when ascending above this elevation. In fact, it affects about <a href="https://wwwnc.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/high-elevation-travel-and-altitude-illness">25% of visitors to the mountains of Colorado</a>, where I conduct most of my research. </p>
<p>The risk rapidly increases with higher ascents. Above 9,800 feet (3,000 meters), up to <a href="https://www.ncbi.nlm.nih.gov/books/NBK430716/">75% of travelers</a> may develop symptoms. Symptoms of altitude sickness are usually mild and consist of <a href="https://doi.org/10.1089/ham.2017.0164">headache, dizziness, nausea, fatigue and insomnia</a>. They usually <a href="https://doi.org/10.1016/j.rceng.2019.12.009">resolve after one to two days</a>, as long as travelers stop their ascent, and the symptoms quickly resolve with descent. </p>
<p>When travelers do not properly acclimatize, they can be susceptible to life-threatening altitude illnesses, such as <a href="https://doi.org/10.1016/j.resp.2007.05.002">high-altitude pulmonary edema</a> or <a href="https://doi.org/10.1089/1527029041352054">high-altitude cerebral edema</a>. These conditions are characterized by fluid accumulation within the tissues of the lungs and brain, respectively, and are the <a href="https://wwwnc.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/high-elevation-travel-and-altitude-illness#">most severe forms of altitude sickness</a>.</p>
<p>Altitude sickness symptoms are thought to be caused by <a href="https://doi.org/10.1093%2Fbjaceaccp%2Fmks047">increased pressure surrounding the brain</a>, which results from the failure of the body to acclimatize to higher elevations. </p>
<p>As people enter into an environment with lower air pressure and, therefore, <a href="https://doi.org/10.1001/jamanetworkopen.2023.18036">lower oxygen content</a>, their <a href="https://doi.org/10.1093%2Fbjaceaccp%2Fmks047">breathing rate increases</a> in order to compensate. This causes an increase in the amount of <a href="https://doi.org/10.1016/s1357-2725(03)00050-5">oxygen in the blood as well as decreased CO₂ levels</a>, which then increases blood pH. As a result, the <a href="https://doi.org/10.1093%2Fbjaceaccp%2Fmks047">kidneys compensate</a> by removing a chemical called bicarbonate from the blood into the urine. This process makes people urinate more and helps correct the acid and alkaline content of the blood to a more normal level.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/iv1vQPIdX_k?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Tips for preventing or reducing the risk of altitude sickness.</span></figcaption>
</figure>
<h2>The importance of gradual ascent</h2>
<p>High-altitude medicine experts and other physicians <a href="https://doi.org/10.1016/s0140-6736(76)91677-9">have known for decades</a> that <a href="https://doi.org/10.1089/ham.2010.1006">taking time to slowly ascend is the best way</a> to prevent the development of altitude sickness. </p>
<p>This strategy gives the body time to complete its natural physiologic responses to the changes in air pressure and oxygen content. In fact, spending just <a href="https://doi.org/10.1089/ham.2010.1006">one night at a moderate elevation</a>, such as Denver, Colorado, which is at 5,280 feet (1,600 meters), has been shown to <a href="https://doi.org/10.7326/0003-4819-118-8-199304150-00003">significantly reduce the likelihood of developing symptoms</a>. </p>
<p>People who skip this step and travel directly to high elevations are <a href="https://doi.org/10.1093/jtm/taad011">up to four times more likely</a> to develop altitude sickness symptoms. When going to elevations greater than 11,000 feet, multiple days of acclimatization are necessary. Experts generally recommend ascending <a href="https://doi.org/10.1089/ham.2010.1006">no more than 1,500 feet per day</a> once the threshold of 8,200 feet of elevation has been crossed. </p>
<p>Workers at high altitude, such as <a href="https://doi.org/10.1089/ham.2020.0004">porters in the Nepali Himalaya</a>, are at <a href="https://doi.org/10.1016/j.wem.2018.06.002">particular risk of altitude-related illness</a>. These workers often do not adhere to acclimatization recommendations in order to maximize earnings during tourist seasons; as a result, they are more likely to experience <a href="https://www.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/high-elevation-travel-and-altitude-illness#">severe forms of altitude sickness</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Five tents glow against the night sky with a tall mountain in the background." src="https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577771/original/file-20240225-24-nb9e6p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Adventure tourism is growing rapidly, but general awareness and education around altitude sickness and ways to prevent it remains low.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/milky-way-over-mitre-peak-view-from-concordia-camp-royalty-free-image/1936855402?phrase=mountain+adventure+travel&adppopup=true">Punnawit Suwuttananun/Moment via Getty Images</a></span>
</figcaption>
</figure>
<h2>Effective medications</h2>
<p>For more than 40 years, <a href="https://doi.org/10.1056/nejm196810172791601">a medicine called acetazolamide</a> has been used to <a href="https://medlineplus.gov/druginfo/meds/a682756.html">prevent the development of altitude sickness</a> and to treat its symptoms. Acetazolamide is <a href="https://www.ncbi.nlm.nih.gov/books/NBK557838/">commonly used as a diuretic</a> and for the <a href="https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma#">treatment of glaucoma</a>, a condition that causes increased pressure within the eye.</p>
<p>If started <a href="https://doi.org/10.1378/chest.09-2445">two days prior</a> to going up to a high elevation, acetazolamide can <a href="https://doi.org/10.1378/chest.09-2445">prevent symptoms of acute illness</a> by speeding up the acclimatization process. Nonetheless, it does not negate the recommendations to ascend slowly, and it is <a href="https://doi.org/10.1016/j.wem.2019.04.006">routinely recommended only</a> when people cannot slowly ascend or for people who have a history of severe altitude sickness symptoms even with slow ascent.</p>
<p>Other medications, including ibuprofen, have <a href="https://doi.org/10.1016/j.wem.2012.08.001">shown some effectiveness</a> in treating acute mountain sickness, although <a href="https://doi.org/10.1016/j.amjmed.2018.10.021">not as well as acetazolamide</a>. </p>
<p>A <a href="https://pubmed.ncbi.nlm.nih.gov/2028586/">steroid medication called dexamethasone</a> is effective in both treating and preventing symptoms, but it does not improve acclimatization. It is <a href="https://doi.org/10.1016/j.wem.2019.04.006">recommended only when acetazolamide is not effective</a> or cannot be taken. </p>
<p>Additionally, it is important to <a href="https://wwwnc.cdc.gov/travel/page/travel-to-high-altitudes#">avoid alcohol during the first few days at higher altitudes</a>, as it impairs the body’s ability to acclimatize.</p>
<h2>Unproven therapies and remedies are common</h2>
<p>As high-altitude tourism becomes increasingly popular, multiple commercial products and remedies have emerged. Most of them are not effective or provide no evidence to suggest they work as advertised. Other options have mixed evidence, making them difficult to recommend.</p>
<p>Medications such as <a href="https://doi.org/10.1089/ham.2007.1037">aspirin</a>, <a href="https://doi.org/10.1183/13993003.01355-2017">inhaled steroids</a> and <a href="https://doi.org/10.1089/ham.2011.0007">sildenafil</a> have been proposed as possible preventive agents for altitude sickness, but on the whole they have not been found to be effective.</p>
<p><a href="https://doi.org/10.1093/qjmed/hcp026">Supplements and antioxidants have no proven benefit</a> in preventing or treating altitude sickness symptoms. Both normal and high-altitude exercise are popular ways to prepare for high elevations, especially among athletes. However, beyond <a href="https://doi.org/10.1097/jes.0b013e31825eaa33">certain pre-acclimatization strategies</a>, such as brief sojourns to high altitude, <a href="https://doi.org/10.1016/j.tmaid.2013.12.002">physical fitness and training is of little benefit</a>. </p>
<p><a href="https://missouripoisoncenter.org/canned-oxygen-is-it-good-for-you">Canned oxygen</a> has also exploded in popularity with travelers. While <a href="https://doi.org/10.1016/0140-6736(90)93240-p">continuously administered medical oxygen</a> in a health care setting can alleviate altitude sickness symptoms, portable oxygen cans <a href="https://doi.org/10.1016/j.wem.2019.04.006">contain very little oxygen gas</a>, casting doubt on their effectiveness.</p>
<p>Some high-altitude adventure travelers sleep in <a href="https://doi.org/10.2165/00007256-200131040-00002">specialized tents</a> that simulate increased elevation by lowering the quantity of available oxygen in ambient air. The lower oxygen levels within the tent are thought to accelerate the acclimatization process, but the tents aren’t able to decrease barometric pressure. This is an important part of the high-altitude environment that induces acclimatization. Without modifying ambient air pressure, these <a href="https://doi.org/10.1016/j.wem.2014.04.004">tents may take multiple weeks</a> to be effective. </p>
<p>Natural medicines, such as <a href="https://doi.org/10.1580/08-weme-br-247.1">gingko</a> and <a href="https://doi.org/10.1186/s40794-019-0095-7">coca leaves</a>, are touted as natural altitude sickness treatments, but few studies have been done on them. The modest benefits and significant side effects of these options makes their use <a href="https://doi.org/10.1016/j.wem.2019.04.006">difficult to recommend</a>. </p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/8469948/">Staying hydrated</a> is very important at high altitudes due to fluid losses from increased urination, dry air and increased physical exertion. <a href="https://doi.org/10.1186%2Fs12889-018-6252-5">Dehydration symptoms</a> can also mimic those of altitude sickness. But there is <a href="https://doi.org/10.1580/1080-6032(2006)17%5B215:AMSIOF%5D2.0.CO;2">little evidence that consuming excessive amounts of water</a> can prevent or treat altitude sickness.</p>
<p>The mountains have something for visitors of all interests and expertise and can offer truly life-changing experiences. While there are health risks associated with travel at higher elevations, these can be lessened by making basic preparations and taking time to slowly ascend.</p><img src="https://counter.theconversation.com/content/222057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brian Strickland does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Whether you’re ascending to high altitudes for casual travel or for adventure tourism, there are specific strategies to help you acclimate and reduce the likelihood of altitude sickness.Brian Strickland, Senior Instructor in Emergency Medicine, University of Colorado Anschutz Medical CampusLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2172552024-01-04T13:48:42Z2024-01-04T13:48:42ZThe chickadee in the snowbank: A ‘canary in the coal mine’ for climate change in the Sierra Nevada mountains<figure><img src="https://images.theconversation.com/files/564542/original/file-20231208-19-uw3l7c.jpg?ixlib=rb-1.1.0&rect=0%2C148%2C4139%2C2775&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mountain chickadees struggle with snow extremes.</span> <span class="attribution"><span class="source">Benjamin Sonnenberg</span></span></figcaption></figure><p>Wet snow pelts my face and pulls against my skis as I climb above 8,000 feet in the Sierra Nevada of eastern California, tugging a sled loaded with batteries, bolts, wire and 40 pounds of sunflower seeds critical to our mountain chickadee research.</p>
<p>As we reach the remote research site, I duck under a tarp and open a laptop. A chorus of identification numbers are shouted back and forth as fellow behavioral ecologist <a href="https://scholar.google.com/citations?user=KfEtp4gAAAAJ&hl=en">Vladimir Pravosudov</a> and I program <a href="https://youtu.be/a69lKv65mZk?feature=shared">“smart” bird feeders</a> for an upcoming experiment.</p>
<p>I have spent the past six years <a href="https://scholar.google.com/citations?user=PBLRszkAAAAJ&hl=en">monitoring a population of mountain chickadees</a> here, tracking their life cycles and, importantly, their memory, working in a system <a href="https://chickadeecognition.com/">Pravosudov established in 2013</a>. The long, consistent record from this research site has allowed us to observe how chickadees survive in extreme winter snowfall and to identify ecological patterns and changes. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A ring of tall, rectangular metal bird feeders mounded high with snow on top." src="https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564534/original/file-20231208-19-4f18vw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Snow piles up on the experiment’s bird feeders. Each chickadee has a radio frequency identification tag that opens its assigned feeder, allowing scientists to track its movements and memory.</span>
<span class="attribution"><span class="source">Vladimir Pravosudov</span></span>
</figcaption>
</figure>
<p>In recent history, intense winters are often followed by drought years here in the Sierra Nevada and in much of <a href="https://doi.org/10.1038/s41598-021-95979-4">the U.S. West</a>. This teeter-totter pattern has been identified as one of the unexpected symptoms of climate change, and its impact on the chickadees is providing an early warning of the disruptions ahead for the dynamics within these coniferous forest ecosystems. </p>
<p>Our research shows that a mountain chickadee facing deep snow is, to borrow a cliche, like a canary in a coal mine – its survivability tells us about the challenges ahead.</p>
<figure class="align-center ">
<img alt="A chickadee sits on a man's finger as the two look at each other." src="https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564900/original/file-20231211-17-53wkl2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The author, Benjamin Sonnenberg, and one of his research subjects − a young chickadee with a transponder tag on its leg.</span>
<span class="attribution"><span class="source">Benjamin Sonnenberg</span></span>
</figcaption>
</figure>
<h2>The extraordinary memory of a chickadee</h2>
<p>As Pravosudov calls out the next identification number, and as my legs slowly get colder and wetter, a charming and chipper “<a href="https://www.allaboutbirds.org/guide/Mountain_Chickadee/sounds#">DEE DEE DEE</a>” chimes down from a nearby tree. How is it that a bird weighing barely more than a few sheets of paper is more comfortable in this storm than I am?</p>
<p>The answer comes down to the chickadees’ incredible spatial cognitive abilities.</p>
<p>Cognition is the processes by which animals acquire, process, store and act on information from <a href="https://doi.org/10.1006/anbe.2000.1606">their environment</a>. It is critical to many species but is often subtle and difficult to measure in nonhuman animals.</p>
<p>Chickadees are food-storing specialists that hide tens of thousands of individual food items throughout the forest under edges of tree bark, or even between pine needles, each fall. Then, they use their specialized spatial memory to <a href="https://doi.org/10.1146/annurev-ecolsys-110512-135904">retrieve those food caches</a> in the months to come.</p>
<p>Conditions in the high Sierras can be harsh, and if chickadees can’t remember where their food is, they die.</p>
<p>We measure the spatial memory of chickadees using a classic associative learning task but in a very atypical <a href="https://doi.org/10.1016/j.anbehav.2015.10.015">location</a>. To do this, we hang a circular array of eight feeders equipped with radio-frequency identification and filled with seed in several locations across our <a href="https://doi.org/10.3389/fevo.2019.00257">field site</a>. Birds are tagged with “keys” – transponder tags in leg bands that contain individual identification numbers and allow them to open the doors of their assigned feeders to get a food reward.</p>
<p>The setup allows us to measure the spatial memory performance of individual chickadees, because they have to remember which feeder their key enables them to open. Over eight years, our findings demonstrate that chickadees with better spatial memory ability are <a href="https://doi.org/10.1016/j.cub.2019.01.006">more likely to survive</a> in the high mountains than those with worse memories. </p>
<p>However, chickadees may be facing increasing challenges that will shape their future in the high mountains. In 2017, a year with record-breaking snow levels, adult chickadees showed the lowest probability of survival <a href="https://doi.org/10.1007/s00265-020-2817-2">ever measured at our site</a>. This exceptionally extreme winter came with recurrent storms containing cold weather and high winds, making it difficult for even the memory savvy chickadees to forage and survive. </p>
<p>Nevertheless, triumphant populations have persisted in high-elevation mountain environments, but their future is becoming uncertain.</p>
<h2>What’s the problem?</h2>
<p>“It’s weather whiplash,” says <a href="https://scholar.google.com/citations?user=iEEye1UAAAAJ&hl=en">Adrian Harpold</a>, a mountain ecohydrologist. Harpold works to understand variations in climate patterns within forest environments, and one of his field sites lies alongside our chickadee research site. </p>
<p>The Sierra Nevada and other mountain ranges in western North America have been experiencing more <a href="https://statesummaries.ncics.org/chapter/ca/">extreme snow years and drought years</a>, amplified by climate change. Extreme snow linked to global warming might seem counterintuitive, but it’s basic physics. Warmer air can hold more moisture – <a href="https://climate.nasa.gov/explore/ask-nasa-climate/3143/steamy-relationships-how-atmospheric-water-vapor-amplifies-earths-greenhouse-effect/">about 7% more for every degree Celsius</a> (every 1.8 degrees Fahrenheit) that temperatures rise. This can result in heavier snowfall when storms strike.</p>
<p><iframe id="VfiF9" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/VfiF9/4/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>In 2023’s record winter, over 17 feet (5 meters) of snow covered the landscape that our chickadees were using every day. In fact, these intense storms and cold temperatures not only made it difficult for birds to survive the winter but made it almost impossible for them to breed the next summer: 46% of chickadee nests at our higher elevation site failed to produce any offspring. This was likely due to the deep snow that prevented them from finding emerging insects to feed nestlings or even reaching nesting sites at all until July.</p>
<h2>The cascading harms from too much snow</h2>
<p>Even in years of tremendous snowfall, chickadees can still use their finely honed spatial memories to recover food. However, severe storms can shorten their survival odds. And if they do survive the winter, their nesting sites – tree cavities – may be buried under feet of snow in the spring. </p>
<p>It doesn’t matter how smart you are if you can’t reach your nest.</p>
<p>Extreme snow oscillations also affect insects that are critical for feeding chickadee chicks. Limited resources lead to smaller chickadee offspring that are less likely to survive high in the mountains. </p>
<figure class="align-center ">
<img alt="A tiny baby chickadee sits in a man's hand. It's mouth below a still developing beak is bright yellow." src="https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565552/original/file-20231213-15-r59z40.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mountain chickadee chicks can struggle to survive during winters with extreme snow.</span>
<span class="attribution"><span class="source">Benjamin Sonnenberg</span></span>
</figcaption>
</figure>
<p>Snow cover is good for overwintering insects in most cases, as it provides an insulating blanket that saves them from dying during those freezing months. However, if the snow persists too long into the summer, insects can run out of energy and die before they can emerge, or emerge after chickadees <a href="https://doi.org/10.1111/brv.12105">really need them</a>. Drought years also can drive insect population decline. </p>
<p>Extremes at both ends of the spectrum are making it harder for chickadees to thrive, and more and more we are seeing oscillations between these extremes.</p>
<p>These compounded effects mean that in some years chickadees simply don’t successfully nest at all. This leads to a decline in chickadee populations in years with worse whiplash – drought followed by high snow on repeat – especially at high elevations. This is especially concerning, as many <a href="https://doi.org/10.1111/gcb.16187">mountain-dwelling avian species are forecasted to move up in elevation</a> to escape warming temperatures, which may turn out to be hazardous. </p>
<figure class="align-center ">
<img alt="Eight little chickadees in a circle in a wooden box, their tails all together in the center to keep their bodies warm." src="https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564540/original/file-20231208-17-vwxtfo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Baby chickadees stay warm inside a wooden box.</span>
<span class="attribution"><span class="source">Benjamin Sonnenberg</span></span>
</figcaption>
</figure>
<h2>Lessons for the future</h2>
<p>Chickadees may be portrayed as radiating tranquil beauty on holiday cards, but realistically, these loud, round ruffians are tough survivors of harsh winter environments in northern latitudes.</p>
<p>Our long-term research following these chickadees provides a unique window into the relationships between winter snow, chickadee populations and the biological community around them, such as <a href="https://link.springer.com/article/10.1007/s10584-007-9358-9">coniferous forests</a> and <a href="https://www.pnas.org/doi/abs/10.1073/pnas.2023989118">insect</a> populations. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/a69lKv65mZk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Benjamin Sonnenberg and Vladimir Pravosudov show how the feeders work to test birds’ memories in a video about the early stages of their research.</span></figcaption>
</figure>
<p>These relationships illustrate that climate change is a more complicated story than just the temperature climb – and that its whiplash and cascading effects can destabilize ecosystems.</p><img src="https://counter.theconversation.com/content/217255/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benjamin Sonnenberg receives funding from the National Science Foundation. </span></em></p>These tiny songbirds have extraordinary memories for the tens of thousands of spots where they hide food. But that doesn’t help when heavy snow blocks their access.Benjamin Sonnenberg, Ph.D. Candidate in Ecology, Evolution and Conservation Biology, University of Nevada, RenoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2187312024-01-04T10:08:56Z2024-01-04T10:08:56ZWill we be able to ski in a +2°C world?<p>Over the last months, the <em>raison d’être</em> of winter sports has been threatened more than ever by a range of challenges and controversies. From the occupation by activists of the <a href="https://reporterre.net/Glacier-en-danger-une-nuit-a-la-zad-la-plus-haute-d-Europe">glacier of Girose</a>, Southeastern France, to protest against plans for a new cable car, to doubts over whether to hold pre-season sporting events following the partial destruction of the <a href="https://www.20min.ch/fr/video/coupe-du-monde-de-ski-a-zermatt-vs-le-glacier-est-esquinte-et-le-trouble-regne-sur-la-legalite-du-trace-934896922375">Théodule glacier</a> in Switzerland, scarce snow is pitting people against one another. Behind all these tensions lies the same question: what does the future hold for skiing on an overheating planet?</p>
<p>In recent decades, France has seen some ski resorts close due to a lack of snow or a sustainable business model. However, the majority of resorts continue to cling on to the hope of adapting to rising temperatures. But will reproducing the tried and tested recipes of the past be enough to meet the climate challenges ahead?</p>
<p>Published in <a href="https://www.nature.com/articles/s41558-023-01759-5"><em>Nature Climate Change</em></a>, our <a href="https://hal.science/hal-04192000">study</a> of 2,234 winter sports resorts in Europe sought to measure the impact of global warming on snowmaking in resorts, and the possible room for manoeuvre available to adapt.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=497&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=497&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=497&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560805/original/file-20231121-27-xomtnb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Winter sports resorts are unevenly distributed in 18 mountain massifs across Europe.</span>
<span class="attribution"><span class="source">Adapted from François et al., 2023</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<p>This question is not just a concern for amateur or professional skiers. Skiing is also an economic issue, with a total turnover estimated at 30 billion euros in Europe. In France alone, 120,000 jobs depending directly and indirectly on the ski economy.</p>
<h2>53% of ski resorts are at risk of running out of snow at +2°C</h2>
<p>Climate change is a global phenomenon impacting resorts worldwide, but not all mountain areas are affected to the same degree or with the same speed, and the ability to limit the impact of these changes through snow production also varies greatly. We have measured the impact of climate change on winter sports resorts based on the level of global warming, using the graphical representation, commonly used in IPCC reports, of <a href="https://www.nature.com/articles/s43017-020-0088-0">“burning embers”</a>.</p>
<p>At 2°C of global warming above pre-industrial levels, 53% of European resorts are at very high risk of low snowfall. We assess the risk of low snowfall on the basis of the frequency of snow conditions considered to be the most unfavourable, those encountered on average one season in five between 1961 and 1990, the golden age of resort development.</p>
<p>However, the picture varies at a national level: in the French Alps, this proportion concerns a third of resorts, while in the Pyrenees and in the Franco-Swiss mid-mountain massifs, 89% and 80% respectively of resorts are affected by a very high level of risk of low snowfall.</p>
<p>At 4°C of global warming, 98% of European resorts are at very high risk of low snowfall. With this level of warming, the climate leaves winter sports resorts little margin for adaptation.</p>
<h2>Changes in the use of snow production</h2>
<p>One of the most popular solutions to adapt to scarcer snow is <a href="https://theconversation.com/production-de-neige-le-piege-de-la-dependance-pour-les-stations-de-ski-198469">snowmaking</a>, also known as “artificial snow”. Snow production involves projecting micro-droplets of water into the atmosphere so that they freeze before falling back to the ground. The resulting snow, made up of small balls of ice, is a suitable material for making an underlay.</p>
<p>In the past, snow was produced mainly to limit the impact of natural fluctuations in snow cover from one season to the next. Snow is now mainly produced in the pre-season, without any knowledge of the weather conditions for the coming winter, and then on a more ad hoc basis if necessary between the Christmas and winter holidays.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560803/original/file-20231121-17-91hlvv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">La Plagne Montchavin.</span>
<span class="attribution"><span class="source">Lucas Berard Chenu</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
À lire aussi :
<a href="https://theconversation.com/les-stations-de-ski-forcees-de-repenser-leur-modele-132381">Les stations de ski forcées de repenser leur modèle</a>
</strong>
</em>
</p>
<hr>
<h2>Snow production also affected by rising temperatures</h2>
<p>Like natural snow, snow production is affected by rising temperatures, because snow production requires sufficiently cold weather conditions. This dual pressure is leading to increased investment to ensure that sufficient snow can be produced, thereby increasing the dependency of mountain resorts on snow tourism.</p>
<p>Not all ski resorts will equally be able to adapt to rising temperatures by producing snow. At +2°C global warming, snowmaking, if applied to 50% of the ski area, would reduce the proportion of resorts exposed to a very high risk of low snowfall in the Alps and Pyrenees to 7% and 9% respectively, while in the mid-range mountain ranges the proportion would be 56%. These differences are even more marked at higher levels of warming.</p>
<p>However, it should be remembered that while the level of snow cover is critical to ensuring resorts’ long-term socio-economic viability, other criteria are just as fundamental, such as the state of the ski lift network, promotion/marketing methods, or accommodation capacity and its attractiveness. It is therefore not possible to draw any direct conclusions from the figures for the risk of low snowfall as to the proportion or number of resorts likely to cease skiing.</p>
<h2>The carbon footprint of snow production</h2>
<p>What’s more, snow production is not carbon-neutral, so it’s important to bear this in mind before setting this technique up as the ultimate answer to reducing snow cover.</p>
<p>We have therefore also calculated the water requirements, production and energy demand involved, and the carbon footprint of the electricity used to produce snow. Over the reference period (1961-1990), the total quantity of snow produced on the slopes covered by the installations represents 13% of the total precipitation that falls annually on these same slopes. Assuming that 50% of the slopes are covered by snowmaking facilities, the total volume should increase by between 8% and 25%, depending on the country, for a warming of +2°C, and even more for a more marked warming.</p>
<p>This demand also tends to stagger over time, with lower production in November due to fewer cold spells favourable to production at the start of winter. It is therefore likely that the services provided by snow production will not be the same as in the past, which could make snow cover even more fragile over the high season.</p>
<p>In any case, the total volume of water that could be needed remains moderate, and a large part of this water is returned to the rivers as it melts. This is not to say complications can’t occur at a local scale further down the line, depending on how the water is drawn and of the makeup of affected ecosystems.</p>
<figure class="align-center ">
<img alt="Snowman in Pralognan (Savoie, France)." src="https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560807/original/file-20231121-19-zrwd0i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Snow cannon in Pralognan (Savoie, France).</span>
<span class="attribution"><span class="source">Lucas Berard Chenu</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<p>Similarly, at around 80 kt eq CO<sub>2</sub>, the carbon footprint of the electricity used to produce snow remains limited, even if it varies greatly depending on countries’ energy mix.</p>
<h2>Skiers’ transport and accommodation still emit a lot of CO₂</h2>
<p>Finally, it is impossible to dissociate snow production from the <a href="https://www.ski-planet.com/fr/actualites-ski/479/empreinte-carbone-pour-1-journee-de-ski.html">tourism activity</a> that calls for it. In reality, it is responsible for only a fraction of the carbon footprint of a winter sports tourist destination, with skiers’ transport and accommodation proving most polluting. Carbon emissions could nevertheless rise as people travel further and further afield to find snow.</p>
<p>Would the economic benefits be worth it? Our study calls on the tourism sector to craft a strategy based on climate adaptation and decarbonisation as resorts look to the future.</p>
<figure class="align-center ">
<img alt="Real estate project poster in Valmorel, Panorama de La Plagne" src="https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=164&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=164&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=164&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=207&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=207&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560809/original/file-20231121-19-i3u1c5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=207&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Real estate project poster in Valmorel, Panorama de La Plagne.</span>
<span class="attribution"><span class="source">Lucas Berard-Chenu</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/218731/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The research laboratory to which Hugues François belongs (INRAE, Lyon Grenoble Center, LESSEM) has received funding from various public and private organizations for its research projects</span></em></p><p class="fine-print"><em><span>The Météo-France department (DCSC) for which Raphaëlle Samacoïts works has received funding from various public and private organizations for its research projects.</span></em></p><p class="fine-print"><em><span>The research laboratory to which Samuel Morin belongs (CNRM, Météo-France - CNRS) has received funding from various public and private organizations for its research projects.</span></em></p>Skiing is central to the economy of many mountain regions across Europe. How are they coping with climate change and what room for adaptation do they have?Hugues François, Ingénieur de recherche tourisme et système d'information, InraeRaphaëlle Samacoïts, Ingénieur Climatologie et services climatiques, Météo-FranceSamuel Morin, Chercheur et directeur du Centre national de recherches météorologiques (Météo-France - CNRS), Météo FranceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2172862023-11-29T23:11:39Z2023-11-29T23:11:39ZNew unified theory shows how past landscapes drove the evolution of Earth’s rich diversity of life<p>Earth’s surface is the living skin of our planet – it connects the physical, chemical and biological systems.</p>
<p>Over geological time, this surface evolves. Rivers fragment the landscape into an environmentally diverse range of habitats. These rivers also transfer sediments from the mountains to the continental plains and ultimately the oceans. </p>
<p>The idea that landscapes have influenced the trajectory of life on our planet has a long history, dating back to the early 19th century scientific narratives of German polymath <a href="https://learningfromlandscapes.com/2019/06/11/humboldt-the-invention-of-nature/">Alexander von Humboldt</a>. While we’ve learnt more since then, many aspects of biodiversity evolution remain enigmatic. For example, it’s still unclear why there is a 100-million-year gap between the explosion of marine life and the development of plants on continents.</p>
<p>In research <a href="https://www.nature.com/articles/s41586-023-06777-z">published in Nature</a> today, we propose a new theory that relates the evolution of biodiversity over the past 540 million years to sediment “pulses” controlled by past landscapes.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Uxutnt44NKU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>10 years of computational time</h2>
<p>Our simulations are based on an open-source code released as part of a <a href="https://theconversation.com/scientists-just-revealed-the-most-detailed-geological-model-of-earths-past-100-million-years-200898">Science paper</a> published earlier this year.</p>
<p>To drive the evolution of the landscape through space and time in our computer model, we used a series of reconstructions for what the climate and tectonics were like in the past.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two colourful computer simulated Earth globes side by side" src="https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=291&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=291&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=291&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=365&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=365&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558304/original/file-20231108-27-yqmk6n.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=365&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These two globes from our simulation show landscapes 200 million years ago (just before the Pangea supercontinent broke up, left) and 15 million years ago (right), after the formation of the Andes, Alps and Himalayas.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>We then compared the results of our global simulations with reconstructions of marine and continental biodiversity over the past 540 million years.</p>
<p>To perform our computer simulations, we took advantage of Australia’s <a href="https://nci.org.au/">National Computational Infrastructure</a> running on several hundreds of processors. The combined simulations presented in our study are equivalent to ten years of computational time.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-earths-last-supercontinent-broke-apart-to-form-the-world-we-have-today-131632">How the Earth's last supercontinent broke apart to form the world we have today</a>
</strong>
</em>
</p>
<hr>
<h2>Marine life and river sediment were closely linked</h2>
<p>In our model, we discovered that the more sediment rivers carried into the oceans, the more the sea life diversified (a positive correlation). You can see this tracked by the red line in the chart below. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=222&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=222&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=222&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=279&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=279&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560720/original/file-20231121-3914-t01a3j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=279&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Reconstructed sediment fluxes to the oceans (red line) versus diversity of marine animals (black line, adapted from C. Bentley using Sepkoski’s compendium) from the Cambrian through to the Neogene.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>As the continents weather, rivers don’t just carry sediment into the oceans, they also bring a large quantity of nutrients. These nutrients, such as carbon, nitrogen and phosphorus, are essential to the <a href="https://www.britannica.com/science/biogeochemical-cycle">biological cycles</a> that move vital elements through all living things.</p>
<p>This is why we think rivers delivering more or less nutrients to the ocean – on a geological timescale of millions of years – is related to the diversification of marine life.</p>
<p>Perhaps even more surprisingly, we found that episodes of mass extinctions in the oceans happened shortly after significant decreases in sedimentary flow. This suggests that a lack or deficiency of nutrients can destabilise biodiversity and make it vulnerable to catastrophic events (like asteroid impacts or volcanic eruptions).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-a-mass-extinction-and-are-we-in-one-now-122535">What is a 'mass extinction' and are we in one now?</a>
</strong>
</em>
</p>
<hr>
<h2>Landscapes also drove the diversity of plants</h2>
<p>On the continents, we designed a variable that integrates sediment cover and landscape ruggedness to describe the continents’ capacity to host diverse species. </p>
<p>Here we also found a striking correlation (see below) between our variable and plant diversification for the past 400 million years. This highlights how changes in landscape also have a strong influence on species diversifying on land. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=232&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=232&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=232&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=291&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=291&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560719/original/file-20231121-27-hlx0p3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=291&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sediment cover in continental regions (black line) versus the long-term trend in land-plant diversity. Illustrations from Rebecca Horwitt.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>We hypothesise that as Earth’s surface was gradually covered with thicker soil, richer in nutrients deposited by rivers, plants could develop and diversify with more elaborate root systems. </p>
<p>As plants slowly expanded across the land, the planet ended up hosting varied environments and habitats with favourable conditions for plant evolution, such as the emergence of flowering plants some 100 million years ago.</p>
<h2>A living planet</h2>
<p>Overall, our findings suggest the diversity of life on our planet is strongly influenced by landscape dynamics. At any given moment, Earth’s landscapes determine the maximum number of different species continents and oceans can support.</p>
<p>This shows it’s not just tectonics or climates, but their interactions that determine the long-term evolution of biodiversity. They do this through sediment flows and changes to the landscapes at large.</p>
<p>Our findings also show that biodiversity has always evolved at the pace of plate tectonics. That’s a pace incomparably slower than the current rate of extinction caused by human activity.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-ways-you-can-help-stop-biodiversity-loss-in-your-area-and-around-the-world-196746">Five ways you can help stop biodiversity loss in your area – and around the world</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/217286/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research was undertaken with resources from the National Computational Infrastructure supported by the Australian Government and from Artemis HPC supported by the University of Sydney. This work was supported by an Australian Research Council grant.</span></em></p><p class="fine-print"><em><span>Beatriz Hadler Boggiani, Laurent Husson, and Manon Lorcery do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>For decades, scientists have tried to uncover the cause of long-term changes in Earth’s biodiversity. New simulations point at geography playing a critical role.Tristan Salles, Senior Lecturer, University of SydneyBeatriz Hadler Boggiani, PhD Candidate, University of SydneyLaurent Husson, Earth sciences researcher, Université Grenoble Alpes (UGA)Manon Lorcery, PhD Candidate, Université Grenoble Alpes (UGA)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2138842023-10-19T13:18:57Z2023-10-19T13:18:57ZNamibia and Angola’s remote Ovahimba mountains reveal a haven for unique plants – new survey<p>The Kaokoveld region, covering north-western Namibia and south-western Angola, is one of the remotest areas in southern Africa. Although it’s extremely dry, it is a centre of species endemism: many species occur only there and nowhere else on earth. </p>
<p>New species continue to be found, especially in the Ovahimba mountain range, which runs parallel to the cold Atlantic ocean and is separated from it by the gravel plains and dunes of the northern Namib Desert.</p>
<p>The highest mountain peaks of this range are so inhospitable and difficult to access, because of the lack of roads and water, that few have ever scaled them. The exceptions are local herders of the semi-nomadic <a href="https://www.lcfn.info/ovahimba/information/ethnology">Himba</a>, who drive their cattle and goats to richer pastures in the mountains during dry periods. </p>
<p>In 2021, I was part of a team of researchers from Namibia and Angola who aimed to investigate the biodiversity and endemism on some of the most remote peaks. We hypothesised that the mountain peaks harboured a large number of species, especially plants, insects and reptiles. That’s because there’s a rapid change in climate and topography (land features) from the hyper-arid, cool desert near the coast and the arid and seasonally warmer plains further inland to the cooler mountainous escarpment. </p>
<p>Through an EU-funded transfrontier conservation <a href="http://sciona.nust.na/">project, SCIONA</a>, we had the opportunity to use the only safe option to get to the Ovahimba mountain peaks: a helicopter.</p>
<p>It is incredibly exciting to plan a trip to such a remote and beautiful wilderness area where few people have intervened in the ecosystem. </p>
<p>Because of the high cost and complicated logistics, we had to limit <a href="https://conservationnamibia.com/pdfs/cn2021-helicopter-science.pdf">the visit</a> to a few days on each of three mountain tops. Two were in Angola – Serra Cafema and Serra Tchamalindi in <a href="https://www.africanparks.org/the-parks/iona">Iona National Park</a> – and one was in the Otjihipa range of Namibia. The mountain tops were selected based on their altitude and remoteness. They also have many ecological niches based on exposure to wind and sun. </p>
<p>At each campsite, we left excitedly in different directions, to return and exchange findings and stories after sunset.</p>
<p>Even in this short visit, we <a href="https://www.tandfonline.com/doi/full/10.1080/0035919X.2023.2211040">found</a> plenty of interest and some surprises. Of the 285 plant species we encountered, 34 species are endemic to the Kaokoveld. One is new to science and at least six endemics fall in the endangered <a href="https://www.iucnredlist.org/">IUCN red list</a> category. Sixteen plant species that were previously known only from Namibia were found in Angola. We also <a href="https://www.researchgate.net/publication/374413378_First_records_for_Angola_of_Cape_Eagle_Owl_and_Layard's_Warbler">recorded</a> two bird species, the Cape Eagle Owl and Layard’s Warbler, in Angola for the first time. </p>
<p>These mountain flora deserve priority conservation efforts to protect endemic and other plants that have survived in these refuge sites, providing a habitat for some unique fauna.</p>
<h2>Helicopter adventure</h2>
<p>Our helicopter hops between the mountains gave us unforgettable, magnificent views of the mountains, through which the glittering Kunene River meanders. The first campsite was in the Otjihipa range, at a mountain that we named Middelberg (1,941 metres above sea level).</p>
<p>The ridge boasts a diverse shrub and woodland vegetation, unlike the barren plains surrounding it, because of the cooler temperatures, the water bearing capacities of rocks, less grazing and browsing, and what we assume is higher rainfall (there are no records). It was adorned by beautiful Kaoko tree-euphorbias (<em>Euphorbia eduardoi</em>).</p>
<p>We also found a large underground cave with intact stalactite and stalagmite formations. This is unusual in the area and may indicate that there was much more water there in the past. </p>
<p>The second campsite was near a mountain top in the eastern part of the large Tchamalinde range, at an elevation of 1,420 metres above sea level. The helicopter could not land higher up the mountain where it was covered with a continuous tree layer. The Kaokoveld endemic flower <em>Turnera oculata var. paucipilosa</em> thrives in this area, as well as the resurrection bush (<em>Myrothamnus flabellifolius</em>) and the black stick lily (<em>Xerophyta retinervis</em>). Resurrection plants appear to be dead during the dry season but suddenly turn green with the rains.</p>
<p>Our last campsite was 100 metres from the top of the highest mountain of Iona National Park, Serra Cafema (2,050 metres above sea level). Of the three mountain tops we visited, it was the closest to the coast (85km) and therefore also the coldest and windiest.</p>
<p>Despite the harsh climate, there was a surprising amount of vegetation, mainly a mosaic of hardy <a href="https://pza.sanbi.org/vegetation/fynbos-biome">Cape fynbos</a>-like shrubs and dry savanna vegetation with large-stemmed Namib resin trees (<em>Ozoroa crassinervia</em>). It was a surprise to find the tall <em>Euphorbia monteiroi subsp. brandbergensis</em> as it was previously only known further south in Namibia. Another beautiful <em>Turnera</em> flower (<em>Turnera oculata var. oculata</em>) was common at Serra Cafema, as well as large specimens of mother-in-law’s-tongue (<em>Sansevieria pearsonii</em>).</p>
<p>Even on the mountain top of Serra Cafema, the highest and remotest of all, there were signs of human impact via grazing. </p>
<p>The findings show the highest plant biodiversity on Serra Cafema, with 56 species per 1,000m² compared to 47 species per 1,000m² for the other mountains. Of the three mountains, Serra Cafema is the most influenced by fog caused by the cold Benguela current. Species composition is very different from the surrounding lowlands.</p>
<h2>Protecting biodiversity</h2>
<p>We unlocked only a fraction of the mystery held by these biodiversity hotspots. There is no doubt that yet more unusual and interesting plants and animals are waiting to be discovered on these inaccessible peaks, especially because our visit took place after 10 years of drought. Huge swarms of <a href="https://theconversation.com/brown-locusts-have-survived-a-long-drought-in-south-africa-heres-how-158488">locusts</a> were in the barren plains at that time.</p>
<p>However, our reconnaissance survey did show that the plants here need protection. They are threatened by <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/factsheets/IPCC_AR6_WGI_Regional_Fact_Sheet_Africa.pdf">climate change</a> and <a href="https://www.researchgate.net/publication/374413480_An_Integrated_Ecosystem_Management_Framework_for_the_Skeleton_Coast-Iona_Transfrontier_Park">overgrazing by livestock</a>. Management of the Ovahimba highlands is in the hands of Namibian communal conservancies, the NGO <a href="https://www.africanparks.org/">African Parks</a> and the Namibian and Angolan governments. African Parks recently took over management of <a href="https://www.africanparks.org/the-parks/iona">Iona National Park</a>, which may offer opportunities to protect the mountain habitats.</p><img src="https://counter.theconversation.com/content/213884/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vera De Cauwer was Principal Investigator of the SCIONA project that received funding from
the European Union under grant agreement FED/2017/394-802.</span></em></p>Mountain flora in the Kaokoveld deserve priority conservation efforts.Vera De Cauwer, Associate Professor Natural Resource Management, Namibia University of Science and TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2152212023-10-17T09:24:28Z2023-10-17T09:24:28ZWhat 2,500 years of wildfire evidence and the extreme fire seasons of 1910 and 2020 tell us about the future of fire in the West<figure><img src="https://images.theconversation.com/files/553881/original/file-20231015-29-pxqkiy.jpg?ixlib=rb-1.1.0&rect=84%2C333%2C3611%2C2357&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rocky Mountain fires leave telltale ash layers in nearby lakes like this one.</span> <span class="attribution"><span class="source">Philip Higuera</span></span></figcaption></figure><p>Strong winds blew across mountain slopes after a record-setting warm, dry summer. Small fires began to blow up into huge conflagrations. Towns in crisis scrambled to escape as fires bore down. </p>
<p>This could describe any number of recent events, in places as disparate as <a href="https://www.cpr.org/2021/01/25/colorados-east-troublesome-wildfire-may-signal-a-new-era-of-big-fire-blow-ups/">Colorado</a>, <a href="https://www.nist.gov/news-events/news/2021/02/new-timeline-deadliest-california-wildfire-could-guide-lifesaving-research">California</a>, <a href="https://www.cbc.ca/news/canada/british-columbia/bc-wildfires-june-30-2021-1.6085919">Canada</a> and <a href="https://www.washingtonpost.com/climate-environment/2023/08/13/maui-wildfire-started-spread/">Hawaii</a>. But this fire disaster happened over 110 years ago in the Northern Rocky Mountains of Idaho and Montana.</p>
<p>The “<a href="https://www.pbs.org/video/american-experience-big-burn/">Big Burn</a>” of 1910 still holds the record for the largest fire season in the Northern Rockies. Hundreds of fires burned over 3 million acres – roughly the size of Connecticut – most in just two days. The fires destroyed towns, killed 86 people and galvanized public policies committed to putting out every fire.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A black and white photo from 1910 shows rail lines and the burned shells of buildings" src="https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=487&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=487&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=487&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=612&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=612&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553871/original/file-20231015-23-f0ar90.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=612&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many residents of Wallace, Idaho, fled on trains ahead of the 1910 blaze. Volunteers who stayed saved part of the town, but about a third of it burned.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/fsnorthernregion/4929826527/in/album-72157624814120716/">R.H. McKay/U.S. Forest Service archive</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Today, as the climate warms, fire seasons like in 1910 are becoming more likely. The <a href="https://doi.org/10.1111/gcb.15388">2020 fire season</a> was an example. But are extreme fire seasons like these really that unusual in the context of history? And, when fire activity begins to surpass anything experienced in thousands of years – as research suggests is happening in the Southern Rockies – what will happen to the forests?</p>
<p>As paleoecologists, we study how and why ecosystems changed in the past. In a multiyear project, highlighted in <a href="https://doi.org/10.1088/1748-9326/acee16">two new</a> <a href="https://doi.org/10.1111/1365-2745.14201">publications</a>, we tracked how often forest fires occurred in high-elevation forests in the Rocky Mountains over the past 2,500 years, how those fires varied with the climate and how they affected ecosystems. This long view provides both hopeful and concerning lessons for making sense of today’s extreme fire events and impacts on forests.</p>
<h2>Lakes record history going back millennia</h2>
<p>When a high-elevation forest burns, fires consume tree needles and small branches, killing most trees and lofting charcoal in the air. Some of that charcoal lands on lakes and sinks to the bottom, where it is preserved in layers as sediment accumulates. </p>
<p>After the fire, trees regrow and also leave evidence of their existence in the form of pollen grains that fall on the lake and sink to the bottom.</p>
<p>By <a href="https://www.youtube.com/watch?v=0DixyJZCvVQ">extracting a tube</a> of those lake sediments, like a straw pushed into a layer cake from above, we were able to measure the amounts of charcoal and pollen in each layer and reconstruct the history of fire and forest recovery around a dozen lakes across the footprint of the 1910 fires.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman sitting an inflatable boat, wearing a life jacket, holds a long tube filed with lake bottom sediment." src="https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553883/original/file-20231016-28-18q8gm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Author Kyra Clark-Wolf holds a sediment core pulled from a lake containing evidence of fires over thousands of years.</span>
<span class="attribution"><span class="source">Philip Higuera</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Long tubes of lake floor sediment are opened on a table." src="https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553888/original/file-20231016-26-18q8gm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Researchers at the University of Montana examine a sediment core from a high-elevation lake in the Rocky Mountains. Each core is sliced into half-centimeter sections, reflecting around 10 years each, and variations in charcoal within the core are used to reconstruct a timeline of past wildfires.</span>
<span class="attribution"><span class="source">University of Montana</span></span>
</figcaption>
</figure>
<h2>Lessons from Rockies’ long history with fire</h2>
<p>The <a href="https://doi.org/10.1111/1365-2745.14201">lake sediments revealed</a> that high-elevation, or subalpine, forests in the Northern Rockies in Montana and Idaho have consistently bounced back after fires, even during periods of <a href="https://doi.org/10.1017/qua.2022.17">drier climate</a> and more frequent burning than we saw in the 20th century.</p>
<p>High-elevation forests only burn about once <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/subalpine-forest">every 100 to 250 or more years</a> on average. <a href="https://doi.org/10.1088/1748-9326/acee16">We found</a> that the amount of burning in subalpine forests of the Northern Rockies over the 20th and 21st centuries remained within the bounds of what those forests experienced over the previous 2,500 years. Even today, the Northern Rockies <a href="https://doi.org/10.1016/j.foreco.2023.121283">show resilience to wildfires</a>, including <a href="https://doi.org/10.1016/j.foreco.2022.120487">early signs of recovery</a> after extensive fires <a href="https://doi.org/10.3390/fire1010017">in 2017</a>.</p>
<figure class="align-center ">
<img alt="Three illustrated charts show forest density increasing and time between fires falling over the past 4,800 years at one location." src="https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=769&fit=crop&dpr=1 600w, https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=769&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=769&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=966&fit=crop&dpr=1 754w, https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=966&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/554164/original/file-20231017-21-tsez5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=966&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Long-term changes in climate, forest density and fire frequency over the past 4,800 years in one high-elevation forest in the Northern Rockies, reconstructed from lake sediments. The red dots reflect timing of past fires.</span>
<span class="attribution"><span class="source">Kyra Clark-Wolf</span></span>
</figcaption>
</figure>
<p>But <a href="https://doi.org/10.1073/pnas.2103135118">similar research</a> in high-elevation forests of the Southern Rockies in Colorado and Wyoming tells a different story.</p>
<p>The record-setting 2020 fire season, with <a href="https://dfpc.colorado.gov/sections/wildfire-information-center/historical-wildfire-information">three of Colorado’s largest fires</a>, helped push the rate of burning in high-elevation forests in Colorado and Wyoming into <a href="https://theconversation.com/rocky-mountain-forests-burning-more-now-than-any-time-in-the-past-2-000-years-162383">uncharted territory</a> relative to the past 2,000 years.</p>
<p>Climate change is also having bigger impacts on <a href="https://theconversation.com/the-wests-iconic-forests-are-increasingly-struggling-to-recover-from-wildfires-altering-how-fires-burn-could-boost-their-chances-200668">whether and how forests recover after wildfires</a> in warmer, drier regions of the West, including the <a href="https://doi.org/10.1111/geb.13174">Southern Rockies</a>, the <a href="https://doi.org/10.1073/pnas.2208120120">Southwest and California</a>. When fires are followed by especially warm, dry summers, seedlings can’t establish and forests struggle to regenerate. In some places, shrubby or grassy vegetation replace trees altogether.</p>
<figure class="align-center ">
<img alt="Graphs show fire activity rising with temperature over time." src="https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553861/original/file-20231015-29-f0ar90.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=451&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fire history reconstructions from 20 high-elevation lakes in the Southern Rockies show that historically, fires burned every 230 years on average. That has increased significantly in the 21st century.</span>
<span class="attribution"><a class="source" href="https://theconversation.com/rocky-mountain-forests-burning-more-now-than-any-time-in-the-past-2-000-years-162383">Philip Higuera</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Changes happening now in the Southern Rockies could serve as an early warning for what to expect further down the road in the Northern Rockies.</p>
<h2>Warmer climate, greater fire activity, higher risks</h2>
<p>Looking back thousands of years, it’s hard to ignore the consistent links between the climate and the prevalence of wildfires.</p>
<p>Warmer, drier springs and summers <a href="https://doi.org/10.1038/s43247-021-00299-0">load the dice</a> to make extensive fire seasons more likely. This was the case <a href="https://doi.org/10.1371/journal.pone.0127563">in 1910</a> in the Northern Rockies and <a href="https://doi.org/10.1111/gcb.15388">in 2020</a> in the Southern Rockies. </p>
<p>When, where and how climate change will push the rate of burning in the rest of the Rockies into uncharted territory is harder to anticipate. The difference between 1910 and 2020 was that 1910 was followed by decades with low fire activity, whereas 2020 was part of an overall trend of increasing fire activity linked with global warming. Just one fire like 1910’s Big Burn in the coming decades, in the context of 21st-century fire activity, would push the Northern Rockies beyond any known records.</p>
<figure class="align-center ">
<img alt="A tiny pine seedling in a vast landscape of burned trees and soil." src="https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=801&fit=crop&dpr=1 600w, https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=801&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=801&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1006&fit=crop&dpr=1 754w, https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1006&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/554092/original/file-20231016-21-sz8p4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1006&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A lodgepole pine tree seedling begins to grow one year after the October 2020 East Troublesome Fire in Rocky Mountain National Park. Recovery in high-elevation forests takes decades.</span>
<span class="attribution"><span class="source">Philip Higuera</span></span>
</figcaption>
</figure>
<h2>Lessons from the long view</h2>
<p>The clock is ticking. </p>
<p><a href="https://doi.org/10.1111/geb.13496">Extreme wildfires will become more and more likely</a> as the climate warms, and it will be <a href="https://theconversation.com/the-wests-iconic-forests-are-increasingly-struggling-to-recover-from-wildfires-altering-how-fires-burn-could-boost-their-chances-200668">harder for forests to recover</a>. Human activity is also raising the risk of fires starting.</p>
<p>The Big Burn of 1910 left a lasting impression because of the devastating impacts on lives and homes and, <a href="https://www.coloradoan.com/story/news/2022/06/03/east-troublesome-fire-cause-colorado-arapaho-national-forest/7506191001/">as in the 2020 fire season</a> and many other recent fire disasters, because of the <a href="https://doi.org/10.1093/pnasnexus/pgad005">role humans played</a> in igniting them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photo shows burned trees across miles of hillsides along a railroad line" src="https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=479&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=479&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=479&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=602&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=602&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553876/original/file-20231015-25-m2xrcy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=602&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The aftermath of the 1910 fire near the North Fork of the St. Joe River in the Coeur d’Alene National Forest, Idaho.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/fsnorthernregion/4929815653/in/album-72157624814120716/">R.H. McCoy/U.S. Forest Service archive</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Accidental ignitions – from downed power lines, escaped campfires, dragging chains, railroads – expand <a href="https://doi.org/10.1073/pnas.1617394114">when and where fires occur</a>, and <a href="https://theconversation.com/western-wildfires-destroyed-246-more-homes-and-buildings-over-the-past-decade-fire-scientists-explain-whats-changing-197384">they lead to the majority of homes lost to fires</a>. The fire that <a href="https://www.cnn.com/2023/08/11/business/maui-fire-residential-damage-preliminary-estimate/index.html">destroyed Lahaina, Hawaii</a>, is the most recent example.</p>
<h2>So what can we do?</h2>
<p><a href="https://www.unep.org/interactive/six-sector-solution-climate-change/">Curbing greenhouse gas emissions</a> from vehicles, power plants and other sources can help slow warming and the impacts of climate change on wildfires, ecosystems and communities. <a href="https://theconversation.com/the-us-is-spending-billions-to-reduce-forest-fire-risks-we-mapped-the-hot-spots-where-treatment-offers-the-biggest-payoff-for-people-and-climate-210051">Forest thinning and prescribed burns</a> can <a href="https://doi.org/10.1002/eap.2433">alter how forests burn</a>, protecting humans and <a href="https://theconversation.com/the-wests-iconic-forests-are-increasingly-struggling-to-recover-from-wildfires-altering-how-fires-burn-could-boost-their-chances-200668">minimizing the most severe ecological impacts</a>.</p>
<p><a href="https://doi.org/10.1088/1748-9326/ac5c0c">Reframing the challenge of living with wildfire</a> – building with fire-resistant materials, reducing accidental ignitions and increasing preparedness for extreme events – can <a href="https://theconversation.com/well-see-more-fire-seasons-like-2020-heres-a-strategy-for-managing-our-nations-flammable-landscapes-149323">help minimize damage</a> while maintaining the critical role that fires have played in forests across the Rocky Mountains for millennia.</p><img src="https://counter.theconversation.com/content/215221/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kyra Clark-Wolf has received funding from the National Science Foundation and the Joint Fire Science Program</span></em></p><p class="fine-print"><em><span>Philip Higuera receives funding from the National Science Foundation, United States Geological Survey, and Joint Fire Science Program.</span></em></p>As the climate warms, devastating fires are increasingly likely. The 2020 fires pushed the Southern Rockies beyond the historical average. Is there hope for the Northern Rockies?Kyra Clark-Wolf, Postdoctoral Associate in Ecology, University of Colorado BoulderPhilip Higuera, Professor of Fire Ecology, University of MontanaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2111042023-08-14T02:11:49Z2023-08-14T02:11:49ZTrapped: Australia’s extraordinary alpine insects are being marooned on mountaintops as the world warms<figure><img src="https://images.theconversation.com/files/541953/original/file-20230809-15-o4ry1l.JPG?ixlib=rb-1.1.0&rect=672%2C585%2C2277%2C1999&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Kate Umbers/Invertebrates Australia</span></span></figcaption></figure><p>We may not pay invertebrates much thought, but they’re the <a href="https://theconversation.com/they-might-not-have-a-spine-but-invertebrates-are-the-backbone-of-our-ecosystems-lets-help-them-out-193447">workhorses of all ecosystems</a>. Insects and other invertebrates do essential jobs such as <a href="https://australian.museum/learn/animals/insects/pollination/">pollinating plants</a>, <a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.17553">improving soils</a> and controlling pests. They’re also food for many larger animals, which <a href="http://www.titag.org/whyinverts.html#:%7E:text=Invertebrates%20occupy%20critical%20roles%20in,pollinators%E2%80%94to%20name%20a%20few.">moves nutrients</a> up the food chain. </p>
<p>Invertebrates are vulnerable to rising global temperatures. In response to climate change, many are <a href="https://www.theguardian.com/environment/2023/may/28/why-the-climate-crisis-is-making-our-insects-run-for-the-hills">moving</a> to cooler areas, be that across land towards the poles, or upward in elevation.</p>
<p>But not all invertebrates have that option. In Australia, invertebrates already living at the highest possible elevation – on mountain summits – have nowhere higher to go. So how will they cope? And how can we help them? </p>
<p>Answering these questions is important. Invertebrates underpin Earth’s ecosystems – so if their numbers decline, the ecological damage will be felt far and wide.</p>
<figure class="align-center ">
<img alt="grasshopper on a bush" src="https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542032/original/file-20230809-19-ym9gxg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A blistered pyrgomorph grasshopper. How will Australia’s alpine invertebrates cope as the climate warms?</span>
<span class="attribution"><span class="source">Kate Umbers</span></span>
</figcaption>
</figure>
<h2>A life at the top</h2>
<p>The invertebrates of the <a href="https://www.dcceew.gov.au/parks-heritage/heritage/places/national/australia-alps">Australian Alps</a> are <a href="https://play.google.com/store/apps/details?id=com.github.charmasaur.alpsinsects&hl=en_US&pli=1">beautiful and diverse</a>. As in all ecosystems, they make up the <a href="https://www.dcceew.gov.au/science-research/abrs/publications/other/numbers-living-species/executive-summary">largest proportion</a> of our alpine animal species. </p>
<p><a href="https://www.dcceew.gov.au/science-research/abrs/publications/other/numbers-living-species/executive-summary">Most</a> of our alpine invertebrates are <a href="https://australian.museum/learn/teachers/learning/what-are-invertebrates/#:%7E:text=It%20is%20estimated%20that%20Australia,found%20in%20Australia%20are%20endemic.">found nowhere else</a> If we don’t look after them they’re gone forever. And each species extinction is like losing a rivet in an aeroplane wing; eventually whole ecosystems will crash.</p>
<p>Warmer temperatures can affect invertebrates <a href="https://www.buglife.org.uk/blog/cop26-how-does-climate-change-impact-upon-invertebrates/">in many ways</a>. For example, pollinating insects that collect nectar may hatch before plants flower – creating issues for both the insects and the plants. Species that rely on wet or damp conditions may find their habitat dried out. Less harsh, cold conditions may also bring new predators and competitors into their habitats. </p>
<p>Overseas, where mountain ranges are typically <a href="https://www.visualcapitalist.com/cp/mapping-highest-mountains-by-continent/">much higher</a>, animals have been moving up in elevation to survive. But Australia’s mountains <a href="https://www.ga.gov.au/scientific-topics/national-location-information/landforms/highest-mountains">are small</a> – less than half the height of many key mountain ranges overseas. This leaves little room to move higher. </p>
<p>Alpine invertebrates tend to live in small, isolated populations on mountain tops. This limits their genetic diversity and therefore the potential that offspring can survive and adapt to changing conditions.</p>
<p>What’s more, many invertebrates don’t have wings, so can’t fly away to a more hospitable place. And being trapped on mountain tops also makes them vulnerable to devastating local threats such as unusually severe or extensive bushfires. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/they-might-not-have-a-spine-but-invertebrates-are-the-backbone-of-our-ecosystems-lets-help-them-out-193447">They might not have a spine, but invertebrates are the backbone of our ecosystems. Let's help them out</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="A spider from the Australian Alps looking out from her hole." src="https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=458&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=458&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542512/original/file-20230814-25-hj60oo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=458&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A spider from the Australian Alps looking out from her hole.</span>
<span class="attribution"><span class="source">Kate Umbers</span></span>
</figcaption>
</figure>
<h2>Extraordinary bogong moths</h2>
<p>Some species might seem to be moving higher up the Australian Alps. For example, it seems bogong moths inhabit low elevation caves <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/aen.12517">less frequently</a> than they once did. But this probably just shows the species’ habitat is shrinking upward. </p>
<p>Each year, bogong moths undertake an <a href="https://doi.org/10.1016/j.jtherbio.2023.103538">extraordinary nocturnal migration</a>. From their starting point many hundreds of kilometres away, they use the <a href="https://www.sciencedirect.com/science/article/pii/S0960982218306328">stars and Earth’s magnetic field to navigate to the Australian Alps</a> in search of cool caves and rock crevices. There, they rest and take refuge from the summer heat, before returning to their winter pastures. </p>
<p>In 2021, bogong moths were listed as <a href="https://www.iucnredlist.org/species/190513532/196183274">endangered</a> because the availability of their summer habitat is declining.</p>
<p>Bogong moths bring an incredibly important influx of nutrients to the alps. They provide food for many animals, including the adorable, critically endangered mountain pygmy possum, as well as many types of birds.</p>
<p>The <a href="https://taungurung.com.au/">Taungurung people</a> refer to the bogong moth as “<a href="https://taungurung.com.au/product/bijil-ba-wudhi-deberra-childrens-book/">Deberra</a>”. The annual concentration of Deberra in the alps is culturally significant to the Taungurung and other traditional custodians.</p>
<p>Deberra have a high fat content and were harvested by Taungurung and other groups for eating. During the harvest, large gatherings of many Aboriginal nations were held and cultural business was conducted.</p>
<p>So Deberra offers not only a rich source of food, but also connection with deeply significant cultural landscapes. They are an important element in the cyclical movement of people and exchange of knowledge within and between Indigenous nations.</p>
<p>For Traditional Owners, Deberra is, like all things, part of the interrelated web of Country. When Deberra travels, human and non-human entities follow. It supports energy flows of many kinds.</p>
<p>The decline of Deberra is a sign that Country is sick. Sick Country tells us the land is not being managed well.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/next-time-you-see-a-butterfly-treasure-the-memory-scientists-raise-alarm-on-these-26-species-159798">Next time you see a butterfly, treasure the memory: scientists raise alarm on these 26 species</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="A rock outcrop on the alpine high plain during summer" src="https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541942/original/file-20230809-24377-bdgvwg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bogong moth habitat on Mount Kosciuszko in summer. The moths migrate to alpine areas in summer.</span>
<span class="attribution"><span class="source">James Trezise/author supplied</span></span>
</figcaption>
</figure>
<h2>Colour-changing skyhoppers</h2>
<p>The adults of many alpine invertebrate species live for just a single summer, lay their eggs, then die. They include <a href="https://www.australiangeographic.com.au/blogs/creatura-blog/2018/07/chameleon-grasshopper/">skyhoppers</a>, a group of alpine grasshoppers unique to Australia, many species of which are <a href="https://www.iucnredlist.org/search?query=kosciuscola&searchType=species">threatened</a>.</p>
<p>Skyhoppers rely on a thick snow layer to protect their eggs in winter. But Australia’s snow cover is <a href="https://www.abc.net.au/news/2022-09-27/bumper-snow-season-conceals-worrying-trend-climate-change/101463202">becoming increasingly unreliable</a> as the planet warms. </p>
<p>Thermocolour skyhoppers, <a href="https://www.iucnredlist.org/species/209399685/212099065">listed as endangered</a>, are unique among grasshoppers in that they change colour from black to turquoise <a href="https://www.sciencedirect.com/science/article/abs/pii/S0022191011001624">when their body temperature exceeds 25°C</a>. </p>
<p>Until recently, five skyhopper species were known to science. But when researchers <a href="https://doi.org/10.1071/PC21015">walked the entire 655-kilometre</a> Australian Alps walking track, they <a href="https://doi.org/10.1071/PC21015">discovered</a> 15 species of skyhopper exist – each separated by the rugged mountain landscape. </p>
<p>The true biodiversity of the alps is unknown. What we do know is that it is heavily fragmented. What may look like one species across the alps is <a href="https://www.publish.csiro.au/PC/PC21015">likely to be </a> many species each occupying small areas. This means they’re even more vulnerable than currently recognised. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/more-than-60-billion-leaf-litter-invertebrates-died-in-the-black-summer-fires-heres-what-that-did-to-ecosystems-207032">More than 60 billion leaf litter invertebrates died in the Black Summer fires. Here's what that did to ecosystems</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="A blue grasshopper on a yellow flower" src="https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541935/original/file-20230809-16-kc47ot.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Skyhoppers lay their eggs under snow cover.</span>
<span class="attribution"><span class="source">Kate Umbers</span></span>
</figcaption>
</figure>
<h2>Helping them hang on</h2>
<p>Much of the Australian Alps region is <a href="https://theaustralianalpsnationalparks.org/">contained in national parks</a>, but this alone is not adequate protection for our alpine biodiversity. </p>
<p>Greenhouse gas emissions to date have put our alpine biodiversity on a knife’s edge. Australian and international governments must swiftly undertake far more ambitious climate action to cool the alps. </p>
<p>And more effort is needed to give our alpine ecosystems the best chance of coping with climate change. This includes allowing Traditional Owners to connect to and manage Country and removing threats such as feral species, disease and habitat destruction.</p><img src="https://counter.theconversation.com/content/211104/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kate Umbers is based at the School of Science at Western Sydney University and receives funding from the Australian Research Council, NSW Government, Hermon Slade Foundation. She works for Invertebrates Australia, a not-for-profit environmental conservation charity. She is affiliated with the IUCN and the Biodiversity Council. </span></em></p><p class="fine-print"><em><span>Jaana Dielenberg is based at The University of Melbourne and works for the Biodiversity Council. She is a member of Invertebrates Australia and the Ecological Society of Australia. She previously worked for the now ended Threatened Species Recovery Hub of the Australian Government's National Environmental Science Program. </span></em></p><p class="fine-print"><em><span>Matthew Shanks works for Taungurung Land and Waters Council and receives funding from the Department of Energy, Environment and Climate Action. He is affiliated with the Biodiversity Council and Back to Country.</span></em></p>Invertebrates underpin Earth’s ecosystems – so if their numbers decline, the ecological damage will be felt far and wide.Kate Umbers, Senior Lecturer in Zoology, Western Sydney UniversityJaana Dielenberg, University Fellow, Charles Darwin UniversityMatthew Shanks, Director, Cultural Land Management at Taungurung Land and Waters Council, Indigenous KnowledgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2051002023-05-15T15:43:20Z2023-05-15T15:43:20ZA political mountain to climb: why the Alps are such a commonly used metaphor in European thought<figure><img src="https://images.theconversation.com/files/525702/original/file-20230511-37636-r2hri4.jpg?ixlib=rb-1.1.0&rect=59%2C47%2C3926%2C2187&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sacra-di-san-michele-unusual-views-1617051133">Shutterstock/Federico Cappone</a></span></figcaption></figure><blockquote>
<p><em>È qui, su queste montagne, in queste valli … che la Repubblica celebra oggi le sue radici con la festa della Liberazione</em>.</p>
<p>It is here on these mountains, in these valleys, that the Republic today celebrates the day of its Liberation.</p>
</blockquote>
<p>With <a href="https://www.repubblica.it/editoriali/2023/04/26/news/25_aprile_festa_della_liberazione-397603402/?ref=RHLF-BG-I397631762-P2-S1-T1">these words</a> and evocative references, Italian president Sergio Mattarella recently marked the 78th anniversary of the end of the fascist dictatorship in Italy. He was speaking during a visit to <a href="https://www.ideawebtv.it/2023/04/25/mattarella-e-qui-che-la-repubblica-celebra-oggi-le-sue-radici-celebra-la-festa-della-liberazionea-video/">Cuneo</a>, in the north of the country. </p>
<p>This was the first time Italy has celebrated the date under the leadership of prime minister Giorgia Meloni and Fratelli d’Italia, a <a href="https://www.theguardian.com/commentisfree/2023/apr/23/the-guardian-view-on-giorgia-meloni-normalising-the-radical-right">party</a> that finds its <a href="https://foreignpolicy.com/2023/02/06/why-giorgia-meloni-wont-distance-herself-from-italys-fascist-past/">roots in Mussolini’s fascism</a> and <a href="https://www.lemonde.fr/en/international/article/2023/04/25/in-italy-the-memory-of-anti-fascism-is-being-abused_6024177_4.html">often flirts with its ideas today</a>. Mattarella used his status as a <a href="https://www.politico.eu/article/sergio-mattarella-italy-captive-president/">unity figure</a> to elevate anti-fascism above party politics and to uphold it as a constitutive element of a democratic state.</p>
<p>He quoted eminent Italian legal expert and a founding father of the Italian constitution, Piero Calamandrei:</p>
<blockquote>
<p>If you want to go on pilgrimage to the place where our constitution was born, go to the mountains where partisans fell.</p>
</blockquote>
<p>The location of Mattarella’s speech was evidently significant even before he uttered these words. As early as <a href="http://cuneo.anpi.it/cuneo">1947</a>, the Piedmontese province of Cuneo was recognised as one of the most symbolic sites of the Italian resistance against the Italian fascist and the German Nazi regimes.</p>
<p>And Mattarella’s decision to specifically mention mountains is no coincidence. He was following a long tradition of using such imagery to make a political point. During my research for an <a href="https://global.oup.com/academic/product/the-emotions-of-internationalism-9780198848325?cc=gb&lang=en&">academic monograph</a> on this topic, I found that communists, Catholics and fascists alike have deployed images of mountains – and particularly the Alps – in their rhetoric, each ascribing them with their own meaning.</p>
<p>In Italy, for instance, communist workers’ groups such as the Club Alpino Operaio and the Unione Operaia Escursionisti Italiani organised mountain stays for workers they wished to keep away from drinking and other vices. In an alpine setting, they thought it would be easier to instil solidarity among proletarians across borders. </p>
<p>Fascists used the Alps as grounds on which to improve the health of the nation. Like the Nazis in Germany, they opened <a href="http://www.lecolonie.com/Colonia_montana_PNF_Genova_Rovegno_en.htm">summer camps and colonies for children</a> to increase their physical strength and to boost their fascist education. </p>
<p>Catholics also organised hiking trips and camping stays for young people, stressing that class differences could be erased and moral and religious values be upheld more easily in an alpine environment.</p>
<h2>Literary trope</h2>
<p>From the 19th century, books such as Johanna Spyri’s Heidi depicted mountains as healthy and conducive to friendship. But after the first world war, the Alps came to represent the <a href="https://www.histecon.magd.cam.ac.uk/frontiers/landscape_memory.html">violent fighting that took place on them</a>. Indeed, as global warming melts the ice, <a href="https://www.nationalgeographic.com/science/article/141017-white-war-first-world-war-italy-austro-hungarian-mountains-history">some relics</a> of the carnage that unfolded there continue to emerge. </p>
<p>More than other geographical features such as seas or lakes, mountains came to represent higher political ideals. As famously noted by German critic <a href="https://archive.org/details/fromcaligaritohi00krac">Sigfried Kracauer</a>, Bergfilm (or “mountain films”) by directors such as <a href="https://www.imdb.com/name/nm0266691/">Arnold Fanck</a> and his mentee <a href="https://encyclopedia.ushmm.org/content/en/article/leni-riefenstahl">Leni Riefenstahl</a> pitted individuals against nature and immortalised the Alps as the embodiment of national “purity”. That aesthetic would go on to be appropriated by the Nazi regime. </p>
<p>For other movements, the Alps expressed the imperative of avoiding another conflict after the first world war and ensuring permanent peace. The “Alpinist” Pope Achille Ratti (1857–1939), who reigned as Pope Pius XI from 1922 to 1939, in 1923 proclaimed Bernard of Menthon the patron saint of the mountains, and <a href="https://archive.org/details/scrittialpinisti00pius/page/n11/mode/2up">wrote</a> about the Alps as a preferred place for peaceful interaction among people.</p>
<p>The League of Nations, whose main site was in Geneva, often emphasised its proximity to the mountains. In its publicity, it often used alpine imagery to present itself as strong, clean and noble.</p>
<h2>Political metaphor</h2>
<p>Such references and associations are not simply decorative. Indeed, as my research shows, historically they proved quite powerful. The League’s choice of alpine imagery and overall “emotional style” proved long-lasting, though in the late 1930s it backfired as it allowed the institution to be stereotyped as distant and ill-equipped to deal with a gritty, real world.</p>
<p>In modern times, localist movements like the Italian political party the Lega Nord, or Northern League, have appropriated mountain foods such as <a href="http://www.iitaly.org/magazine/dining-in-out/articles-reviews/article/polenta-vs-cous-cous-legally-banning-ethnic-food">polenta</a> as a means to question both national and European institutions. In their rhetoric, this quintessentially alpine dish serves as a marker of local identity and the embodiment of natural and artisan production. It is the opposite of the artificial, industrial, cosmopolitan goods coming in via global trade.</p>
<p>Meloni’s own Fratelli d’Italia organised a large gathering <a href="https://www.fratelliditaliasenato.it/stati-generali-della-montagna/">in the Italian Apennines</a> in 2020, a kind of general assembly aimed at developing specific measures to protect and support the mountain regions, including their “traditions” and “identity”.</p>
<p>The party later <a href="https://www.fratelli-italia.it/2021/02/17/giorgia-meloni-la-montagna-merita-rispetto-non-speranza-video/">campaigned against closing</a> Italy’s ski resorts during the pandemic, <a href="https://www.fratelli-italia.it/2021/02/17/giorgia-meloni-la-montagna-merita-rispetto-non-speranza-video/">arguing</a>:</p>
<blockquote>
<p><em>La montagna è parte fondamentale dell’identità italiana e non può essere umiliata.</em></p>
<p>Mountains are a fundamental part of Italian identity and cannot be humiliated.</p>
</blockquote>
<p>The use of the term “humiliated” is reminiscent of fascist rhetoric and slogans that often equated compromise with humiliation and often glorified pride – or <a href="https://www.thelocal.it/20160229/trump-causes-storm-by-tweeting-quote-from-italys-mussolini">“living a day as a lion”</a> – as a marker of moral fortitude and strength. “Italian identity” refers to the fascist use of mountains as natural borders, as well as to the policies of forced <a href="https://www.eurac.edu/en/blogs/eureka/when-conflict-is-written-in-stone">Italianisation of the populations living within them</a>.</p>
<p>Seen against this backdrop, Mattarella’s choice to point out the symbolic value of mountains and to reclaim their significance in the history of Italian anti-fascism thus acquire new significance. By adopting a strong emotional style, the Italian president put forth an alternative version of pride and a bold response to growing far-right movements. </p>
<p>As in the <a href="https://www.doppiozero.com/beppe-fenoglio-montagna">writings by Beppe Fenoglio</a>, one of Cuneo’s landmark resistance fighters and writers, mountains in Mattarella’s narrative serve as a space to uphold the country’s moral fabric and a vantage point from which to ponder how to save the world in trouble down below.</p><img src="https://counter.theconversation.com/content/205100/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ilaria Scaglia received funding for part of this research through a Volkswagen–Mellon Postdoctoral Fellowship for Research in Germany (2016–2017). She sits on the board of the Coordinating Council for Women in History (CCWH).</span></em></p>For the Italian president, the region is where his nation’s constitution was born.Ilaria Scaglia, Senior Lecturer in History, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2039512023-04-19T13:53:15Z2023-04-19T13:53:15ZThe long history of Bannau Brycheiniog – the true name of the Brecon Beacons for centuries<figure><img src="https://images.theconversation.com/files/521633/original/file-20230418-1223-oh543t.jpg?ixlib=rb-1.1.0&rect=38%2C0%2C4273%2C2827&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Brecon Beacons National Park is now officially only known by its native Welsh name. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/brecon-beacons-sun-rising-over-pen-210410398">Mel Manser Photography/Shutterstock</a></span></figcaption></figure><p><em>You can also read <a href="https://theconversation.com/hanes-cyfoethog-bannau-brycheiniog-203964">this article in Welsh</a>.</em></p>
<p>On its 66th birthday, <a href="https://bannau.wales">Bannau Brycheiniog National Park</a> launched a new <a href="https://bannau.wales/the-authority/press-and-news/press-releases/april-2023/brecon-beacons-national-park-reclaims-its-welsh-name/">management plan</a> seeking to combat its greatest challenges: the nature and climate emergencies. This plan includes projects to plant trees, protect endangered species and their habitats, and improve the quality of its rivers. </p>
<p>But despite the best efforts of a promotional video featuring the actor Michael Sheen, another aspect of the plan has <a href="https://www.bbc.co.uk/news/uk-wales-65274952">generated most interest</a>. From now on, the national park will use only its Welsh name, Bannau Brycheiniog, rather than Brecon Beacons. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/CLP3yh_XSo4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Michael Sheen describes Bannau Brycheiniog as ‘a name from our past, to take us into our future’.</span></figcaption>
</figure>
<p>In reality, little has changed. Bannau Brycheiniog was always the Welsh name for the park, used since it was established in 1957. Indeed, the first person to refer to Bannau Brycheiniog in writing was the poet and antiquary <a href="https://www.britannica.com/biography/John-Leland">John Leland</a>, who lived during the first half of the 16th century.</p>
<p>Leland was an avid traveller and undertook several trips around Wales and England. He took detailed notes of what he saw, heard and learned. One of his trips took him to the mountains of south Wales and he described the mountain, Pen-y-Fan, in his notes. Leland wrote that that there were many “diverse hilles” and together they were called “Banne Brekeniauc” (sic).</p>
<figure class="align-center ">
<img alt="A stone with a plaque on it which reads " src="https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521640/original/file-20230418-20-6j3u4h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Pen-y-Fan is the highest summit in south Wales.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sign-marking-peak-pen-y-fan-1707274690">Edd Mitchell/Shutterstock</a></span>
</figcaption>
</figure>
<p>In Welsh, <em>bannau</em> is the plural of <em>ban</em>, which means “summit” or “peak”, and is a common name for “mountain”. We can see several mountains so-named in the national park today, including Pen-y-Fan, Fan Fawr and Fan Hir. Around Leland’s time, we often see references to <em>Y Fan</em> (a single mountain) and <em>Y Bannau</em> (a collection of mountains). These names are common and it is often difficult to know precisely which mountains are being described. </p>
<h2>Poetry</h2>
<p>For other examples, we can turn to the work of the Welsh poets. In the 15th century, Ieuan Llawdden composed <a href="https://adnoddau.s3.eu-west-2.amazonaws.com/Beirdd/31+Gwaith+Llawdden.pdf"><em>Moliant Brycheiniog</em></a> (In Praise of Brycheiniog). As its title suggests, the poem is a celebration of Brycheiniog’s rivers, trees, saints, inhabitants and mountains. The poem encompasses the region “<em>o’r Fan hyd ar Y Fenni</em>” (“from the Fan as far as Y Fenni”). </p>
<p>In an elegy composed in the 16th century, Lewys Morgannwg writes that everywhere is sad <a href="https://adnoddau.s3.eu-west-2.amazonaws.com/Beirdd/27+Gwaith+Lewys+Morgannwg.pdf">“<em>o Hafren i’r Bannau</em>”</a> (“from the Severn to the Bannau”). </p>
<p>And a poem by a bard known as Y Nant (the Stream) from the 15th century includes a reference to <a href="https://adnoddau.s3.eu-west-2.amazonaws.com/Beirdd/40+Gwaith+y+Nant.pdf"><em>“tu yma i’r Banne”</em></a> (“this side of the Bannau”). We don’t know the poet’s real name or anything about them, but their poems are full of references to the people and places of Brycheiniog. </p>
<p>These were poets not cartographers, of course, writing poems not designing maps. We shouldn’t expect them to have described the location of each and every name they mention specifically. But there is clearly a tradition of referring to the mountains of Brycheiniog as <em>Y Bannau</em>.</p>
<h2>A medieval kingdom</h2>
<p>Brycheiniog was a medieval kingdom in south-east Wales. It was common to add <a href="https://www.jstor.org/stable/25509590?saml_data=eyJzYW1sVG9rZW4iOiIyOTU1ZDhhZi1hMmY4LTRmN2YtODkwYi1jMGZkNGY0N2RkODciLCJpbnN0aXR1dGlvbklkcyI6WyI5OTE5YmNmYi1mOWYwLTRlYTktYmEzNi0wNzMwOTQxODcyMzciXX0">suffixes such as <em>-iog</em> or <em>-ion</em></a> to a personal name to indicate “the people of”, “the descendants of”, or “the territory held by”. We see this in the contemporary county of Ceredigion, which is the personal name Ceredig with the suffix <em>-ion</em>, and in Brycheiniog, with the personal name Brychan and the suffix <em>-iog</em>. </p>
<p><a href="https://biography.wales/article/s-BRYC-APA-0419">Brychan</a> was a 5th- or 6th-century king who, according to medieval lore, came from Ireland. He was also allegedly the father of tens of children, many of them saints, including the Welsh patron saint of love, <a href="https://theconversation.com/how-st-dwynwen-wrongly-became-known-as-the-welsh-valentine-71520">Dwynwen</a>. </p>
<figure class="align-center ">
<img alt="Mist hangs over a calm lake. On the other side of the shore is a triangular construction." src="https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521674/original/file-20230418-26-l2sxgr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A view of Llyn Syfaddan and its crannog, built by the king of Brycheiniog.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/llangorse-lake-crannog-island-morning-mist-1947174256">Robert Harding/Shutterstock</a></span>
</figcaption>
</figure>
<p>It must be stressed that these are later stories – we don’t know anything for sure about the historical Brychan. But there is evidence of Irish influence on the land of Brycheiniog in the middle ages. For example, there are a number of stones inscribed with <a href="https://www.historytoday.com/story-ogham">ogham</a>, an alphabet used for writing Irish, and these include Irish names.</p>
<p>In the 10th century, the king of Brycheiniog constructed a <em>crannog</em> (artificial island) on <a href="https://museum.wales/articles/1350/The-Palace-in-the-Lake/">Llyn Syfaddan (Llan-gors Lake)</a>. This is the only example of a medieval crannog in Wales, but they are common in Ireland and Scotland. Whatever Brychan’s history, it is likely that real connections with Ireland inspired the stories about his Irish background.</p>
<h2>Reclamation</h2>
<p>The loss of Welsh place-names is a matter of <a href="https://theconversation.com/welsh-place-names-are-being-erased-and-so-are-the-stories-they-tell-197832#:%7E:text=The%20decision%20to%20use%20Eryri,to%20use%20the%20Welsh%20names.">increasing concern</a>. As early as the 12th century, the cleric, historian and traveller <a href="https://www.britannica.com/biography/Giraldus-Cambrensis">Gerald of Wales</a> complained that the place name Llanddewi Nant Honddu was being corrupted to Llanthony. </p>
<p>More recently, groups such as the <a href="https://www.cymdeithasenwaulleoedd.cymru/en/">Welsh Place-Name Society</a> have been working tirelessly to protect Welsh names. Bannau Brycheiniog follows <a href="https://www.bbc.co.uk/news/uk-wales-63649930">Eryri</a> as the second national park to commit to using only its Welsh version. </p>
<p>And it isn’t just a matter of language either. The park feels the name Bannau Brycheiniog is “more in keeping with its Welsh heritage”. But amid both nature and climate emergencies, much more must be done to protect this precious place and its rich history.</p><img src="https://counter.theconversation.com/content/203951/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca Thomas is Bannau Brycheiniog National Park's Welsh writer in residence (2022/3). </span></em></p>The mountain range in south Wales is now officially only known by its native Welsh-language nameRebecca Thomas, Lecturer in Medieval History, Cardiff UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2034722023-04-19T12:44:18Z2023-04-19T12:44:18ZFire danger in the high mountains is intensifying: That’s bad news for humans, treacherous for the environment<figure><img src="https://images.theconversation.com/files/521666/original/file-20230418-22-zv27xr.jpg?ixlib=rb-1.1.0&rect=0%2C2%2C1731%2C1065&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fires are increasing in high mountain areas that rarely burned in the past.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Deerfire_high_res.jpg">John McColgan, Bureau of Land Management, Alaska Fire Service</a></span></figcaption></figure><p>As wildfire risk rises in the West, wildland firefighters and officials are keeping a closer eye on the high mountains – regions once considered too wet to burn.</p>
<p>The growing fire risk in these areas became startling clear in 2020, when Colorado’s <a href="https://www.cpr.org/2021/01/25/colorados-east-troublesome-wildfire-may-signal-a-new-era-of-big-fire-blow-ups/">East Troublesome Fire</a> burned up and over the Continental Divide to become the state’s second-largest fire on record. The following year, California’s <a href="https://www.latimes.com/california/story/2021-09-14/californias-wildfires-burning-at-greater-elevations">Dixie Fire</a> became the first on record to burn across the Sierra Nevada’s crest and start down the other side.</p>
<p>We study wildfire behavior as <a href="https://scholar.google.com/citations?user=ZaW8ZbsAAAAJ&hl=en">climate scientists</a> and <a href="https://scholar.google.com/citations?user=tGGNDyUAAAAJ&hl=en">engineers</a>. In a <a href="https://doi.org/10.1038/s41467-023-37311-4">new study</a>, we show that fire risk has intensified in every region across the West over the past four decades, but the sharpest upward trends are in the high elevations. </p>
<figure class="align-center ">
<img alt="Fire burns in the mountains above a building and ranch fence." src="https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&rect=25%2C17%2C5670%2C3236&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=431&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=431&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521653/original/file-20230418-826-n7xjsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=431&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In 2020, Colorado’s East Troublesome fire jumped the Continental Divide.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/Exchange-ColoradoWildfires-Blow-ups/8e10c8213c3847f3a7ef14e7ff81eddf/photo">AP Photo/David Zalubowski</a></span>
</figcaption>
</figure>
<p>High mountain fires can create a cascade of risks for local ecosystems and for millions of people living farther down the mountains.</p>
<p>Since cooler, wetter high mountain landscapes rarely burn, vegetation and dead wood can build up, so <a href="https://doi.org/10.1073/pnas.2009717118">highland fires tend to be intense and uncontrollable</a>. They can affect everything from water quality and the timing of meltwater that communities and farmers rely on, to erosion that can bring debris and mud flows. Ultimately, they can change the hydrology, ecology and <a href="https://www.britannica.com/science/geomorphology">geomorphology</a> of the highlands, with complex feedback loops that can transform mountain landscapes and endanger human safety.</p>
<h2>Four decades of rising fire risk</h2>
<p>Historically, higher moisture levels and cooler temperatures created a flammability barrier in the highlands. This enabled fire managers to leave fires that move away from human settlements and up mountains to run their course without interference. Fire would hit the flammability barrier and burn out.</p>
<p>However, our findings show that’s no longer reliable as the climate warms.</p>
<p>We <a href="https://doi.org/10.1038/s41467-023-37311-4">analyzed fire danger trends</a> in different elevation bands of the Western U.S. mountains from 1979 to 2020. Fire danger describes conditions that reflect the <a href="https://www.fs.usda.gov/detail/inyo/home/?cid=stelprdb5173311">potential for a fire to ignite and spread</a>.</p>
<p>Over that 42-year period, <a href="https://doi.org/10.1126/sciadv.aaz4571">rising temperatures and drying trends</a> increased the number of critical fire danger days in every region in the U.S. West. But in the highlands, certain environmental processes, such as <a href="https://doi.org/10.1038/nclimate2563">earlier snowmelt</a> that allowed the earth to heat up and become drier, intensified the fire danger faster than anywhere else. It was particularly stark in high-elevation forests from about 8,200 to 9,800 feet (2,500-3,000 meters) in elevation, just above the elevation of Aspen, Colorado.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Chart showing changing wildfire risks in the high mountains" src="https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521494/original/file-20230418-18-ombvln.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Mohammad Reza Alizadeh</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We found that the high-elevation band had gained on average 63 critical fire danger days a year by 2020 compared with 1979. That included 22 days outside the traditional warm season of May to September. In previous research, we found that high-elevation fires had been advancing upslope in the West at <a href="https://doi.org/10.1073/pnas.2009717118">about 25 feet (7.6 meters) per year</a>.</p>
<h2>Cascading risks for humans downstream</h2>
<p>Mountains are <a href="https://doi.org/10.1029/2006WR005653">water towers</a> of the world, providing <a href="https://doi.org/10.1002/2017GL073551">70% of the runoff that cities across the West</a> rely on. They support millions of people who live downstream.</p>
<p>High-elevation fires can have a significant impact on snow accumulation and meltwater, even long after they have burned out. </p>
<p>For example, fires remove vegetation cover and tree canopies, which can <a href="https://doi.org/10.1038/s41467-019-09935-y">shorten the amount of time</a> the snowpack stays frozen before melting. Soot from fires also darkens the snow surface, increasing its ability to absorb the Sun’s energy, which facilitates melting. Similarly, darkened land surface increases the absorption of solar radiation and heightens soil temperature after fires.</p>
<p>The result of these changes can be spring flooding, and less water later in the summer when communities downstream are counting on it.</p>
<p>Fire-driven tree loss also removes anchor points for the snowpack, increasing <a href="https://doi.org/10.1016/j.foreco.2009.01.050">the frequency and severity of avalanches</a>.</p>
<figure class="align-center ">
<img alt="A burned area on a mountain ridge with a large reservoir far below." src="https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521655/original/file-20230418-26-rde43z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wildfire burn scars can have many effects on the water quality and quantity reaching communities below.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/iron-mountain-and-whiskeytown-lake-site-of-the-destructive-news-photo/1334892056">George Rose/Getty Images</a></span>
</figcaption>
</figure>
<p>Frequent fires in high-elevation areas can also have a significant impact on the sediment dynamics of mountain streams. The loss of tree canopy means rainfall hits the ground at a higher velocity, increasing the <a href="https://doi.org/10.1073/pnas.1814627116">potential for erosion</a>. This can trigger mudslides and increase the <a href="https://doi.org/10.1038/s41467-019-09864-w">amount of sediment</a> sent downstream, which in turn can affect water quality and aquatic habitats.</p>
<p><a href="https://doi.org/10.1073/pnas.1814627116">Erosion linked to runoff after fire damage</a> can also deepen streams to the point that excess water from storms can’t spread in high-elevation meadows and recharge the groundwater; instead, they route the water quickly downstream and cause flooding.</p>
<h2>Hazards for climate-stressed species and ecosystems</h2>
<p>The highlands generally have long fire return intervals, burning once every several decades if not centuries. Since they don’t burn often, their ecosystems aren’t as fire-adapted as lower-elevation forests, so they may not recover as efficiently or survive repeated fires. </p>
<p>Studies show that more frequent fires could <a href="https://doi.org/10.1111/ele.12889">change the type of trees that grow</a> in the highlands or even convert them to shrubs or grasses. </p>
<figure class="align-center ">
<img alt="A team of pack mules carries supplies up a high mountain in Glacier National Park. Some of the trees have burned, even at this high elevation." src="https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521663/original/file-20230418-682-fl98ua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">High-elevation tree species like whitebark pines face an increasing risk of blister rust infections and mountain pine beetle infestations that can kill trees, creating more fuel for fires.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/park-service-animal-packers-jill-michalak-and-jacob-ellis-news-photo/1175612536">Chip Somodevilla/Getty Images</a></span>
</figcaption>
</figure>
<p>Wet mountain areas, with their cooler temperatures and higher precipitation, are often peppered with hot spots of biodiversity and provide refuges to various species from the warming climate. If these areas lose their tree canopies, <a href="https://doi.org/10.1073/pnas.1103097108">species with small ranges</a> that depend on cold-water mountain streams can face existential risks as <a href="https://doi.org/10.1890/09-0822.1">more energy from the Sun</a> heats up stream water in the absence of tree shading. </p>
<p>While the risk is rising fastest in the high mountains, most of the West is now at increasing risk of fires. With continuing greenhouse gas emissions fueling global warming, this trend of worsening fire danger is expected to intensify further, straining firefighting resources as crews battle more blazes.</p><img src="https://counter.theconversation.com/content/203472/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mojtaba Sadegh receives funding from the Joint Fire Science Program and the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Mohammad Reza Alizadeh does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Fires here can affect meltwater timing and water quality, worsen erosion that triggers mudslides, and much more, as two scientists explain.Mohammad Reza Alizadeh, Postdoctoral Researcher in Environmental Engineering, Massachusetts Institute of Technology (MIT)Mojtaba Sadegh, Assistant Professor of Civil Engineering, Boise State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2017422023-03-14T12:24:57Z2023-03-14T12:24:57ZWhy rain on snow in the California mountains worries scientists<figure><img src="https://images.theconversation.com/files/515057/original/file-20230314-17-sv7ygq.jpg?ixlib=rb-1.1.0&rect=0%2C31%2C5200%2C3464&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A series of atmospheric rivers in early 2023 covered the Sierra Nevada in snow.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-an-aerial-view-a-person-shovels-on-a-snowy-roadway-lined-news-photo/1473159767">Mario Tama/Getty Images</a></span></figcaption></figure><p><em>Another round of powerful atmospheric rivers is hitting California, following storms in January and February 2023 that dumped record amounts of snow. This time, the storms are warmer, and they are <a href="https://twitter.com/NWSWPC/status/1635405410449358848/photo/1">triggering flood warnings</a> as they bring rain higher into the mountains – on top of the snowpack.</em></p>
<p><em>Professor <a href="https://www.colorado.edu/instaar/keith-musselman">Keith Musselman</a>, who studies water and climate change at the University of Colorado’s Institute of Arctic and Alpine Research, explained the complex risks rain on snow creates and how they might change in a warming climate.</em></p>
<h2>What happens when rain falls on snowpack?</h2>
<p>For much of the United States, storms with heavy rainfall can coincide with seasonal snow cover. When that happens, the resulting runoff of water can be much greater than what is produced from rain or snowmelt alone. The combination has resulted in <a href="https://data.sacriver.org/assets/5ffd2763a1b5d1a3078c4bd991651244/application/pdf/Flooding_from_rain-on-snow_events_in_the_Sierra_Nevada.pdf">some of the nation’s</a> most destructive and costly floods, including the <a href="https://www.weather.gov/media/publications/assessments/Flood_Northeast_1996.pdf">1996 Midwest floods</a> and the 2017 flood that <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL088189">damaged California’s Oroville Dam</a>.</p>
<p>Contrary to common belief, rainfall itself has limited energy to melt snow. Rather, it is the warm temperatures, strong winds and high humidity, which can transport substantial energy in the form of <a href="https://www.britannica.com/science/latent-heat">latent</a> and <a href="https://energyeducation.ca/encyclopedia/Sensible_heat">sensible heat</a>, <a href="https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=1bbb9311d5932d6cdef0600ec16a4f124fde082d">that predominantly drive snowmelt</a> during rain-on-snow events.</p>
<p>Snowpack has air spaces that water can move through. As the rain falls, the water can travel relatively rapidly through the snowpack’s layers to reach the underlying soil. How streams respond to that runoff depends on how much water is already flowing and how saturated the soil is. </p>
<p>When the soil isn’t yet saturated, it can dampen or delay a flood response by soaking up rain and melting snow. But when the ground is saturated, snowmelt combined with rain can lead to fast and devastating flooding.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1635405410449358848"}"></div></p>
<p>One of the challenges for dealing with these rain-on-snow events is that the flood risk is hard to forecast.</p>
<p>To predict whether a flood will occur requires knowledge of weather and hydrological conditions. It requires knowing the soil moisture and snowpack conditions before the storm, the elevation at which rain transitions to snow, the rainfall rate, the wind speed, air temperature and humidity, and estimates of how those factors contribute to snowmelt. Additionally, each factor varies in time during a storm and varies in complex ways, especially across a mountainous landscape.</p>
<p>This is why rain-on-snow floods are characterized as <a href="https://journals.ametsoc.org/view/journals/bams/88/3/bams-88-3-319.xml">compound extreme events</a>. Despite the extensive damage they can cause, it may be surprising how little is known about how they vary in time, spatial extent and intensity.</p>
<h2>California is getting another atmospheric river, with more rain on snow expected. How does the rain-on-snow effect differ by elevation in the mountains there?</h2>
<p>In the California mountains right now, it’s the middle elevations that people need to pay attention to.</p>
<p>The lower elevations have primarily seen rainfall rather than snow, so there is less snowpack to melt. And in the highest elevations, colder temperatures promote the continued accumulation of deep snowpack and rainfall is less likely.</p>
<p>In <a href="https://doi.org/10.1175/JHM-D-20-0028.1">the middle transition zone</a> – where either substantial rainfall or snowfall can occur – rain-on-snow events are most common, causing both melting and risk of roof collapses.</p>
<p>If all storms were created equal, there would be well-defined rain zones and snow zones, and the rain-on-snow flood risk would be low. But that isn’t what happens. Instead, not only does the snow zone elevation vary during an event, but it also varies substantially from one storm to the next.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1635329743099949059"}"></div></p>
<p>The most destructive rain-on-snow events occur when rivers are already running high and soils are saturated, which can occur in response to a series of warm atmospheric rivers interacting with a deep snowpack – like California’s mountains have right now. The order in which these storms occur – or the storm sequencing – is especially important for assessing flood risk because these events are, in part, caused by rapid shifts between cold periods of snow accumulation followed by warm rainfall events.</p>
<h2>What does research show about the future risk of rain-on-snow events in a warming climate?</h2>
<p>Even less is known about how rain-on-snow flood risk may respond as the planet warms.</p>
<p>In a warmer climate, there will be less risk of rain falling on snow in the lower elevations <a href="https://doi.org/10.1038/s41612-018-0012-1">as the snowpack declines</a>, particularly in warmer regions such as the Pacific Northwest.</p>
<p>But at higher elevations, <a href="https://doi.org/10.1175/JCLI3850.1">more frequent rain-on-snow</a> events are expected. While <a href="https://doi.org/10.3354/cr00953">warmer temperatures</a> are expected to increase rainfall intensity, research shows that’s not the most important driver of this risk. Much of the expected increase in rain-on-snow flood risk is a result of the <a href="https://doi.org/10.1038/s41558-018-0236-4">rain-snow transition zone expanding higher</a> in elevation to include alpine areas that historically received predominantly snowfall.</p>
<p>Flood control and reservoir management systems in these mountainous regions will have to consider these future changes in rain-on-snow events – in addition to changes in rainfall intensity and storm sequencing – to <a href="https://doi.org/10.1038/s41558-018-0236-4">fully understand and prepare for</a> the local flood risk as the planet warms.</p>
<p>So, will projected increases in precipitation extremes and winter rainfall increase rain-on-snow occurrence and the associated flood risk? Or will less snow cover and larger soil moisture deficits reduce rain-on-snow flood risk in a warmer climate?</p>
<p>In a future climate, the response of rain-on-snow flood risk is expected to change in complex and often contradictory ways. The projected changes are <a href="https://doi.org/10.1038/s41558-018-0236-4">likely to vary</a> by region, season, climate model, emissions scenario and future time horizon. It’s a <a href="https://www.rms.com/newsroom/press-releases/press-detail/2023-01-25/moodys-rms-estimates-us5-7-billion-in-total-us-economic-losses-from-california-flooding">costly risk</a> that requires more research.</p><img src="https://counter.theconversation.com/content/201742/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Keith Musselman does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Rain falling on deep snow from a series of atmospheric rivers has heightened California’s flood risk. It’s a growing problem as the planet warms.Keith Musselman, Assistant Professor in Geography, Mountain Hydrology, and Climate Change, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2000242023-02-17T14:12:28Z2023-02-17T14:12:28ZHow Sylvia Plath’s profound nature poetry elevates her writing beyond tragedy and despair<blockquote>
<p>I cannot stop writing poems! … They come from the vocabulary of woods and animals and earth.</p>
</blockquote>
<p><strong><em>From a letter from Sylvia Plath to her mother, 1956</em></strong></p>
<p>Popular perceptions of Sylvia Plath tend to dwell on a deeply troubled version of the young poet due to her well-documented difficulties with depression and the <a href="https://www.poetryfoundation.org/poems/49000/lady-lazarus">morbid imagery</a> found in some of her poetry. So the idea that nature inspired her writing may come as a surprise. </p>
<p>This despairing Plath is a far cry from the poet I have come to know and admire – a poet who writes about the <a href="https://mywordinyourear.com/2021/10/22/watercolour-of-grantchester-meadows-sylvia-plath-comments/">simple beauty of meadows</a> and the <a href="https://allpoetry.com/poem/8498359-Mushrooms-by-Sylvia-Plath">tenacity of fungi</a> as well as the splendours of <a href="https://allpoetry.com/Two-Campers-In-Cloud-Country">rugged wilderness</a>.</p>
<p>Plath’s fascination with the natural world began in childhood, as she makes clear in her essay <a href="https://www.bl.uk/collection-items/ocean-1212-w-by-sylvia-plath">Ocean 1212-W</a>, in which she details the importance of the sea to her poetic imagination. This interest in nature continued into adulthood, when she read the work of biologists such as Rachel Carson, whom she writes about in her <a href="https://www.faber.co.uk/journal/on-sylvia-plaths-letters/">letters</a>.</p>
<p>Any other poet with this background would at least be credited with a passing interest in the natural world. However, Plath’s untimely death by suicide has skewed much interpretation of her poetry. The well-versed argument that Plath only uses nature in her poetry as a “<a href="https://books.google.co.uk/books?id=-iG8AAAAIAAJ&printsec=frontcover#v=onepage&q&f=false*%22">mirror to look deeper into herself</a>, has pervaded critical writing on her work from the 1960s to the 21st century.</p>
<p>It is this blinkered view of Plath which has led to an oversight of the ecological significance of her poetry. As we move past the 60th anniversary of Plath’s death, it is time to embrace more nuanced interpretations of her work and to reimagine what her poetic legacy might look like.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YLL3epbJ2cg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Grand-scale natural beauty</h2>
<p>Plath loved the vast landscapes of national parks as well as smaller-scale wildernesses like those of England’s Yorkshire moors. In letters from 1956, she describes "the great luminous emerald lights” of the Yorkshire countryside, concluding that she has “never been so happy” in her life as among the “wild, purple moors”.</p>
<p>These excerpts from her letters resonate with the celebratory assertion in the poem <a href="https://allpoetry.com/Wuthering-Heights">Wuthering Heights</a> that “there is no life higher than the grasstops or the hearts of sheep”.</p>
<p>She found similar beauty in the national parks of America and Canada, which she visited in the summer of 1959. In letters from this period, she remarks that she has never seen “such wonderful country anywhere in the world”. No doubt these experiences inspired the sublime depiction of the “dominance of rocks and woods” and “man-shaming clouds” in the poem <a href="https://allpoetry.com/Two-Campers-In-Cloud-Country">Two Campers in Cloud Country</a> as well as the spectacular “splurge of vermilions” she describes in the sunsets over Algonquin National Park in Canada.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/zMO5o2K1Nx0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Beauty in smaller places</h2>
<p>However, it is not these grand poetic depictions of the natural world which resonate the most with me. Even the most ardent city enthusiast can pause for a moment of wonder in front of millennia-old mountains, but few among us can render the seemingly prosaic aspects of the natural world with the lyrical grandeur evident in much of her writing.</p>
<p>Plath’s <a href="https://www.bl.uk/20th-century-literature/articles/reviving-the-journals-of-sylvia-plath">journal entries</a>, written from the Yaddo writers’ retreat in upstate New York in the autumn of 1959, demonstrate a sensitive interest in small details of the natural world which many deem mundane or insignifcant. Coming across a patch of toadstools in the gardens at Yaddo, she observes these “round battering rams” with their “orange ruddy tops” and “pale lemon stems”.</p>
<p>Her poem <a href="https://allpoetry.com/poem/8498359-Mushrooms-by-Sylvia-Plath">Mushrooms</a> captures much of this detail with the “soft fists” of the mushrooms which heave aside the garden “bedding”. “Nobody sees us”, the collective voice of the mushrooms in the poem declares, before claiming:</p>
<blockquote>
<p>We shall by morning<br>
Inherit the earth.<br>
Our foot’s in the door. </p>
</blockquote>
<p>In this poem, Plath emphasises the magnificent elements of the natural world that many of us overlook or disregard. She highlights the dangers, as environmental historian <a href="https://williamcronon.net/writing/Trouble_with_Wilderness_Main.html">William Cronon suggests</a>, in appreciating only the kind of big majestic landscapes found in national parks. By doing so, Plath infers, we neglect the significance of nature in more familiar and ordinary places.</p>
<p>While Plath may well be remembered for the melancholic despair of <a href="https://allpoetry.com/Sheep-In-Fog">Sheep in Fog</a> or the angry, flame-haired women of poems such as <a href="https://www.poetryfoundation.org/poems/49000/lady-lazarus">Lady Lazarus</a>, it is also important that she is remembered for the ecological significance of her writing.</p>
<p>Despite personal difficulties in her marriage and worsening mental health, Plath’s interest in nature continued to inspire much of her late poetry. Her 1962 poem <a href="https://genius.com/Sylvia-plath-among-the-narcissi-annotated">Among the Narcissi</a>, for example, captures a poignant but ordinary moment of kinship between an elderly man, who loves the “little flocks” of flowers in his garden, and the flowers themselves who “look up” from the flowerbeds towards him, “like children”.</p>
<p>Just like the small flock of lilac crocuses I was surprised to find growing amid the broken paving in my own much-neglected garden, Plath’s poetry continually surprises me with its uncanny ability to see the unseen in nature. Such deeply felt attunement to nature deserves to be recognised as part of the rich and multifaceted legacy of her work.</p><img src="https://counter.theconversation.com/content/200024/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nassim Jalali does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Plath’s sublime nature poetry deserves widespread appreciation for its unfettered joy and deep attunement to the natural world.Nassim Jalali, Final year PhD student researching Sylvia Plath's nature poetry, University of HuddersfieldLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1966792023-01-11T06:12:34Z2023-01-11T06:12:34ZMountain environments are key to biodiversity – but the threats to them are being ignored<figure><img src="https://images.theconversation.com/files/503025/original/file-20230104-19747-ka27f3.jpg?ixlib=rb-1.1.0&rect=20%2C0%2C6693%2C3764&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mountains are home to a diverse range of plant and animal species.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mountain-peaks-torres-del-paine-patagonia-1931671382">JMP_Traveler/Shutterstock</a></span></figcaption></figure><p>Mountains are home to <a href="https://www.science.org/doi/10.1126/science.aax0149">more than 85%</a> of the world’s amphibian, bird and mammal species. Lowland slopes are rich in animal and plant species. And rugged, high-elevation environments, although lacking such biological diversity, play a key role in maintaining biodiversity in the wider mountain catchment area.</p>
<p>The variation in mountain ecosystems also allows humans to extract <a href="https://doi.org/10.1017/S0376892918000255">multiple benefits</a> from them. These include food, building materials, water, carbon storage, agricultural pasture and nutrient cycling.</p>
<p>Yet, vulnerable to both climate change and human intervention, mountain biodiversity is increasingly under threat. <a href="https://www.science.org/doi/10.1126/science.aax0149">Roughly half</a> of the world’s <a href="https://www.conservation.org/priorities/biodiversity-hotspots">biodiversity hotspots</a> are now located in mountainous regions. These are areas of the Earth with significant levels of biodiversity but threatened to the extent that up to 70% of the original habitat has been lost. </p>
<p>And high mountain environments are <a href="https://www.nature.com/articles/nclimate2563">warming faster</a> than the global average. This is accelerating the rate of change in these ecosystems.</p>
<p>Despite this, mountains are largely ignored by attempts to preserve global biodiversity. </p>
<h2>The importance of mountains</h2>
<p>High mountains receive a lot of rain and experience low rates of evaporation at high elevations. They therefore contain large stores of water as snow and ice which are the foundation for biodiversity in the surrounding catchment. </p>
<p>Seasonal snow melt on Africa’s Mount Kilimanjaro feeds into the swamps of the nearby <a href="http://www.kws.go.ke/amboseli-national-park">Amboseli National Park</a>. The park is home to 420 species of bird and 50 large mammal species, including the African elephant.</p>
<p>Due to their steep elevation gradients, mountain environments also consist of many separate habitats. In temperate latitudes, such as Europe and North America, these habitats range from coniferous forests at low elevations to rugged terrain on higher ground. Habitats in tropical mountains instead range from savannas and lowland rainforests to highland <a href="https://www.frontiersin.org/articles/10.3389/fpls.2021.712748/full">“montane” forest</a> at an elevation of 900 metres to 3,300 metres. </p>
<p>Such habitat diversity supports a wide range of plant and animal species across relatively small spatial scales. Borneo’s lowland rainforests are home to <a href="https://www.oneearth.org/ecoregions/borneo-lowland-rainforests/#:%7E:text=Borneo%20rainforests%20are%20multi%2Dlayered,Vatica%2C%20Burseraceae%2C%20and%20Sapotaceae.">over 15,000 plant species</a> while <a href="https://wwf.panda.org/discover/knowledge_hub/where_we_work/borneo_forests/about_borneo_forests/ecosystems/montane_forests/">over 150 mammal species</a>, including orangutans and gibbons, live in Borneo’s montane forests. </p>
<p>Much of this biodiversity is also exclusive to particular mountain environments. Many mountain ecosystems are islands of suitable and isolated habitat. As a result, they are often home to species characterised by small populations and a limited range.</p>
<p>The <a href="https://ebird.org/species/taithr1">Taita thrush</a>, for example, is confined to the forests of southeast Kenya’s Taita Hills. Here, the species is surrounded by arid savanna within which it could not survive.</p>
<figure class="align-center ">
<img alt="A Taita trush perched on a branch." src="https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=488&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=488&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=488&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=613&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=613&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503067/original/file-20230104-14-uocmr0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=613&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Taita thrush is endemic to southeast Kenya’s Taita Hills.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/taita-thrush-ebird-ethiopia-addis-ababa-2222653291">Mounir akaram halabi/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Vulnerable ecosystems</h2>
<p>Snow reflects much of the incoming solar radiation back out to space. But climate change is increasing rates of snow melt, exposing large areas of dark mountain surface to the sun. This is leading to rising solar absorption rates and significant warming. </p>
<p><a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JD024728">Research</a> reveals that the Tibetan plateau (often called the third pole) has warmed by 0.16°C–0.36°C per decade on average since the 1950s. But this decadal rate of warming has increased to 0.5°C–0.67°C since the 1980s. </p>
<p>Increased warming in mountain environments will further amplify snow melt and reduce snow accumulation. Less snow and ice will result in a reduced availability of water downstream in the future, affecting the functioning of habitats in the mountain catchment. </p>
<p>Mountain environments are also vulnerable to human intervention. Mount Kilimanjaro’s fertile volcanic soil has encouraged human habitation of the surrounding area throughout history. But in recent decades, this has accelerated. </p>
<p>For example, agricultural land use in the Upper Pangani catchment to Kilimanjaro’s south <a href="https://www.sciencedirect.com/science/article/abs/pii/S1642359322000489">expanded</a> from 97,000 hectares in 1987 to over 300,000 hectares by 2017. The amount of groundwater collecting in the mountain’s aquifer decreased by 6.5% over the same period.</p>
<p>Land use change in mountain environments is leading to significant biodiversity loss. The Eastern Arc mountains of Kenya and Tanzania have lost <a href="https://link.springer.com/book/10.1007/978-3-030-88987-6">95% of their forest cover</a> since 1500, reducing the diversity of unique flora and fauna that are found in the area. The <a href="https://www.amphibians.org/amazing-amphibians/kihansi-spray-toad/">Kihansi spray toad</a>, for example, is now extinct in the wild. </p>
<h2>Ignoring mountains</h2>
<p>Yet while it’s clear mountains are important for the ecosystems they support, recognition of these environments from governments and policymakers is insufficient. There is currently no effective international policy in place to protect the biodiversity of mountain environments and there is little cooperation between governments, environmental agencies and conservationists to deliver such a strategy.</p>
<p>Establishing a cost for the services provided by mountain ecosystems would be a step towards reducing their exploitation. </p>
<p>Management of rivers with variable stream flows can be achieved by issuing controllable permits for water use. <a href="https://www.sciencedirect.com/science/article/abs/pii/S0022169419311345?via%3Dihub">Water market reform</a> in southeastern Australia’s Murray-Darling river basin is a successful example. Landowners and businesses here are able to purchase tradeable water entitlements set to levels that do not compromise the environment. </p>
<p>Since its introduction 30 years ago, this system has improved water quality and has allowed more water to be retained in the river basin. The expanding wetlands are also proving a <a href="https://www.sciencedirect.com/science/article/pii/B9780128181522000103">successful nursery habitat</a> for the native Murray cod and silver perch fish species.</p>
<figure class="align-center ">
<img alt="An aerial shot of a river lined with trees." src="https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503460/original/file-20230106-25-u0sftr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Murray-Darling river basin in southeastern Australia.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-view-murray-darling-junction-flood-594574802">Hypervision Creative/Shutterstock</a></span>
</figcaption>
</figure>
<p>But schemes such as this are open to regulatory challenges and issues over who manages the resource. <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020WR028378">Unreliable and inaccurate data</a> on agricultural water and groundwater abstraction also constrains global water management. </p>
<p>Both the recent <a href="https://theconversation.com/cop27-will-be-remembered-as-a-failure-heres-what-went-wrong-194982">UN climate change summit (COP27)</a> and <a href="https://theconversation.com/biodiversity-treaty-un-deal-fails-to-address-the-root-causes-of-natures-destruction-196905">UN biodiversity conference (COP15)</a> ended short of ambition over protecting mountain biodiversity. A series of agreements and targets were established with little disclosure over how they will be financed and enforced. An international treaty that accepts the value of mountain ecosystems and puts measures in place to protect their environmental, economic and biological importance is urgently required.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
<br><em><a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeTop">Get a weekly roundup in your inbox instead.</a> Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. <a href="https://theconversation.com/uk/newsletters/imagine-57?utm_source=TCUK&utm_medium=linkback&utm_campaign=Imagine&utm_content=DontHaveTimeBottom">Join the 10,000+ readers who’ve subscribed so far.</a></em></p>
<hr><img src="https://counter.theconversation.com/content/196679/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rob Marchant receives funding from a number of grant-giving organisations for this work including UKRI, the Royal Society, the European Union and SIDA.</span></em></p>Mountain environments are rich in plant and animal species, but the dual threat of human habitation and climate change means urgent action is needed to protect them.Rob Marchant, Professor of Tropical Ecology, University of YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1951722023-01-02T12:40:42Z2023-01-02T12:40:42ZScientists dig deep and find a way to accurately predict snowmelt after droughts<figure><img src="https://images.theconversation.com/files/497775/original/file-20221128-25-6d5d8u.jpg?ixlib=rb-1.1.0&rect=6%2C324%2C2293%2C1207&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Following historic drought in 2021, reservoir levels dropped down in the Hoover Dam on the Colorado River, which gets its waters from the melting snowpack from the Rocky Mountains of Colorado and Wyoming.</span> <span class="attribution"><a class="source" href="https://pxhere.com/en/photo/623841">(pxhere.com)</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/scientists-dig-deep-and-find-a-way-to-accurately-predict-snowmelt-after-droughts" width="100%" height="400"></iframe>
<p>Where does your water supply come from? </p>
<p>If you live near mountains, for instance in British Columbia, a lot of your water probably comes from mountain snowpack. Over <a href="https://doi.org/10.1038/s41586-019-1822-y">1.9 billion people</a> globally rely on the snow melting and running off from these mountain snowpacks for their water supply.</p>
<p>Accurate predictions of this annual trend is critical for water supply planning. And forecasting models often rely on the <a href="https://www.academia.edu/47863505/Principles_of_snow_hydrology">historical relationship between mountain snowpack and the subsequent water supply</a>. </p>
<p>However, in times of unprecedented drought and a changing climate, these forecasting models seem to no longer be reliable. Following an intense drought in California in 2021, <a href="https://www.theguardian.com/us-news/2021/jun/07/california-drought-oregon-west-climate-change">snowmelt from mountain snowpack delivered significantly less water than historical models predicted</a>, meaning that reservoirs remained drier than anticipated. For the first time in 100 years, water supply models were wrong. </p>
<p>In an attempt to address the gaps in the traditional model, we recently <a href="https://doi.org/10.1029/2022GL100505">developed an updated water supply forecasting model</a> that considers additional factors, like water storage deficits in the soil and bedrock. This new model significantly improves the accuracy of water supply forecasts following drought.</p>
<h2>What are existing water supply models missing?</h2>
<p><a href="https://doi.org/10.1017/CBO9780511535673">Models used for forecasting snowmelt </a>typically consider winter rain and snowpack. But it turns out that water absorbed by the ground matters too. The amount of water absorbed into the soil and bedrock varies from year to year and is especially impacted by drought.</p>
<p>When snow melts or rain falls, almost all of it goes underground first before <a href="https://www.usgs.gov/special-topics/water-science-school/science/runoff-surface-and-overland-water-runoff">heading downstream to water supply systems </a>. The water storage processes below the surface of the ground are key to understanding the ultimate fate of rain and snow in the mountains.</p>
<figure class="align-center ">
<img alt="Schematic diagram of runoff generation in the mountains." src="https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=460&fit=crop&dpr=1 600w, https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=460&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=460&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=578&fit=crop&dpr=1 754w, https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=578&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/497773/original/file-20221128-12-3ska04.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=578&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A diagram showing how water gets from snowpack or rain to water supply systems. Rain and snowmelt seep into the ground. Plants draw water from this region. Once the subsurface is wet, the water flows downstream to water supply systems.</span>
<span class="attribution"><a class="source" href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL100505">(Dana Lapides)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The below ground environment is made up of complex layers of soil, fractures and weathered bedrock that can <a href="https://hydrology.usu.edu/rrp/pdfs/ch2.pdf">store, detain and transport water</a>. The details of these processes are complicated, but the overall effect can be likened to a giant sponge. </p>
<p>Over the summer, the ground dries out and it gets wet again with the arrival of rain and snowmelt in winter and spring. Once the ground is wet enough, it starts to drip. This dripping water enters the groundwater and streams and eventually goes into the water supply systems.</p>
<p>How much water drips depends on how much snowmelt and rain is received, which is included in forecasting models. It also depends on how dry the subsurface was to begin with, which is not traditionally included in forecasting models.</p>
<h2>Plants use a lot of water</h2>
<p>How dry the subsurface is this year can depend on how much water the plants used last year (or even over the last few years). In hotter, drier years, plants can use more water from underground, causing the subsurface to dry out more.</p>
<p>Recent studies show us that <a href="https://doi.org/10.1038/s41586-021-03761-3">trees routinely dry up not just soils but also weathered bedrock metres below the surface</a>.</p>
<p>Scientists are still struggling to identify how dry these mountain environments can get and how far below the surface they dry. With a drier subsurface at the start of the year, more snowmelt is needed before water starts to flow downstream to water supply systems. </p>
<p>As droughts become more frequent and intense with climate change, this process could become more important even in regions that historically haven’t faced much drought.</p>
<h2>Measuring the moisture underground</h2>
<p>Directly observing the moisture levels of the ground’s subsurface is difficult, especially when it’s stored in weathered bedrock, which can extend many metres below the ground surface and be challenging to observe. </p>
<p>In our research, we found the most accurate measurements by lowering geophysical instruments down boreholes and taking water content readings at different depths. By comparing these readings over time, we observe how <a href="https://doi.org/10.1073/pnas.1800141115">the subsurface dries out and gets wet again</a>.</p>
<figure class="align-center ">
<img alt="Researcher measures subsurface wetness conditions" src="https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/497767/original/file-20221128-20492-5u0m49.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A USDA Forest Service employee uses an instrument to measure the moisture conditions deep underground.</span>
<span class="attribution"><span class="source">(Jamie Hinrichs/USDA Forest Service)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>However, this intensive monitoring is nearly impossible to do over large areas.</p>
<p>While we can’t look directly underground everywhere, <a href="https://hess.copernicus.org/articles/20/1459/2016/">we can track how much water enters (rain and snowmelt) and leaves (plant water use) the ground using satellite-derived data</a>.</p>
<p>By taking a running account of water going in and out of the ground, we can estimate how dry the subsurface is — a metric we call the water storage deficit. </p>
<h2>Water supply models must dig deeper</h2>
<p>Our <a href="https://doi.org/10.1038/s41586-021-03761-3">newly-developed water supply forecasting model</a> accounts for water storage deficits in both soil and bedrock. This has improved post-drought forecast accuracy substantially, taking the probability of error in the calculation of predictions from 60 per cent to about 20 per cent.</p>
<p>Since we can calculate deficits before spring snowmelts, they serve as an early warning sign and can aid water management strategies.</p>
<p>As the climate changes, the water supply challenges in California foreshadow issues that will become increasingly prevalent in British Columbia and other regions reliant on mountain snowpack. Using updated forecasting models in the future can help these regions better prepare for <a href="https://drought.ca.gov/current-drought-conditions/#overview-of-2021">continued water shortages even when snowpack seems normal</a>.</p><img src="https://counter.theconversation.com/content/195172/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dana Ariel Lapides receives funding from Simon Fraser University and the US Forest Service Southwest Pacific Research Station with funds administered through Oak Ridge Institute for Science and Engineering (ORISE). </span></em></p><p class="fine-print"><em><span>David Dralle receives funding from the US Forest Service Pacific Southwest Research Station. </span></em></p><p class="fine-print"><em><span>Jesse Hahm receives funding from Simon Fraser University, the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, and the Pacific Institute for Climate Solutions.</span></em></p><p class="fine-print"><em><span>Daniella Rempe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Unprecedented droughts leave the subsurface drier than usual, affecting water supply in subsequent years.Dana Ariel Lapides, Postdoctoral Research Fellow, Geography, Simon Fraser UniversityDaniella Rempe, Assistant professor, Jackson School of Geosciences, The University of Texas at AustinDavid Dralle, Research officer, Hydrology, University of California, BerkeleyJesse Hahm, Department of Geography, Assistant Professor, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1946422022-11-17T11:51:29Z2022-11-17T11:51:29ZAfrican mountains are feeling the heat of climate change<figure><img src="https://images.theconversation.com/files/495306/original/file-20221115-23-c6fqra.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mount Kenya</span> <span class="attribution"><span class="source">WanderingNomad / Getty IMages</span></span></figcaption></figure><p>Mountains are special places. They have distinctive climates that are generally cooler and wetter than surrounding lowlands, and they host plants, animals and landscapes that are uniquely found in these environments. However, mountains are under threat because of climate change, and this has an impact on every single property of mountains, including their climate, weathering and erosion processes, soils, ecosystems, water resources, geological hazards, regional economies, and cultural practices. </p>
<p>My <a href="https://peerj.com/articles/14253/">work</a> on the impacts of ongoing climate change in mountains highlights the sensitivity of mountain properties and processes to changes in temperature and precipitation – mainly expressed in mountains as snowfall. However, there is less understanding of mountain systems in Africa compared to other mountains globally. This article therefore focuses on mountain properties in Africa, why these are particularly sensitive to climate change, and why this is important.</p>
<h2>Ice and snow</h2>
<p>One key property of mountains worldwide is that they are often covered by snow and ice (glaciers). This reflects moist air and cold temperatures over mountain summits. Not only do snow and ice present unique habitats for plant and animal species, they also have a vital role in the regional climate systems of mountains. Snow and ice tend to be light in colour, so they reflect sunlight back out to space, keeping the land surface cold. This is called the <a href="https://scied.ucar.edu/learning-zone/how-climate-works/albedo-and-climate">albedo effect</a>. </p>
<p>However, if snowfall does not take place or the snow melts away, the mountain land surface remains dark. This means it absorbs rather than reflects the sun’s energy, making the surface warmer. This can cause more snowmelt, exposing more dark rocks, with more heating and melting. </p>
<p>The outcome of this process is that changing patterns of snowfall have big implications for mountain heat budgets. Mountains worldwide are already <a href="https://iccinet.org/statecryo22/">warming twice as fast</a> as the global average. This makes them particularly sensitive to climate change. </p>
<p>African mountains are not immune to climate change. Small glaciers still exist in three mountain massifs – Mount Kenya (Kenya), Kilimanjaro (Tanzania) and the Rwenzori mountains (Uganda) – but these are in <a href="https://wgms.ch/">rapid retreat</a>. They are also predicted to <a href="https://unesdoc.unesco.org/ark:/48223/pf0000383551">disappear entirely</a> by the middle of the century. Snowfall is also highly variable, such as over the <a href="https://earthobservatory.nasa.gov/images/88509/lesotho-sees-its-heaviest-snowfall-in-two-decades">Maloti-Drakensberg mountains</a> of southern Africa.</p>
<p>The full implications of this loss of ice and snow, and of climate change in African mountains more generally, have not been fully considered. Ice retreat in other deglacierising mountains worldwide leads to a substantial increase in hazards of different types, including rockfalls, landslides and debris flows. These hazards can also take place thousands of years after initial ice retreat. </p>
<p>This may mean that, even though the glaciers that exist in Africa today are very small, any resulting hazards could potentially be large and unpredictable in their timing and location. These are potentially future issues in African mountains. </p>
<p>Another important factor is how snow and ice melt across African mountains will affect their wider landscapes. Snow and ice often serve as water sources to surrounding communities, especially in locations that are water scarce, which includes East Africa. Water availability in the environment influences soils, ecosystems, river processes and the potential for flood and landslide hazards. </p>
<p>The presence of snow and ice therefore has wider environmental significance across mountain landscapes, and in ways that are not fully understood. </p>
<h2>Other important roles</h2>
<p>African mountains are also important for other reasons. For example, they host the Afromontane biogeographical region, a global <a href="https://www.cepf.net/our-work/biodiversity-hotspots/hotspots-defined">biodiversity hotspot</a> of endemic podocarp (conifer) forest species that extends as a corridor through upland areas of southern and eastern Africa. </p>
<p>Above the treeline, alpine pastures provide grazing land for herders, a key socioeconomic and cultural activity in remote mountains in Africa. </p>
<p>Summer and winter tourism – whether in South Africa or Morocco – is also linked closely to mountain landscapes, snow, water and the presence of endemic species. </p>
<p>All of these activities are under threat because of climate change. Mountain ecosystems are critically linked to temperature and precipitation conditions. Climate change may therefore pose problems for both the survival of keystone species and for overall biome integrity, especially where they are encroached by invasive species, agriculture and forestry. These changes also have secondary effects on ecosystem services, food, fuel and carbon storage. </p>
<p>Thus, mountains have a wide range of properties that are linked to climate, and a key question is how mountain systems as a whole will respond to climate change over future decades.</p>
<h2>Mountain communities</h2>
<p>Sustainable development of <a href="https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_CCP5.pdf">mountain communities</a>, where human activity responds to the changing nature of mountain systems, is a key strategy for minimising the impacts of climate change, both in mountains and in surrounding areas. </p>
<p>This can be done by monitoring and treating sources of hazard risk as a result of melting snow and ice, building resilient infrastructure and community resilience, and protecting mountains as sites of geological, ecological and cultural heritage. These actions can help limit climate change impacts on sensitive mountains in Africa and elsewhere.</p><img src="https://counter.theconversation.com/content/194642/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jasper Knight does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Mountain systems are sensitive to climate change. Loss of snow and ice sets off effects which have wide ranging consequences.Jasper Knight, Professor of Physical Geography, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1929642022-11-14T10:52:04Z2022-11-14T10:52:04ZEarth’s cathedrals: Europe’s mountains are cultural heritage, not just natural heritage<figure><img src="https://images.theconversation.com/files/491056/original/file-20221021-12-zffs34.jpg?ixlib=rb-1.1.0&rect=0%2C23%2C3872%2C2562&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rocca Calascio is a mountaintop fortress in the province of L'Aquila in Italy. It bears witness to the long relationship between humanity and mountains, and how natural landscapes are also culture ones. </span> <span class="attribution"><span class="source">UNESCO</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In 2019, alpinism was recognised by UNESCO as an <a href="https://ich.unesco.org/en/RL/alpinism-01471">intangible heritage of humanity</a> and “shared culture made up of knowledge of the high-mountain environment, the history of the practice and associated values, and specific skills”. However, alpinism is inextricably linked to mountains – places of extraordinary interest that need to be defended even more. The <a href="https://www.alpconv.org/en/">Alpine landscape protection initiatives</a> address issues of territorial planning, sustainable development, tourism, agriculture, and energy, but it is also essential to consider these topics through the lens of mountains’ historical and cultural values.</p>
<p>One session at the 10th International Congress of the <a href="https://aisuinternational.org/torino-2022/">Associazione Italiana di Storia Urbana (Italian Society of Urban History)</a> focused on this very theme. Titled <a href="https://aisuinternational.org/en/torino-2022-sessioni-2/">“The mountain landscape between eremitic contemplation, aesthetic attraction and sporting conquest”</a>, the 6.03 session explored current challenges and called for mountains to be protected not only as a natural heritage, but also as cultural heritage.</p>
<p>To achieve this ambitious goal, we must know and highlight the multiple meanings and cultural values of mountain landscapes. Only then can we implement integrated protection strategies similarly to what happens in the most well-known monumental sites.</p>
<h2>Bearing the brunt of climate change</h2>
<p>Due to melting ice and snow, mountains’ ecosystems are <a href="https://theconversation.com/climate-change-is-transforming-mountains-we-must-act-to-save-them-169886">particularly vulnerable to climate change</a>. They are also exposed to increasingly <a href="http://theconversation.com/dear-tourists-get-lost-when-social-contagion-creates-tourismophobia-130244">intensive visits</a>, which can damage them irreversibly if the values to be protected are not clearly identified. Their cultural relevance is often overlooked, however, or it’s exploited by tourism promotion and distorted by folklorisation phenomena.</p>
<p>Reflection on natural and cultural heritage should not be limited to sites of exceptional universal value; it must recognise mountain territories as places to be preserved not only for their environmental characteristics, but also for their historical and cultural values.</p>
<p>In the last 50 years, many alpine environments have significantly changed in appearance and in a few years’ time, several glaciers could be <a href="https://theconversation.com/listening-to-the-song-of-melting-glaciers-191041">gone for good</a>. This is not only a serious environmental problem, but an irreparable cultural loss. Glaciers are indeed archives of valuable information for science, as well as fading <a href="https://theconversation.com/climate-change-must-be-a-catalyst-for-reform-of-the-world-heritage-system-191798">historical landscapes</a>.</p>
<p>From the 17th until the 19th century, upper-class young European men were expected to take on a ‘<a href="https://www.amazon.fr/Evolution-Grand-Tour-Anglo-Italian-Renaissance/dp/0714644749">Grand Tour</a>’ through Europe up to Italy. 'Eternal snows’ required the travellers to make at least one stop in the Alps on their adventurous and difficult journeys to get there (William Windham 1741; Pierre Martel 1742).</p>
<p>Hannibal <a href="https://www.britannica.com/biography/Hannibal-Carthaginian-general-247-183-BC/The-Alpine-crossing">crossed the Alps in 218 BC</a>, and left traces in the descriptions of historians. Constructed over the centuries, structures such as huts and shelters, roads, pilgrim hospices, and churches have shown how deep our relationship has been with mountain territories. During the First and Second World Wars, more notable material testimonies were left behind, including fortifications, tunnels, trenches, shelters, barracks and places of the Resistance.</p>
<figure class="align-center ">
<img alt="Hermitage of San Bartolomeo in Legio, Italy." src="https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/491057/original/file-20221021-3368-z42jq1.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hermitage of San Bartolomeo in Legio, Italy.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These artefacts are part of a widespread cultural heritage, the knowledge of which is essential to recognise if we are to preserve them. In fact, such sites, often abandoned, are hardly perceived as monumental. What is needed is for them to be seen in a broad perspective that considers them a “system” to be protected for their historical, aesthetic, landscape, identity values, not just as individual artefacts.</p>
<h2>The cultural pull of mountain landscapes</h2>
<p>The spiritual and intellectual attraction to the mountains is testified by hermits, artists and scientists well before the age of mountaineering, which officially starts with the <a href="https://www.vox.com/2015/8/8/9119081/mont-blanc-first-ascent">first ascent of Mont Blanc in 1786</a>. However, expeditions to the mountains began much earlier for scientific and cultural reasons (<a href="https://www.cambridge.org/core/books/abs/heights-of-reflection/from-meadows-to-mountaintops-albrecht-von-hallers-die-alpen/83DCD7EA3DF5AAA440F81421FB472303">Albrecht von Haller 1729</a>; <a href="https://www.edition-originale.com/fr/livres-anciens-1455-1820/philosophie/rousseau-lettres-ecrites-de-la-montagne-1764-47448">Jean-Jacques Rousseau 1764</a>; <a href="https://www.editionsladecouverte.fr/premieres_ascensions_au_mont_blanc_1774_1787-9782707147035">Horace Benedict de Saussure 1774</a>).</p>
<p>Since then, scholars and travellers have turned their interest not only to monuments of antiquity but also toward the wonders of nature, specifically to the alpine glaciers. The first material evidence of Alpine visits was the <a href="https://www.eaae.be/wp-content/uploads/2019/12/EAAE-2019-Conservation-Consumption.pdf">“Temple de la Nature”</a>, a refuge built in 1795 in Montenvers to observe the <a href="https://www.britannica.com/place/Mer-de-Glace">Mer de Glace</a>, still visible today among the hotels built later.</p>
<p>In the same years, Orazio Delfico’s ascent of the Gran Sasso d'Italia in 1794 was considered the first ascent of the highest peak of the Apennines. However, as early as 1573, Francesco de Marchi – an architect following Margaret of Austria – reached the mountain summit and published the chronicle of the ascension in his <a href="http://www.lagagransasso.it/gs/de_marchi.htm">“Treaty of Military Architecture”</a>. Other writers and scientists to have scaled mountains include Francesco Petrarca on Mont Ventoux in Provence (1336), Leon Battista Alberti on Monte Velino in Abruzzo (mid-15th century), Leonardo da Vinci on Monte Rosa and perhaps also in Abruzzo (late 15th century to early 16th Century).</p>
<h2>“Cathedrals of the Earth”</h2>
<p>In the 19th century, the English writer John Ruskin celebrated mountains by describing them as “<a href="https://issuu.com/dida-unifi/docs/volume_1/20">Cathedrals of the Earth</a>”. Following up on Lord Byron’s depiction of them as [“Palaces of Nature”], such an expression captured at once the landscapes’ magnificence and called upon visitors to respect them as sacred. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=356&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=356&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=356&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=448&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=448&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494203/original/file-20221108-18-kzijh6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=448&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">John Ruskin’s sketch of the Aiguille Blaitière, circa 1856.</span>
<span class="attribution"><a class="source" href="https://fr.m.wikipedia.org/wiki/Fichier:The_Aiguille_Blaitiere.jpg">Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>All this demonstrates a very close relationship between the protection of cultural and mountain heritage. Thus, mountains’ cultural values precede the mountaineering interest that developed with the birth of the Alpine Clubs first in the United Kingdom (1857), then in Austria (1862), Italy (1863) and France (1874). Since then, mountains have increasingly become synonymous with competitive challenges, sometimes with alienating outcomes.</p>
<p>Founded by John Muir in 1892 in San Francisco, the <a href="https://www.sierraclub.org/">Sierra Club</a> was, by contrast, one of the first organisations for the conservation of the mountain landscape. Well ahead of his time, Muir held up mountain parks and reserves as a necessity for human well-being and ‘sources of life’.</p>
<blockquote>
<p>“It is by far the grandest of all of His special temples of Nature I was ever permitted to enter. It must be the sanctum sanctorum of the Sierras.” (John Muir, Letters to a Friend. Written to Mrs. Ezra S. Carr (1866-1879) in J. Muir, Andare in montagna è tornare a casa. Scritti sulla natura selvaggia (trad. it. Caterina Bernardini) </p>
</blockquote>
<p>Any reflection about the <a href="https://whc.unesco.org/en/next50/">future of heritage</a> must consider the close interaction between tangible and intangible heritage (otherwise there is the risk of neglecting the material assets connected to intangible values), and then extend it to the safeguard of the planet as a World Heritage. In this sense, it is necessary to integrate the defence of territory and environment with the identification of its multiple cultural values.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=305&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=305&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=305&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=383&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=383&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=383&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://whc.unesco.org/en/next50/">50th anniversary of the World Heritage Convention</a> (16 November 2022): World Heritage as a source of resilience, humanity and innovation.</em></p><img src="https://counter.theconversation.com/content/192964/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Carla Bartolomucci ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Often thought of as eternal, mountains are vulnerable to climate change and tourism. To protect them, they should be recognised for their cultural values, not just their natural characteristics.Carla Bartolomucci, Associate professor of architectural conservation, University of L'AquilaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1897912022-10-24T19:02:40Z2022-10-24T19:02:40ZTriumph, tragedy and climate change: telling the stories of the Sherpas of Everest<figure><img src="https://images.theconversation.com/files/490288/original/file-20221018-18129-9wr57o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Few communities have enjoyed the collective fame and individual obscurity of the Sherpas. This minority group, living across the high-Himalaya border between Tibet (China) and Nepal, has become famous for its many world-class mountain climbers. </p>
<hr>
<p><em>Review: Sherpa: Stories of Life and Death From the Forgotten Guardians of Everest – Pradeep Bashyal, Ankit Babu Adhikari (Cassell)</em></p>
<hr>
<p>The Sherpas first developed this reputation when in 1953, <a href="https://www.thoughtco.com/tenzing-norgay-195628">Tenzing Norgay</a> summitted the world’s tallest mountain with his friend Edmund Hillary. He knew the mountain as Chomolangma, the abode of a capricious goddess, <a href="https://www.himalayanart.org/items/433">Miyolangsangma</a>. The world knows the same mountain as Everest. </p>
<p>Since Norgay’s ascent, the Sherpas have used his fame and their remarkable abilities at high altitudes to develop a lucrative but heartbreakingly dangerous mountain climbing industry. They have transformed their community, creating wealth and opportunities unthinkable for their grandparents. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=498&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=498&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=498&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=626&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=626&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488233/original/file-20221005-11-wvqfq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=626&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sherpa Tenzing Norgay pictured with Sir Edmund Hillary.</span>
<span class="attribution"><span class="source">AP</span></span>
</figcaption>
</figure>
<p>But the industry has also taken an enormous toll, with many lives lost and constant family separations. The Sherpas do all they can to keep their wealthy clientele as safe as possible on the mountain; often these clients become the story, rather than the Sherpas themselves. </p>
<p><a href="https://www.goodreads.com/en/book/show/61781364-sherpa">Sherpa: Stories of Life and Death From the Forgotten Guardians of Everest</a>, is an attempt to fix this injustice by focusing on the lives and deeds of multiple mountaineering Sherpas and their families. It follows a similar path to Jennifer Peedom’s excellent 2015 film, <a href="https://www.imdb.com/title/tt3746250/?ref_=nm_knf_i1">Sherpa</a>, but traverses different timelines and geographical regions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488235/original/file-20221005-16-o0sqkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A still from the 2015 film Sherpa.</span>
<span class="attribution"><span class="source">Screen Australia/AAP</span></span>
</figcaption>
</figure>
<p>Pradeep Bashyal and Ankit Babu Adhikari are both Kathmandu-based Nepali journalists. They tell the stories of the Sherpas they met in Kathmandu, Darjeeling, the Khumbu region at the base of Chomolangma, and other Sherpa high-altitude regions, Makalu and Rowalung, with excitement, heart, and sensitivity. They entwine the climbers’ stories of achievement and disaster on the mountains with tales of family struggles off the mountain. </p>
<p>Through the stories of elders such as Kanchha Sherpa, who assisted on the early missions in the 1950s, and Sirdar Mingma Chhiring Sherpa, a first-generation trekking guard, they trace the history of the industry’s development. </p>
<p>They interview multiple generations of mountain climbers within families, including Tenzing Norgay’s son <a href="https://en.wikipedia.org/wiki/Jamling_Tenzing_Norgay">Jamling Tenzing Norgay</a>, who takes them through his family’s private museum dedicated to his father. And they talk to younger climbers who represent the future of mountain climbing, including, refreshingly, many women. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/death-on-everest-the-boom-in-climbing-tourism-is-dangerous-and-unsustainable-114033">Death on Everest: the boom in climbing tourism is dangerous and unsustainable</a>
</strong>
</em>
</p>
<hr>
<h2>‘A major grudge’</h2>
<p>The climbers’ stories speak not only of the great triumph of standing on the top of the world, often multiple times, but also of the tragedies they have all endured. There are about 114 000 Sherpas living in <a href="https://unstats.un.org/unsd/demographic-social/census/documents/Nepal/Nepal-Census-2011-Vol1.pdf">Nepal</a> and <a href="https://baike.baidu.com/item/%E5%A4%8F%E5%B0%94%E5%B7%B4%E4%BA%BA/3368578#:%7E:text=%E5%A4%8F%E5%B0%94%E5%B7%B4%E4%BA%BA%EF%BC%88Sherpa,%E6%B2%9F%E5%92%8C%E9%99%88%E5%A1%98%E6%B2%9F%E3%80%82">China</a>. Despite this small population, of the approximately 300 climbers who have died climbing Everest, <a href="https://www.npr.org/sections/parallels/2018/04/14/599417489/one-third-of-everest-deaths-are-sherpa-climbers">more than one-third</a> have been Sherpas.</p>
<p>The most moving stories are those of Chomolangma’s widows and their differing attempts to deal with grief and loss. By using long passages of reported speech, Bashyal and Adhikari let the widows speak to us directly. We meet Furdiki Sherpa and Nima Doma Sherpa, who met up after their husbands both died on the mountain and decided to climb it together. </p>
<p>After raising the money and training, they eventually made their ascent in 2019. But as Furdiki explains to us, she still has “a major grudge from the ascent of Everest”. She had expected it “to somehow make [her] heart a little lighter”. But it only made her heart “heavier”. She missed her husband more. </p>
<p>The authors also describe their travels to the Sherpas’ villages and homes, offering an insight into the dramatic geography of the region, and details such as the food they grow and eat, including nettles, potatoes, and millet, and the ways they build their houses with mud, stones and tin-sheeted roofs. </p>
<h2>Changes</h2>
<p>There have been profound changes in Sherpa life since Tenzing Norgay stood on top of Chomolangma. Some, like the building of schools, roads, airports and medical facilities, have been gratefully received. Others, such as the impact of COVID and the damage being slowly brought about by <a href="https://www.nationalgeographic.com/environment/article/perpetual-planet-everests-highest-glacier-has-lost-2000-years-of-ice-in-30-years#:%7E:text=Published%20February%203%2C%202022,ice%20core%20from%20the%20glacier">climate change</a>, present further challenges to all the region’s people, not just its mountain climbers. As the region’s glaciers melt and its seasons contract, they live with the threat of glacial lake floods and must produce food in shorter seasons with less water.</p>
<p>These are the details lost within other stories of Everest’s “conquests” or tragedies. It seems we find it easier to read about the deaths and hardships of wealthy people climbing the mountain than those the villagers around Chomolangma endure year in and year out. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-and-when-did-mount-everest-become-the-tallest-mountain-and-will-it-remain-so-157509">Curious Kids: how and when did Mount Everest become the tallest mountain? And will it remain so?</a>
</strong>
</em>
</p>
<hr>
<p>Bashyal and Adhikar’s honesty about their inability to perform the same feats at the Sherpas and their struggles in even getting to their homes are insightful, but they point to the one element of the book that made this reader uncomfortable. </p>
<p>It is the several assumptions and misreadings of the Sherpas’ language and religion and the absence of any analysis of their lived experiences as minorities within Nepal. The authors present the Sherpas as unproblematically Nepali, despite the fact they live across the Nepal-China border. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=905&fit=crop&dpr=1 600w, https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=905&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=905&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1137&fit=crop&dpr=1 754w, https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1137&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/490287/original/file-20221018-21054-hm8kgt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1137&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>They describe them as being of “Mongol-ethnicity”, an unfortunate, race-based, colonial-era designation. And they sometimes misrepresent the Sherpa language — for example, “pumo” means girl, not boy — and do not acknowledge the similarities between the Sherpa and southern Tibetan languages across the international border. </p>
<p>Still, it is a testament to the warmth, compassion, and humility of the authors’ storytelling that these missteps do not overshadow the book’s many positive attributes. Generally, Bashyal and Adhikar introduce us to the Sherpas’ world with great care. </p>
<p>Ultimately, the Sherpas are still presented as a collective, rather than a series of individuals who have achieved great things. </p>
<p>But this approach is probably the authors’ greatest insight into Sherpa society and the greatest lesson we can take from the book. Up there in Himalayan villages and on the world’s highest peaks, collective stories support life and bring joy much more than any individual tale.</p><img src="https://counter.theconversation.com/content/189791/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ruth Gamble receives funding from the Australian Research Council</span></em></p>The mountain climbing industry has transformed the lives of the Sherpas – both for good and bad. A new book focuses on their lives and deeds.Ruth Gamble, Lecturer, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1719502022-10-12T19:02:08Z2022-10-12T19:02:08ZThese stunning satellite images look like abstract art – and they reveal much about our planet<figure><img src="https://images.theconversation.com/files/487986/original/file-20221004-12-13cupg.jpg?ixlib=rb-1.1.0&rect=14%2C14%2C4977%2C4977&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This is an enhanced satellite image of Western Australia's Great Sandy Desert. Yellow sand dunes cover the upper right, red splotches indicate burned areas, and other colours show different types of surface geology.
</span> <span class="attribution"><span class="source">USGS/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><em>Environmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique <a href="https://theconversation.com/au/topics/photos-from-the-field-92499">photos from the field</a>.</em></p>
<hr>
<p>There’s something to be said for a job that pays you to stroll over the Scottish Highlands, scoot around a Greek Island, or go on an expedition to Antarctica – all in the name of geoscience, the study of the Earth. </p>
<p>But during COVID travel restrictions, many geologists had to mine the collection of samples and data they already had. Other geologists used satellite and other images to make geological interpretations.</p>
<p>This field of geology is called remote sensing, which is the process of using, for instance, satellites or aeroplanes to observe the physical features of an area at a distance. It’s often easier to see how geology shapes our landscapes by taking this birds-eye view.</p>
<p>In terrific news for remote sensing geologists, armchair geology enthusiasts and lovers of stunning landscapes, the United States Geological Survey (USGS) has a <a href="https://unsplash.com/@usgs">vast collection</a> of satellite images of the Earth’s surface, capturing breathtaking geological features from space. </p>
<p>Remote sensing geologists use many techniques which make features of interest more distinct. This enhances or alters colours, which you can see in a few of my picks of USGS’s eight most fascinating images. Here’s what they reveal about the planet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/5-rocks-any-great-australian-rock-collection-should-have-and-where-to-find-them-163578">5 rocks any great Australian rock collection should have, and where to find them</a>
</strong>
</em>
</p>
<hr>
<h2>Volcanoes from space</h2>
<p>Volcanoes are usually pretty distinctive when you see them from the ground, whether it’s the iconic Mount Fuji, the lava fields of Iceland, or the <a href="https://www.tandfonline.com/doi/figure/10.1080/08120099.2013.806954?scroll=top&needAccess=true">hundreds of volcanoes</a> that pockmark the fields of western Victoria in Australia. </p>
<p>From above, they can look a little different. In the first image below of Mount Elgon on the border of Uganda and Kenya, you can spot the “caldera” – a bowl-shaped depression in the centre of the volcano where the rock has collapsed after the magma chamber empties. </p>
<p>In the second image of New Zealand’s Mount Taranaki, you can spot the crater, which is also a depression, but forms when the volcano explodes and rocks are ejected.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mount Elgon, Uganda and Kenya.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Volcano crater from above surrounded by a dark green circle of forest" src="https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mount Taranaki in Egmont National Park, New Zealand.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>The products of volcanoes may also be obvious in satellite images. You can see the lava flow from the Haruj volcano in Libya in the third image below. It is a black stain of basalt on the surrounding white and yellow sand, to envy even the finest <a href="https://www.rorschach.org">Rorschach inkblots</a>.</p>
<p>This field of lava is about 185 kilometres wide, a huge distance that’s possible because the <a href="https://www.scirp.org/journal/paperinformation.aspx?paperid=53675">chemical composition</a> of the lava made it runny and able to flow a long distance from the eruption site. </p>
<figure class="align-center ">
<img alt="A black splatter of lava in surrounding sandy desert landscape" src="https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Haruj Volcanic Field, Libya.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Some magma-related features have stumped geologists for years. Only by combining remote sensing with observations on the ground have they been able to solve these geological puzzles. The Richat Structure in Mauritania’s Maur Adrar Desert, shown below, is one such feature. </p>
<p>It looks like a meteorite impact crater or, perhaps, a bullseye for intergalactic visitors. But in recent years, researchers determined – after much debate – that it formed when a series of magmas from deep below the surface <a href="https://link.springer.com/article/10.1007/s12517-021-08734-4">intruded into the existing sediments</a>.</p>
<figure class="align-center ">
<img alt="Grey concentric rings of rock surrounded by green landscape from above" src="https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Richat Structure, Mauritania.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Some of these magmas formed concentric circles, known as ring dikes, which is the main feature we see in satellite imagery. These ring dike magmas never reached the surface and are only exposed now because the overlying rocks eroded away over time. </p>
<p>But other magmas in the series <a href="https://www.sciencedirect.com/science/article/abs/pii/S1464343X14000971?via%3Dihub">did make it to the surface to erupt as lava</a>. You can see the small volcano formed by these surface eruptions on the USGS image where it appears as a white-grey smudge interrupting the southwestern part of the innermost ring dike. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/photos-from-the-field-the-stunning-crystals-revealing-deep-secrets-about-australian-volcanoes-161176">Photos from the field: the stunning crystals revealing deep secrets about Australian volcanoes</a>
</strong>
</em>
</p>
<hr>
<h2>When rocks collide</h2>
<p>The landscapes of Iran’s Zagros Mountains and China’s Keping Shan thrust range have two major things in common. </p>
<p>First, they both look spectacular from above. Second, they were both <a href="https://pubs.geoscienceworld.org/books/book/1510/chapter-abstract/107191433/The-Evolution-of-the-Tethys-Region-throughout-the?redirectedFrom=fulltext">formed at the bottom of oceans</a> and were then <a href="https://www.lyellcollection.org/doi/10.1144/SP348.5">uplifted and deformed</a> by geological forces to form the ridges and valleys which dominate these two regions today. </p>
<figure class="align-center ">
<img alt="View from above of domes of rock between valleys" src="https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Zagros Mountains, Iran.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="A landscape from above showing multi-coloured layers of rock that have been folded and broken apart" src="https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Keping Shan thrust belt, China.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Both mountain belts were created when land masses collided, and the pressure from these collisions caused the rocks to fold over themselves. In some places, the rocks broke apart completely. </p>
<p>These breaks, known as faults, brought up deeper, older rocks to sit on top of younger rocks. These <a href="https://earthobservatory.nasa.gov/images/82853/faults-in-xinjiang">faults form the layered ridges</a> seen in the satellite image of Keping Shan.</p>
<p>Unlike Keping Shan, the ridges in the Zagros Mountains were formed when softer rocks, such as silt and mudstone, <a href="https://www.geolsoc.org.uk/Policy-and-Media/Outreach/Plate-Tectonic-Stories/Hartland-Quay/Zagros-Range#:%7E:text=The%20Zagros%20Mountains%20formed%20as,increase%20in%20height%20each%20year.">were eroded away over time</a>. This erosion formed valleys beside the more resistant rocks of limestone and dolomite, which comprise the arch-shaped folded domes. </p>
<h2>Unravelling rivers</h2>
<p>Rivers make huge changes to our landscapes. Over many years they can find and exploit weaknesses in rocks to carve their way through any terrain. Rivers look and behave differently depending on <a href="https://geo.libretexts.org/Courses/University_of_California_Davis/GEL_109%3A_Sediments_and_Strata_(Sumner)/08%3A_Old_or_Lost_Pages/8.06%3A_Rivers">factors</a> such as flow rate, how much sediment they carry, and the gradient of the slope they’re on. </p>
<p>Rivers can consist of one narrow and winding stream (called a meandering river) such as the Beni River in Bolivia, or a wide channel made up of many branches braided together between bars of sediment (called a braided river), such as the portion of Brazil’s Rio Negro in the last image below. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A blue sinuous river cuts through bright green forest" src="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Beni River, Bolivia.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="View from above of the blue Rio Negro (black river) with a mosaic of rivers surrounded by green plains." src="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rio Negro, Brazil.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Looking at the meandering Beni River from above, you can see how the twists and turns of the river have evolved over time. The u-shaped lakes scattered along the edges of the river are called <a href="https://www.tandfonline.com/doi/abs/10.1080/00049188208702813?journalCode=cage20">oxbow lakes</a>. </p>
<p>These oxbow lakes are the former channel of the river which have since been cut off when the river eroded a new, more direct channel to follow. In Australia, oxbow lakes are also known as billabongs.</p>
<p>Unlike the slowly meandering Beni River, the wide channel of the Rio Negro is created by fast flows and the deposition of coarse sediment. These characteristics form the mosaic of small islands between the branching flow of water. The islands become submerged during Brazil’s wet season when the volume and flow of the water is higher. </p>
<p>Armed with this new knowledge, book a window seat next time you fly and see what geological wonders you can spy from above.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-dingo-fence-from-space-satellite-images-show-how-these-top-predators-alter-the-desert-155642">The dingo fence from space: satellite images show how these top predators alter the desert</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/171950/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Finch has previously received funding from an Australian Postgraduate Award and a Society of Economic Geologists Graduate Student Fellowship.</span></em></p>The United States Geological Survey has a vast collection of satellite images capturing breathtaking geological features of our planet. As a geologist, I’ve picked eight of the most fascinating.Emily Finch, Research Affiliate, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1865482022-07-14T13:20:52Z2022-07-14T13:20:52ZHow the Tour de France helped me think about geology in a new way<p>As I write this, the Tour de France has reached its halfway point, with the cyclists climbing the Alps. Or, to put it another way, the race has left Armorican continent and entered the folded relics of the Valais Ocean and the Briançonnais microcontinent. </p>
<p>For me, as an academic geologist and cycling enthusiast, this year’s edition of the world’s biggest cycle race is particularly exciting as colleagues and I launched the <a href="https://geotdf.org">Geology of the Tour de France</a> blog and the <a href="https://twitter.com/geotdf">@GeoTdF twitter account</a>. </p>
<p>The project first came about when we noticed how much time the TV commentators had to fill while the riders cycle through interesting landscapes. Though viewers watch for hours in anticipation of the action that will end every stage, for most of that time 150 riders are chasing five or so others with little change to the status quo. In that time, the broadcasters explain everything about almost everything you can see on screen. </p>
<p>Organisers of cycling races therefore provide the commentators with a Lonely Planet-style route book with information about castles, cities and individuals. And then it struck me: we are not only watching potential holiday destinations, but also geological excursions. All we had to do is provide the commentators with geo-information. </p>
<p>So I assembled a team of <a href="http://geotdf.org/team-geotdf">28 geoscientists and web developers</a>, several from my department at Utrecht University in the Netherlands, but also from institutes in France, Germany, Denmark, Spain, the UK and the US, who together wrote 29 blogs about the geology along the Tour de France stages, and translated these into seven languages. </p>
<p>For the men’s tour, each blog explains a geological phenomenon or process whose signatures are visible along the stage route. We’re looking at many different topics, from the <a href="http://geotdf.org/men-2022/stage-2-roskilde-nyborg-early-danian">extinction of the dinosaurs</a> to the subduction zones of the Alps, and from the origin of the volcanoes of the Massif Central to the question why the <a href="http://geotdf.org/men-2022/stage-8-dole-lausanne-france-s-youngest-mountain-range">Jura Mountains of stage 8</a> are a separate range from the Alps.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ASOUf0kcqX8?wmode=transparent&start=3" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Scientists used sand to show how the Alps and Jura may have formed in one related process, despite being some distance apart.</span></figcaption>
</figure>
<p>The Tour de France Femmes begins on the day the men’s tour finishes, and the women’s peloton will race over older rocks every day in the Paris Basin and the Vosges mountains of eastern France. Each blog of the Tour de France Femmes explains what the world would have looked like if the race was held when the rocks below the road formed. The blogs offer a five minute read, but if you read them every day, you end up with a extended geology class.</p>
<h2>Public and scientific benefits</h2>
<p>The GeoTdF project aims to be a light-hearted way to educate people about processes that impact our society, from <a href="http://geotdf.org/men-2022/stage-10-morzine-megeve-landslides">landslides</a> and <a href="http://geotdf.org/men-2022/stage-18-lourdes-hautacam-seismic-crisis">earthquakes</a> to the finding of <a href="http://geotdf.org/men-2022/stage-15-rodez-carcassone-hard-rock-with-element-lithium">ore deposits</a> that we need for the green energy revolution. And the public can respond and ask questions through Twitter.</p>
<p>But the project also has scientific benefits. It provides geoscientists and our colleagues with a platform to showcase our findings, for all of us who want to share knowledge and insight freely and enthusiastically. </p>
<p>This is why I like the project so much. Scientists are always trying to find where they are wrong, for that is where they can learn and advance. As a result, they are always scrutinising themselves and each other, through peer review, discussion, debates. The criticism is vocal, the appreciation silent. That wears me down at times. The sense of community and enthusiasm around the GeoTdF project is a nice change. So if you have something to tell or ask, please join in. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1544942865851322375"}"></div></p>
<p>At the same time, letting something as random as cycling routes determine the order in which you read up on geology turns out to be an idea and knowledge generator. Natural scientists logically tend to choose the boundaries of their study areas based on interpreted system boundaries, and dig deeper into the details to find how the natural world works, but it comes with the risk of tunnel vision. </p>
<p>I have studied plate tectonics and mountain building, through systematically finding the same geological systems and boundaries and reconstructing them (for instance in the <a href="https://www.sciencedirect.com/science/article/pii/S1342937X19302230">Mediterranean region</a>). </p>
<p>But cycling route designers force me to cross all those boundaries. No geologist would read up on a region along such a geologically non-organised and random route as a Tour de France stage – and doing so is eye-opening. I learned that the cliffs of Stevns Klint in Denmark close to stage 2, and of Calais in north west France in stage 4 are the same formation of upper Cretaceous chalks. And that the uplift in the past 20 million years of the <a href="http://geotdf.org/men-2022/stage-6-binche-longwy-pushed-up-sleeve">Ardennes hills of stage 6</a> and the Massif Central of stage 15 are both associated with formation of intraplate volcanic fields that may suggest a common underlying process. </p>
<p>Many of these chance observations connect pieces of knowledge that I picked up during my career, and some of them challenge systems that I thought I understood. As the writer Isaac Asimov is <a href="https://quoteinvestigator.com/2015/03/02/eureka-funny/">believed to have said</a>, scientific discovery rarely starts with “Eureka!” but normally with “Hey, that’s funny.” Whether the GeoTdF project will lead to the former remains to be seen, but it certainly is fun.</p><img src="https://counter.theconversation.com/content/186548/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Douwe van Hinsbergen receives funding from the Netherlands Organization of Scientific Research (NWO) and Utrecht University. </span></em></p>The world’s biggest cycling race is a great way to teach people about geology – and test our own ideas.Douwe van Hinsbergen, Chair in Global Tectonics and Paleogeography, Utrecht UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1765142022-02-07T16:01:12Z2022-02-07T16:01:12ZMountain glaciers may hold less ice than previously thought – here’s what that means for 2 billion downstream water users and sea level rise<figure><img src="https://images.theconversation.com/files/444660/original/file-20220206-27-1x4umu8.jpg?ixlib=rb-1.1.0&rect=106%2C44%2C3628%2C2323&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mountain glaciers are under threat from global warming.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-this-photo-taken-on-may-17-mountaineers-make-their-way-news-photo/962297762">Phunjo Lama/AFP via Getty Images</a></span></figcaption></figure><p><em>Mountain glaciers are essential water sources for nearly a quarter of the global population. But figuring out just how much ice they hold – and how much water will be available as glaciers shrink in a warming world – has been notoriously difficult.</em></p>
<p><em>In a new study, scientists mapped the speed of over 200,000 glaciers to get closer to an answer. They discovered that widely used estimates of glacier ice volume <a href="https://www.nature.com/articles/s41561-021-00885-z">may be off by about 20%</a> in terms of how much Earth’s glaciers outside the Greenland and Antarctic ice sheets could contribute to sea level rise.</em></p>
<p><em><a href="https://faculty-directory.dartmouth.edu/mathieu-morlighem">Mathieu Morlighem</a>, a leader in ice sheet modeling and a coauthor of the study, explains why <a href="https://www.nature.com/articles/s41561-021-00885-z">the new results</a> hold a warning for regions that rely on glaciers’ seasonal meltwater, but barely register in the big picture of rising seas.</em> </p>
<h2>1) If mountain glaciers hold less ice than previously believed, what does that mean for people who depend on glaciers for water?</h2>
<p>Globally, <a href="https://theconversation.com/the-worlds-mountain-water-towers-are-melting-putting-1-9-billion-people-at-risk-128501">almost 2 billion people</a> rely on mountain glaciers and snowpack as their main source of drinking water. Many also rely on glacier water for hydropower generation or agriculture, particularly in the dry season. But the vast majority of glaciers around the world are losing more mass than they gain during the year as the climate warms, and they <a href="https://doi.org/10.1038/s41586-021-03436-z">are slowly disappearing</a>. That will <a href="https://www.ipcc.ch/srocc/chapter/chapter-2/">profoundly affect these populations</a>.</p>
<p>These communities need to know how long their glaciers will continue to provide water and what to expect as the glaciers disappear so they can prepare.</p>
<p>In most places, we found significantly lower total ice volumes than previous estimates indicated.</p>
<p>In the tropical Andes, from Venezuela to northern Chile, for example, we found that the glaciers have about 23% less ice than previously believed. This means downstream populations have less time to adjust to climate change than they may have planned for. </p>
<figure class="align-center ">
<img alt="A herder moves sheep down a road next to a large water pipe with mountains in the background." src="https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444748/original/file-20220207-85126-106wv1o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A herder walks beside a water pipe near La Paz, Bolivia. A glacier long relied on for water there is nearly gone.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/local-indigenous-sheep-herder-walks-past-a-water-pipe-at-news-photo/523905156">Tim Clayton/Corbis via Getty Images</a></span>
</figcaption>
</figure>
<p>Even in the Alps, where scientists have a lot of direct ice thickness measurements, we found that the glaciers may have 8% less than previously thought.</p>
<p>The big exception is the Himalayas. We calculated that there may be 37% more ice in these remote mountains than previously estimated. This buys some time for communities that rely on these glaciers, but it does not change the fact that these glaciers are melting with global warming.</p>
<p>Policymakers should look at these new estimates to revise their plans. We do not provide new predictions of the future in this study, but we do provide <a href="https://www.nature.com/articles/s41561-021-00885-z">a better description</a> of what the glaciers and their water supplies look like today.</p>
<p><iframe id="0Qk4G" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/0Qk4G/13/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>2) How do these finding affect estimates of future sea level rise?</h2>
<p>First, it’s important to understand that melting glaciers are only one contributor to sea level rise as the climate warms. About one-third of today’s sea level rise is due to <a href="https://sealevel.nasa.gov/understanding-sea-level/global-sea-level/thermal-expansion">thermal expansion</a> of the ocean – as the ocean warms, water expands and takes up more space. The other two-thirds come from <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level">shrinking mountain glaciers and ice sheets</a>. </p>
<p>We found that if all the glaciers, not including the big ice sheets in Greenland and Antarctica, were to melt entirely, <a href="https://www.nature.com/articles/s41561-021-00885-z">sea level would rise by about 10 inches</a> instead of 13 inches. This may sound like a large difference, considering the size of the ocean, but you have to put things in perspective. A complete disintegration of the Antarctic ice sheet would contribute <a href="https://climate.nasa.gov/news/2749/ramp-up-in-antarctic-ice-loss-speeds-sea-level-rise/">190 feet</a> to sea level and the Greenland ice sheet would contribute <a href="https://www.jpl.nasa.gov/news/nasa-greenland-mission-completes-six-years-of-mapping-unknown-terrain">24 feet</a>.</p>
<p>The 3 inches that we are talking about in this study do not call into question current projections of sea level rise.</p>
<h2>3) Why has it been so hard to figure out the ice volume of glaciers, and what did your study do differently?</h2>
<p>You might be surprised by how much is still unknown about some of the basic characteristics of remote mountain glaciers.</p>
<p>Satellites have transformed our understanding of glaciers since the 1970s, and they provide an increasingly clear picture of <a href="https://www.glims.org/RGI/">glacier locations and surface area</a>. But satellites cannot see “through” the ice. In fact, for 99% of the world’s glaciers, there is no direct measurement of ice thickness. Scientists have spent more time mapping the <a href="https://www.antarcticglaciers.org/glaciers-and-climate/estimating-glacier-contribution-to-sea-level-rise/">Greenland and Antarctica ice sheets</a> and the terrain below, and we have much more detailed volume measurements there. NASA, for example, dedicated an entire airborne mission, <a href="https://www.nasa.gov/mission_pages/icebridge/mission/index.html">Operation IceBridge</a>, to collect ice thickness measurements in Greenland and Antarctica.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=223&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=223&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=223&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=280&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=280&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444625/original/file-20220206-501-1ts25eb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=280&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The new mapping techniques are more precise, as a comparison of Iceland’s Vatnajökull ice cap shows. The image on the left is the new map.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1038/s41561-021-00885-z">R. Millan et al., 2022</a></span>
</figcaption>
</figure>
<p>Scientists have come up with <a href="https://doi.org/10.1038/s41561-019-0300-3">various techniques</a> to <a href="https://doi.org/10.1002/2014RG000470">determine the volume</a> of glaciers, but the uncertainty for remote mountain glaciers has been pretty high.</p>
<p>We did something different compared to previous studies. We used satellite imagery to map the glaciers’ speed. Glacier ice, when it is thick enough, behaves like thick syrup. We can measure how far the ice is moving using two satellite images and map its speed, which goes from a few feet to about 1 mile per year. Mapping the displacement of more than 200,000 glaciers was no easy task, but that created a data set nobody had seen before.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=527&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=527&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=527&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=663&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=663&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444626/original/file-20220206-17-kwn95c.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=663&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Images show the velocity of glacier ice in regions around the world.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1038/s41561-021-00885-z">R. Millan et al., 2022</a></span>
</figcaption>
</figure>
<p>We used this new information of ice speed and simple principles of ice deformation to determine the thickness of the ice at each pixel of these satellite images. In short, the ice speed we observe from space is due to the ice sliding on its bed and also its internal deformation. The internal deformation depends on its surface slope and ice thickness, and the slipperiness of its bed depends on the temperature of the ice at its base, the presence or absence of liquid water, and the nature of the sediments or rocks underneath. Once we could calibrate a relationship between ice speed and sliding, we could calculate ice thickness.</p>
<p>[<em>Over 140,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140ksignup">Sign up today</a>.]</p>
<p>To map the flow speed of all of these glaciers, we analyzed 800,000 pairs of images collected by satellites from the European Space Agency and NASA.</p>
<p>Of course, as with any indirect method, they are not perfect estimates and they will be further improved as we collect more data. But we have made a lot of progress in reducing the overall uncertainty.</p><img src="https://counter.theconversation.com/content/176514/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mathieu Morlighem receives funding from NASA, NASA and the Heising-Simons Foundation.</span></em></p>Glaciers in North America, Europe and the Andes, in particular, have significantly less ice than people realized.Mathieu Morlighem, Professor of Earth Sciences, Dartmouth CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1738082021-12-23T10:56:48Z2021-12-23T10:56:48ZThe Somalayas are the biggest mountain range you will never see<figure><img src="https://images.theconversation.com/files/438897/original/file-20211222-49721-1yuie00.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">200 million years from now Mogadishu and Mumbai will be neighbours along a large mountain range.</span> <span class="attribution"><span class="source">Douwe van Hinsbergen</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Every geography schoolbook has them: maps that look like today’s Earth, but not quite, since all continents are merged into a single supercontinent. Those maps were used to explain why dinosaurs in South America and Africa, or North America and Europe <a href="https://www.geolsoc.org.uk/Plate-Tectonics/Chap1-Pioneers-of-Plate-Tectonics/Alfred-Wegener/Fossil-Evidence-from-the-Southern-Hemisphere">looked so alike</a>. </p>
<p>“Paleogeographic” reconstructions like these provide context to study the processes that shape our planet: the Earth’s engines of plate tectonics, volcanism, and mountain building, and their interactions with the oceans, atmosphere, and sun that shape climate and life. In the past ten years software has been developed that means anyone who is interested can make these reconstructions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Maps of Pangea" src="https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=569&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=569&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=569&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=715&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=715&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438745/original/file-20211221-13-10s0cys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=715&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">200 million years ago, almost all the world’s land was in one supercontinent named Pangea.</span>
<span class="attribution"><span class="source">van Hinsbergen et al (2019)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But if paleogeographic maps were already in our primary school textbooks, then what are geologists like me trying to uncover? Just the details?</p>
<p>To some extent: yes, working out the details of plate motions in the distant past may make all the difference. For instance, major ocean currents can suddenly change course when narrow oceanic corridors open or close, such as <a href="https://theconversation.com/how-events-in-panama-created-the-modern-world-millions-of-years-ago-58357">between the Americas</a> or when water suddenly flooded through the Straits of Gibraltar and <a href="https://www.nationalgeographic.com/science/article/mediterranean-nearly-dried-up-cataclysmic-flood-revived-it">filled up the Mediterranean</a>. And subtle differences in the timing or location of such corridors may support or falsify what we think caused past changes in climate. </p>
<p>But the biggest problem for paleogeography is not the details: it’s that as much as 70% of the Earth’s crust that existed as “recently” as 150-200 million years ago, when dinosaurs were already roaming the planet, has been <a href="https://www.sciencedirect.com/science/article/pii/S0012821X10000191?casa_token=geoPLY_Hw9UAAAAA:DPmeudlbwU6SkXcg17T-mo-DmeiIJrKz3JIq6Oqi-C3tEOro4wRTdtK4H2U22J6vPRt4eUiMBQ">lost to subduction</a> into the Earth’s inner mantle. On paleogeographic maps, we have filled in those now-subducted areas, usually in broad brush strokes using the simplest possible scenarios without much detail. But there are relics of this subducted crust left in the geological record, and in my field of research we try to use these records to learn about Earth’s “lost” surface.</p>
<p>Many mountains, most famously the Himalayas, are made of folded and stacked slices of rock that were scraped off the subducted plate. And the types of rock and the fossils and minerals they contain can tell us when and where these rocks formed. Geologists can then piece together how those continents and deep basins and volcanoes linked together in the distant past.</p>
<h2>Mountains 200 million years from now</h2>
<p>In recent years, when I explained how we make reconstructions of paleogeography from modern mountain ranges, I was sometimes asked if we could also predict future mountains. I always said “sure, but why would I? I’d have to wait a hundred million years to see if I’m right”. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/HSilbObdCZ4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Mountains of the future, based on work by geologists at Utrecht University.</span></figcaption>
</figure>
<p>But then I realised that this could be an interesting thought experiment. Predicting the architecture of future mountain ranges would require formulating a set of “rules of mountain building”, which had not been done before. And we would have to predict how the geography we know well would transform into mountain belts, which would make us realise what the plates that were lost forever could have looked like, particularly the parts that subducted without leaving a record. And would we produce mountain belts that look much like the ones we have?</p>
<p>So we did. I formulated the rules by comparing which features are commonly found in mountain belts. My then-MSc student <a href="https://www.geology.ethz.ch/people/person-detail.Mjc3OTM4.TGlzdC82NjksNTE5NzQ3MzU0.html">Thomas Schouten</a> used the rules to predict the geological architecture of a <a href="https://www.ajsonline.org/content/321/6/955/tab-article-info">mountain belt that will form in the next 200 million years</a>, if Somalia, <a href="https://theconversation.com/africa-is-splitting-in-two-here-is-why-94056">as expected</a>, breaks off from Africa and collides with India. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Indian Ocean plates" src="https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=502&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=502&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=502&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=631&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=631&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438899/original/file-20211222-19-3fm3gx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=631&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Indian Ocean tectonic plates today.</span>
<span class="attribution"><span class="source">Douwe van Hinsbergen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The resulting mountain range, which we called the “Somalaya mountains”, might be the Himalayas of their day. And seeing such similarities between the Somalaya and known mountains today can us with provide possible solutions we never thought of for paleogeographic evolution.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of India and Somalia plate tectonics in future" src="https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438901/original/file-20211222-129369-16g04mj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">200 million years from now Somalia and India will have collided, forming a large mountain range.</span>
<span class="attribution"><span class="source">Douwe van Hinsbergen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For instance, according to our research, a mountain belt may form in the bay between Madagascar and Africa, and it would be strongly curved much like the Carpathians of Eastern Europe or the Banda islands of Indonesia and Timor. And northwest India will first get deeply buried 50 km or so below Somalia, but then Somalia will rotate and northwest India will re-emerge – this is a geological history that looks much like western Norway around 400 million years ago. </p>
<p>Thought experiments like our look at the Somalayas help us to realise what we overlook when reconstructing the history of the Earth’s plates and surface. The better those reconstructions, the better we will predict Earth’s history and behaviour, its resources, and the effects of using them.</p><img src="https://counter.theconversation.com/content/173808/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Douwe van Hinsbergen receives funding from the Netherlands Organization for Scientific Research (NWO). </span></em></p>Why we are predicting the mountains of the far future, and what it can tell us about the world today.Douwe van Hinsbergen, Chair in Global Tectonics and Paleogeography, Utrecht UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1678692021-12-20T13:14:33Z2021-12-20T13:14:33ZWhat’s the record for how long it’s ever rained without stopping?<figure><img src="https://images.theconversation.com/files/436774/original/file-20211209-172173-1watr8u.jpg?ixlib=rb-1.1.0&rect=7%2C29%2C4881%2C3224&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some places rarely see the sun.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/close-up-of-raindrops-on-plant-royalty-free-image/963251882">Donat Photography / EyeEm</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>What is the longest time it has ever rained for? – Wayne</strong></p>
</blockquote>
<hr>
<p>The answer is – it depends. If you live in a dry place, like the Atacama Desert in South America, and it rains for an hour, that may be the precipitation record for that location. If you live in a wet place, like the Amazon rain forest, raining for 40 days in a row wouldn’t be a big deal. </p>
<p>As <a href="https://scholar.google.com/citations?hl=en&user=sWxyDPYAAAAJ">scientists who</a> <a href="https://scholar.google.com/citations?user=kok88kUAAAAJ&hl=en&oi=sra">study the weather</a>, we love rain data – and use it to learn how storm systems work. We’ve also learned what conditions produce rain records.</p>
<h2>What happens inside clouds</h2>
<p>Rain forms when moist air is lifted into the sky where it cools. As moist air chills, the water vapor molecules press together to form tiny microscopic droplets. <a href="https://theconversation.com/what-would-it-feel-like-to-touch-a-cloud-133219">Together they look like clouds</a>. Air motion inside clouds can sometimes cause the droplets to bang into each other and become larger droplets. In the upper parts of clouds, the temperature is cold enough to make ice crystals, which eventually get heavy enough to fall – and melt into rain on their way to the ground. </p>
<p>Rain can come from many different types of storms. Thunderstorms, for example, have a short life span and can produce intense downpours. Other storms, such as winter storms, can linger for several days and produce gentle rain, steady rain or, if it’s cold enough, snow. </p>
<p>In most places, weather alternates between dry and wet periods. That’s because each period of stormy weather is followed by a period of dry air with plentiful sunshine and few clouds.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A person walks with an umbrella on a rain soaked trail." src="https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431086/original/file-20211109-19-1awmni3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A new record for the amount of rain in a three-day period was set in Hilo, Hawaii - 31.85 inches fell in August 2018.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/visitors-stand-in-the-rain-at-an-overlook-for-rainbow-falls-news-photo/1023655644">Mario Tama via Getty Images News</a></span>
</figcaption>
</figure>
<p>An exception to this rule is where mountains are near oceans. In that case, as moist ocean air blows toward the land, it encounters the mountains and is forced to lift over them. Clouds can form there almost continuously, bringing rainfall that can last for weeks or longer. </p>
<h2>Days and days of rain</h2>
<p>Rainfall records exist only in places where people live and keep records. Many towns and cities don’t bother collecting rainfall data. And records don’t exist for the many uninhabited locations on Earth, like over the ocean or deep in rain forests. So rainfall data is incomplete. </p>
<p>In modern record keeping, rainfall is measured by the amount in a given time period, usually hourly or daily. A few drops of rain is called a “trace” of rain. Rainfall is “measurable” if it adds up to 0.01 inch (0.25 millimeters) or more. </p>
<p>In the U.S., the longest periods of daily rain have occurred in Hawaii, where easterly trade winds blow toward the mountains. An incredible <a href="https://weather.com/news/weather/news/rain-331-days-hawaii-record">331 consecutive days of measurable rainfall</a> were recorded at Manuawili Ranch, Maui, in 1939-40. If you include a trace of rain, the record is 881 consecutive days, or <a href="https://weather.com/news/weather/news/rain-331-days-hawaii-record">nearly three straight years</a>, at Honomu Maki, Oahu, from 1913 to 1916. This dependable and continuous rainfall is the reason that region is a tropical rainforest.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An enormous tree trunk." src="https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/436721/original/file-20211209-21-1j5xll6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A western cedar in the Olympic National Park rainforest in Port Angeles, Washington.</span>
<span class="attribution"><span class="source">Bill Baccus</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In the continental U.S., the longest daily rainfalls have occurred in winter near the coastal mountain ranges of the Pacific Northwest. In 1997-98, <a href="https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?orotis">Otis, Oregon, received 79 straight days</a> of measurable rainfall. The Pacific Northwest has temperate rainforests, where the continuously wet cold season nurtures huge trees, even though it is often relatively dry in the summer.</p>
<p>There are plenty of <a href="https://www.escape.com.au/escape-travel/the-top-10-wettest-places-on-earth/news-story/993eaffca1d3d5fabc0c9d73bef06b96">other rainy places in the world</a> where moist air flows over mountains. The Meteorological Observatory in <a href="https://cherrapunjee.com/daily-weather-data/">Cherrapunjee, India, recorded 86 consecutive days of measurable rainfall</a> during the monsoon in 1995. Other rainy places include Southern New Zealand, Bioko Island in Equatorial Guinea and western Colombia in South America.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Closeup of a rain gauge." src="https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431091/original/file-20211109-19-143i1sb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rain gauges are the most common tool for measuring rain.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/empty-rain-gauge-during-periods-of-low-rainfall-and-drought-news-photo/1296529895">Morel J/Andia/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<p>If you want to know how much it rains where you live, the best way is to install a rain gauge and start recording your own daily rainfall measurements. A great resource is the <a href="https://www.cocorahs.org/">CoCoRahs Network</a>, a community of volunteers working to measure and map rain, hail and snow. </p>
<p>Collecting data about the location and intensity of all kinds of precipitation really helps scientists like us understand weather systems and improve our weather forecasting. </p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/167869/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Extended periods of rain are most likely found in locations where mountains are near oceans.Lynn McMurdie, Research Associate Professor of Atmospheric Sciences, University of WashingtonJoe Boomgard-Zagrodnik, Postdoctoral Research Associate in Crop and Soil Sciences, Washington State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1730762021-12-02T14:54:42Z2021-12-02T14:54:42ZHow plankton helped create the Earth’s mountains 2 billion years ago<figure><img src="https://images.theconversation.com/files/435296/original/file-20211202-17-eiblss.jpg?ixlib=rb-1.1.0&rect=12%2C0%2C3669%2C1510&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Himalayas.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/magnificent-blossoms-rhododendrons-on-background-white-582993493">Liudmila Kotvictchkaia/Shutterstock</a></span></figcaption></figure><p>A world without the great mountain ranges – the <a href="https://www.pbs.org/wnet/nature/the-himalayas-himalayas-facts/6341/">Himalayas</a>, the <a href="https://wwf.panda.org/discover/knowledge_hub/where_we_work/alps/">Alps</a>, the <a href="https://www.britannica.com/place/Rocky-Mountains">Rockies</a>, the <a href="https://www.britannica.com/place/South-America/The-Andes-Mountains">Andes</a> – is unimaginable, but they were not always a part of the Earth’s geography. Mountains didn’t start forming widely until <a href="https://www.seismosoc.org/news/seismic-signs-of-earliest-subduction-network-found-in-china/">2 billion years ago</a>, half way through the planet’s history. Now our <a href="https://www.nature.com/articles/s43247-021-00313-5">research</a> has revealed how primitive life played a key role in their introduction to the planet.</p>
<p>While the formation of mountains is usually associated with the collision of tectonic plates causing huge slabs of rock to be thrust skywards, our study has shown that this was triggered by an abundance of nutrients in the oceans 2 billion years ago which caused an explosion of planktonic life.</p>
<figure class="align-center ">
<img alt="A diagram showing the timeline of mountains on Earth." src="https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435299/original/file-20211202-23-7gvpo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Timeline for the formation of mountains on Earth.</span>
<span class="attribution"><span class="source">J Johnston/University of Aberdeen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Making mountains</h2>
<p>Mountains are not just a beautiful backdrop for recreation, they are essential to the way the world works, through their influence on weather, climate, the distribution of fresh water and the erosion of rock to make cultivable soil. </p>
<p>Before there were mountains, the plate movements that reshape the distribution of oceans and continents only occurred on a limited scale. But the movement of these plates are essential to making mountains. The pressure of one plate pushing against another – typically an ocean plate hitting a continental plate – causes slabs of ocean rock to break off and stack up on top of each other as they are pushed from behind.</p>
<p>Over millions of years the stack of rocks builds up, creating mountains, just as the Himalayas were built from ocean rocks between India and Eurasia, pushed northwards until the ocean disappeared and its remains were left piled high.</p>
<p>We know these mountains came originally from the ocean by the sea fossils found on the Tibetan plateau, thousands of metres above sea level. But piling up huge slabs of rock on such a scale needs serious lubrication, otherwise friction would stop them. That lubricant is carbon, which became part of the ocean rock when dead plankton fell to the ocean floor and became buried.</p>
<p>Plankton have lived in our oceans for over 3 billion years, but 2 billion years ago their numbers exploded when abundant nutrients entered the water. At the time, life was no more complex than their single cells. But the cells became much bigger, and they contained more carbon.</p>
<p>When they died they sank quickly and were buried in mud which created rock with unprecedented amounts of carbon, which was turned into graphite by heat and pressure. Graphite makes a great lubricant. Locks, hinges, gears, wheels and even zips all move more easily with graphite – and so do rocks. </p>
<figure class="align-center ">
<img alt="Diagram showing how mountains are formed by tectonic pressure and carbon." src="https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=369&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=369&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=369&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=463&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=463&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435301/original/file-20211202-25-6wgoof.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=463&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Slabs of rock stacked up by lubricating carbon, which creates mountains when tectonic plates collide; precise geometry is much more complex, and slabs may stack in the opposite direction.</span>
<span class="attribution"><span class="source">J Bowie/University of Aberdeen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Lubrication</h2>
<p>The plentiful graphite that accumulated beneath the ocean floor had a profound effect, by lubricating the building of mountains. While it has long been known that tectonic processes were lubricated, our research shows that it was the sheer abundance of carbon in the ocean that played a crucial role in the thickening of the Earth’s crust that built its mountain ranges.</p>
<p>The process has continued since then, and other geological layers like salt have also played their part, but the graphite beds of 2 billion years ago were especially slippery, and some have been involved in making mountains more than once. </p>
<p>The biggest mountains on Earth, the Himalayas, are <a href="https://www.britannica.com/place/Himalayas">geologically young</a> – about 50 million years old – but rocks made in a much older ocean slid over each other to help create them. They had already slid in the first millions of years after they formed, and then after a long dormancy they slid again to help the rise of the Himalayas. They may slide again in the distant future.</p>
<p>Long after mankind is gone, those ancient plankton will continue their influence on the planet. The mountains made 2 billion years ago are worn down now, but we can still see their roots in places like Scotland, for example.</p>
<p>Our study looked at 20 cases of mountain building around the world from that time, from Australia to China, South America to the Arctic and in north-west Scotland, where we can see the slip surfaces in graphite-bearing rocks in Harris, Iona and Gairloch, formed during earthquakes that accompanied the earliest mountain building. The island of Tiree is one of the flattest places in Britain, but the seabirds that run over its sandy beaches cross the foundations of huge, long-gone mountains.</p>
<figure class="align-center ">
<img alt="A beach fringing turquoise waters on the Hebridean island of Tiree off the West Coast of Scotland." src="https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435306/original/file-20211202-19-1qorakp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Hebridean island of Tiree is now utterly flat, its 2 billion-year-old mountains worn away.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/picture-taken-caolas-beach-on-scottish-368446253">Alistair MacLean/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Graphite resources</h2>
<p>In each of the 20 ancient mountain ranges that were studied, exceptional amounts of graphite were recorded. In many cases the graphite is abundant enough to have been mined as a resource.</p>
<p>Graphite is now a hot commodity, as it is needed in the batteries that are central to green technology (far more graphite is required than lithium in a lithium ion battery). Many of the largest graphite deposits in the world were formed about 2 billion years ago. The graphite that helped bring us mountains may prove critical to the planet once more, and play a key role in its preservation for future generations.</p>
<p>Without the carbon from countless cells of plankton, the distribution of tectonic plates may have evolved rather differently, and we would not have mountains as we know them. Ours is a planet fundamentally shaped by life.</p><img src="https://counter.theconversation.com/content/173076/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Parnell receives funding from NERC.</span></em></p>Mountains can’t be created without lubricant, and 2 billion years ago that lubricant was graphite produced by the carbon broken down from layers of dead plankton on the ocean floor.John Parnell, Professor of Geology and Petroleum Geology, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1698862021-11-08T20:40:19Z2021-11-08T20:40:19ZClimate change is transforming mountains – we must act to save them<figure><img src="https://images.theconversation.com/files/430861/original/file-20211108-21-1288vb6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C11413%2C4151&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Dirk Schmeller</span>, <span class="license">Fourni par l'auteur</span></span></figcaption></figure><p>Mountain ecosystems provide vital <a href="https://www.sciencedirect.com/science/article/pii/S2212041620301558#b0135">services to human life</a>. Mountains sequester CO<sub>2</sub>, clean water and the air and regulate floods. Worldwide, they provide for the livelihoods of <a href="https://www.fao.org/3/W9300E/w9300e03.htm">more than half of human society</a>.</p>
<p>Climate change is particularly acute in mountains. The highly developed relief of the ranges creates many microclimates, ecosystems and therefore living spaces for numerous species. Quite a few of those species can <a href="https://www.iucnredlist.org/search?query=mountains&searchType=species">only be found in mountains</a>.</p>
<p>High-altitude mountain areas are projected to warm much faster than lowland regions. For the Pyrenees, which run along the border of France and Spain, warming of <a href="https://doi.org/10.1002/joc.4823">0.57°C per decade</a> has already been observed, while the rate is only 0.18°C in lowland France.</p>
<p>It is difficult to precisely predict temperature increases in mountains, but for the Pyrenees, the mean annual temperature has been estimated to be <a href="https://doi.org/10.1002/joc.4823">2°C warmer than 1970</a>, compared to 1.2°C in lowland France. This difference will only increase in the future.</p>
<hr>
<p>
<em>
<strong>
À lire aussi :
<a href="https://theconversation.com/mountains-a-fragile-source-of-life-153400">Mountains, a fragile source of life</a>
</strong>
</em>
</p>
<hr>
<p>Increased temperatures in mountain regions decrease the amount of snow that falls, causes snow and ice to melt earlier and accelerates deglaciation – the process by which glaciers retreat.</p>
<p>Increased temperatures also accelerate biochemical reactions such as photosynthesis in plants, increase the rates of many biological and ecological processes such as decomposition and sedimentation, <a href="https://doi.org/10.1016/bs.agron.2016.10.011">organic carbon mineralisation</a>, organismic growth (such as the time from egg hatching to metamorphosis in frogs), and biomass production (for example, the regrowth of grazed meadows).</p>
<h2>How climate change affects mountains</h2>
<p>We can thus accurately predict that profound ecological changes will follow the temperature increases that are already taking place, destabilising mountain ecosystems.</p>
<p>European mountains like the Pyrenees are far from the remote and pristine ideals we often imagine, and many show the marks of centuries-long human activities. In the Pyrenees, mining activities have largely ceased, but still have an impact in the form of ongoing heavy metal pollution through increased flooding due to climate change, <a href="https://doi.org/10.1002/9781119413332.ch9">releasing stored heavy metals from peatbogs and peatlands</a>.</p>
<p>At the same time, toxic organic pollutants are carried from lowlands to sensitive mountain ecosystems by atmospheric transport – the process of evaporation, cloud formation, wind and precipitation – but also via local activities such as the use of insect repellents by farmers and tourists.</p>
<p>Meanwhile, introduced fish species in mountain lakes bring with them <a href="https://doi.org/10.1021/acs.est.8b01299">high levels of mercury</a>, which is known for its negative effects on the nervous system of animals and humans.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/QixWuVD2mA4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Climate change impacts in mountains.</span></figcaption>
</figure>
<p>Introducing fish into mountain lakes also lead to a processes called <a href="https://oceanservice.noaa.gov/facts/eutrophication.html">eutrophication</a> – where water systems are flooded with too many nutrients. Together with increased temperatures, this causes algae to bloom in greater numbers and lowers oxygen in waterways. These algae also produce poisons known as cyanotoxins in high enough concentrations to <a href="https://doi.org/10.1080/10408440701749454">cause illness in animals and humans</a>.</p>
<p>Climate change in mountains will challenge downstream freshwater ecosystems and along with them, an important source of drinking water. <a href="https://ec.europa.eu/environment/water/water-drink/reporting_en.html">Water quality has already decreased</a> and, as it is difficult to detect all the different toxic molecules in water samples, the amount of toxins in current drinking water remains unclear.</p>
<h2>Transformative change</h2>
<p>As human health is <a href="https://www.who.int/news-room/q-a-detail/one-health">inextricably linked</a> to animal and environmental health, it is important to understand that the Pyrenees and many other mountain ranges are not as healthy as many of us think.</p>
<p>In the future, they may no longer provide us with the clean drinking water, clean air and other ecosystem services we need.</p>
<p>We need a new approach for how we treat mountain ecosystems. That’s why many, including the <a href="https://ipbes.net/transformative-change">Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services</a>, are calling for a <a href="https://link.springer.com/article/10.1007/s10531-021-02261-0">“transformative change”</a>.</p>
<p>This new buzzword replaces the term “sustainable development” of previous years. Transformative change goes much further than sustainable development – because we waited too long to take small steps toward a sustainable future, we now need to make much bigger strides.</p>
<p>These strides are very likely to affect many of us – we will need to drastically reduce our mobility, change our food habits (by reducing or entirely cutting out meat from our diets), and give up many of the commodities of modern life.</p>
<p>Transformative change in the Pyrenees specifically might include restricting access to sensitive sites for tourists and farmers, reducing herd sizes of sheep and cows, and ending the use of veterinary and human insect repellents in the mountains.</p>
<p>Transformative change will have to have an impact on every facet of our lives, if it has to have an effect. Our society needs to adapt to save mountains and the essential services they provide.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=158&fit=crop&dpr=1 600w, https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=158&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=158&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=198&fit=crop&dpr=1 754w, https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=198&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/310261/original/file-20200115-134768-1tax26b.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=198&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the AXA Research Fund has been supporting nearly 650 projects around the world conducted by researchers from 55 countries. To learn more, visit the site of the <a href="https://www.axa-research.org">Axa Research Fund</a> or follow on Twitter <a href="https://twitter.com/axaresearchfund?lang=fr">@AXAResearchFund</a>.</em></p><img src="https://counter.theconversation.com/content/169886/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dirk Schmeller a reçu des financements de Axa Research Fund. </span></em></p>Mountain ecosystems are not as pristine as we may think – and climate change could trigger devastating transformations that will affect us all.Dirk S. Schmeller, Professor for Conservation Biology, Axa Chair for Functional Mountain Ecology at the École Nationale Supérieure Agronomique de Toulouse, Université de Toulouse III – Paul SabatierLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1677062021-09-13T12:14:50Z2021-09-13T12:14:50ZWestern fires are burning higher in the mountains and at unprecedented rates as the climate warms<figure><img src="https://images.theconversation.com/files/420425/original/file-20210910-21-1pbdpxm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3000%2C1994&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Heat and dryness are leaving high mountain areas more vulnerable to forest fires.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-241-square-mile-station-fire-continues-to-blacken-news-photo/90351732"> David McNew/Getty Images</a></span></figcaption></figure><p>The Western U.S. is experiencing <a href="https://disasterphilanthropy.org/disaster/2021-north-american-wildfire-season/">another severe fire season</a>, and a recent study shows that even high mountain areas once considered too wet to burn are at increasing risk as the climate warms.</p>
<p>With <a href="https://www.nifc.gov/fire-information/nfn">more than 5 million acres already burned by early September</a>, the 2021 U.S. fire season is <a href="https://www.nifc.gov/fire-information/nfn">about on pace</a> with the extreme fire season of 2020. This summer has been <a href="https://www.ncei.noaa.gov/news/national-climate-202108">the hottest</a> on record and one of the driest in the region, with <a href="https://droughtmonitor.unl.edu/data/jpg/20210907/20210907_usdm.jpg">80% of the Western U.S.</a> in severe to exceptional drought. That combination of heat and dryness is a recipe for <a>disastrous wildfires</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of the contiguous United States with historic temperature ranks on each state. Several were the hottest on record or close to it." src="https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=431&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=431&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=431&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=542&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=542&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420624/original/file-20210912-46896-ipnb6j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=542&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Several states saw their hottest June-August period since consistent record keeping began in the 1890s.</span>
<span class="attribution"><a class="source" href="https://www.ncei.noaa.gov/news/national-climate-202108">NOAA</a></span>
</figcaption>
</figure>
<p>In a study in the Proceedings of the National Academy of Sciences released in May 2021, <a href="https://scholar.google.com/citations?user=S1J4kAoAAAAJ&hl=en">our team of fire</a> and <a href="https://scholar.google.com/citations?user=tGGNDyUAAAAJ&hl=en">climate scientists</a> <a href="https://scholar.google.ca/citations?user=ZaW8ZbsAAAAJ&hl=en">and engineers</a> found that forest fires are now <a href="https://www.pnas.org/content/118/22/e2009717118">reaching higher, normally wetter elevations</a>. And they are burning there at rates unprecedented in recent fire history. Two fires burning in northern California in 2021 – the Dixie and Caldor fires – are examples: They were the first and second wildfires on record to cross the Sierra Nevada crest and burn on both sides.</p>
<p>While <a href="https://theconversation.com/how-years-of-fighting-every-wildfire-helped-fuel-the-western-megafires-of-today-163165">historical fire suppression</a> and other forest management practices play a role in the West’s worsening fire problem, the high-elevation forests we studied have had little human intervention. The results provide a clear indication that climate change is enabling these normally wet forests to burn. </p>
<p>As wildfires creep higher up mountains, another tenth of the West’s forest area is now at risk, our study found. That creates new hazards for mountain communities, with impacts on downstream water supplies and the plants and wildlife that call these forests home.</p>
<figure class="align-center ">
<img alt="Map showing how high-elevation forest fires advanced uphill." src="https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=627&fit=crop&dpr=1 600w, https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=627&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=627&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=787&fit=crop&dpr=1 754w, https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=787&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/402231/original/file-20210523-21-1xdrd55.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=787&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Forest fires advanced to higher elevations as the climate dried from 1984 to 2017. Every 200 meters equals 656 feet.</span>
<span class="attribution"><span class="source">Mojtaba Sadegh</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Rising fire risk in the high mountains</h2>
<p>In the <a href="https://www.pnas.org/content/118/22/e2009717118">new study</a>, we analyzed records of all fires larger than 1,000 acres (405 hectares) in the mountainous regions of the contiguous Western U.S. between 1984 and 2017.</p>
<p>The amount of land that burned increased across all elevations during that period, but the largest increase occurred above 8,200 feet (2,500 meters). To put that elevation into perspective, Denver – the mile-high city – sits at 5,280 feet, and Aspen, Colorado, is at 8,000 feet. These high-elevation areas are largely remote mountains and forests with some small communities and ski areas.</p>
<p>The area burning above 8,200 feet more than tripled in 2001-2017 compared with 1984-2000. </p>
<figure class="align-center ">
<img alt="Fire lights up a ridge behind a farm." src="https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=431&fit=crop&dpr=1 754w, https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=431&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/402236/original/file-20210523-15-1hxi37i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=431&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of Colorado’s largest wildfires, 2020’s East Troublesome Fire, crossed the Continental Divide and was burning at elevations around 9,000 feet in October, when snow normally would have been falling.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/Exchange-ColoradoWildfires-Blow-ups/8e10c8213c3847f3a7ef14e7ff81eddf/photo">AP Photo/David Zalubowski</a></span>
</figcaption>
</figure>
<p>Our results show that climate warming has diminished the high-elevation flammability barrier – the point where forests historically were too wet to burn regularly because the snow normally lingered well into summer and started falling again early in the fall. Fires advanced about 826 feet (252 meters) uphill in the Western mountains over those three decades.</p>
<p>The <a href="https://inciweb.nwcg.gov/incident/6964/">Cameron Peak Fire in Colorado</a> in 2020 was the largest fire in the state’s history, burning over 208,000 acres (84,175 hectares), and is a prime example of a high-elevation forest fire. The fire burned in forests extending to 12,000 feet (3,658 meters) and reached the upper tree line of the Rocky Mountains. </p>
<p>We found that rising temperatures in the past 34 years have helped to extend the fire territory in the West to an additional 31,470 square miles (81,507 square kilometers) of high-elevation forests. That means a staggering 11% of all Western U.S. forests – an area similar in size to South Carolina – are susceptible to fire now that weren’t three decades ago. </p>
<h2>Can’t blame fire suppression here</h2>
<p>In lower-elevation forests, several factors contribute to fire activity, including the presence of more people in wildland areas and a history of fire suppression. </p>
<p>In the early 1900s, Congress commissioned the U.S. Forest Service to <a href="https://foresthistory.org/research-explore/us-forest-service-history/policy-and-law/fire-u-s-forest-service/u-s-forest-service-fire-suppression/">manage forest fires</a>, which resulted in a focus on suppressing fires – a policy that continued through the 1970s. This caused flammable underbrush that would normally be cleared out by occasional natural blazes to accumulate. The increase in biomass in many lower elevation forests across the West has been associated with increases in <a href="https://doi.org/10.1890/ES13-00217.1">high-severity fires and megafires</a>. At the same time, <a href="https://doi.org/10.1073/pnas.1607171113">climate warming has dried out forests in the Western U.S.</a>, making them more prone to large fires. </p>
<figure class="align-center ">
<img alt="Illustration of two mountains showing fires higher, less snow and more dead trees" src="https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/402233/original/file-20210523-19-46yvai.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On average, fires have spread 826 feet (252 meters) higher into the mountains in recent decades, exposing an additional 31,470 square miles (81,507 square kilometers) of forests to fire.</span>
<span class="attribution"><span class="source">Mojtaba Sadegh</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>By focusing on high-elevation fires in areas with little history of fire suppression, we can more clearly see the influence of climate change. </p>
<p>Most high-elevation forests haven’t been subjected to much fire suppression, logging or other human activities, and because trees at these high elevations are in wetter forests, they historically have long <a href="https://www.fs.fed.us/database/feis/fire_regime_table/PNVG_fire_regime_table.html">return intervals between fires</a>, typically a century or more. Yet they experienced the highest rate of increase in fire activity in the past 34 years. We found that the increase is strongly correlated with the observed warming.</p>
<p><iframe id="87j2d" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/87j2d/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>High mountain fires create new problems</h2>
<p>High-elevation fires have implications for natural and human systems. </p>
<p>High mountains are natural water towers that normally provide a sustained source of water to millions of people during dry summer months in the Western U.S. The scars that wildfires leave behind – known as burn scars – affect how much snow can accumulate at high elevations. This can influence the timing, <a href="https://doi.org/10.1021/es500130g">quality and</a> <a href="https://www.fs.fed.us/rm/pubs/rmrs_gtr042_4.pdf">quantity of water</a> that reaches reservoirs and rivers downstream.</p>
<p>High-elevation fires also remove standing trees that act as anchor points that normally stabilize the snowpack, <a href="https://doi.org/10.1016/j.foreco.2009.01.050">raising the risk of avalanches</a>.</p>
<p>The loss of tree canopy also exposes mountain streams to the Sun, <a href="https://doi.org/10.1890/09-0822.1">increasing water temperatures</a> in the cold headwater streams. Increasing stream temperatures can harm fish and the larger wildlife and predators that rely on them. </p>
<p>Climate change is increasing fire risk in many regions across the globe, and <a href="https://doi.org/10.1073/pnas.1003669107">studies show that this trend will continue</a> as the planet warms. The increase in fires in the high mountains is another warning to the U.S. West and elsewhere of the risks ahead as the climate changes.</p>
<p><em>This is an update to a story published <a href="https://theconversation.com/drafts/159699/edit">May 24, 2021</a>.</em></p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/167706/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mojtaba Sadegh receives funding from the US National Science Foundation and the Joint Fire Science Program.</span></em></p><p class="fine-print"><em><span>John Abatzoglou receives funding from the National Science Foundation and the National Oceanic and Atmospheric Administration.</span></em></p><p class="fine-print"><em><span>Mohammad Reza Alizadeh does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As the risk of fires rises in areas once considered too wet to burn, it creates hazards for mountain communities and for downstream water supplies.Mojtaba Sadegh, Assistant Professor of Civil Engineering, Boise State UniversityJohn Abatzoglou, Associate Professor of Engineering, University of California, MercedMohammad Reza Alizadeh, Ph.D. Student in Engineering, McGill UniversityLicensed as Creative Commons – attribution, no derivatives.