tag:theconversation.com,2011:/africa/topics/winter-5527/articlesWinter – The Conversation2024-03-05T14:00:28Ztag:theconversation.com,2011:article/2225712024-03-05T14:00:28Z2024-03-05T14:00:28ZLithium-ion batteries don’t work well in the cold − a battery researcher explains the chemistry at low temperatures<figure><img src="https://images.theconversation.com/files/579001/original/file-20240229-20-z7oy0y.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2120%2C1414&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Why do batteries lose charge more quickly when it's cold? </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/man-charging-electric-car-in-front-his-cabin-in-royalty-free-image/1977511649?phrase=battery+cold&adppopup=true">Halfpoint Images/Moment</a></span></figcaption></figure><p>Rechargeable batteries are great for storing energy and powering electronics from smartphones to electric vehicles. In cold environments, however, they can be more difficult to charge and may even catch on fire. </p>
<p>I’m a mechanical engineering professor who’s been interested in batteries since college. I now lead a <a href="https://research.drexel.edu/mem/changlab">battery research group</a> at Drexel University. </p>
<p>In just this past decade, I have watched the <a href="https://about.bnef.com/blog/lithium-ion-battery-pack-prices-hit-record-low-of-139-kwh/">price of lithium-ion batteries drop</a> as the production market <a href="https://www.iea.org/reports/global-ev-outlook-2023/trends-in-batteries">has grown much larger</a>. Future projections predict the market could reach <a href="https://www.mckinsey.com/industries/automotive-and-assembly/our-insights/battery-2030-resilient-sustainable-and-circular">thousands of GWh per year by 2030</a>, a significant increase. </p>
<p>But, lithium-ion batteries aren’t perfect – this rise comes with risks, such as their tendency to slow down during cold weather and even catch on fire.</p>
<h2>Behind the Li-ion battery</h2>
<p>The <a href="https://www.sciencedirect.com/topics/chemistry/electrochemical-energy-storage">electrochemical energy storage</a> within batteries works by storing electricity <a href="https://www.britannica.com/science/ion-physics">in the form of ions</a>. Ions are atoms that have a nonzero charge because they have either too many or not enough electrons. </p>
<p>When you plug in your electric car or phone, the electricity provided by the outlet <a href="https://www.youtube.com/watch?v=4-1psMHSpKs&ab_channel=TheLimitingFactor">drives these ions</a> from the battery’s positive electrode into its negative electrode. The electrodes are solid materials in a battery that can store ions, and all batteries have both a positive and a negative electrode. </p>
<p>Electrons pass through the battery as electricity. With each electron that passes to one electrode, a lithium ion also passes into the same electrode. This ensures the balance of charges in the battery. As you drive your car, the stored ions in the negative electrode move back to the positive electrode, and the resulting flow of electricity powers the motor. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing three boxes, one labeled cathode, one labeled electrolyte, and one labeled anode. Small circles representing lithium ions move to the anode to charge and the cathode to discharge." src="https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=564&fit=crop&dpr=1 600w, https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=564&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=564&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=708&fit=crop&dpr=1 754w, https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=708&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/578759/original/file-20240228-8828-q6kh1t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=708&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">When a lithium-ion battery delivers energy to a device, lithium ions – atoms that carry an electrical charge – move from the negative electrode, the anode, to the positive electrode, the cathode. The ions move in reverse when recharging.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/argonne/5029455937">Argonne National Laboratory</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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<p>While AA or AAA batteries can power small electronics, they can be used only once and cannot be charged. Rechargeable Li-ion batteries can operate for thousands of cycles of full charge and discharge. For each cycle, they can also store a much higher amount of charge than an AA or AAA battery.</p>
<p>Since lithium is the lightest metal, it has a high <a href="https://doi.org/10.1039/C3EE40795K">specific capacity</a>, meaning it can store a <a href="https://chang-lab.notion.site/How-To-Become-a-Battery-Expert-20a8edebe395403c9a158d7caca06ef4?pvs=4">huge amount of charge per weight</a>. This is why lithium-ion batteries are useful not just for portable electronics but for powering modes of transportation with limited weight or volume, such as electric cars. </p>
<h2>Battery fires</h2>
<p>However, lithium-ion batteries have risks that AA or AAA batteries don’t. For one, they’re more likely to catch on fire. For example, the number of <a href="https://gothamist.com/news/e-bike-battery-fires-keep-climbing-in-nyc">electric bike battery fires</a> reported in New York City has increased from 30 to nearly 300 in the past five years. </p>
<p>Lots of different issues can cause a battery fire. Poorly manufactured cells could contain defects, such as trace impurities or particles left behind from the manufacturing process, that increase the risk of an internal failure. </p>
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<a href="https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A car in a garage is on fire with the door cracked open, a firefighter carrying a hose runs towards it." src="https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=497&fit=crop&dpr=1 754w, https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=497&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/578754/original/file-20240228-30-b8mmfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=497&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The lithium-ion batteries in electric vehicles have a higher risk of catching on fire when it’s cold out.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/ElectricCarsBatteryFires/0624a4c4cadb4ee0be42d58b8aab0161/photo?Query=ev%20battery%20fire&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=300&digitizationType=Digitized&currentItemNo=0&vs=true&vs=true">Orange County Sheriff’s Department/National Transportation Safety Board via AP</a></span>
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<p>Climate can also affect battery operation. <a href="https://about.bnef.com/electric-vehicle-outlook/">Electric vehicle sales</a> have increased across the U.S., particularly in cold regions such as the Northeast and Midwest, where the frigid temperatures can hinder battery performance. </p>
<p>Batteries contain fluids called electrolytes, and cold temperatures cause fluids to flow more slowly. So, the electrolytes in batteries slow and thicken in the cold, causing the lithium ions inside to move slower. This slowdown can prevent the lithium ions from properly inserting into the electrodes. Instead, they may deposit on the electrode surface and form <a href="https://doi.org/10.1016/j.xcrp.2020.100035">lithium metal</a>. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/G_TCFgEdEGc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The molecules in fluids move slower at colder temperatures – the same thing happens inside batteries.</span></figcaption>
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<p>If too much lithium deposits on the electrode’s surface during charging, it may cause an internal short circuit. This process can <a href="https://theconversation.com/lithium-ion-battery-fires-are-a-growing-public-safety-concern-heres-how-to-reduce-the-risk-209359">start a battery fire</a>.</p>
<h2>Making safer batteries</h2>
<p><a href="https://research.coe.drexel.edu/mem/changlab">My research group</a>, along with many others, is studying how to make batteries that operate more efficiently in the cold. </p>
<p>For example, researchers are exploring swapping out the usual battery electrolyte and replacing it with an alternative electrolyte that doesn’t thicken at cold temperatures. Another potential option is <a href="https://www.washingtonpost.com/climate-solutions/2024/01/19/electric-vehicle-battery-cold/">heating up the battery pack</a> before charging so that the charging process occurs at a warmer temperature. </p>
<p>My group is also investigating new types of batteries beyond lithium ion. These could be battery types that are more stable at wider temperature ranges, types that don’t even use liquid electrolytes at all, or batteries that use sodium instead of lithium. <a href="https://www.technologyreview.com/2023/05/11/1072865/how-sodium-could-change-the-game-for-batteries/">Sodium-ion batteries</a> could work well and cost less, as sodium is a very abundant resource.</p>
<p><a href="https://doi.org/10.1038/s41560-023-01208-9">Solid-state batteries</a> use solid electrolytes that aren’t flammable, which reduces the risk of fire. But these batteries don’t work quite as well as Li-ion batteries, so it’ll take more research to tell whether these are a good option.</p>
<p>Lithium-ion batteries power technologies that people across the country use every day, and research in these areas aims to find solutions that will make this technology even safer for the consumer.</p><img src="https://counter.theconversation.com/content/222571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wesley Chang receives funding from Solid Energy Systems, Inc., Electric Power Research Institute, Drexel University. Wesley Chang consults for The Electrochemical Society. </span></em></p>Electric vehicles are catching on across the US, but they’re also catching on fire in colder regions like the Northeast and Midwest.Wesley Chang, Assistant Professor of Mechanical Engineering and Mechanics, Drexel UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2243312024-03-03T14:27:31Z2024-03-03T14:27:31ZNo, overwintering turtles don’t breathe through their butts: Getting to the bottom of a popular misconception<figure><img src="https://images.theconversation.com/files/579265/original/file-20240301-22-9mghi4.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C1000%2C544&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Northern map turtles hibernate underwater during the winter.</span> <span class="attribution"><span class="source">(G. Bulté)</span></span></figcaption></figure><p>On a crisp February day, a filmmaker and I were walking across the 45-centimetre-thick ice covering Opinicon Lake, a small lake in eastern Ontario. We were heading for a very special spot where hundreds of <a href="https://ontarionature.org/programs/community-science/reptile-amphibian-atlas/northern-map-turtle/">northern map turtles</a> coalesce every year to spend the winter months. The filmmaker stuck a camera attached to a long pole in holes drilled through the ice to capture turtles for a nature documentary.</p>
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Read more:
<a href="https://theconversation.com/northern-map-turtles-survive-cold-winter-conditions-by-staying-active-under-ice-195050">Northern map turtles survive cold winter conditions by staying active under ice</a>
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<p>As we spotted our first turtles on the monitor, the filmmaker confided that he would like to get a shot of a turtle’s rear end. Strange as it sounds, this request didn’t surprise me. The filmmaker wanted to show overwintering turtles breathing with their butts. I had disappointing news for him.</p>
<p>I can’t blame the filmmaker for expecting to observe this bizarre form of respiration in our overwintering turtles. A quick Google search turns up several stories about butt-breathing turtles, many from credible sources. </p>
<p>A handful of turtles <em>can</em> breathe through their butts — it’s called cloacal gas exchange — but they are distant relatives of the North American species often claimed to do so in winter. But as far as scientific evidence goes, North American turtles overwintering in ice-covered water bodies don’t survive by breathing through their butts.</p>
<h2>Mysterious cloacal sacs</h2>
<p>In turtles, as in other reptiles (<a href="https://evolution.berkeley.edu/what-are-evograms/the-origin-of-birds/">including birds</a>), the reproductive and digestive tracts merge into a single pipe called the cloaca. Some species of turtles have a pair of sacs sprouting from their cloacal passage. These sacs, called cloacal bursae, are different from the single urinary bladder. </p>
<p>The function of cloacal bursae has baffled anatomists and physiologists for more than two centuries. In 1998, C. Barker Jørgenson published a <a href="https://www.cambridge.org/core/journals/biological-reviews/article/abs/role-of-urinary-and-cloacal-bladders-in-chelonian-water-economy-historical-and-comparative-perspectives/010D5928EF15B4A15C9589034B29EE14">historical overview</a> of the research on these structures since their discovery. </p>
<p>According to Jørgensen, the anatomist Hans Gadow was the first to invoke a respiratory function for the sacs in a <a href="https://www.biodiversitylibrary.org/item/268756#page/9/mode/1up">1901 book called <em>Amphibia and Reptiles</em></a>. Gadow wrote that “these sacs, which have highly vascularised walls, are incessantly filled and emptied with water through the vent, and act as important respiratory organs.” </p>
<p>This suggestion of a respiratory function, Jørgenson pointed out, became widely accepted without any supporting evidence.</p>
<h2>Butt-breathing turtles</h2>
<p>Evidence of cloacal respiration did eventually come from research on Australian freshwater turtles, such as the <a href="http://dx.doi.org/10.2307/1447197">saw-shelled turtle</a> and the <a href="http://dx.doi.org/10.7882/AZ.2010.016">white-throated snapping turtle</a>. The inner surface of the bursae in these species is densely lined with tiny finger-like projections called papillae which are themselves packed with tiny blood vessels. The papillae appear to function like gills. </p>
<p>A turtle pumps water into its cloaca and the oxygen dissolved in the water is absorbed by the blood vessels in the papillae while carbon dioxide diffuses from the blood to the water. The turtle then expels the stale water out of its cloaca and pumps fresh water back in. Even when the water is warm and the demand for oxygen high, some of these Australian turtles remain submerged for hours, relying on their cloacal bursae to get the oxygen they need.</p>
<p>These findings are remarkable, but North American turtles do not have the same cloacal superpowers.</p>
<h2>Distant cousins</h2>
<p>All living turtles fall in one of two groups: the <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cryptodira">hidden-necked</a> and the <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/pleurodira">side-necked</a>. The groups are named after the way the necks of their members bends.</p>
<p>More importantly, these two groups represent two branches in the turtle family tree. The Australian cloacal breathers are on the side-necked branch. These turtles are only found in the southern hemisphere. </p>
<p>All turtles living in the cold northern hemisphere are on the hidden-necked branch. The hidden-necked and side-necked branches split around <a href="https://doi.org/10.1073/pnas.2012215118">200 million years ago</a>. </p>
<p>Lots of evolution can happen in 200 million years. For context, placental mammals like us parted ways from our egg-laying cousins like the duck-billed platypus about 166 million years ago. </p>
<p>Side-necked and hidden-necked turtles have amassed many differences during their 200-million-years-long journey apart, despite their physical similarities. Some of these differences appear to be in their cloaca. </p>
<p>To date, there is no evidence that hidden-necked turtles — like painted turtles, sliders, map turtles and snapping turtles — <a href="https://www.proquest.com/docview/1981235671">sport the gas exchange hardware of their distant side-necked cousins</a>.</p>
<p>It is worth noting that not all turtles have cloacal bursae. For instance, the <a href="https://ontarionature.org/programs/community-science/reptile-amphibian-atlas/spiny-softshell/">spiny softshell</a> and the <a href="https://ontarionature.org/programs/community-science/reptile-amphibian-atlas/eastern-musk-turtle/">common musk turtle</a> lack them. </p>
<p>Both species range as far north as southern Canada where they spend several months under the ice every year.</p>
<h2>Breathing through the winter</h2>
<p>The first published suggestion that overwintering turtles employ cloacal gas exchange appeared in 1958. Herpetologists Hobart Smith and Louis James published a review on cloacal bursae, where they wrote: “It is our opinion that the presence of bursae indicates a capacity to survive under water at low temperatures for long periods.” </p>
<p>In a followup study, <a href="https://archive.org/details/MiscellaneaN178/mode/2up">published in 1961</a>, Smith experimentally tested the gas exchange hypothesis and failed to convincingly demonstrate a respiratory function for the bursae in several North American species known to overwinter in water. Successive attempts have showed no, or a minute amount of, gas exchange within the cloaca. </p>
<p>The most recent test of cloacal gas exchange in a hidden-necked turtle was led by the late physiologist Donald C. Jackson, author of <a href="https://www.hup.harvard.edu/books/9780674072305"><em>Life in a Shell: A Physiologist’s View of a Turtle</em></a>. In this 2004 study, Jackson and his collaborators examined <a href="http://dx.doi.org/10.1016/j.cbpb.2004.09.005">gas exchange in painted turtles</a> submerged in cold water.</p>
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<a href="https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="two turtles on a rock" src="https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579269/original/file-20240301-48028-7ibytw.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>
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<span class="caption">Painted turtles can survive for months without oxygen.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>Painted turtles, found throughout North America, have one of the longest overwintering periods of any aquatic turtles. Although they can survive for <a href="https://doi.org/10.1113/jphysiol.2002.024729">months without oxygen</a>, they can breathe underwater when oxygen is present. The physiologists experimentally manipulated the ability of painted turtles to breathe through their skin, mouth and cloaca to figure out which of these body parts are involved in gas exchange. </p>
<p>The researchers found no evidence that aquatic gas exchange took place in the cloaca, but showed that it was the turtles’ skin that performed this function.</p>
<h2>Hot air</h2>
<p>It is ironic that the one species in which cloacal gas exchange has been thoroughly rejected on morphological and physiological grounds is often used as the poster child for winter butt-breathing. The image of a turtle using its butt to breathe while locked under the ice for months is appealing, but as far as scientific evidence goes, it is nothing but hot air.</p>
<p>The notion that cloacal gas exchange helps North American turtles survive long winters trapped under the ice is pervasive in pop science, but to date, there is no solid evidence that hidden-necked turtles use cloacal gas exchange. The skin and mouth lining are where gas exchange happens during winter hibernation.</p>
<p>As for the cloacal bursae, their function in hidden-necked turtles remains unclear, but they may help control <a href="https://doi.org/10.1126/science.166.3913.1649">buoyancy in some species</a>.</p><img src="https://counter.theconversation.com/content/224331/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Grégory Bulté 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>A phenomenon observed in a small group of organisms cannot always be generalized across a species — contrary to popular belief, overwintering turtles don’t breathe through their butts.Grégory Bulté, Instructor, Ecology and Evolutionary Biology, Carleton UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2228512024-02-26T13:38:23Z2024-02-26T13:38:23ZHow is snow made? An atmospheric scientist describes the journey of frozen ice crystals from clouds to the ground<figure><img src="https://images.theconversation.com/files/576863/original/file-20240220-22-v6kq2o.jpg?ixlib=rb-1.1.0&rect=22%2C5%2C3764%2C2055&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some parts of the U.S. see well over 100 inches (2.5 meters) of snow per year.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/downhill-sledging-royalty-free-image/488074477?phrase=sledding+in+snow">Edoardo Frola/Moment Open via Getty Images</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">
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<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>
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<blockquote>
<p><strong>How is snow made? – Tenley, age 7, Rockford, Michigan</strong></p>
</blockquote>
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<p>The thought of snow can conjure up images of powdery slopes, days out of school or hours of shoveling. For millions of people, it’s an inevitable part of life – but you may rarely stop to think about what made the snow.</p>
<p>As a <a href="https://www.eaps.purdue.edu/people/profile/ablanch.html">professor of atmospheric and planetary sciences</a>, <a href="https://scholar.google.com/citations?user=xClwTzUAAAAJ&hl=en&oi=ao">I’ve studied how ice crystals floating</a> in the sky become the snow that coats the ground.</p>
<p>It all starts in the clouds.</p>
<p>Clouds form when air near the Earth’s surface rises. This happens when sunlight warms the ground and the air closest to it, just like the Sun can warm your face on a cold winter day. </p>
<p>As the slightly warmer air rises, it cools – and the water vapor in that rising air condenses to form liquid water or water ice. From that, <a href="https://climatekids.nasa.gov/cloud-formation/#:%7E">a cloud is born</a>. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/Cf6El0mI1fM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">You need just two things for snow to form.</span></figcaption>
</figure>
<h2>Endless pathways</h2>
<p>When temperatures are well below freezing on the ground, the clouds are primarily made of water in the form of ice. Under 32 degrees Fahrenheit – that’s zero degrees Celsius – the frozen water molecules arrange themselves into a hexagonal, or six-sided, crystalline shape. As ice crystals grow and clump together, they become too heavy to stay aloft. With the help of gravity, they begin to fall back down through and eventually out of the cloud.</p>
<p>What these ice crystals look like once they reach land depends on the temperature and humidity of the atmosphere. As the humidity – or the amount of water vapor in the cloud – increases, some of the ice crystals will grow intricate arms at their six corners. That branching process creates what we think of as the <a href="https://www.timeforkids.com/g2/snowflake-science-g2-5-plus/?rl=en-500">characteristic shapes of snowflakes</a>. </p>
<p>No two ice crystals take the same path through a cloud. Instead, every ice crystal experiences different temperatures and humidities as it travels through the cloud, whether going up or down. The ever-changing conditions, combined with the infinite number of paths the crystals could take, result in a unique growth history and crystalline shape for each and every snowflake. This is why you’ve likely heard the saying, “<a href="https://www.willyswilderness.org/post/no-two-snowflakes-are-alike-it-s-actually-true">No two snowflakes are exactly alike</a>.” </p>
<p>Many times, these differences are visible to the naked eye; sometimes a microscope is required to tell them apart. Either way, scientists who study clouds and snow can examine a snowflake and ultimately understand the path it took through the cloud to land on your hand. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Snow crystals attached to a window." src="https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=636&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=636&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=636&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=799&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=799&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576901/original/file-20240220-23-n5kry6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=799&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It takes approximately one hour for a snowflake to reach the ground.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/snowflakes-royalty-free-image/158720307?phrase=snowflakes">LiLi/iStock via Getty Images Plus</a></span>
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<h2>Liquid water as glue</h2>
<p>When snow falls from the sky, you don’t usually see individual ice crystals, but rather clumps of <a href="https://scied.ucar.edu/learning-zone/storms/snowflakes">crystals stuck together</a>. One way ice crystals aggregate is through what’s called mechanical interlocking. When ice crystals bump into each other, crystals with intricate branches and arms intertwine and stick to others. </p>
<p>This mechanism is the main sticking process in cooler, drier conditions – what people call a “<a href="https://compuweather.com/the-important-difference-between-wet-snow-and-dry-snow/">dry snow</a>.” The result is a snow perfect for skiing, and easily picked up by the wind, but that won’t hold together when formed into a snowball. </p>
<p>The second way to stick ice crystals together is to warm them up a bit. When ice crystals fall through a region of cloud or atmosphere where the temperature is slightly above freezing, the edges of the crystals start to melt. Just a tiny bit of liquid water allows ice crystals that bump into each other to stick together very efficiently, almost like glue. </p>
<p>The result? Large clumps of ice crystals falling from the sky, what we call a “<a href="https://www.acurite.com/blog/types-of-snow.html">wet snow</a>” – less than ideal for hitting the slopes but perfect for building a snowman. </p>
<p>Snow formed in clouds typically reaches the ground only in winter. But almost all clouds, no matter the time of year or location, <a href="https://scijinks.gov/clouds/">contain some ice</a>. This is true even for clouds in warm tropical regions, because the atmosphere above us is much colder and can reach temperatures below freezing even on the warmest of days. In fact, scientists who study weather discovered that clouds containing ice produce more rain than those that don’t contain any ice at all.</p>
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<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/222851/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexandria Johnson receives funding from NASA. </span></em></p>There are an infinite number of paths an ice crystal can take before you touch it.Alexandria Johnson, Professor of Atmospheric and Planetary Sciences, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2223292024-02-20T22:35:26Z2024-02-20T22:35:26ZHow global warming is reshaping winter life in Canada<p>As we begin to emerge out of yet another mild winter, Canadians are once again being reminded of just how acutely global warming has changed Canada’s winter climate. </p>
<p>The impacts of this mild winter were felt across the country and touched all aspects of winter culture. From <a href="https://montreal.ctvnews.ca/quebec-winter-carnival-closes-palais-de-bonhomme-due-to-warm-weather-1.6764453">melting ice castles at Québec’s winter carnival</a>, to a dismal lack of snow at <a href="https://www.theglobeandmail.com/canada/british-columbia/article-bc-ski-resorts-struggle-with-lack-of-snow-as-warm-weather-persists/">many Western Canada ski resorts</a>, seemingly no part of Canada was unaffected. But the change that will likely be felt most keenly by many Canadians is the <a href="https://iopscience.iop.org/article/10.1088/1748-9326/7/1/014028">loss of a reliable outdoor skating season</a>.</p>
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<strong>
Read more:
<a href="https://theconversation.com/cop28-why-we-need-to-break-our-addiction-to-combustion-218019">COP28: Why we need to break our addiction to combustion</a>
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<p>For the second year running, <a href="https://ncc-ccn.gc.ca/places/rideau-canal-skateway">Ottawa’s Rideau Canal Skateway</a> was closed for what should be the peak of the skating season. In 2022-2023, the Skateway did not open at all for the first time ever. This winter, a portion of the Skateway opened briefly in January, but continuing mild temperatures forced a closure again after only four days of skating. In Montréal, <a href="https://www.patinermontreal.ca/f/paysagee/patin-libre/sports-dequipe">fewer than 40 per cent of the city’s outdoor rinks were open</a> in the middle of February.</p>
<p>There is no obvious upside to this story. Outdoor skating in Canada is fast becoming the latest casualty of our failure to confront the reality of the climate crisis.</p>
<h2>On thin ice</h2>
<p>More than a decade ago, our research group published <a href="https://doi.org/10.1088/1748-9326/7/1/014028">our first analysis</a> of how outdoor skating was being affected by warming winter temperatures in Canada. We showed that even as of 2005, there was already evidence of later start dates, and shorter skating seasons across most of the country. </p>
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<figcaption><span class="caption">A report on the management of the Rideau Canal Skateway in 2023, produced by the CBC.</span></figcaption>
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<p>These conclusions were echoed by <a href="https://www.rinkwatch.org">subsequent publications from the RinkWatch project</a>, which has reported <a href="https://doi.org/10.1111/cag.12878">consistent declines in skating season length and quality</a> in many Canadian cities.</p>
<p>Meanwhile in Ottawa, skating days on the <a href="https://rideaucanalskateway.com/">Rideau Canal Skateway</a> have been trending downwards over the last 20 years. In this time, the typical skating season has decreased by almost 40 per cent, a trend that is clearly correlated with increasing winter temperatures over the same period. </p>
<h2>Moving in the wrong direction</h2>
<p>Climate mitigation progress continues to be far too slow. </p>
<p>Global CO2 emissions reached their <a href="https://globalcarbonbudget.org/fossil-co2-emissions-at-record-high-in-2023/">highest level ever recorded in 2023</a>, and average global temperatures have now reached <a href="https://berkeleyearth.org">1.3 C above pre-industrial temperatures</a>. If these trends continue, we are on track to reach 1.5 C — the lower threshold of the Paris Agreement temperature target — in <a href="https://climateclock.net">less than seven years</a>.</p>
<p>In our <a href="https://doi.org/10.1111/cag.12878">2012 paper</a>, we estimated that suitable rink flooding days could disappear across most of southern Canada by mid-century. In <a href="https://doi.org/10.1088/2515-7620/ab8ca8">a more recent analysis of Montréal’s outdoor rinks</a>, we estimated that the number of viable skating days in Montréal could decrease to zero by as early as 2070. </p>
<p>In hindsight, these and other similar projections may have been far too optimistic. In a <a href="https://doi.org/10.1038/nclimate2465">study of Rideau canal skating days published in 2015</a>, the authors projected declining but sustained skating conditions throughout this century, even in a high future emissions scenario. The reality of the past two seasons shows that skating conditions have deteriorated far more quickly than predicted. </p>
<p>Global temperatures in 2023 were the highest ever recorded, as were winter temperatures in December 2023 and January 2024. Since 1950, winter temperatures in Canada have increased by more than 3 C, <a href="https://theconversation.com/2023-was-the-hottest-year-in-history-and-canada-is-warming-faster-than-anywhere-else-on-earth-220997">which is about three times the rate of global warming over this same period</a>. </p>
<p>Outdoor rinks require at least three consecutive very cold days to establish a foundation of ice, followed by enough cold days to maintain a good ice surface. Temperatures above freezing are poorly tolerated by outdoor rinks, and rain is often disastrous. </p>
<p>A few degrees of warming in January and February temperatures can be the difference between a rink that is skatable and one that is not. As winters continue to warm, the case for building and maintaining outdoor municipal rinks will become harder to justify.</p>
<h2>A stark and still changing new reality</h2>
<p>As years go by without any real progress on climate mitigation, it is becoming increasingly difficult to imagine a future in which outdoor rinks will be widely available without artificial refrigeration. Other winter activities will also be affected by changing snow conditions, but outdoor skating will likely be hit first in direct response to warming winter temperatures.</p>
<p>Wayne Gretzky famously <a href="https://gretzky.com/bio.php">learned to skate and play hockey in Branford, Ont. in the 1960s on an outdoor rink built by his father</a>. Reliable winter skating conditions in southern Ontario are already mostly a thing of the past, and are becoming more and more scarce as global warming progresses. It is increasingly unlikely that current and future generations will be able to follow Gretzky’s path. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/could-the-good-news-story-about-the-ecological-crisis-be-the-collective-grief-we-are-feeling-215658">Could the good news story about the ecological crisis be the collective grief we are feeling?</a>
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<p>This reality is both a tragic injustice for many young Canadians and an existential threat to a core aspect of the Canadian winter identity.</p>
<p>Preserving what remains of Canada’s winter skating culture will require that we rapidly step up our efforts to drive down CO2 emissions and stabilize global temperatures. Otherwise, Joni Mitchell’s “<a href="https://genius.com/Joni-mitchell-river-lyrics">river I could skate away on</a>” will become an increasingly wishful dream that soon will exist only in the lyrics of old songs.</p><img src="https://counter.theconversation.com/content/222329/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>H. Damon Matthews receives funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p><p class="fine-print"><em><span>Mitchell Dickau receives funding from the Natural Sciences and Engineering Research Council of Canada. </span></em></p>Global warming is melting away an iconic cornerstone of Canadian culture — outdoor skating.H. Damon Matthews, Professor and Climate Scientist, Department of Geography, Planning and Environment, Concordia UniversityMitchell Dickau, PhD Candidate, Geography, Planning, and Environment Department, Concordia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2208182024-02-02T13:17:06Z2024-02-02T13:17:06ZHow can I get ice off my car? An engineer who studies airborne particles shares some quick and easy techniques<figure><img src="https://images.theconversation.com/files/572255/original/file-20240130-29-7n5wna.jpeg?ixlib=rb-1.1.0&rect=0%2C3%2C1024%2C763&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Condensation and cold combine to create that layer of ice on car windshields in winter. </span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Oblodzone_szyby_samochodu,_zima_2009_%28ubt%29.jpeg">Tomasz Sienicki/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>If you live somewhere that gets cold in the winter, you’ve probably seen cars parked outdoors covered in a thin layer of ice on a chilly morning. But what causes this frost, and how can you get rid of it quickly?</p>
<p>I’m a <a href="https://scholar.google.com/citations?user=xcpTqRYAAAAJ&hl=en">mechanical engineering professor</a> who studies how water vapor interacts with airborne particles under different atmospheric conditions. Frosty windshields are similar to some of the thermodynamic questions I study in the lab, and they’re also a pesky issue that I deal with every winter on my way to work. </p>
<h2>Windshield condensation</h2>
<p>The air in Earth’s atmosphere always contains a certain amount of water vapor, but there’s only so much water vapor the air can hold. Scientists call that limit 100% <a href="https://www.britannica.com/science/humidity">relative humidity</a>. <a href="https://www.weather.gov/arx/why_dewpoint_vs_humidity">The dew point</a> refers to the temperature at which relative humidity reaches 100%. </p>
<p>Wet air has high dew point temperature, while dry air has a low dew point temperature. With each degree drop in temperature, the air gets closer to its dew point temperature – or its water vapor carrying capacity. Any cooling after the dew point temperature has been reached causes <a href="https://sealevel.jpl.nasa.gov/ocean-observation/understanding-climate/air-and-water/">water to condense onto surfaces</a>, or form into fog.</p>
<p>Overnight, car windshields facing the cold dark sky are <a href="https://www.energy.gov/energysaver/principles-heating-and-cooling">radiatively cooled</a>, meaning they release heat out into their surrounding area in the form of visible and invisible light. As air comes in contact with the cold windshield, it can reach its dew point temperature. Then, the water vapor condenses onto the windshield.</p>
<p>When this radiative cooling drops the temperature on the windshield’s surface to <a href="https://www.britannica.com/science/freezing-point">below the freezing point</a>, 32 degrees Fahrenheit (zero degrees Celsius), the layer of condensed water on the windshield turns to frost. </p>
<h2>Defrosting your car</h2>
<p>To defrost an icy windshield, you can follow a few different approaches, some of which take longer and require more effort than others.</p>
<p>One option is to directly spray a small amount of warm liquid on the layer of frost to help melt it. For this approach to work, the spray liquid must be hot enough to raise the overall temperature of the frost layer to above <a href="https://pubchem.ncbi.nlm.nih.gov/ptable/melting-point/">the melting point</a>. But the temperature can’t be way hotter than the temperature of the glass or you’ll crack your windshield. </p>
<p>A better way to melt the ice without damaging your car is to spray your windows with a warm liquid that has a lower freezing point than water, like a mixture of rubbing alcohol and water. This warm mixture will melt the frost layer without heating up the glass, and the resulting liquid layer on the windshield will have a lower freezing point than water. It will remain liquid, and you can wipe it away with your windshield wipers. </p>
<p>Similar alcohol and water mixtures – <a href="https://www.britannica.com/science/glycol">glycol, for example</a> – are commonly used to maintain the <a href="https://mayekawa.es/images/pdf/ASHRAE_ENERGY_EFFICIENT_ICE_RINK_2015.pdf">icy surface of skating rinks</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/A2Kl04dHm4k?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A mix of water and rubbing alcohol can melt ice on your windshield.</span></figcaption>
</figure>
<p>This approach can melt the ice reasonably quickly and easily, without too much effort. You don’t even have to turn on your car. </p>
<p>If you have a little more time, you can start the car and run <a href="https://www.lifewire.com/how-do-car-defrosters-work-534663">the air defrost system</a> to blow hot air – aim for above 80 degrees Fahrenheit – onto the inside of the windshield. This warms the windshield and will eventually melt the frost layer. Once you see some melting, you can use the windshield wipers to wipe the rest of the ice away. </p>
<p>This option consumes more energy, as your car will have to heat up the windshield, but it doesn’t require you to do much. </p>
<p>Using the defrost system to blow warm air toward the windshield will also help to clear the inside of the windshield when it gets fogged up from condensation. Otherwise, if it’s dry outside, you can also clear up windshield fog by opening the car window and letting in outside air.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A person wearing a winter jacket uses a scraper on their frost-covered windshield." src="https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=497&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=497&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572257/original/file-20240130-23-r3f30r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=497&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">You can use an ice scraper to break the ice on your windshield into chunks, so your wiper blades can clean them off.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/ColoradoWeather/c8d71e03eb5144afad7c01e72eccf5c2/photo?Query=windshield%20wipers&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=296&digitizationType=Digitized&currentItemNo=17&vs=true&vs=true">AP Photo/David Zalubowski</a></span>
</figcaption>
</figure>
<p>If you are in a hurry or need some exercise, you can use an ice scraper to break up frost on your windshield, creating smaller islands of ice. The windshield wiper can then mechanically dislodge the chunks by moving them around and melting them. This requires more energy on your part, but it doesn’t require much from your car.</p>
<p>If you have a relaxed start to your day, you can let the Sun warm the windshield and slowly melt the frost layer for you. This technique saves energy in every way imaginable.</p><img src="https://counter.theconversation.com/content/220818/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Suresh Dhaniyala 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>When you’re running late in the winter, you don’t want to have to spend time scraping frost off your windshield. Try some expert-recommended techniques instead.Suresh Dhaniyala, Bayard D. Clarkson Distinguished Professor of Mechanical and Aeronautical Engineering, Clarkson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2217092024-01-30T13:35:00Z2024-01-30T13:35:00ZDog care below freezing − how to keep your pet warm and safe from cold weather, road salt and more this winter<figure><img src="https://images.theconversation.com/files/571552/original/file-20240125-22431-dyxkh4.jpg?ixlib=rb-1.1.0&rect=21%2C0%2C4715%2C3067&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dogs get cold in the winter too, but there are things pet owners can do to help them feel comfortable. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/NYColdWeather/de8019836ce9475e91bf816b1401fa3b/photo?Query=dog%20in%20snow&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=310&digitizationType=Digitized&currentItemNo=NaN&vs=true&vs=true">AP Photo/David Duprey</a></span></figcaption></figure><p>Time outside with your dog in the spring, summer and fall can be lovely. Visiting your favorite downtown café on a cool spring morning, going to a favorite dog park on a clear summer evening or going on walks along a river when the leaves are changing color are all wonderful when the weather is favorable. But in much of the country, when winter rolls around, previously hospitable conditions can <a href="https://theconversation.com/is-winter-miserable-for-wildlife-108734">quickly turn chilly and dangerous</a> for people and pups alike. </p>
<p>Winter brings some unique challenges for dog owners, since dogs still need activity and socialization during colder seasons. Studies have shown that dog owners are almost 50% less likely to walk their dogs <a href="https://doi.org/10.3390/ani11113302">when the weather gets cold</a>. Knowing the basics of winter safety is critical to maintaining a healthy lifestyle for your dog. </p>
<p>I am an <a href="https://www.vetmed.ucdavis.edu/faculty/erik-olstad">assistant professor</a> at the University of California Davis School of Veterinary Medicine who weathered polar vortexes with my dog while living in Michigan early in my career. While I’ve since moved to sunny California, I’ve seen how quickly frigid temperatures can turn dangerous for pets.</p>
<h2>Breed and age differences</h2>
<p>Not all dogs have the same abilities to deal with cold weather. A short-coated dog like a Chihuahua is much more susceptible to the dangers of cold weather than a thick-coated husky. When the weather dips below 40 degrees Fahrenheit (4 degrees Celsius), the well-acclimated husky may be comfortable, whereas the Chihuahua would shiver and be at risk of hypothermia. </p>
<p>Additionally, if your dog is used to warm weather, but you decide to move to a colder region, the dog will need time to acclimate to that colder weather, even if they have a thick coat. </p>
<p>Age also affects cold-weather resilience. Puppies and elderly dogs can’t withstand the chill as well as other dogs, but every dog is unique – each may have individual health conditions or physical attributes that make them more or less resilient to cold weather. </p>
<h2>When is my dog too cold?</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A small dog wearing a thick, fluffy red coat." src="https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571548/original/file-20240125-29-dudlyh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dog jackets can keep pets warm in the cold.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/WinterWeatherTexas/b82392611da74eb69750dd2a12c73817/photo?Query=dog%20jacket&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=320&digitizationType=Digitized&currentItemNo=1&vs=true&vs=true">AP Photo/David J. Phillip</a></span>
</figcaption>
</figure>
<p>Pet owners should be able to recognize the symptoms of a dog that is getting too cold. Dogs will shiver, and some may vocalize or whine. Dogs may resist putting their feet down on the cold ground, or burrow, or try to find warmth in their environment when they are uncomfortable. </p>
<p>Just like people, <a href="https://vcahospitals.com/know-your-pet/frostbite-in-dogs">dogs can get frostbite</a>. And just like people, the signs can take days to appear, making it hard to assess them in the moment. The most common sites for frostbite in dogs are their ears and the tips of their tails. Some of the initial signs of frostbite are skin discoloring, turning paler than normal, or purple, gray or even black; red, blistered skin; swelling; pain at the site; <a href="https://www.britannica.com/science/ulcer">or ulceration</a>.</p>
<p>Other <a href="https://vcahospitals.com/know-your-pet/frostbite-in-dogs">serious signs of hypothermia</a> include sluggishness or lethargy, and if you observe them, please visit your veterinarian immediately. A good rule to live by is if it is too cold for you, it is too cold for your dog. </p>
<p>Getting your dog a <a href="https://www.cnn.com/cnn-underscored/pets/best-winter-dog-coats-jackets">sweater or jacket</a> and <a href="https://www.akc.org/expert-advice/vets-corner/protect-dogs-paws-snow-ice-salt/">paw covers</a> can provide them with protection from the elements and keep them comfortable. Veterinarians also recommend closely monitoring your dog and limiting their time outside when the temperature nears the freezing point or drops below it.</p>
<h2>Road salt dangers</h2>
<p>Road salt that treats ice on streets and sidewalks <a href="https://www.cbc.ca/news/canada/kitchener-waterloo/ice-salt-toxic-for-pets-1.5020088">can also harm dogs</a>. When dogs walk on the salt, the sharp, rough edges of the salt crystals can irritate the sensitive skin on their paws. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A fluffy dog sits in the snow wearing two cloth, polka dot paw covers." src="https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=559&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=559&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=559&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=703&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=703&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571542/original/file-20240125-19-4pvz2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=703&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Paw covers for dogs can keep their feet warm and protected from road salt.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PetsColdFeet/711807120a854c5787e5dfdaba307a44/photo?Query=dog%20boots&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=379&digitizationType=Digitized&currentItemNo=12&vs=true&vs=true">AP Photo/Jim Cole</a></span>
</figcaption>
</figure>
<p>Dogs will often lick their feet when they’re dirty, wet or irritated, and if they ingest any salt doing that, they may face GI upset, dehydration, kidney failure, seizures or even death. Even small amounts of pure salt can <a href="https://www.petpoisonhelpline.com/pet-tips/my-dog-ate-road-salt-will-they-be-okay/">disrupt critical body functions</a> in dogs.</p>
<p>Some companies make pet-safe salt, but in public it can be hard to tell what type of salt is on the ground. After walking your dog, wash off their feet or boots. You can also keep their paw fur trimmed to prevent snow from balling up or salt collecting in the fur. Applying a thin layer of petroleum jelly or <a href="https://www.akc.org/expert-advice/lifestyle/how-to-make-your-own-paw-balm-for-winter/">paw pad balm</a> to the skin of the paw pads can also help protect your pet’s paws from irritation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A snowy sidewalk covered in tiny chunks of salt." src="https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=473&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=473&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571553/original/file-20240125-28-o148ri.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=473&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Road salt can be harmful to dogs’ sensitive paws.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Road_salt_in_Moscow_01.jpg">Stolbovsky/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Antifreeze risks</h2>
<p><a href="https://www.britannica.com/science/antifreeze-chemical-substance">Antifreeze, or ethylene glycol</a>, is in most vehicles to prevent the fluids from freezing when it gets cold out. Some people pour antifreeze into their toilets when away from their home to prevent the water in the toilet from freezing.</p>
<p>Antifreeze is an exceptionally dangerous chemical to dogs and cats, as it tastes sweet but can be deadly when ingested. If a pet ingests even a small amount of antifreeze, the substance causes a chemical cascade in their body that results in severe kidney damage. If left untreated, the pet may have <a href="https://www.petpoisonhelpline.com/pet-owner-blog/antifreeze-poisoning/">permanent kidney damage or die</a>.</p>
<p>There are safer antifreeze options on the market that use ingredients other than ethylene glycol. If your dog ingests antifreeze, please see your veterinarian immediately for treatment.</p>
<p>When temperatures dip below freezing, the best thing pet owners can do is keep the time spent outside as minimal as possible. Try some <a href="https://www.akc.org/expert-advice/lifestyle/great-indoor-games-to-play-with-your-dog/">indoor activities</a>, like hide-and-seek with low-calorie treats, fetch or even an interactive obstacle course. Food puzzles can also keep your dog mentally engaged during indoor time.</p>
<p>Although winter presents some unique challenges, it can still be an enjoyable and healthy time for you and your canine companion.</p><img src="https://counter.theconversation.com/content/221709/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erik Christian Olstad 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>Dogs might have furry coats, but they can still get cold when the temperature drops.Erik Christian Olstad, Health Sciences Assistant Professor of Clinical Veterinary Medicine, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2219562024-01-25T13:17:10Z2024-01-25T13:17:10ZDiagnosing ‘warming winter syndrome’ as summerlike heat sweeps into central and eastern US<figure><img src="https://images.theconversation.com/files/578072/original/file-20240226-22-sj8mc9.jpg?ixlib=rb-1.1.0&rect=0%2C43%2C7333%2C4830&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chicago topped 70 degrees on Feb. 26, 2024. That's not normal.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/WarmWeatherChicago/e74246d1976f4048a494c6cb1ce2c0dd/photo">AP Photo/Charles Rex Arbogast</a></span></figcaption></figure><p>One of the most robust measures of Earth’s changing climate is that winter is warming more quickly than other seasons. The cascade of changes it brings, including ice storms and rain in regions that were once reliably below freezing, are symptoms of what I call “warming winter syndrome.”</p>
<p>Wintertime warming represents the global accumulation of heat. During winter, direct heat from the Sun is weak, but storms and <a href="https://theconversation.com/extreme-cold-still-happens-in-a-warming-world-in-fact-climate-instability-may-be-disrupting-the-polar-vortex-221276">shifts in the jet stream bring warm air</a> up from more southern latitudes into the northern U.S. and Canada. As <a href="https://climate.copernicus.eu/copernicus-2023-hottest-year-record">global temperatures</a> and <a href="https://climatereanalyzer.org/clim/sst_daily/">the oceans warm</a>, that stored heat has an influence on both temperature and precipitation. </p>
<p>The U.S. has been feeling this warming in the winter of 2023-24, the <a href="https://www.ncei.noaa.gov/news/national-climate-202402">warmest on record</a> for the Lower 48 states. </p>
<p>Snowfall has been <a href="https://twitter.com/NWSEastern/status/1757548891602358455">below average</a> in much of the country. On the Great Lakes, the ice cover has been at <a href="https://www.climate.gov/news-features/event-tracker/ice-coverage-nearly-nonexistent-across-great-lakes-historical-peak">record lows</a>. Late February saw a wave of <a href="https://twitter.com/NWS/status/1762158623793233989">summerlike temperatures</a> spread up into the central and eastern U.S., along with <a href="https://www.accuweather.com/en/severe-weather/severe-storms-with-nocturnal-tornado-risk-to-blitz-over-a-dozen-states/1625378">dangerous thunderstorms</a> and wildfires, including <a href="https://theconversation.com/texas-fires-with-over-1-million-acres-of-grassland-burned-cattle-ranchers-face-struggles-ahead-to-find-and-feed-their-herds-224840">Texas’ largest on record</a>. And forecasters expected <a href="https://graphical.weather.gov/sectors/conusLoop.php#tabs">another above-average warm spell in early March</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571278/original/file-20240124-21-v3590w.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The average lowest annual temperature, which affects where certain plants can grow, has shifted over the past half-century, reflecting the changing freezing line across the U.S.</span>
<span class="attribution"><a class="source" href="https://www.climatecentral.org/climate-matters/shifting-planting-zones-2023">Climate Central</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The longer warming trend is evident in changes to growing seasons, reflected in recent updates to plant hardiness zones printed on the <a href="https://planthardiness.ars.usda.gov/">back of seed packages</a>. These maps show the northward and, sometimes, westward movement of freezing temperatures in eastern North America. </p>
<h2>Ice storms and wet snow</h2>
<p>I <a href="https://scholar.google.com/citations?user=viGxwOwAAAAJ&hl=en">study the impact of global warming</a> and have documented changes to the climate and weather over the decades.</p>
<p>On average, <a href="https://nca2023.globalchange.gov/chapter/2/">freezing temperatures are moving</a> northward and, along the Atlantic coast, toward the interior of the continent. For individual storms, the transition to freezing temperatures even in the dead of winter can now be as far north as Lake Superior and southern Canada in places where, 50 years ago, it was reliably below freezing from early December through February.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two bar charts and a bell curve show the shifting average temperatures to more Januaries above freezing in recent decades." src="https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=290&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=290&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=290&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=365&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=365&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571354/original/file-20240125-23-x46q84.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">In northwest Wisconsin, along Lake Superior, there were no Januarys in the 1951-1980 time frame in which the average high temperature was even close to exceeded freezing. That has changed in recent years.</span>
<span class="attribution"><a class="source" href="https://www.ncei.noaa.gov/access/monitoring/dyk/us-climate-divisions#grdd_">Omar Gates/GLISA</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>When temperatures are close to the freezing point, water can be rain, snow or ice. Regions on the colder side, which historically would have been below freezing and snowy, are seeing an <a href="https://glisa.umich.edu/freezing-rain/">increase in ice storms</a>. </p>
<p>The character of snow also changes near the freezing line. When the temperature is well below freezing, the snow is dry and fluffy. Near freezing, snow has big, wet, heavy flakes that turn roads into slush and stick on tree branches and bring down power lines.</p>
<p>Because the climate in which snowstorms are forming is warmer due to global accumulation of heat, and wetter because of more evaporation and warmer air that can hold more moisture, individual snowstorms can also result in <a href="https://www.washingtonpost.com/weather/2019/11/26/with-climate-change-washington-may-have-entered-era-more-blockbuster-snowstorms-less-snow-overall/">more intense snowfalls</a>. However, as temperatures get warmer in the future, the scales will tilt toward rain, and the <a href="https://glisa.umich.edu/resources-tools/climate-impacts/lake-effect-snow-in-the-great-lakes-region/">total amount of snow</a> will decrease.</p>
<p><iframe id="mRX0t" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/mRX0t/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Indeed, on the warmer side of the freezing line, winter rain is already <a href="https://glisa.umich.edu/resources-tools/climate-impacts/lake-effect-snow-in-the-great-lakes-region/">becoming the dominate type of precipitation</a>, a trend that is expected to continue. With the warmer oceans as a major source of moisture, the already wet eastern U.S. can expect <a href="https://nca2023.globalchange.gov/chapter/2/">more winter precipitation over the next 30 years</a>. Looking to the future, soggy wet winters are more likely.</p>
<h2>Disaster and water planning gets harder</h2>
<p>For communities, planning for water supplies and extreme weather gets more complicated in a rapidly changing climate. Planners can’t count on the weather 30 years in the future being the same as weather today. It’s changing too quickly.</p>
<p>In many places, snow will not persist as late into spring. In regions like California and the Rockies that rely on the snowpack for water through the year, those supplies will <a href="https://nca2023.globalchange.gov/chapter/front-matter/">become less reliable</a>.</p>
<p>Rain falling on snowpack can also speed up melting, trigger flooding and change the flows of creeks and rivers. This shows up in changing <a href="https://theconversation.com/climate-change-is-driving-rapid-shifts-between-high-and-low-water-levels-on-the-great-lakes-118095">runoff patterns in the Great Lakes</a>, and it led to <a href="https://weather.com/news/weather/video/rain-melting-snow-tidal-water-bring-flooding-to-east-coast">flooding on the East Coast</a> in January 2024.</p>
<p>For road planners, the rate of freeze-thaw cycles that can damage roads will increase during winters in many regions unaccustomed to such quick shifts.</p>
<figure class="align-center ">
<img alt="A satellite image shows open water on the western shores the Great Lakes and storms forming to dump snow on the eastern shores." src="https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=577&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=577&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=577&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=725&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=725&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571288/original/file-20240124-29-okndmd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=725&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A lake-effect snowstorm in 2020 shows how cold, dry air passing over the Great Lakes picks up moisture and heat, becoming snow on the other side.</span>
<span class="attribution"><a class="source" href="https://en.m.wikipedia.org/wiki/File:Lake_Effect_Snow_on_Earth.jpg">NASA</a></span>
</figcaption>
</figure>
<p>An especially interesting effect happens in the Great Lakes. Already, the <a href="https://research.noaa.gov/2024/01/18/why-low-ice-coverage-on-the-great-lakes-matters/">Great Lakes do not freeze as early</a> or as completely as in the past. This has large effects on the famous lake-effect precipitation zones.</p>
<p>With the lakes not frozen, more water evaporates into the atmosphere. In places where the wintertime air temperature is still below freezing, <a href="https://glisa.umich.edu/resources-tools/climate-impacts/lake-effect-snow-in-the-great-lakes-region/">lake-effect snow is increasing</a>. The Buffalo, New York, region saw <a href="https://theconversation.com/what-causes-lake-effect-snow-like-buffalos-extreme-storms-194953">6 feet of snow</a> from one lake-effect storm in 2022. As the air temperature flirts with the freezing line, these events are more likely to be rain and ice than snow.</p>
<p>These changes <a href="https://theconversation.com/extreme-cold-still-happens-in-a-warming-world-in-fact-climate-instability-may-be-disrupting-the-polar-vortex-221276">don’t mean cold is gone for good</a>. There will be occasions when Arctic air dips down into the U.S. This <a href="https://www.wilx.com/2024/01/24/fog-rain-wednesday-todays-headlines/">can cause flash freezing</a> and fog when warm wet air surges back over the frozen surface.</p>
<h2>Enormous consequences for economies</h2>
<p>What we are experiencing in warming winter syndrome is a consistent and robust set of symptoms on a fevered planet. </p>
<p>Novembers and Decembers will be milder; Februarys and Marches will be more like spring. Wintry weather will become more concentrated around January. There will be unfamiliar variability with snow, ice and rain. Some people may say these changes are great; there is less snow to shovel and heating bills are down.</p>
<figure class="align-center ">
<img alt="People walk with umbrellas in freezing rain in New York in January 2024." src="https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&rect=0%2C2%2C1917%2C1270&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571457/original/file-20240125-21-uuw03m.jpeg?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">Rain or snow? As global temperatures rise, cities accustomed to snowy winters will see more rain and ice storms during the winter months.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-walk-through-light-snow-in-manhattan-as-new-york-news-photo/1945522082">Spencer Platt/Getty Images</a></span>
</figcaption>
</figure>
<p>But on the other side, <a href="https://www.freep.com/in-depth/news/local/michigan/2021/01/03/michigan-winter-festivals-climate-change/3954384001/">whole economies are set up for wintertime</a>, many <a href="https://www.climatehubs.usda.gov/sites/default/files/Chill%20Hours%20Ag%20FS%20_%20120620.pdf">crops rely on cool winter temperatures</a>, and many farmers rely on freezing weather to control pests. Anytime there are changes to temperature and water, the <a href="https://www.wbez.org/stories/less-ice-on-the-great-lakes-due-to-warmer-winters/af180e73-78ac-4c64-acd5-d7118c46f89c">conditions in which plants and animals thrive are altered</a>. </p>
<p>These changes, which affect <a href="https://theconversation.com/how-climate-change-threatens-the-winter-olympics-future-even-snowmaking-has-limits-for-saving-the-games-177040">outdoor sports and recreation</a>, <a href="https://glisa.umich.edu/resources-tools/climate-impacts/fish-wildlife/">commercial fisheries</a> and agriculture, <a href="https://nca2023.globalchange.gov/chapter/11">have enormous consequences</a> not only to the ecosystems but also to our relationship to them. In some instances, traditions will be lost, such as ice fishing. Overall, people just about everywhere will have to adapt.</p>
<p><em>This article, originally published Jan. 25, 2024, has been updated with above-average heat across much of the central and eastern U.S. in late February and forecast in early March.</em></p><img src="https://counter.theconversation.com/content/221956/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard B. (Ricky) Rood receives funding from the National Oceanographic and Atmospheric Administration (NOAA).</span></em></p>As the climate changes and weather warms, the freezing line is shifting, bringing rain to many regions more accustomed to snow.Richard B. (Ricky) Rood, Professor Emeritus of Climate and Space Sciences and Engineering, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2211752024-01-16T18:03:04Z2024-01-16T18:03:04ZWhat is frostbite, what are the signs and how should we treat it?<figure><img src="https://images.theconversation.com/files/569540/original/file-20240116-17-9m16xs.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5801%2C3855&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Identifying the early symptoms of cold injury could help to prevent frostbite</span> <span class="attribution"><a class="source" href="https://www.gettyimages.co.uk/detail/news-photo/ice-crystals-on-a-frozen-leaf-during-frosty-weather-in-news-photo/1245472287?adppopup=true">Victoria Jones/PA Images via Getty Images</a></span></figcaption></figure><p>As countries in the northern hemisphere face <a href="https://www.newsweek.com/arctic-blast-map-states-brace-50-degree-temperature-drop-1859564">a bitterly cold snap</a>, there is serious risk of injury – and even death – from freezing weather. </p>
<p>Thankfully, with the right preventative and protective measures, the human body can survive these icy temperatures. </p>
<p>Here’s what you need to know about identifying and treating the <a href="https://pubmed.ncbi.nlm.nih.gov/15715518/">most common cold injury</a>: frostbite. </p>
<p>The body runs most optimally at <a href="https://www.ncbi.nlm.nih.gov/books/NBK279457/">37°C</a> and has a number of inbuilt mechanisms to adjust to cold or hot changes in environments. </p>
<p>These include changing our <a href="https://pubmed.ncbi.nlm.nih.gov/1115695/">breathing rate</a>, adjusting <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2963327/">blood supply</a> to various areas of the body or altering our <a href="https://pubmed.ncbi.nlm.nih.gov/9694412/">fluid intake</a> to ensure we replenish what we lose through <a href="https://www.ncbi.nlm.nih.gov/books/NBK232870/">respiration, exertion and urination</a>.</p>
<p>However, despite our bodies’ inherent temperature controls, without the right protection, we might still be vulnerable to cold weather injuries.</p>
<p>Frostbite is the result of damage to tissues – usually skin – on exposure to subzero temperatures. </p>
<p>Most commonly damaged areas are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4922379/">ears, fingers</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9559177/">toes</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528788/">cheeks</a>, lips, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4922379/">nose</a> and other extremities that are exposed – or not covered enough – such as the <a href="https://theconversation.com/polar-penis-the-hazards-of-winter-sports-177654">penis in winter sports</a> or the <a href="http://www.grandroundsjournal.com/articles/gr120002/gr120002.pdf">eyes</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman's face with purple discolouration on cheek from frostbite injury" src="https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569549/original/file-20240116-25-pw5ha0.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">Indian Everest climber Ameesha Chauhan was hospitalised with frostbite in 2019.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.co.uk/detail/news-photo/indian-everest-climber-ameesha-chauhan-speaks-during-an-news-photo/1146410955?adppopup=true">GOPEN RAI/AFP via Getty Images</a></span>
</figcaption>
</figure>
<p>For frostbite to occur, exposed body parts need to be subjected to a temperature that is below <a href="https://www.nhs.uk/conditions/frostbite/">minus 0.55°C</a>. At this temperature it will take several hours for exposed skin to become frostbitten.</p>
<p>But length of exposure to the cold is not the sole factor. The further below zero the temperature, the quicker the onset of frostbite. </p>
<p><a href="https://www.weather.gov/bou/windchill">Windchill</a> has a significant impact on the likelihood of getting frostbite too. For example, temperatures in the -20s can cause frostbite on exposed skin in under 30 minutes.</p>
<p>Wet clothing also increases the risk of developing frostbite: the moisture removes heat away from the body far quicker than air does, reducing the time taken to develop it.</p>
<h2>Who does it affect?</h2>
<p>Frostbite is seen more <a href="https://journals.sagepub.com/doi/10.1177/1534734620941479?icid=int.sj-full-text.citing-articles.1">commonly in men</a> and is increasingly found in certain occupational groups such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3023354/">farming</a> and <a href="https://journals.sagepub.com/doi/full/10.1016/j.wem.2018.03.001">fishing</a> professionals, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1725087/">mountaineers</a>, manual labourers and the <a href="https://pubmed.ncbi.nlm.nih.gov/38051632/">military</a>. However, with the global population beginning to live in <a href="https://www.sciencedirect.com/science/article/abs/pii/S0306456520304885">harsher</a> environments and an increase in winter and snow sports, this is likely to increase in the general population.</p>
<p>Those who are <a href="https://www.nature.com/articles/s41572-019-0092-1">diabetic or pre-diabetic</a> are also at increased risk, not because of their inability to metabolise glucose, but because <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5583955/">damage to the nervous system</a> means they are less likely to feel and respond to the cold. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8115134/">Reduced ability to sense the cold</a> also increases the frostbite vulnerability of those who’ve had a stroke or have <a href="https://www.sciencedirect.com/topics/neuroscience/peripheral-nerve-injury">peripheral nerve damage</a>.</p>
<p>People with heart conditions are also more at risk because the cold, especially the wind, takes the heat away from the body placing increased strain on the heart, which must work harder to keep warm. </p>
<p>Significant alcohol consumption is a further risk factor for frostbite. Heavy intoxication inhibits the body’s <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486564/">protective response to low temperatures</a> and can result in the sufferer not recognising the pain and discomfort as an early warning sign of cold damage. </p>
<p>The consumption of alcohol also <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8130994/">reduces blood pressure</a>, which may also reduce the amount of blood pumped to extremities. </p>
<h2>Symptoms</h2>
<p>Cold weather causes exposed skin temperature to drop, which triggers a response from the body to <a href="https://pubmed.ncbi.nlm.nih.gov/31045297/">reduce the blood flow – known as vasoconstriction</a> – to these cold areas to maintain core body temperature. Preserving the core body temperature is key to keeping the brain, heart, kidneys and lungs functioning and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593810/">preventing hypothermia</a>. </p>
<p>Withdrawing blood from the extremities reduces the risk of <a href="https://pubmed.ncbi.nlm.nih.gov/9460447/">ice crystals forming</a> in blood, however, over time with continued exposure to the cold, the water in the tissues begins to freeze, causing ice crystals to damage the tissues.</p>
<p>This cooling brings about <a href="https://www.sciencedirect.com/science/article/pii/S0020138322005186">tingling and numbness</a> of the exposed areas, and skin flushes red or white as the body frantically tries to rewarm itself. </p>
<p>This initial stage is known as <a href="https://gpnotebook.com/en-GB/pages/geriatric-medicine/frostnip">frostnip</a>, and, although uncomfortable, leaves no permanent damage to tissues. Beyond this stage, tissues begin to freeze. </p>
<p>If only the skin and the underlying connective tissues are frozen, this is termed superficial frostbite. The skin turns pale or even <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2278351/">greyish blue</a> because of decreased blood flow, ice crystal formation, limited blood supply – and there’s total numbness in the affected areas.</p>
<p>As exposure progresses, the freezing of tissue moves deeper involving <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10731172/">muscles and tendons</a>, blood vessels and even <a href="https://www.sciencedirect.com/science/article/pii/S1080603219300973?via%3Dihub">bones</a>. This level of freezing is deep frostbite and is associated with <a href="https://www.sciencedirect.com/science/article/pii/S1080603219300973?via%3Dihub">more extreme outcomes</a>, such as amputation. </p>
<h2>Treatment and prevention</h2>
<p>For frostbite, immediate medical treatment should be sought – sadly the pain of recovery is often far worse than the injury. </p>
<p><a href="https://www.aafp.org/pubs/afp/issues/2020/0401/p440.html">Rewarming</a> is the process of bringing the affected parts back to functioning body temperature. However, where ice crystals have damaged tissue, <a href="https://www.cureus.com/articles/108090-severe-frostbite-due-to-extreme-altitude-climbing-in-south-america-a-case-report#!/">blisters</a> are common and the nerves become hypersensitive, causing excruciating <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994495/">pain</a>. </p>
<p>In severe cases, <a href="https://extremephysiolmed.biomedcentral.com/articles/10.1186/2046-7648-3-7">debridement surgery may be needed to remove dead</a> tissue. </p>
<p>In the most extreme cases, however, there is the possibility that the affected area cannot be saved and requires amputation – if the tissue hasn’t <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2615432/">already died</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2615432/">fallen off</a>. </p>
<p>During this cold snap, if you have to go out in the cold weather, minimise your time outside. </p>
<p>Ensure that you have multiple layers on, this minimises heat loss. Wearing anything to provide a barrier to your extremities to the cold. Hats, gloves and scarfs can protect the areas most affected by frostbite.</p><img src="https://counter.theconversation.com/content/221175/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor 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>How to protect your extremities to avoid frostbite in cold weather.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2188712024-01-05T16:14:27Z2024-01-05T16:14:27ZThe curious link between animal hibernation and ageing – and what humans could learn from it<figure><img src="https://images.theconversation.com/files/566564/original/file-20231219-23-pbwlq4.jpg?ixlib=rb-1.1.0&rect=0%2C24%2C5355%2C3535&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/woman-being-cold-rubbing-her-hands-2234194923">Nicoleta Ionescu/Shutterstock</a></span></figcaption></figure><p>When the cold and dark winter is setting in, some of us envy animals that can hibernate. This long, deep rest is an example of how nature develops clever solution to difficult problems. In this case, how to survive a long, cold and dark period without much food and water. </p>
<p>But hibernation has closer links to human history than you might expect. </p>
<p>An article in a copy of the British Medical Journal from 1900 describes a strange human dormancy-like hibernation called “<em>lotska</em>” that was <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1117993/">common among farmers</a> in Pskov, Russia. In this area, food was so scarce during the winter that the problem was solved by sleeping through the dark part of the year. </p>
<p>Once a day people woke up to eat a piece of bread and drink a glass of water. After the simple meal, they went back to sleep and family members then took turns keeping the fire alive. You will also find descriptions in <a href="https://pubmed.ncbi.nlm.nih.gov/15881270/">Inuit Greenlandic</a> stories of a prolonged hibernation-like sleep during the long dark winter months. In parts of Greenland it is dark from November to the end of January.</p>
<p>There is a study from 2020 which suggests the ancient ancestors of man, called hominins, may have been able to hibernate 400,000 years ago. Bones discovered in a cave in Spain show seasonal disruption in growth, suggesting that one of man’s predecessors may have used <a href="https://www.researchgate.net/publication/347706305_Hibernation_in_hominins_from_Atapuerca_Spain_half_a_million_years_ago">the same strategy</a> as cave bears to survive long winters.</p>
<h2>Animals and hibernation</h2>
<p>Hibernation is deeper and more complex than usual sleep, including dramatic changes in metabolism. This long resting period combines several conditions linked to longevity, reduced calorie intake, low body temperature and lowered metabolism.</p>
<p>Animals that hibernate <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2011.0190">usually live longer</a> compared to other species of the same size. Recent studies using epigenetic clocks, which map activity within genes over time, suggest that hibernation slows down <a href="https://www.nature.com/articles/s41559-022-01679-1">ageing in marmots</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/35946154/">bats</a>. So hibernation may hold important clues on how to slow down ageing processes. </p>
<p>There are different forms of ageing – chronological and biological age. </p>
<p>Chronological age is actually only about how many revolutions the earth has circled around the sun since we were born. </p>
<p>It is not time itself that ages us but rather “wear and tear”. <a href="https://pubmed.ncbi.nlm.nih.gov/37635161/">Biological age</a> measures wear and tear. It is a more comprehensive and personal measure of health than chronological age and a better predictor of longevity. A 2023 study established that biological age varies and that a temporary increase, for example during surgery and stress, is reversed <a href="https://pubmed.ncbi.nlm.nih.gov/37086720/">when you have recovered</a>. </p>
<p>Diseases that are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8331090/">linked to lifestyle</a> and accumulate with age, such as such as cardiovascular disease, obesity, dementia and chronic kidney disease are driven by “wear and tear”. This result in inflammation, altered composition of the gut microbiota and increased <a href="https://www.hindawi.com/journals/omcl/2017/8416763/">oxidative stress</a>. Oxidative stress is when there are too many <a href="https://www.medicalnewstoday.com/articles/318652">free radicals</a> (unstable atoms that damage cells) in your body. </p>
<p>New science based on epigenetic clocks and lessons from hibernating animals could help us to treat patients who have diseases driven by “wear and tear”. We could use drugs that may slow down ageing. </p>
<p>For example, <a href="https://www.nhs.uk/medicines/metformin/">metformin</a> is the main first-line medication for the treatment of type-2 diabetes. It regulates inflammation, insulin-sensitivity and slows down DNA damage caused by oxidative-stress. There is growing evidence it may help manage other “wear and tear” diseases such as <a href="https://cardiab.biomedcentral.com/articles/10.1186/s12933-019-0860-y">cardiovascular disease</a> and long term use of the drug may be associated with <a href="https://www.frontiersin.org/articles/10.3389/fnagi.2021.773797/full">lower cognitive impairment</a>. </p>
<p>Learning more about hibernation may benefit human medicine for the treatment of <a href="https://www.sciencedirect.com/science/article/abs/pii/S0891584901006281?via%3Dihub">traumatic brain injuries</a>, <a href="https://journals.lww.com/shockjournal/fulltext/2018/07000/hibernation_based_approaches_in_the_treatment_of.3.aspx">severe blood loss</a>, preservation of muscle and bone mass and providing better protection during <a href="https://www.liebertpub.com/doi/10.1089/ars.2017.7127">organ transplantation</a>.</p>
<p>A 2018 study found that mimicking hibernation conditions for the storage of renal grafts from deceased donors seemed to improve their preservation. Muscular skeletal degeneration is often determined by genes, but these genes seemed to be deactivated in <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215489">hibernating bears</a>. </p>
<h2>Animals and longevity</h2>
<p>There are long-lived, non-hibernating animals we can learn from too such as the Greenland shark, naked mole rat, Icelandic clam and Rougheye rockfish. These species have developed superior mechanisms that <a href="https://pubmed.ncbi.nlm.nih.gov/31366472/">protect them against ageing</a>. It seems like protection against inflammation, oxidative stress and modifications of proteins that happen with age are mechanism that in general benefit all long-lived animals. </p>
<p>Genetic studies of rougheye rockfish, which can <a href="https://wdfw.wa.gov/species-habitats/species/sebastes-aleutianus">live for over 200 years</a>, suggest that a food group called flavonoids is related to longevity. Citrus fruits, berries, onions, apples and parsley are high in flavonoids, which have anti-inflammatory properties and protect against organ damage, for example, from chemicals or ageing. </p>
<p>The <a href="https://www.science.org/doi/10.1126/sciadv.add2743">2023 study</a> of rougheye rockfish found that one set of its genes which could be linked to longevity were associated with flavonoid metabolism. So a long-lived fish may have something to teach us about what to eat to live longer. </p>
<p>Lessons from nature and hibernating animals tell us that preserving cells, regulation metabolism and genetic adaptions play key roles in longevity. Our life style and eating habits are our best tools to mimic some of these mechanisms. </p>
<h2>Forty winks</h2>
<p>There is still so much we don’t understand about hibernation but we do know that normal sleep is connected to longevity too. For example, a March 2023 study showed that with <a href="https://www.jacc.org/doi/10.1016/S0735-1097%2823%2902119-8">good quality sleep</a>, you can add five years to the life of men and two and a half years if you are a woman. The researchers defined good quality sleep as getting seven to eight hours of sleep per day, not needing sleep medication and waking up feeling rested at least five days a week. </p>
<p>Animals have huge variations in their sleeping patterns, from bears and marmots hibernating for eight months of the year to <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0171903">elephants that get only two hours a day</a>.<br>
How elephants can become so old while sleeping so little is still a mystery to scientists. </p>
<p>Finding out how nature resolved these extremes may help scientists decipher new ways to improve human health.</p><img src="https://counter.theconversation.com/content/218871/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Stenvinkel receives funding from Astra Zeneca, Fresenius, Baxter, Novo Nordisk, Bayer, Invizius, Vifor for lectures and scientific advisory boards</span></em></p>Animals that hibernate live longer, so could hold clues on how to slow down ageing.Peter Stenvinkel, Professor of Nephrology, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2191832023-12-28T19:34:18Z2023-12-28T19:34:18ZLarger and more frequent solar storms will make for potential disruptions and spectacular auroras on Earth<figure><img src="https://images.theconversation.com/files/564592/original/file-20231208-29-521tjc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1669%2C1669&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A sunspot emitting a flare on the surface of the sun. </span> <span class="attribution"><a class="source" href="https://images.nasa.gov/details/PIA22645">(NASA/GSFC/Solar Dynamics Observatory)</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/larger-and-more-frequent-solar-storms-will-make-for-potential-disruptions-and-spectacular-auroras-on-earth" width="100%" height="400"></iframe>
<p>Bright auroras, with dancing lights in the sky, characterize the clear winter nights of northern Canada. Longer nights during the fall and winter also favour seeing more auroras, but the show is best outside of light-polluted cities. Impressive auroral events allowed bright auroras to be seen <a href="https://spaceweathergallery2.com/indiv_upload.php?upload_id=202170">as far south as the United States recently</a>. </p>
<p>Auroras are produced through the sun’s interaction with the Earth’s magnetic field. The number of auroras is increasing as <a href="https://www.swpc.noaa.gov/products/solar-cycle-progression">the sun’s activity becomes stronger</a>, approaching a solar maximum. </p>
<p>Perhaps surprisingly, the same space disturbances that cause auroras can affect our technologies.</p>
<p>In 1859, a geomagnetic storm — the largest in recorded history — disrupted technological systems, such as they were at the time, on Earth. Referred to as the “<a href="https://www.space.com/the-carrington-event">Carrington Event</a>” after Richard Carrington, the amateur astronomer who made the connection between a bright solar flare and subsequent auroral and magnetic effects. </p>
<p>That Sun-Earth link was slow to be accepted, but we now know that the Sun can trigger disturbances in near-Earth space, although it seems that events as large as that of 1859 are rare. </p>
<h2>Night visions</h2>
<p>Space is filled with thin hot gas called plasma that <a href="https://svs.gsfc.nasa.gov/14299/">carries magnetic fields</a>. The Earth, in the sun’s outer atmosphere, is surrounded by hot magnetic plasma which rushes past us at speeds of several hundred kilometres per second <a href="https://www.nasa.gov/solar-system/parker-solar-probe-and-the-birth-of-the-solar-wind/">in a flow called the solar wind</a>.</p>
<p>The sun is so massive that loss of the solar wind has a negligible effect on it, but Earth by comparison is a mere speck, three parts in a million as massive. <a href="https://www.nasa.gov/image-article/earths-magnetosphere-3/">Earth has a magnetic field</a>, which protects us from the solar onslaught, but is pushed back by it as well.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a blue ball of light" src="https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564595/original/file-20231209-17-dta2j1.gif?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">These active regions may dramatically flare up in X-ray intensity, affecting Earth’s upper atmosphere and making a hazard for astronauts.</span>
<span class="attribution"><span class="source">(Solar Dynamics Observatory/NASA)</span></span>
</figcaption>
</figure>
<p>Under certain conditions, energy can flow into the near-Earth region from the solar wind, largely building up on the opposite side from the sun in a comet-like “<a href="https://www.jstor.org/stable/24975910">magnetotail</a>.”</p>
<p>This can become unstable if too much energy builds up, blasting particles into the nightside atmosphere to light up auroras. This explains why auroras are seen at night: not only is it dark, but the sun’s energy takes an indirect route by first being stored in the magnetotail.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/o4FSg-90XlA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A NASA video explaining the magnetosphere.</span></figcaption>
</figure>
<p>The dancing auroras can also generate magnetic fields, which are strong enough to be detected by a compass, as discovered nearly 300 years ago by <a href="https://www.britannica.com/biography/Anders-Celsius">Swedish astronomer Anders Celsius</a>.</p>
<p>If the magnetic fields change rapidly, they can affect large regions of the Earth, building up to cause problems for power networks. This notably happened in North America in 1989, on the “<a href="https://spaceweatherarchive.com/2021/03/12/the-great-quebec-blackout">day the sun brought darkness</a>.”</p>
<h2>Solar cycles</h2>
<p>Italian astronomer Galileo studied sunspots in a systematic way in <a href="http://galileo.rice.edu/sci/observations/sunspots.html">the early 1600s</a>. About 300 years later, American astronomer George Hale showed that sunspots had intense magnetic fields, <a href="https://www2.hao.ucar.edu/education/scientists/george-ellery-hale-1868-1938">several thousand times stronger than Earth’s</a>. </p>
<p>In the 400 years since Galileo’s observations, we have found that the number of sunspots varies dramatically over <a href="https://www.swpc.noaa.gov/phenomena/sunspotssolar-cycle">an 11-year long cycle</a>. But it is only recently, in the Space Age, that we can relate its effects on Earth.</p>
<h2>Energy storage</h2>
<p>Magnetic fields store energy, and sometimes, as in Earth’s magnetotail or near sunspots, this energy can be changed to other forms. In the strong fields of sunspots, it can be released as X-rays in <a href="https://www.youtube.com/watch?v=64CTIrWBGTc">rapid, unpredictable flares</a>. </p>
<p>Sunspots and flares are near the surface or light-emitting layer of the sun, but <a href="https://www.swpc.noaa.gov/news/strongest-solar-flare-solar-cycle-25">material can escape from the sun’s strong gravity field</a>. Blobs of gas — <a href="https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections">coronal mass ejections</a> — can be hurtled into space. Some small fraction of these are shot out toward Earth, and auroras and their magnetic effects occur when they reach Earth’s atmosphere. They can also cause intensification of our radiation belts in ways that <a href="https://doi.org/10.1511/2014.110.374">can damage satellites</a>.</p>
<p>Counting sunspots on the sun’s surface allows us to get a general idea of what space disturbances may occur as the solar cycle progresses. Similarly, on Earth we can follow the seasons and have a general idea of what storms are likely. In both cases, however, exact prediction is difficult.</p>
<h2>Space weather forecasts</h2>
<p>From long-term trends, it was expected that the upcoming solar maximum would be small, as indeed <a href="https://doi.org/10.1051/swsc/2020060">the one that peaked in 2014 was</a>. However, in this, <a href="https://www.nasa.gov/news-release/solar-cycle-25-is-here-nasa-noaa-scientists-explain-what-that-means/">the following solar cycle</a>, we have already exceeded predicted numbers of sunspots and had large magnetic storms, so predictions may need to be revised upward. </p>
<p>Although direct measurement of incoming disturbances by satellites in the solar wind gives us only about an hour’s warning of stormy space weather, we can also predict a bit further in advance by watching sunspots rotate into view as the sun turns. </p>
<p>One solar rotation takes about as long as it does for the moon to go around Earth, that is to say, a month. So if a particular sunspot brings lots of activity, it likely will repeat in about a month.</p>
<h2>Rare storms</h2>
<p>The strongest flare of <a href="https://www.swpc.noaa.gov/news/sunspot-region-produces-x28-flare-largest-sep-10-2017">Solar Cycle 25 so far occurred on Dec. 14</a>, and was the most powerful eruption the sun has produced <a href="https://www.nasa.gov/missions/goes/september-2017s-intense-solar-activity-viewed-from-space">since the great storms of September 2017</a>.</p>
<p>Large solar storms are rare, but we must calmly prepare for possible space weather impacts that should maximize in a few years. We must be creative, since space weather effects can bring surprises. In 2022, unexpected heating of the atmosphere caused <a href="https://www.space.com/spacex-starlink-satellite-loss-space-weather-forecast">multiple satellite losses</a>. </p>
<p>As our knowledge of space physics steadily improves, so too will the new science of space weather prediction, allowing us to protect our technological assets. </p>
<p>In the meantime, we can look forward to spectacular auroras that should come as we near the 2025 solar maximum, with only measured and reasonable amounts of worry about the potential impacts of space weather.</p><img src="https://counter.theconversation.com/content/219183/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Gerard Connors receives funding from Canada's NSERC. </span></em></p>The sun is expected to reach its solar maximum in 2025. Recent auroras suggest that the maximum may be bigger than predicted.Martin Connors, Professor of Space Science and Physics, Athabasca UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2199892023-12-27T09:09:09Z2023-12-27T09:09:09ZWhich zoo animals are most active in winter and what times are best to see them?<figure><img src="https://images.theconversation.com/files/566032/original/file-20231215-15-11mkge.jpg?ixlib=rb-1.1.0&rect=29%2C67%2C4970%2C3261&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Amur tigers are evolved for winter weather</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/snowflakes-wild-cat-tiger-winter-nature-1231255066">Ondrej Prosicky/Shutterstock</a></span></figcaption></figure><p>The temperature has dropped, the nights have drawn in. The winter holidays have started, families are gathered – so where can you go to fuel the imagination and get some fresh air? A zoo might not be your first thought – but with some offering reduced ticket prices and smaller crowds than in summer, your nearest zoo on a cold, crisp winter’s day might be just the place.</p>
<p>We might think that their most popular animals, large mammals, are only active in summer, because that time of year suits us better. However, not all animals love sunshine and the hot days of summer. Some prefer cooler weather and are more active in colder temperatures. Here are ten animals to look out for on a winter visit to the zoo:</p>
<h2>1. Amur tiger</h2>
<p>In the wild, Amur tigers live in northern China and Russia so are used to the cold, making them more active during our winter months. These endangered animals are crepuscular (<a href="https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/jzo.12622?casa_token=TyJcM9gUMaMAAAAA%3AoVnzcHYYTEod9Eg8s_eQgr8XANC9hekc7rGkYultZ3ecCqRzAU469_oW_j5vaDEQeqqhyzBel4FY0mQ">active at dawn and dusk</a>), so I would head over to see them towards the end of your day at the zoo. There are currently 40 Amur tigers living in 17 UK zoos.</p>
<h2>2. Grey wolf</h2>
<p><a href="https://www.iucnredlist.org/species/3746/247624660">Native to</a> Eurasia, the US, Canada and Greenland, the grey wolf lives in many different habitats, including places where temperatures drop as low as -40°C. Grey wolves can communicate across up to ten miles using <a href="https://y86aca.p3cdn1.secureserver.net/wp-content/uploads/2023/03/Spontaneoushowling.pdf">individually recognisable howls</a>. They also howl during the breeding season (February-March), so you might be lucky and hear them in the zoo during late winter or early spring.</p>
<h2>3. Bison</h2>
<p>In the wild, bison live in <a href="https://www.iucnredlist.org/species/2814/45156279">northern Europe and Russia</a> as well as in the <a href="https://www.iucnredlist.org/species/2815/123789863">US and Canada</a>, so they cope well in UK winters. These animals <a href="https://link.springer.com/article/10.1007/s00265-003-0599-y">will be foraging</a> for most of the day, and are likely to be out in all weathers.</p>
<h2>4. Red panda</h2>
<p>Wild red pandas live in the forests of the <a href="https://www.iucnredlist.org/species/714/110023718">Himalayas and China</a>, between 2,500m and 4,800m above sea level. These endangered animals will be active around feeding time – check the zoo’s schedule so you can time your visit to watch them climb down from their treetop snooze spot.</p>
<h2>5. Red squirrel</h2>
<p>Native to the UK, these cute mammals are already used to British winter conditions. There are still places where you can see them in the wild, such as the Isle of Wight and Scottish woodlands. But their numbers have <a href="https://irep.ntu.ac.uk/id/eprint/43424/1/1450935_Fingland.pdf">been in decline</a> since grey squirrels from the US were introduced in the 19th century. Some zoos in the UK are part of a <a href="https://www.dudleyzoo.org.uk/red-squirrel-success/">captive breeding</a> and release programme, working to restore their numbers in the wild.</p>
<h2>6. Polar bear</h2>
<p>It won’t come as a surprise that this much-loved winter animal is on our list – and you should see playful polar bears swimming and splashing around in their pools a lot more in winter. Four UK zoos house them: Peak Wildlife Park near Stoke-on-Trent, Yorkshire Wildlife Park in Doncaster, Highland Wildlife Park in Cairngorms National Park, and Jimmy’s Farm & Wildlife Park in Ipswich.</p>
<h2>7. Snow leopard</h2>
<p>The name gives this one away as another big cat that likes the cold. Snow leopards live in the rugged mountains of central Asia. They are <a href="https://snowleopardconservancy.org/pdf/Jackson%20PhD%20thesis%20+%20photo.pdf">quite elusive</a> so spotting them, even in zoos in the winter, may be a challenge. However, if you aim for late afternoon, you’re more likely to be rewarded.</p>
<h2>8. Penguin</h2>
<p>A lot of penguins found in UK zoos are not from the freezing Antarctic. African and Humboldt penguins, for example, are from much warmer regions of the southern hemisphere. But that doesn’t stop them wanting to engage with zoo visitors through the windows while swimming in winter – just like those from colder climates, such as the gentoo penguins shown here at Belfast Zoo.</p>
<h2>9. Reindeer</h2>
<p>The reindeer you see at the zoo may be getting some rest before they make their estimated <a href="https://inews.co.uk/inews-lifestyle/christmas/santas-reindeer-would-have-to-travel-a-distance-of-over-41-million-miles-to-deliver-presents-238014">31-hour journey of 41 million miles</a> to deliver all the presents on Christmas Eve. Males shed their antlers in autumn and winter, while females keep theirs until spring – meaning that Santa’s sleigh is probably pulled by female reindeer.</p>
<h2>10. Reptile house (to defrost)</h2>
<p>There is nothing better than a reptile house or aquarium to help you defrost after being outside. The animals housed here need warm conditions to survive, so the whole area normally feels warm. They will also be more peaceful places given the lower zoo visitor numbers at this time of year, so you can take your time looking at these fascinating animals.</p>
<p>You may be wondering how animals from warmer climates cope with British winters. Zoos should always be conscious of animal welfare and this includes providing heated indoor areas. The best way for zoos to maintain high animal welfare is to let the animals decide where they want to go. Inside with protection from the weather, or outside in the fresh cold air – the <a href="https://www.mdpi.com/2076-2615/9/6/318">choice should be theirs</a>.</p><img src="https://counter.theconversation.com/content/219989/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Samantha Ward 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>Not all animals retreat to their shelters in cold weather.Samantha Ward, Associate Professor of Zoo Animal Welfare, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2200272023-12-26T17:16:54Z2023-12-26T17:16:54ZHow to jump-start your New Year with cold weather running<figure><img src="https://images.theconversation.com/files/567208/original/file-20231222-29-cdexst.jpg?ixlib=rb-1.1.0&rect=494%2C8%2C5497%2C3979&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Checking the weather frequently can serve to preemptively avoid injury pitfalls from extreme cold or slippery surfaces.</span> <span class="attribution"><span class="source">(Pexels)</span></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/how-to-jump-start-your-new-year-with-cold-weather-running" width="100%" height="400"></iframe>
<p>As 2024 approaches, many people look to begin the year with resolutions to become more fit. Some people find it challenging to get enthusiastic about outdoor exercise during the winter. However, don’t discount the joys of running in a winter wonderland. It’s accessible, available to all and doesn’t involve gym fees or expensive equipment.</p>
<h2>Health benefits</h2>
<p>First off, exercising has immense physical health benefits such as <a href="https://doi.org/10.1210/jc.2014-2440">increased heart and blood vessel health, increased metabolism</a>, favorable <a href="https://doi.org/10.3390%2Fhealthcare11162348">body composition</a> and enhanced immune function. <a href="https://www.miracle-recreation.com/blog/benefits-of-outdoor-exercise/?lang=can">Regular exercise can also help with mental health including reducing depression, anxiety and improving overall mood</a>. </p>
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Read more:
<a href="https://theconversation.com/exercise-can-help-prevent-and-treat-mental-health-problems-and-taking-it-outside-adds-another-boost-to-those-benefits-202343">Exercise can help prevent and treat mental health problems, and taking it outside adds another boost to those benefits</a>
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<p>In fact, there is some recent evidence to show that outdoor exercise may provide <a href="https://doi.org/10.1038/s41598-022-26093-2">additional improvements in well-being</a>. These improvements could also contribute to combating <a href="https://doi.org/10.1080/09291010802067171">seasonal affective disorders</a> during the winter months and help to combat a slew of <a href="https://doi.org/10.1136/bjsports-2022-106644">seasonal illnesses</a>. So, what can we do to jump in and reap these health benefits in winter? </p>
<h2>Motivation 101</h2>
<p>Before you start running, think about what motivates you. <a href="https://theconversation.com/got-health-goals-research-based-tips-for-adopting-and-sticking-to-new-healthy-lifestyle-behaviours-173740">New year’s resolutions</a> are a great start, but there needs to be a consistent motivator — something that won’t <a href="https://www.cbc.ca/news/canada/newfoundland-labrador/new-years-resolution-janine-hubbard-1.5412777">go away by February</a> — to get you out and running when the weather forecast begins with a minus sign. </p>
<p>If you’re looking for motivation, <a href="https://blog.mercy.com/staying-motivated-exercise-during-cold-weather/">start with these tips for pumping yourself up</a>. Once you’ve found your motivation, lacing up and taking the first (and next) steps, consistently, won’t be as tough. Here’s a few helpful hints to make that winter run a bit easier and much more enjoyable. </p>
<h2>Getting started</h2>
<p>The biggest injury concerns to cold weather running are slippery conditions and <a href="https://www.hopkinsmedicine.org/health/conditions-and-diseases/frostbite">frostbite</a>. With that in mind, make sure you’re set with the right equipment. When out in the winter, think <strong>COLD</strong>. This is not only an assessment of the weather. <a href="https://lowellstrauss.com/stay-warm-with-c-o-l-d">It’s an acronym that stands for</a>: </p>
<ul>
<li><strong>CLEAN:</strong> Keeping your gear (clothing and shoes) clean, allows them to work properly. Mud and slush on your hands and feet can make you lose heat quickly.<br></li>
<li>Avoid <strong>OVERHEATING</strong>: If it’s your first time exercising in the cold, you might think you have to put on a snowsuit. However, with poorly chosen outfits, you run the risk of overheating.<br></li>
<li><strong>LAYERED</strong> clothing: Wearing a fitted and moisture-wicking base layer, a light but insulating middle layer, and a breathable, but wind- and water-repellent jacket will give you the best of all worlds. Cover the parts of your body most likely to be exposed such as your hands, neck, and face with running gloves, a neck gaiter or scarf, and toque to keep these sites warm. Consider running with a waist bag or backpack, to carry these items along with your phone for safety.<br></li>
<li>Keep your clothing <strong>DRY</strong>: Breathable, but wind and water repellant clothing will keep your clothes from becoming too damp with either sweat or the environmental conditions, which could suck your heat away.<br></li>
</ul>
<p>Finally, understand that clothing is a matter of personal preference. As a coach of local, national and international (Olympic) track and field athletes, Kurt Downes, co-author of this story, has coached athletes who run in shorts with mittens and others who can barely move with so many layers on. Experiment with what works for you, and makes you comfortable. </p>
<h2>Tips for success and safety</h2>
<figure class="align-center ">
<img alt="A runner's shoes standing in snow" src="https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567214/original/file-20231222-23-bsi02m.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">Keeping your gear (clothing and shoes) clean allows them to work properly. Mud and slush on your hands and feet can make you lose heat quickly.</span>
<span class="attribution"><span class="source">(Piqsels)</span></span>
</figcaption>
</figure>
<p>Make sure you have a clearly defined goal. Do you want to increase fitness, burn calories, enjoy some fresh air or just move your body? Whatever your goal, make it something that is <a href="https://health.clevelandclinic.org/smart-fitness-goals">short-term, sweet and attainable</a>. Leave room to adjust and scale up as you crush those running goals. </p>
<p><strong>Schedule and plan:</strong> Find a slot of time that works best for you and block it out. In winter, it is especially important to plan your runs. My sound advice is to start slow and follow a gradual progression. </p>
<p>Don’t skip ahead despite how well you may be doing. Think about your current level of fitness: you might set out with the intention of running 10 kilometres, but if you’re five kilometres from home and get tired or twist an ankle, the long walk (or hobble) home increases the risks of cold injuries like <a href="https://www.cdc.gov/disasters/winter/staysafe/hypothermia.html">hypothermia and frostbite</a>, and may also mean you’re returning in the dark. </p>
<p><strong>Connect:</strong> Get to nature. Find a local well-lit and travelled trail, a riverfront, a park or take to your neighbourhood streets. Grab a partner, connect with people in your workplace, download a running app or join a running club. Meet at a local spot or pick a hang out spot after your running session. Make it a weekly social event. </p>
<p><strong>Weather check:</strong> Lastly for those of us who have smartphones connected to our hip, have a solid weather app on your home screen. Checking the weather frequently can serve to preemptively avoid injury pitfalls from extreme cold or slippery surfaces. </p>
<h2>Injury prevention</h2>
<p>Be mindful of the times that you head out for runs; if possible, find a time during sunlight hours. It will add a bit of warmth, <a href="https://doi.org/10.1289%2Fehp.116-a160">positively affect mood and increase vitamin D production</a> for bone health and immune function. Run in well-lit areas and wear bright colours so you’re visible to others, especially if running on the road.</p>
<p><strong>Fix your eyes forward:</strong> Focus on what’s coming ahead. It’s easy to get into the zone and lose yourself in thoughts or your favourite tune, but judging the terrain ahead is important to prevent a misplaced step, a twisted ankle <a href="https://www.youtube.com/watch?v=JKZj2W2YyKY">or a slip</a>. </p>
<p><strong>Stride wise:</strong> First, focus on settling into a rhythm at a fixed tempo. This will allow you to create a stride pattern that’s neither too short nor too long to keep on moving. Shortening your stride length will provide more stability when ice and snow are present (this is not the time to work on an Olympic-level stride pattern). If you can’t avoid a snowy or icy patch, it’s probably best to stop and walk around it. </p>
<p><strong>Breathing:</strong> Check your breath. The effects of cold exposure can often impede normal physiological function. Specifically, inhaling cold dry air during physical activity can have <a href="https://doi.org/10.1136/bjsports-2012-091296">adverse health effects on breathing</a>. Especially true for those with compromised respiratory systems or those predisposed to asthma. </p>
<p><strong>Hydration:</strong> Even though it may not seem like an immediate need, it’s important to be well hydrated before and throughout your workouts. Cold and snow don’t mean the air is wet (much of the arctic is actually <a href="https://www.britannica.com/science/cold-desert">classified as a desert</a> because of the lack of precipitation). Also, your body generates a lot of heat, even more when you’re exercising, causing heat loss from sweat. </p>
<p>If you’re just getting started with winter running, know that there are plenty of others out there too. In cities across North America, runners kick-start their year by hitting the streets to cover five-kilometre and 10-kilometre distances <a href="https://www.newyearsrun.com/">on New Year’s Day</a>, which could be a great inspiration to jump-start your winter exercising. Remember, as you get started, make a plan to do it safely.</p><img src="https://counter.theconversation.com/content/220027/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kurt Michael Downes is affiliated with The Border City Athletics Club, a not-for-profit athletics club.</span></em></p><p class="fine-print"><em><span>Kevin Milne 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>Winter running has all the health benefits of aerobic exercise, as well as fresh air. However, be aware of the specific safety and injury-prevention concerns that come with cold weather.Kurt Michael Downes, PhD Student, Kinesiology, University of WindsorKevin Milne, Associate professor, Kinesiology, University of WindsorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2173502023-12-14T13:13:03Z2023-12-14T13:13:03ZWinter brings more than just ugly sweaters – here’s how the season can affect your mind and behavior<figure><img src="https://images.theconversation.com/files/562242/original/file-20231128-15-6g8udc.jpg?ixlib=rb-1.1.0&rect=672%2C84%2C5212%2C4063&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Short winter days can influence your brain chemistry.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/holiday-cottage-in-the-dark-in-winter-royalty-free-image/1443007227">Schon/Moment via Getty Images</a></span></figcaption></figure><p>What comes to mind when you think about winter? Snowflakes? Mittens? Reindeer? In much of the Northern Hemisphere, winter means colder temperatures, shorter days and year-end holidays.</p>
<p>Along with these changes, <a href="https://doi.org/10.1177/17456916231178695">a growing body of research in psychology</a> and related fields suggests that winter also brings some profound changes in how people think, feel and behave.</p>
<p>While it’s one thing to identify seasonal tendencies in the population, it’s much trickier to try to untangle why they exist. Some of winter’s effects have been tied to cultural norms and practices, while others likely reflect our bodies’ innate biological responses to changing meteorological and ecological conditions. The natural and cultural changes that come with winter often occur simultaneously, making it challenging to tease apart the causes underlying these seasonal swings.</p>
<p><a href="https://scholar.google.com/citations?hl=en&user=mbqOySoAAAAJ&view_op=list_works&sortby=pubdate">With</a> <a href="https://scholar.google.com/citations?user=InwaMwEAAAAJ&hl=en&oi=ao">our</a> colleagues <a href="https://scholar.google.com/citations?user=GsJOu0sAAAAJ&hl=en&oi=ao">Alexandra Wormley</a> and <a href="https://scholar.google.com/citations?user=7BGThtkAAAAJ&hl=en&oi=ao">Mark Schaller</a>, we recently conducted an <a href="https://doi.org/10.1177/17456916231178695">extensive survey of these findings</a>.</p>
<h2>Wintertime blues and a long winter’s nap</h2>
<p>Do you find yourself feeling down in the winter months? You’re not alone. As the days grow shorter, the American Psychiatric Association estimates that <a href="https://www.psychiatry.org/patients-families/seasonal-affective-disorder">about 5% of Americans will experience</a> a form of depression known as seasonal affective disorder, or SAD.</p>
<p><a href="https://doi.org/10.1016/S0140-6736(98)01015-0">People experiencing SAD</a> <a href="https://doi.org/10.1176/ajp.146.7.829">tend to have feelings of hopelessness</a>, decreased motivation to take part in activities they generally enjoy, and lethargy. <a href="https://doi.org/10.1111/j.1600-0447.1998.tb09954.x">Even those who don’t meet the clinical threshold</a> for this disorder may see increases in anxiety and depressive symptoms; in fact, some estimates suggest <a href="https://doi.org/10.1001/archpsyc.1989.01810090065010">more than 40% of Americans experience these symptoms</a> to some degree in the winter months.</p>
<p>Scientists link SAD and more general increases in depression in the winter to decreased exposure to sunlight, which <a href="https://doi.org/10.1001/archpsyc.65.9.1072">leads to lower levels of the neurotransmitter serotonin</a>. Consistent with the idea that sunlight plays a key role, SAD tends to be more common <a href="https://doi.org/10.1176/ajp.149.9.1176">in more northern regions of the world</a>, like Scandinavia and Alaska, where the days are shortest and the winters longest.</p>
<p>Humans, special as we may be, are not unique in showing some of these seasonally linked changes. For instance, our primate relative the <a href="https://doi.org/10.1016/j.bbr.2015.07.005">Rhesus macaque shows seasonal declines in mood</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="man lying in bed in a room with dim daylight" src="https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/562243/original/file-20231128-17-e58d24.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">It can feel hard to get out of bed on dark mornings.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/side-view-of-a-tired-man-in-bed-royalty-free-image/1411640794">Lighthouse Films/DigitalVision via Getty Images</a></span>
</figcaption>
</figure>
<p>Some scientists have noted that <a href="https://doi.org/10.31887/DCNS.2007.9.3/rlevitan">SAD shows many parallels to hibernation</a> – the long snooze during which brown bears, <a href="https://theconversation.com/gut-microbes-help-hibernating-ground-squirrels-emerge-strong-and-healthy-in-spring-175610">ground squirrels</a> and many other species turn down their metabolism and skip out on the worst of winter. Seasonal affective disorder may have its roots in adaptations that conserve energy at a time of year when food was typically scarce and when <a href="https://doi.org/10.1002/ajpa.23071">lower temperatures pose greater energetic demands</a> on the body.</p>
<p>Winter is well known as a time of year when many people put on a few extra pounds. Research suggests that <a href="https://doi.org/10.1093/aje/kwz087">diets are at their worst</a>, and <a href="https://doi.org/10.1038/sj.ejcn.1602346">waistlines at their largest</a>, during the winter. In fact, a <a href="https://doi.org/10.1016/j.physbeh.2014.03.018">recent review</a> of studies on this topic found that average weight gains around the holiday season are around 1 to 3 pounds (0.5 to 1.3 kilograms), though those who are overweight or obese tend to gain more.</p>
<p>There’s likely more going on with year-end weight gain than just overindulgence in abundant holiday treats. In our ancestral past, in many places, winter meant that food became more scarce. <a href="https://doi.org/10.1038/sj.ejcn.1602346">Wintertime reductions in exercise</a> and increases in how much and what people eat may have been an evolutionary adaptation to this scarcity. If the ancestors who had these reactions to colder, winter environments were at an advantage, evolutionary processes would make sure the adaptations were passed on to their descendants, coded into our genes.</p>
<h2>Sex, generosity and focus</h2>
<p>Beyond these winter-related shifts in mood and waistlines, the season brings with it a number of other changes in how people think and interact with others.</p>
<p>One less discussed seasonal effect is that people seem to get friskier in the winter months. Researchers know this from analyses of condom sales, sexually transmitted disease rates and <a href="https://doi.org/10.1007/s10508-012-9996-5">internet searches for pornography and prostitution</a>, all of which <a href="https://doi.org/10.1111/j.1741-3737.2002.00871.x">show biannual cycles</a>, <a href="https://doi.org/10.1080/07448481.1993.9940826">peaking in the late summer</a> and then <a href="https://doi.org/10.1177/014107689909200204">in the winter months</a>. Data on birth rates also shows that in the United States and other countries in the Northern Hemisphere, babies are <a href="https://theconversation.com/tis-the-season-for-conception-106663">more likely to be conceived in the winter months</a> than at other times of the year.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman with hand on man's shoulder at a holiday gathering" src="https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/562245/original/file-20231128-20-8a0vq7.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">There’s more to a holiday bump in romance than just opportunity.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/multi-ethnic-young-couple-in-love-enjoying-a-home-royalty-free-image/1424097623">RgStudio/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>Although this phenomenon is widely observed, the reason for its existence is unclear. <a href="https://doi.org/10.1108/09654280810842120">Researchers have suggested many explanations</a>, including health advantages for infants born in late summer, when food may historically have been more plentiful, changes in sex hormones altering libido, desires for intimacy motivated by the holiday season, and simply increased opportunities to engage in sex. However, changes in sexual opportunities are likely not the whole story, given that winter brings not just increased sexual behaviors, but greater <a href="https://doi.org/10.1007/s10508-012-9996-5">desire and interest in sex</a> as well.</p>
<p>Winter boosts more than sex drive. Studies find that during this time of year, people may have an easier time paying attention at school or work. Neuroscientists in Belgium found that performance on <a href="https://doi.org/10.1073/pnas.1518129113">tasks measuring sustained attention</a> was best during the wintertime. Research suggests that seasonal changes in levels of serotonin and dopamine driven by less exposure to daylight may help explain <a href="https://doi.org/10.1073/pnas.1518129113">shifts in cognitive function during winter</a>. Again, there are parallels with other animals – for instance, African striped mice <a href="https://doi.org/10.1007/s10071-015-0892-y">navigate mazes better</a> during winter.</p>
<p>And there may also be a kernel of truth to the idea of a generous Christmas spirit. In countries where the holiday is widely celebrated, rates of charitable giving tend to <a href="https://doi.org/10.1016/j.jebo.2018.07.004">show a sizable increase around this time of year</a>. And <a href="https://doi.org/10.1016/j.jebo.2013.10.014">people become more generous tippers</a>, leaving about 4% more for waitstaff during the holiday season. This tendency is likely not due to snowy surroundings or darker days, but instead a response to the altruistic values associated with winter holidays that encourage behaviors like generosity.</p>
<h2>People change with the seasons</h2>
<p>Like many other animals, we too are seasonal creatures. In the winter, people eat more, move less and mate more. You may feel a bit more glum, while also being kinder to others and having an easier time paying attention. As psychologists and other scientists research these kinds of seasonal effects, it may turn out that the ones we know about so far are only the tip of the iceberg.</p><img src="https://counter.theconversation.com/content/217350/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Varnum has received past grant funding from the National Science Foundation and the China Postdoctoral Science Foundation.</span></em></p><p class="fine-print"><em><span>Ian Hohm 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>Some of winter’s effects have been tied to cultural norms and practices, while others likely reflect our bodies’ innate biological responses to shorter days and colder weather.Michael Varnum, Associate Professor of Psychology, Arizona State UniversityIan Hohm, Graduate Student of Psychology, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2176562023-12-13T20:53:51Z2023-12-13T20:53:51ZI’m your man: How Leonard Cohen’s life, poetry and song make him a prophet of love in a particularly dark midwinter<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/im-your-man-how-leonard-cohens-life-poetry-and-song-make-him-a-prophet-of-love-in-a-particularly-dark-midwinter" width="100%" height="400"></iframe>
<p>Leonard Cohen is hardly the first name that comes to mind as a spokesperson for “the true meaning of the holidays.” </p>
<p>As a religious studies scholar <a href="https://theconversation.com/life-of-brian-terry-joness-legacy-of-a-surprisingly-historical-jesus-130582">specializing in the history of earliest Christianity</a>, and a <a href="https://www.cbc.ca/player/play/2279666243993">Cohen fan from a Christian background</a>, I recognize that “festivity” is simply not a word that sits with Cohen — who was always more slyly depressing than holly jolly.</p>
<p>But <a href="https://podcasts.apple.com/ca/podcast/a-conversation-with-matthew-r-anderson/id1650272494?i=1000637487270">the beloved and late Jewish poet, novelist, and singer-songwriter from Montréal does talk about light, and profoundly so</a>. His words bring a certain bitter-sweetness to the shortest, darkest days of the year in the northern hemisphere, days which coincide with religious festivals involving light. </p>
<h2>Exterior, interior darkness</h2>
<p>Despite wide differences in their celebrations and what they commemorate, <a href="https://theconversation.com/hanukkahs-true-meaning-is-about-jewish-survival-88225">Hanukkah</a>, <a href="https://theconversation.com/apocalypse-booze-and-christmas-an-ancient-abc-172014">Christmas</a>, <a href="https://theconversation.com/yule-a-celebration-of-the-return-of-light-and-warmth-218779">Yule</a> and earlier in the year, <a href="https://theconversation.com/diwali-a-celebration-of-the-goddess-lakshmi-and-her-promise-of-prosperity-and-good-fortune-191992">Diwali</a> all feature candles and twinkling lights. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-blaze-of-light-in-every-word-vale-leonard-cohen-68690">A blaze of light in every word: vale Leonard Cohen</a>
</strong>
</em>
</p>
<hr>
<p>Whether or not these festivals were made for this purpose, they help people cope with short days, exterior darkness and even increased <em>interior</em> darkness accompanying <a href="https://www.cbc.ca/news/health/sad-science-why-winter-brings-us-down-but-won-t-for-long-1.2981920">seasonal affective disorder (SAD)</a> and other stresses as the nights get longer headed towards winter solstice.</p>
<h2>This year feels gloomier</h2>
<p>However, while violence never ceases, this year feels even gloomier, with a sharp rise in <a href="https://www.cbc.ca/news/canada/toronto/hate-crime-record-levels-toronto-1.7037413">hate crimes</a>, <a href="https://www.apa.org/monitor/2021/03/controlling-misinformation">polarizing disinformation</a> — some spread by <a href="https://www.routledge.com/American-Evangelicals-for-Trump-Dominion-Spiritual-Warfare-and-the-End/Gagn/p/book/9781032415680">“Christian” nationalists who deny democracy</a> while seeking to <a href="https://theconversation.com/the-christian-rights-efforts-to-transform-society-120878">remake North American society in their image</a> — <a href="https://theconversation.com/violent-and-disturbing-war-images-from-the-mideast-can-stir-deep-emotions-a-ptsd-expert-explains-how-to-protect-yourself-and-your-kids-from-overexposure-216405">and with war</a>. (Now we’re starting to sound more like Cohen.)</p>
<p>In reaction to the Israel-Hamas war and its global effects, instead of embracing festivals of light, some are choosing to downplay them. The city of Moncton, New Brunswick <a href="https://www.cbc.ca/news/canada/new-brunswick/moncton-city-hall-menorah-hanukkah-francis-weil-1.7046813#">decided not to display their traditional menorah and nativity scene</a>. But the decision provoked a strong negative response <a href="https://www.cbc.ca/news/canada/new-brunswick/moncton-menorah-mayor-dawn-arnold-statement-1.7048461">across Canada and globally, occasioning a speedy reversal</a>. </p>
<p>Cohen’s frequent mentions of failure, regret, suffering, violence and mortality make him far more <a href="https://www.youtube.com/watch?v=B6WnnZRSKYs">blue, than Christmas</a>. But I can identify at least four ways Cohen’s life and poetry make <a href="https://www.mqup.ca/prophets-of-love-products-9780228018643.php">him a prophet of love</a> who illuminates these dark times, based on my recent research on religious imagery in his poetry and music.</p>
<p><strong>1. Cohen wasn’t afraid to lean into the fact that, worldwide, people are religious, and religious symbols have power.</strong> Remove religious allusions from Cohen’s writing and you’d lose most of his work. His book titles, from the first <em>Let Us Compare Mythologies</em> (1956) to final <em>The Flame</em> (2018), show just how aware of <a href="https://www.firstthings.com/blogs/firstthoughts/2016/11/leonard-cohen-the-christ-haunted">the near universal symbolic currency of religion</a> Cohen was. </p>
<p>Religion was a handy way for Cohen to talk about sex. But equally true is that sex offered a device for him to talk about religion. For him, these insights were entwined with the sense that each person reflects the Divine. He observed, “I think that everybody leads a spiritual life… in touch… <a href="https://books.google.ca/books/about/Leonard_Cohen.html?id=s8RbAgAACAAJ&redir_esc=y">with their own deep pools of divine activity</a>.”</p>
<p><strong>2. Cohen never caricatured religious traditions. He pointed to the richness of many faiths while stating his own positionality.</strong> Cohen knew that understanding others starts with understanding oneself. “<a href="https://books.google.ca/books/about/Leonard_Cohen.html?id=s8RbAgAACAAJ&redir_esc=y">I would never say anything else but that I am a Jew</a>,” he repeatedly insisted. Cohen’s maternal grandfather was a noted scriptural scholar and his paternal <a href="https://globalnews.ca/news/9707000/shaar-hashomayim-celebrates-century-in-westmount/">great-grandfather helped found Montréal’s Congregation Shaar Hashomayim</a>. Yet as deeply rooted as he was in Judaism, Cohen’s knowledge of other faiths was both profound and wide-ranging. </p>
<p>In my research I show <a href="https://atlanticbooks.ca/stories/im-your-saint-cohen-and-st-paul-studied-in-prophets-of-love/">how important Jesus was to Cohen</a>, without making the mistake of claiming he was Christian. I explore the profound impact of Catholicism on his childhood. I also note how interwoven through Cohen’s corpus is his decades-long practice of Zen Buddhism, his readings in Sufi mysticism and his study of Hinduism. </p>
<p><a href="https://www.theguardian.com/music/2021/oct/17/how-leonard-cohen-mined-sacred-texts-for-lyrics-to-his-songs">Jewish tales from the Mishnah and Talmud</a>, <a href="https://www.heyalma.com/leonard-cohens-rabbi-reveals-the-jewish-theology-behind-the-music/">kabbalistic philosophy</a>, ancient Christian legends, poetry from Federico Garcia Lorca and Rumi, and <a href="https://www.npr.org/2016/10/21/498810429/leonard-cohen-on-poetry-music-and-why-he-left-the-zen-monastery">Zen reflections on longing</a>, attachment and nothingness all combine in his work. </p>
<p>As a poet, writer and thinker Cohen abhorred cliché, while leaning into religious complexity and diversity.</p>
<p><strong>3. Cohen respected faith and spirituality but called out religious hypocrisy.</strong> In 1984 he remarked: “<a href="https://books.google.ca/books/about/Leonard_Cohen.html?id=s8RbAgAACAAJ&redir_esc=y">There’s always the possibility of mystification and manipulation</a> …. There are evil forces in the world ready to imperialize religion but I’m confident the forces of good are stronger.” </p>
<p>These words seem optimistic for the man who also wrote:</p>
<blockquote>
<p>“Give me Stalin and St. Paul / I’ve seen the future, brother / It is murder” (“The Future,” from Stranger Music). </p>
</blockquote>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/LYzPVKg3wyo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Leonard Cohen’s ‘The Future.’</span></figcaption>
</figure>
<p>Cohen himself was not immune to abusing the power that comes with being revered. He was fortunate in successfully transforming his <a href="https://web.archive.org/web/20201211115215/https:/www.theglobeandmail.com/arts/article-leonard-cohens-tales-of-seduction-look-different-through-a-metoo/">seemingly misogynist relations with women</a> into lyrics rather than litigation, partly by the complicated and disarming ways he wrote about regret, apology and forgiveness, and partly <a href="https://sharpmagazine.com/2018/11/06/how-do-we-come-to-terms-with-leonard-cohens-legacy-in-the-metoo-era/">through age and death</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/marianne-and-leonard-a-new-film-tells-us-little-about-the-woman-fixed-in-the-role-of-musicians-muse-128112">Marianne & Leonard: a new film tells us little about the woman fixed in the role of musician's muse</a>
</strong>
</em>
</p>
<hr>
<p><strong>4. Most importantly, Cohen used religious stories and images to find common cause with and give courage to others in dark times.</strong> His most famous lines are perhaps from his song <em>Anthem</em>: </p>
<blockquote>
<p>“Ring the bells that still can ring / forget your perfect offering / There is a crack in everything / that’s how the light gets in.” </p>
</blockquote>
<p>Harry Freedman, in <em><a href="https://www.bloomsbury.com/ca/leonard-cohen-9781472987273/">Leonard Cohen: The Mystical Roots of Genius</a></em> finds multiple Jewish religious references behind <em>Anthem</em>. I’ve discovered even more. Cohen took on the mantle (importantly, for him a <em>biblical</em> mantle) of recognizing and lifting up the light that can be discovered in, despite, and through human suffering. As I have written elsewhere, “<a href="https://www.mqup.ca/prophets-of-love-products-9780228018643.php">A crack in everything means especially a crack in human beings</a>.”</p>
<p>In his last years Cohen lived into his name <a href="https://www.britannica.com/topic/cohen">of cohen (priest)</a>. Friends and colleagues of mine who attended his final concerts, some religious, but many <a href="https://theconversation.com/what-does-it-mean-to-be-spiritual-87236">“spiritual but not religious,”</a> described them as sacred spaces.</p>
<p>Cohen’s lyrics dwell on human failure, regret and violence. Yet according to his musical collaborator Sharon Robinson, <a href="https://www.rollingstone.com/music/music-features/sharon-robinson-reflects-on-touring-with-leonard-cohen-194281/">touring became “a type of meditation” for Cohen</a>, and his final concerts ended with him blessing the crowd. Typically for Cohen, who never let a line have only one meaning, the title of the album <em>You Want It Darker</em> refers to both his fans and his God. There is <a href="https://jewishreviewofbooks.com/articles/2315/darkness-and-light-leonard-cohen-and-the-new-cantors-a-playlist-for-the-high-holidays/">both a challenge to the Divine, and acceptance of an end</a>, in it.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/v0nmHymgM7Y?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Leonard Cohen’s ‘You Want it Darker.’</span></figcaption>
</figure>
<h2>Cohen’s ominous passing, ongoing relevance</h2>
<p>Cohen’s 2016 death on <a href="https://lithub.com/cohen-dies-trump-wins-and-we-will-sing-about-these-dark-times/">the eve of a sharp turn toward hate politics when Donald Trump was elected</a> seems doubly ominous seven years after the passing of the <a href="https://www.rollingstone.com/music/music-features/leonard-cohen-remembering-the-life-and-legacy-of-the-poet-of-brokenness-192994">poet of brokenness</a>. </p>
<p>Knowledgeable of many faiths, but observant above all of the human condition; daring the Divine to answer humanity’s sorrows: this is what makes Cohen an unlikely but fitting spokesperson for another dark midwinter season. </p>
<p>My own vote for a <a href="https://www.msn.com/en-ca/news/canada/douglas-todd-leonard-cohen-may-help-us-find-hope-in-today-s-holy-broken-world/ar-AA1izeLe">Cohen holiday favourite</a> might be <em>Come Healing</em>. It’s why Cohen, a man about whom surely no Hallmark festive movie will ever be made, just might be this year’s answer to the darkness: </p>
<blockquote>
<p>“And let the heavens falter / Let the earth proclaim / Come healing of the altar /
Come healing of the name.”</p>
</blockquote><img src="https://counter.theconversation.com/content/217656/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Robert Anderson 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>Leonard Cohen, a man about whom surely no Hallmark festive movie will ever be made, dared the Divine to answer humanity’s sorrows.Matthew Robert Anderson, Adjunct professor, Theological Studies, Concordia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2187792023-12-07T14:24:36Z2023-12-07T14:24:36ZYule – a celebration of the return of light and warmth<figure><img src="https://images.theconversation.com/files/564046/original/file-20231206-23-nd15am.jpg?ixlib=rb-1.1.0&rect=104%2C26%2C5701%2C3838&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People gather for Pagan sunrise celebrations in Ireland, on the morning of the winter solstice.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-gather-for-sunrise-at-newgrange-co-meath-on-the-news-photo/1245764534?adppopup=true">Brian Lawless/PA Images via Getty Images</a></span></figcaption></figure><p>Yule will be celebrated by Wiccans and many other Pagans in the Northern Hemisphere on Dec. 21, the day of the winter solstice. For Pagans, the shortest day of the year marks the <a href="https://uscpress.com/Search?q=A+community+of+Witches">end of the descent into darkness</a> and the beginning of the return of the light as the days begin to get longer after the solstice. Like many other religious holidays, <a href="https://www.theatlantic.com/photo/2016/12/festivals-of-light/510518/">Yule is a celebration of light</a>.</p>
<p>As a <a href="https://www.helenaliceberger.com/">sociologist who has been studying contemporary Pagans</a> for more than 30 years, I know that Yule is also a time of reflection. The cold dark period of the year, many Wiccans feel, encourages us to not only spend more time at home, but also to become more reflective about our lives – and often about spirituality. </p>
<h2>Marking the beginning of winter</h2>
<p>Wicca is a minority religion that is part of the larger contemporary Pagan movement. Pagans normally define their religion as earth-based. By this they mean <a href="https://theconversation.com/what-is-wicca-an-expert-on-modern-witchcraft-explains-165939">they see divinity in nature</a> and connect their rituals to the changing seasons. All forms of contemporary Paganism look to pre-Christian European religions to inform their religious practice. </p>
<p>Wiccans regularly call themselves Witches, although not all Witches are Wiccans. The religion puts more emphasis on participating in rituals and having spiritual experiences than on particular beliefs.</p>
<p>Yule is one of the eight major holidays or “sabbats” that divide the year into the beginning and peak of each season. Yule denotes the beginning of winter. There is a <a href="https://global.oup.com/academic/product/wicca-9781845197544?cc=us&lang=en&">ritual for each holiday</a> that focuses on what is occurring in nature and correspondingly in people’s lives. At this time of year, people are experiencing both the height of darkness and the knowledge and hope that the light and warmth will return. </p>
<p>When I began my research about this religion in 1986, the norm for contemporary Pagans was to form into small groups, which Wiccans call covens. These spiritual congregations meet regularly for holidays, learning and discussions. While covens still exist, the primary way of practicing is as “solitaires.” These solitary practitioners may join others for one or more of these sabbats, or they may do their own ritual. </p>
<h2>Yule rituals</h2>
<p>I have always found the group rituals I have attended for Yule, as part of my research, to be joyous occasions. </p>
<p>As with all Wiccan rituals, participants gather in a circle. Those leading the ritual sanctify the space by walking around the circle chanting and sprinkling salt and water. This is followed by representations of the four elements – water, fire, air and earth. Often, a candle is lit to denote fire, a shell to represent water, a feather for air, and a crystal for earth. </p>
<p>Divinities or spirits are called into the circle to help with the ritual. There is always a reading or meditation <a href="https://uscpress.com/Search?q=A+community+of+Witches">related to the holiday and the changes that are occurring</a> in the natural world at that season. </p>
<p>At Yule there is always a fire or lights to symbolize the returning sun. In one outdoor ritual I attended, a bonfire was built in a clearing in the woods. The night was cold and dark, and there was snow on the ground. The circle was formed around the fire. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large number of people gathered around a big bonfire in the woods." src="https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563758/original/file-20231205-23-25zbmn.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">Bonfires can be built at Yule in the clearing of the woods.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/people-celebration-around-big-huge-traditional-fire-royalty-free-image/922771128?phrase=winter+solstice+fire&adppopup=true">Drepicter/iStock via Getty images plus</a></span>
</figcaption>
</figure>
<p>However, most of the rituals I have attended, particularly for Yule, are indoors, and fires are made in cauldrons, or by lighting candles. However, at one large ritual I attended, <a href="https://uscpress.com/Search?q=A+community+of+Witches">there was a large, bright, yellow-and-orange paper mache image of the sun</a> on a long stick. </p>
<p>All of the attendees were asked to wear shiny clothing. Some people had glitter in their hair and on their face; some wore golden or silver clothing; the room and the people glowed with light and sparkles. At other rituals I have attended, people were asked to bring a small candle or light. In all instances the participants are symbolically part of the returning light, either by carrying a light or, in this one ritual, reflecting the room light. </p>
<p>The reading or meditation at Yule rituals normally includes reference to the darkness of winter that people experience around this time of year. </p>
<h2>Light during darkest time</h2>
<p>The rituals normally end with dancing and chanting. At the ritual in which there was a large representation of the sun, all the participants danced joyously behind the person carrying the sun, chanting about the sun returning. </p>
<p>The ritual I attended in the forest ended with everyone dancing around the fire before making sure it was completely put out. We then turned on our flashlights and found our way in the dark out of the woods. </p>
<p>The juxtaposition of the celebration of the returning sun and having the time and inclination for reflection during a dark and cold time makes this an interesting holiday.</p><img src="https://counter.theconversation.com/content/218779/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen A. Berger 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>Yule, celebrated by Wiccans and many other Pagans in the Northern Hemisphere on Dec. 21, the day of the winter solstice, is a time for reflection.Helen A. Berger, Affliated Scholar at the Women's Studies Research Center, Brandeis UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2169512023-11-21T16:54:17Z2023-11-21T16:54:17ZSAD lamps: do they work? Experts explain how they help the winter blues<p>Have you ever noted that you sleep more in the winter months? Or eat more carbs or have low energy? If you do, then you might be one of the around <a href="https://www.theguardian.com/lifeandstyle/2017/oct/30/sad-winter-depression-seasonal-affective-disorder">6% of the</a> higher latitude populations with seasonal affective disorder (SAD). </p>
<p>If you’ve searched the internet for <a href="https://news.sky.com/story/seasonal-affective-disorder-or-sad-isnt-just-winter-blues-12983739">tips on how to fight the winter blues</a> you’ve probably been advised to buy a therapy lamp. So you may be wondering what research says about whether they are effective and how they work. </p>
<p>Before we examine the evidence for light therapy it’s important to understand why mood might be affected by sunlight. Vitamin D is produced <a href="https://www.tandfonline.com/doi/full/10.4161/derm.24494">when your skin is exposed to sunlight</a> and some scientists believe there is a link between <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10255717/">depression and low vitamin D levels</a>. </p>
<p>Studies have found about 10% of the population of <a href="https://www.tandfonline.com/doi/full/10.2147/PRBM.S114906">the far north</a>, for example in Alaska and Finland, experience SAD. Interestingly, Icelanders, who also live in these very northern latitudes, <a href="https://jamanetwork.com/journals/jamapsychiatry/article-abstract/496414">do not appear to suffer so much from SAD</a>. This might be <a href="https://www.ifis.org/blog/icelands-diet-health-problems-solutions-part-1#:%7E:text=Icelanders%20typically%20dine%20on%20a,%2C%20Arctic%20char%2C%20and%20monkfish.">because of their fish-packed diet</a>, which is rich in vitamin D. </p>
<p>Light also stimulates your visual system, regulating activity in the so-called circadian pacemaker. This is the <a href="https://www.sciencedirect.com/topics/neuroscience/suprachiasmatic-nucleus">suprachiasmatic nucleus</a> (SCN), a small region of the brain. The SCN gets direct input from the retina and is also packed with melatonin receptors. Melatonin supplements are now being touted as a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060443/">treatment for depression</a>. So there are multiple reasons why <a href="https://pubmed.ncbi.nlm.nih.gov/37239299/">light might be important for mood</a>.</p>
<p>SAD was first described around 1980 in the US when a man, who experienced the symptoms outlined above, invented a light box to treat himself. </p>
<p>There have been many studies since examining light therapy in SAD with mixed and contradicting results. However, data from all these studies can be combined and examined using <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/meta-analysis">meta-analyses</a> to give a more accurate overall picture. A meta-analysis merges the findings of several independent studies. There have been several meta-analyses of this topic and most show that light therapy has a positive effect, not only on SAD, but also on major depression.</p>
<h2>Does light intensity matter</h2>
<p>Light intensity is <a href="https://www.britannica.com/science/lux">measured in lux</a>. A <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0447.1999.tb07236.x">1999 meta-analysis</a> of 39 scientific papers found that strong light intensity (6,000-10,000 lux) had a greater effect than medium light intensity (1,700-3,500 lux). Medium light intensity had a greater effect than dim lighting (less than 600 lux) on depressive symptoms in people with SAD. A <a href="https://pubmed.ncbi.nlm.nih.gov/31574513/">2019 meta-analysis</a> of 19 studies also found that brighter light (greater than than 1,000 lux) is needed to treat SAD.</p>
<figure class="align-center ">
<img alt="Young woman reading by a therapy lamp" src="https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558066/original/file-20231107-252894-tstzhi.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">Therapy lamp.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-light-therapy-171525149">Image Point Fr/Shutterstock</a></span>
</figcaption>
</figure>
<p>You might be wondering whether light colour matters.</p>
<p>A <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0447.1997.tb09915.x">1997 meta-analysis</a> looked at 40 scientific papers examining different colours of light. It revealed that light of short to medium wavelengths (blue, green and yellow) were effective but that red or UV wavelengths did not seem to treat SAD. This study also reviewed the timing of the phototherapy. The data, although not significant (which means more studies are needed), suggested that phototherapy in both the morning and the evening was more effective than morning or evening alone.</p>
<h2>Does phototherapy work in non-seasonal depression?</h2>
<p>A <a href="https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.162.4.656?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">2005 meta-analysis</a> of 23 studies found phototherapy worked for people with SAD and for people with non-seasonal depression. This paper reviewed six studies of combined treatment for non-seasonal depression. It found that phototherapy, although effective alone, did not produce a greater effect on depression symptoms when given together with antidepressant medication. </p>
<p>However, more recent studies agree that the combination treatment is more effective. A <a href="https://pubmed.ncbi.nlm.nih.gov/27835725/">2016 meta-analysis</a> of ten studies did find phototherapy augmented drug treatment of depression. A <a href="https://pubmed.ncbi.nlm.nih.gov/31600678/">2019 meta-analysis</a> of seven studies also found it increased the power of antidepressants.</p>
<p>So if you suffer from non-seasonal depression, then phototherapy may work as a first line treatment and will probably boost the effects of any antidepressant drug that you may be taking. </p>
<p>There is also a condition called <a href="https://www.sciencedirect.com/science/article/pii/S0165032707003515">sub-syndromal SAD</a> (SSAD or sub-SAD) affecting about <a href="https://www.theguardian.com/lifeandstyle/2017/oct/30/sad-winter-depression-seasonal-affective-disorder">10-15%</a> of higher latitude populations, where symptoms are milder or less frequent than SAD. Sub-SAD can also be treated with light therapy. </p>
<p>Vitamin D is <a href="https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/">essential for physical health</a> as well as mental health as it regulates calcium and phosphate levels, is critical for good bone density and for muscle and teeth health. It’s also essential for a healthy immune system. </p>
<p>There are other studies that look at <a href="https://pubmed.ncbi.nlm.nih.gov/29498416/">lighting in the workplace</a> and the effect on employees, for example certain types of light might improve alertness, while other lighting might increase headaches.</p>
<p>If you suffer from SAD, choose a higher intensity light for a faster effect, use the light for longer, for example, both morning and evening sessions. Avoid UV light which is ineffective for SAD and can lead to sunburn or skin cancer. And don’t forget to eat some fish to boost your vitamin D levels too.</p><img src="https://counter.theconversation.com/content/216951/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 organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>SAD is a debilitating condition affecting many people, but there is light at the end of the tunnel.Colin Davidson, Professor of Neuropharmacology, University of Central LancashireClaire Hutchinson, Professor of Experimental Psychology, University of the West of ScotlandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2151312023-11-19T13:00:27Z2023-11-19T13:00:27Z‘Forever contaminant’ road salts pose an icy dilemma: Do we protect drivers or our fresh water?<p>As winter approaches, many communities in Canada and around the world arm themselves against icy roads and sidewalks with a time-honoured ally: road salt. For decades, applying road salt has been regarded as a simple but vital tool in countering the dangers of slippery road conditions, but the downsides of its use are apparent with implications that <a href="https://doi.org/10.1007/s11270-018-4060-2">extend beyond the cold months</a>. </p>
<p>Scientists have long known that the substance which has safeguarded us through the colder months poses a threat to aquatic life and drinking water quality. But now we are finding that this chemical also <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">disrupts the delicate balance of oxygen and nutrients</a> in our freshwater lakes and ponds. </p>
<p>Road salt, commonly referred to as rock salt, is a mixture primarily composed of sodium chloride (NaCl). It is used to de-ice roads and highways during winter to enhance safety by preventing the formation of ice and reducing slippery conditions. Road salt persists as an environmental contaminant due to its chemical stability and the cyclic nature of its dispersal. </p>
<p>Introduced through activities like road de-icing, salts move from roads to surface water such as streams and lakes, groundwater, remaining indefinitely in the environment without significant degradation. The continual cycling and lack of substantial transformation underscore the long-term impact of sodium chloride as a “forever contaminant.”</p>
<p>With a growing awareness of its ecological repercussions, a critical dilemma emerges. Do we prioritize driver safety or acquatic ecosystem health?</p>
<h2>Negative impacts revisited</h2>
<p>The detrimental effects of road salt on aquatic ecosystems and drinking water supplies <a href="https://doi.org/10.1016/j.scitotenv.2021.150289">have long been recognized</a>. Its heavy application during winter months leads to a buildup of road salt ions in both soil and water bodies, altering their natural chemical composition. </p>
<p>These elevated salt concentrations can harm freshwater organisms and vegetation, change soil structure, and, when <a href="https://doi.org/10.1016/j.scitotenv.2023.166466">seeping into groundwater</a>, compromise the potable water supply of nearby communities.</p>
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Read more:
<a href="https://theconversation.com/winter-road-salting-has-year-round-consequences-173621">Winter road salting has year-round consequences</a>
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<p><a href="https://doi.org/10.1016/j.scitotenv.2022.157336">Recent research</a> has shed light on a less conspicuous yet equally significant consequence of road salt usage: its contribution to oxygen depletion in lakes. The occurrence of <a href="https://doi.org/10.1029/2023JG007558">very low oxygen concentrations, or hypoxia, in a lake is generally attributed to an excessive input of nutrients, especially that of phosphorus</a>. </p>
<p>Nutrient enrichment can trigger algal blooms that, in turn, lower the oxygen level in the lake’s deeper waters. The continued expansion of hypoxic conditions deteriorates the lake’s water quality and may ultimately cause the die-off of most aquatic life. This nutrient-driven process, <a href="https://doi.org/10.5194/bg-14-3585-2017">known as eutrophication</a>, is affecting the ecological health of a growing number of lakes around the world.</p>
<h2>Salt and oxygen in water</h2>
<p><a href="https://doi.org/10.5194/egusphere-egu2020-16637">Phosphorus</a>, the nutrient frequently implicated in lake eutrophication, plays a multifaceted role in this scenario. <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">Salinization</a> increases the density of the water reducing the mixing of the lake waters and. Consequently, this reduces the amount of oxygen that reaches the lake’s depths. </p>
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Read more:
<a href="https://theconversation.com/road-salt-makes-winter-driving-safer-but-what-does-it-do-to-the-environment-87860">Road salt makes winter driving safer, but what does it do to the environment?</a>
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<p>Oxygen depletion, paradoxically, favours the remobilization of phosphorus from the sediments accumulating at the bottom of the lake. That is, the sediments become an increasingly important <em>internal</em> source of phosphorus, escalating the nutrient enrichment of the lake. </p>
<p>In that way, salinization — driven by extensive road salt application — <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">intensifies eutrophication symptoms</a> that are usually associated with phosphorus supplied to lakes from external sources in the surrounding landscape.</p>
<h2>Navigating the saline challenge</h2>
<p>Canada has been <a href="https://doi.org/10.1016/j.scitotenv.2021.151717">proactive in responding</a> to eutrophication. For instance, reduced phosphorus pollution in Lake Erie in the 1980s and 1990s led to significant <a href="https://doi.org/10.1029/2019WR025019">water quality improvements</a>. However, addressing accelerating salinization of lakes requires new thinking and innovative solutions that recognize the complexity of the issue. It’s not just de-icers, such as road salts, that need to be considered. </p>
<p><a href="https://doi.org/10.1098/rstb.2018.0019">Other sources of salt</a>, such as agricultural runoff, discharges from water softeners and other domestic activities and drainage from mine waste and geological salt deposits, are all part of the problem. Salinization is a <a href="https://doi.org/10.1073/pnas.1620211114">threat to water resources globally</a>, not just those of cold regions.</p>
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<figcaption><span class="caption">A brief overview of the process of eutrophication, produced by the National Oceanic and Atmospheric Administration.</span></figcaption>
</figure>
<p>Chloride, a key component of road salt, has earned the moniker of a “forever contaminant” <a href="https://doi.org/10.1016/j.scitotenv.2018.10.242">due to its persistence in soil and water systems</a>. When introduced into the environment, chloride ions readily dissolve into water <a href="https://doi.org/10.1016/j.scitotenv.2018.10.242">where they tend to remain</a>. </p>
<p>Over time, chloride not only accumulates in surface water bodies <a href="https://doi.org/10.1016/j.scitotenv.2023.166466">but also in groundwater</a>. In fact, ground (or subsurface) water has been identified as a persistent source of chloride to surface freshwater bodies, especially during the summer months. </p>
<p>While <a href="https://doi.org/10.2166/wqrjc.2011.105">proactive management practices have been introduced</a>, the accumulation of chloride and other problematic <a href="https://doi.org/10.1111/j.1747-6593.2012.00371.x">salt ions</a>, including sodium, in soil and water will require expensive and <a href="https://doi.org/10.2134/jeq2009.0108">time-consuming restoration efforts</a>. </p>
<h2>Paving the path to solutions</h2>
<p>To mitigate the impacts of salinization, evidence-based approaches are urgently required. Solutions and policy recommendations must promote the reduction of salt runoff from road salt applications and other sources, and establish effective and comprehensive monitoring programs. </p>
<p>We have much to learn from how we’ve successfully managed excessive nutrient pollution — these lessons can help inform salt management strategies that work hand in hand with water quality and climate change solutions.</p>
<p>One potential alternative to the application of road salts is to use other de-icers. This requires a cautious stance because, as history teaches us, replacing one troublesome chemical with another often comes with unexpected ecological consequences. </p>
<p>Thorough examination and research are vital to ensure that alternatives don’t inadvertently introduce new threats.</p>
<h2>Protecting people and ecosystems</h2>
<p>The stakes are high when it comes to road salts: compromised drinking water, shrinking aquatic habitats and long-term pollution from legacy salt stores in soil and groundwater requiring costly remediation. It’s imperative that research, investment and public awareness converge to address this challenge holistically. </p>
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Read more:
<a href="https://theconversation.com/to-make-less-harmful-road-salts-were-studying-natural-antifreezes-produced-by-fish-153087">To make less-harmful road salts, we're studying natural antifreezes produced by fish</a>
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<p>The impacts of road salt’s application extend far beyond the icy surfaces it’s intended to protect us from. As winter approaches, policy should work towards protecting our ecosystems and the many services they provide.</p><img src="https://counter.theconversation.com/content/215131/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jovana received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>David L Rudolph receives funding from the Natural Sciences and Engineering Research Council of Canada, the Ontario Ministry of the Environment, Conservation and Parks and the Regional Municipality of Waterloo. </span></em></p><p class="fine-print"><em><span>Fereidoun received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Nancy received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Philippe received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Jiangyue Ju 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>Increasing awareness of the dangers ‘forever chemical’ road salts pose to our fresh water systems highlights the urgent importance of finding new approaches to de-icing our roads.Jovana Radosavljevic, Postdoctoral Fellow, Ecohydrology Research Group, University of WaterlooDavid L Rudolph, Professor of Hydrogeology, Department of Earth & Environmental Sciences, University of WaterlooFereidoun Rezanezhad, Research Associate Professor, Department of Earth & Environmental Sciences, University of WaterlooJiangyue Ju, PhD Student in Earth and Environmental Sciences, University of WaterlooNancy Goucher, Knowledge Mobilization Specialist, University of WaterlooPhilippe Van Cappellen, Professor of Biogeochemistry and Canada Excellence Research Chair Laureate in Ecohydrology, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2153952023-10-12T12:30:45Z2023-10-12T12:30:45ZWhat is a strong El Niño? Meteorologists anticipate a big impact in winter 2023-2024, but the forecasts don’t all agree<figure><img src="https://images.theconversation.com/files/553361/original/file-20231011-29-363wak.png?ixlib=rb-1.1.0&rect=32%2C873%2C3211%2C2058&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The El Niño pattern stands out in the warm sea surface temperature anomalies in the Pacific in 2023</span> <span class="attribution"><a class="source" href="https://www.climate.gov/maps-data/data-snapshots/data-source/sst-enso-region-monthly-difference-average">NOAA Climate.gov</a></span></figcaption></figure><p><em>Meteorologists have been talking for weeks about <a href="https://www.accuweather.com/en/winter-weather/us-winter-forecast-for-the-2023-2024-season/1583853">a snowy season ahead</a> in the southern Rockies and the Sierra Nevada. They anticipate <a href="https://www.powder.com/trending-news/el-nino-huge-snow-east">more storms</a> in the U.S. South and Northeast, and warmer, drier conditions across the already dry Pacific Northwest and the upper Midwest.</em></p>
<p><em>One phrase comes up repeatedly with these projections: <a href="https://www.wcpo.com/weather/weather-101/a-strong-el-nino-expected-this-winter-heres-what-that-means-for-our-weather">a strong El Niño</a> is coming.</em></p>
<p><em>It sounds ominous. But what does that actually mean? We asked <a href="https://scholar.google.com/citations?user=z7CXcXkAAAAJ&hl=en">Aaron Levine</a>, an atmospheric scientist at the University of Washington whose research focuses on El Niño.</em></p>
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<figcaption><span class="caption">NOAA explains in animations how El Niño forms.</span></figcaption>
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<h2>What is a strong El Niño?</h2>
<p>During a normal year, the warmest sea surface temperatures are in the western Pacific and the Indian Ocean, in what’s known as the <a href="https://doi.org/10.1186/s40562-016-0054-3">Indo-Western Pacific warm pool</a>.</p>
<p>But every few years, the trade winds that blow from east to west weaken, allowing that warm water to slosh eastward and <a href="https://www.pmel.noaa.gov/elnino/schematic-diagrams">pile up along the equator</a>. The warm water causes the air above it to warm and rise, fueling precipitation in the central Pacific and shifting atmospheric circulation patterns across the basin.</p>
<p>This pattern is <a href="https://www.pmel.noaa.gov/elnino/what-is-el-nino">known as El Niño</a>, and it can <a href="https://www.climate.gov/media/13628">affect weather around the world</a>.</p>
<figure class="align-center ">
<img alt="An animation shows how warm water builds up along the equator off South America. The box where temperatures are measured is south of Hawaii." src="https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=272&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=272&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=272&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=342&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=342&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553048/original/file-20231010-23-c36xip.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=342&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The box shows the Niño 3.4 region as El Niño begins to develop in the tropical Pacific, from January to June 2023.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/">NOAA Climate.gov</a></span>
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<p>A strong El Niño, in the most basic definition, occurs once the average sea surface temperature in the equatorial Pacific is at least 1.5 degrees Celsius (2.7 Fahrenheit) warmer than normal. It’s measured in an imaginary box along the equator, roughly south of Hawaii, known as the <a href="https://svs.gsfc.nasa.gov/4695">Nino 3.4 Index</a>.</p>
<p>But El Niño is a coupled ocean-atmosphere phenomenon, and the atmosphere also plays a crucial role.</p>
<p>What has been surprising about this year’s El Niño – and still is – is that the atmosphere hasn’t responded as much as we would have expected based on the rising sea surface temperatures.</p>
<h2>Is that why El Niño didn’t affect the 2023 hurricane season the way forecasts expected?</h2>
<p>The 2023 Atlantic hurricane season is a good example. Forecasters often use El Niño as a predictor of <a href="https://www.weather.gov/ilx/swop-springtopics">wind shear</a>, which can tear apart Atlantic hurricanes. But with the atmosphere not responding to the warmer water right away, the impact on Atlantic hurricanes was lessened and it turned out to be a <a href="https://www.nytimes.com/article/tropical-storm-sean-hurricane.html">busy season</a>.</p>
<p><a href="https://doi.org/10.1175/JCLI-D-12-00097.1">The atmosphere is what transmits El Niño’s impact</a>. Heat from the warm ocean water causes the air above it to warm and rise, which fuels precipitation. That air sinks again over cooler water. </p>
<p>The rising and sinking creates giant loops in the atmosphere <a href="https://www.climate.gov/news-features/blogs/enso/walker-circulation-ensos-atmospheric-buddy">called the Walker Circulation</a>. When the warm pool’s water shifts eastward, that also shifts where the rising and sinking motions happen. The atmosphere reacts to this change like ripples in a pond when you throw a stone in. These ripples affect the jet stream, which steers weather patterns in the U.S.</p>
<p>This year, in comparison with other large El Niño events – such as <a href="https://www.climate.gov/news-features/blogs/enso/united-states-el-ni%C3%B1o-impacts-0">1982-83, 1997-98</a> and <a href="https://www.climate.gov/news-features/understanding-climate/2015-state-climate-el-ni%C3%B1o-came-saw-and-conquered">2015-16</a> – we’re not seeing the same change in where the precipitation is happening. It’s taking much longer to develop, and it’s not as strong.</p>
<p>Part of that, presumably, is related to the whole tropics being very, very warm. But <a href="https://doi.org/10.1029/2019GL086182">this is still an emerging field of research</a>.</p>
<p>How El Niño will change with global warming is a big and open question. El Niño <a href="https://www.climate.gov/news-features/understanding-climate/climate-variability-oceanic-nino-index">only happens every few years</a>, and there’s a fair amount of variability between events, so just getting a baseline is tough.</p>
<h2>What does a strong El Niño typically mean for US weather?</h2>
<p>During <a href="https://www.climate.gov/enso">a typical El Niño winter</a>, the U.S. South and Southwest are cooler and wetter, and the Northwest is warmer and drier. The upper Midwest tends to be drier, while the Northeast tends to be a little wetter. </p>
<p>The likelihood and the intensity generally scale with the strength of the El Niño event.</p>
<p>El Niño has traditionally been good for the mountain snowpack in California, which the state relies for a large percentage of its water. But it is often not so good for the Pacific Northwest snowpack.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two maps showing wetter, cooler weather in the Southeast and drier warmer air in the north during El Nino." src="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=834&fit=crop&dpr=1 600w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=834&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=834&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1047&fit=crop&dpr=1 754w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1047&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/553424/original/file-20231012-15-3wfvdw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1047&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 jet stream takes a very different path in a typical El Niño vs. La Niña winter weather pattern. But these patterns have a great deal of variability. Not every El Niño or La Niña year is the same.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/media/14484">NOAA Climate.gov</a></span>
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</figure>
<p>The <a href="https://www.climate.gov/news-features/featured-images/how-el-ni%C3%B1o-and-la-ni%C3%B1a-affect-winter-jet-stream-and-us-climate">jet stream plays a role</a> in that shift. When the polar jet stream is either displaced very far northward or southward, storms that would normally move through Washington or British Columbia are steered to California and Oregon instead.</p>
<h2>What do the forecasts show for the months ahead?</h2>
<p>Whether forecasters think a strong El Niño will develop depends on whose forecast model they trust.</p>
<p>This past spring, the <a href="https://www.weather.gov/media/climateservices/NWS%20Climate%20Forecast%20and%20Tools.pdf">dynamical forecast models</a> were <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table">already very confident</a> about the potential for a strong El Niño developing. These are big models that solve basic physics equations, starting with current oceanic and atmospheric conditions. </p>
<p>However, statistical models, which use statistical predictors of El Niño calculated from historical observations, were less certain.</p>
<p>Even in the <a href="https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table">most recent forecast model outlook</a>, the dynamical forecast models were predicting a stronger El Niño than the statistical models were.</p>
<p>If you go by just a sea surface temperature-based El Niño index, the forecast is for a fairly strong El Niño. </p>
<p>But the indices that incorporate the atmosphere are not responding in the same way. We’ve seen <a href="https://psl.noaa.gov/enso/enso.current.html">atmospheric anomalies</a> – as measured by cloud height monitored by satellites or sea-level pressure at monitoring stations – on and off in the Pacific since May and June, <a href="https://images.theconversation.com/files/553327/original/file-20231011-15-kprvx9.png">but not in a very robust fashion</a>. Even in September, they were nowhere near as large as they were in 1982, in terms of overall magnitude.</p>
<p>We’ll see if the atmosphere catches up by wintertime, when El Niño peaks.</p>
<h2>How long do El Niños last?</h2>
<p>Often during El Niño events – particularly strong El Niño events – the sea surface temperature anomalies collapse really quickly during the Northern Hemisphere spring. Almost all end in April or May.</p>
<p>One reason is that El Niño sows the seeds of its own demise. When El Niño happens, it <a href="https://doi.org/10.1175/1520-0469(1997)054%3C0811:AEORPF%3E2.0.CO;2">uses up that warm water</a> and the warm water volume shrinks. <a href="https://doi.org/10.1175/1520-0442(2000)013%3C3551:OOWWVC%3E2.0.CO;2">Eventually, it has eroded its fuel</a>.</p>
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<p>The surface can stay warm for a while, but once the heat from the subsurface is gone and the trade winds return, the El Niño event collapses. At the end of past El Niño events, the sea surface anomaly dropped very fast and we saw conditions typically switch to La Niña – El Niño’s cooler opposite.</p><img src="https://counter.theconversation.com/content/215395/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Levine receives funding from NOAA and has received funding in the past from the National Research Council. He is a member of the American Geophysical Union </span></em></p>An atmospheric scientist explains how El Niño works, this year’s oddities and why this phenomenon doesn’t last long.Aaron Levine, Atmospheric Research Scientist, CICOES, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2146192023-10-04T16:40:14Z2023-10-04T16:40:14ZUnderstanding the dynamics of snow cover in forests can help us predict flood risks<figure><img src="https://images.theconversation.com/files/551050/original/file-20230926-17-3adew2.jpg?ixlib=rb-1.1.0&rect=23%2C5%2C3914%2C2964&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A better understanding of the interactions between snow cover and forest will help improve hydrological models and thus ensure public protection against flooding.</span> <span class="attribution"><span class="source">(Benjamin Bouchard)</span>, <span class="license">Fourni par l'auteur</span></span></figcaption></figure><p>For more than six months a year, Quebec’s boreal forest is covered in a thick blanket of snow. While this is essential for the balance of our ecosystems, for the people living downstream from forested watersheds the snow can be like a sword of Damocles hanging over their heads. </p>
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<p><strong>This article is part of <em>La Conversation Canada’s</em> series <a href="https://theconversation.com/ca-fr/topics/foret-boreale-138017">The boreal forest: A thousand secrets, a thousand dangers</a></strong></p>
<p><br><em>La Conversation Canada invites you to take a virtual walk in the heart of the boreal forest. In this series, our experts focus on management and sustainable development issues, natural disturbances, the ecology of terrestrial wildlife and aquatic ecosystems, northern agriculture and the cultural and economic importance of the boreal forest for Indigenous peoples. We hope you have a pleasant — and informative — walk through the forest!</em></p>
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<p>The major floods of spring 2023 in the Charlevoix region show why the snow cover poses a risk. </p>
<p>Last winter, the Rivière du Gouffre watershed, of which <a href="https://charlevoixmontmorency.ca/l-obv-cm/territoire/">nearly 75 per cent is covered by forests</a>, accumulated a large amount of snow. The melting of this snow cover combined with an extremely intense rainfall event helped push the river out of its bed, causing <a href="https://www.cbc.ca/news/canada/montreal/flood-baie-saint-paul-residents-cleaning-1.6829490">unprecedented flooding in Baie-Saint-Paul</a>.</p>
<p>As part of my PhD at Université Laval, in collaboration with <a href="https://sentinellenord.ulaval.ca/en/home">Sentinel North</a>, I am looking at the impact of snow cover properties on watershed hydrology in the boreal forest.</p>
<h2>Rain as an energy carrier</h2>
<p>As we saw in the spring of 2023, rain events combined with snow cover can lead to a sudden rise in river water levels. One reason for this is that rainwater transfers heat to the snow. </p>
<p>A heat exchange occurs between rain and snow when their temperatures differ. The snow warms up, and the rain cools down. Once the snow has reached a temperature of 0°C, any additional heat from the rain causes melting.</p>
<p>So, a snow cover of near 0 C, common in spring, and heavy rainfall at high temperatures, together create conditions where both meltwater and rainwater contribute to a higher flow of water. This increases the likelihood of flooding. However, this will only happen if the water produced can flow easily through the snow cover. </p>
<p>On the other hand, a cold snow cover combined with low-temperature rainfall can lead to rainwater freezing in the snow. This water will then remain trapped in the snow and won’t present a flooding risk. </p>
<p>After all, heat exchange goes both ways!</p>
<h2>The snow cover, a complexly structured environment</h2>
<p>The snow cover is a porous medium that does not have uniform physical properties. Rather, it is a stack of snow layers that represent the history of the winter’s meteorological events. Rainwater must percolate through all the snow layers to reach the ground, and eventually, the watercourse.</p>
<p>Some layers, such as fine-grained layers and layers of ice, limit the flow of water through the snow. In contrast, coarse-grained layers, which have larger pores, facilitate the flow of water. As a result, they enable rainwater and meltwater to reach the ground quickly.</p>
<h2>The role of the forest</h2>
<p>The structure of the snow cover influences the risk of flooding. But what effect do forests have on snow structure? </p>
<p>By intercepting part of the precipitation in its solid form (snow), trees limit the accumulation of snow on the ground. That, in turn, contributes to the <a href="https://doi.org/10.1029/JC088iC09p05475">growth of snow grains and pores on the ground</a> through upward water vapour flux. In addition, the discharge of snow intercepted by trees in solid or liquid form <a href="https://doi.org/10.1016/j.foreco.2019.01.052">increases the heterogeneity of the snow cover</a>. These processes promote rapid water flow in the snow cover that forms beneath the trees.</p>
<h2>The same everywhere?</h2>
<p>Forest cover is far from uniform in the boreal forest. It’s more akin to sparse vegetation with treeless zones known as gaps. In these gaps, the structure of the snow cover is very different from that under the trees.</p>
<p>The greater accumulation of snow in the gaps favours the compaction of snow layers and the formation of fine grains. In addition, daily cycles of surface refreezing lead to the formation of low-permeability ice layers. </p>
<p>The snow cover in the gaps is, therefore, less favourable to the percolation of water to the ground <a href="https://doi.org/10.1002/hyp.14681">than that found under the trees</a>.</p>
<p>But does this mean that the presence of gaps reduces the risk of flooding? Not quite.</p>
<h2>Snow melts faster in gaps</h2>
<p>The structure of the snow cover is just one of the factors that influences flooding. Ground that is frozen, which limits infiltration, as well as rapid snowmelt also increase the risk of flooding. </p>
<p>In Québec’s boreal forests, although the ground does not freeze in the gaps between trees due to the insulating nature of the snow cover, the <a href="https://doi.org/10.5194/hess-2023-191">melt rate is much higher</a> because solar radiation is stronger than it is under the trees, particularly in spring. </p>
<p>Although more snow would accumulate in the gaps, it takes less time to melt and reaches the watercourse more quickly than the snow under the trees. That increases waterflow and, as a consequence, the risk of flooding.</p>
<p>The combination of thicker snow cover in the gaps and more permeable snow layers under the trees contributed to the Rivière du Gouffre flooding Baie-Saint-Paul during the extreme rainfall of spring 2023.</p>
<p>Rainfall events like this <a href="https://www.ouranos.ca/en/precipitations-projected-changes">will continue to increase in frequency as global temperatures warm</a>. However, increased knowledge of the interactions between snow cover and forest will help improve hydrological models and ensure better public protection against flooding.</p><img src="https://counter.theconversation.com/content/214619/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benjamin Bouchard has received funding from the Fonds de recherche Nature et technologie du Québec (FRQNT), the Natural Sciences and Engineering Research Council of Canada (NSERC) and Sentinel North. </span></em></p><p class="fine-print"><em><span>Daniel Nadeau has received funding from Environment and Climate Change Canada, as well as from the Natural Sciences and Engineering Research Council of Canada.</span></em></p><p class="fine-print"><em><span>Florent Domine has received funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p>A better understanding of the interactions between the boreal forest and snow will make it possible to improve hydrological models and ensure optimal management of the resource.Benjamin Bouchard, Étudiant-chercheur au doctorat en génie des eaux, Université LavalDaniel Nadeau, Professeur titulaire en hydrologie des régions froides, Université LavalFlorent Domine, Professeur, chimie, Université LavalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2115712023-09-05T21:45:34Z2023-09-05T21:45:34ZNew research may point the way towards frost-free heat pumps<p>A chilly winter morning, the car windshield shrouded in a thick layer of frost. Who has not experienced the frustration of scraping ice or waiting for the defroster to work? It is a daily winter struggle, but what if this frost issue extends far beyond your car, into your very home? Welcome to the hidden battle with frost in our energy systems.</p>
<p>Frost forms when humid air comes into contact with freezing cold surfaces. The colder the surface and the more humid the air is, the <a href="https://doi.org/10.1016/j.enbuild.2020.110219">more likely</a> frost will form on the surface.</p>
<p>In buildings, frosting is a problem that impacts several systems, including heat pumps that keep indoor spaces warm. Researchers at the University of Saskatchewan are working to eliminate this chilly scenario by creating frost-resistant heat pumps.</p>
<h2>Current challenges</h2>
<p>Frost poses <a href="https://doi.org/10.1016/j.enbuild.2022.112387">serious challenges</a> to the functionality of heat pumps. The frost layer acts as an insulator, reducing the <a href="https://publications.ibpsa.org/conference/paper/?id=usim2022_p108">heat transfer capability</a>, which <a href="https://doi.org/10.3390/en14185737">increases energy use</a> and <a href="https://doi.org/10.3390/en14092646">negatively impacts the comfort of users</a>. Frost also blocks air passages, and a severe frost buildup can even <a href="http://cchrc.org/media/ASHP_SE_Report.pdf">damage or destroy the system</a>. </p>
<p><a href="https://www.iea.org/energy-system/buildings/heat-pumps">Heat pumps</a> <a href="https://www.iea.org/energy-system/electricity/electrification">electrify</a> <a href="https://www.iea.org/energy-system/buildings/heating">heating</a> and play a pivotal role in our quest for energy efficiency and eco-friendliness, owing to their relatively high efficiencies. Acting as devices that transfer heat from one place to another, they are promising solutions for the <a href="https://www.iea.org/reports/the-future-of-heat-pumps">future of heating</a>. With the potential to cut down <a href="https://www.iea.org/energy-system/buildings">energy consumption and emissions</a>, improving heat pumps is crucial in our eco-conscious world.</p>
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Read more:
<a href="https://theconversation.com/heat-pumps-can-cut-your-energy-costs-by-up-to-90-its-not-magic-just-a-smart-use-of-the-laws-of-physics-185711">Heat pumps can cut your energy costs by up to 90%. It’s not magic, just a smart use of the laws of physics</a>
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<p>To tackle frosting, commercial heat pumps usually go into <a href="https://doi.org/10.1016/j.apenergy.2017.12.022">recurrent defrosting cycles</a>, during which heating is not accessible. Therefore, most heat pumps in cold climates are installed with <a href="http://cchrc.org/media/ASHP_SE_Report.pdf">backup fuel-burning or electric heating systems</a>. Several <a href="https://doi.org/10.1080/15435075.2023.2199329">optimization techniques</a> have been suggested for the defrosting cycles to become more effective.</p>
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<figcaption><span class="caption">An overview of the basic principle of a heat pump system produced by This Old House.</span></figcaption>
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<p>Given <a href="https://doi.org/10.1016/j.tsep.2019.03.002">the challenges</a> of removing frost from heat pumps, the prospect of creating frost-free systems becomes increasingly appealing. However, preventing frost without consuming excessive energy is a complex task, filled with intricate technical hurdles.</p>
<h2>Ongoing research</h2>
<p>A major part of the ongoing endeavours to develop frost-free heat pumps has roots in <a href="https://doi.org/10.1016/j.rser.2013.10.038">research into frost-free energy exchangers</a>. The outdoor unit of a heat pump system is a heat exchanger. It facilitates heat transfer from outdoor air to the refrigerant fluid running through the coils. </p>
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Read more:
<a href="https://theconversation.com/do-heat-pumps-work-in-the-uks-climate-an-expert-answers-your-low-carbon-heating-questions-211150">Do heat pumps work in the UK's climate? An expert answers your low-carbon heating questions</a>
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<p>If heat exchangers prevent condensation, they can <a href="https://doi.org/10.1115/1.4041557">reduce the risk of frosting</a>. This is what membrane energy exchangers do by removing moisture and preventing air saturation.</p>
<p>Future heat pumps can benefit from membrane energy exchangers that use <a href="https://patents.google.com/patent/WO2016026042A1">liquid working fluids</a>. The membrane energy exchanger would replace the traditional finned tubes in heat pump outdoor units and make them frost-resistant.</p>
<p>Using membranes to develop frost-free solutions for heat pumps is not without its challenges. We need to address several issues regarding membrane energy exchangers. Finding commercial membranes and non-corrosive <a href="https://doi.org/10.1016/j.apenergy.2022.119853">liquids</a> suitable for the application are two examples. <a href="http://dx.doi.org/10.1016/j.expthermflusci.2016.04.009">Frost detection</a> is another challenge in membrane energy exchangers. </p>
<p><a href="https://doi.org/10.1016/j.ijheatmasstransfer.2018.12.116">Properties</a>, <a href="https://doi.org/10.1016/j.ijheatmasstransfer.2021.121912">behaviour</a> and the <a href="https://doi.org/10.1115/1.4041185">triggering conditions</a> of frosting have already been investigated. Ongoing research by my team at the University of Saskatchewan is now trying to identify ideal membrane characteristics and design factors for the application.</p>
<h2>Shaping a sustainable future</h2>
<p>Future frost-resistant heat pumps will dramatically enhance energy efficiency, <a href="https://theconversation.com/heat-pumps-can-cut-your-energy-costs-by-up-to-90-its-not-magic-just-a-smart-use-of-the-laws-of-physics-185711">slash household bills</a> and take a significant step toward a more sustainable future. Scientists are contributing to the technological advancements required to realize this futuristic concept. </p>
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Read more:
<a href="https://theconversation.com/how-heating-your-home-fuels-climate-change-and-why-government-measures-are-failing-to-stop-it-208518">How heating your home fuels climate change – and why government measures are failing to stop it</a>
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<p>These advancements are not just about the science; they symbolize a transformation in our everyday lives, making winter days more convenient and our homes and buildings more environmentally friendly at the same time.</p><img src="https://counter.theconversation.com/content/211571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amirreza Mahmoudi 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>Heat pumps are essential for the large-scale adoption of more carbon friendly heating systems and recent research suggests a way forward for reducing one of the technology’s biggest hurdles — frost.Amirreza Mahmoudi, PhD Candidate in Mechanical Engineering, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1950502023-08-28T20:43:17Z2023-08-28T20:43:17ZNorthern map turtles survive cold winter conditions by staying active under ice<figure><img src="https://images.theconversation.com/files/544833/original/file-20230825-27248-hk37fo.jpg?ixlib=rb-1.1.0&rect=0%2C49%2C4683%2C3063&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">As climate change increases temperatures, it is important to understand how freshwater turtles survive the winter.</span> <span class="attribution"><span class="source">(Shutterstock)</span></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/northern-map-turtles-survive-cold-winter-conditions-by-staying-active-under-ice" width="100%" height="400"></iframe>
<p>Imagine it’s winter, and you’re standing on a frozen lake or pond, when suddenly below your feet you notice hundreds of turtles. What are they doing down there below the ice? </p>
<p>Freshwater turtles in temperate regions like Canada spend several months of the year braced against frigid winter conditions of temperatures around or below 0 C <a href="https://doi.org/10.1093/biosci/biab032">and the formation of ice on water bodies</a>. </p>
<p>For all <a href="https://www.natureconservancy.ca/en/what-we-do/resource-centre/featured-species/turtles-of-canada.html">eight species of freshwater turtles in Canada</a>, this ice barrier — and more importantly the liquid water below it — is a refuge from the freezing temperatures above. While ice coverage protects these turtles from the harsh cold, it also presents them with a challenge: restricted access to atmospheric oxygen.</p>
<h2>Life under ice</h2>
<p>Some species, like snapping turtles (<em>Chelydra serpentina</em>) and painted turtles (<em>Chrysemys picta</em>), are <a href="https://doi.org/10.1017/S1464793106007032">perfectly comfortable spending several months submerged in water depleted in oxygen</a>. However, some species do not fare as well without oxygen and can only survive a few weeks at a time if submerged without adequate oxygen. These species need to extract the oxygen dissolved in the water to survive.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a turtle visible under frozen ice" src="https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544831/original/file-20230825-27-vpciz1.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>
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<span class="caption">A snapping turtle under ice in southern Ontario.</span>
<span class="attribution"><span class="source">(Lucas Foerster/iNaturalist)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>The northern map turtle (<em>Graptemys geographica</em>) is an example of such a species. They have also been observed engaging in locomotor activity — they keep moving around under the ice during the winter.</p>
<p>Northern map turtles were observed over a century ago by <a href="https://journals.iupui.edu/index.php/ias/article/view/14633/14709">marine biologists Barton Warren Evermann and Howard Walton Clark</a>. </p>
<p>During a dive at a communal hibernation site in November 1991 in Vermont, marine biologists observed <a href="https://www.biodiversitylibrary.org/item/106990#page/537/mode/1up">map turtles walking across the bottom of a river before ice coverage when temperatures were dropping to near 0 C</a>. </p>
<p>These observations lead us to believe that this behaviour may be important to a map turtle’s ability to survive the winter. Why else would they tap into their limited winter energy stores to move?</p>
<p>But how much do turtles really move in the winter?</p>
<h2>Advances in technology</h2>
<p>To track the movement of northern map turtles under the ice, our team glued tri-axial accelerometers — a type of biologging device that collects data — on 40 turtles at a known overwintering site in eastern Ontario. These devices recorded the movement, depth and temperature of the turtles for the seven months they remained under the ice. </p>
<p>Tri-axial accelerometers function similarly to a FitBit or Apple Watch — the devices produce <a href="https://doi.org/10.1111/j.2041-210X.2010.00057.x">a value called overall dynamic body acceleration</a>. This number is a measure of how much each turtle moves on a daily basis. </p>
<p>Combining this information with measurements of depth and temperature, we were able to paint a detailed picture of each turtle’s behaviour without ever seeing them. </p>
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<a href="https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a turtle swims underwater with a device attached to its back" src="https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498317/original/file-20221130-22-kthfq4.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"></a>
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<span class="caption">A northern map turtle swims underwater with a tri-axial accelerometer attached to its back.</span>
<span class="attribution"><span class="source">(Grégory Bulté)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<h2>Daily movement</h2>
<p>Our findings surprised us. The data showed that northern map turtles move, albeit locally, every day of the winter. While that may look different across individuals, the interesting thing here is that movement is indeed continuous throughout the winter and not that different than in the weeks before the ice locks them in for the winter. </p>
<p>Although we expected some level of activity based on previous observations, we did not expect the turtles to be so fidgety all winter long. </p>
<p>Oxygen appears to be <a href="https://doi.org/10.1139/cjz-2022-0100">in short supply under the ice</a>, and map turtles cannot live without it for very long, so one would expect them to take it easy to limit their oxygen consumption. Our devices also told us the turtles were milling about in water hovering around 1 C, <a href="https://doi.org/10.1139/cjz-2022-0100">a temperature at which most reptiles become uncontrollably lethargic</a>.</p>
<p>Staying cool may in fact be what allows turtles to remain active. It’s likely that by staying at near-freezing temperatures, map turtles can slow their metabolic demands, thereby decreasing their need for oxygen and extending their use of this limited resource. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/DyOZf2qC5Ik?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A video showing underwater northern map turtle activity during the winter.</span></figcaption>
</figure>
<h2>Implications of movement</h2>
<p>We suspect that map turtles remain active in winter to meet their need for oxygen in order to survive the winter. Small amounts of activity may allow this species to replace the oxygen-depleted boundary layer of water on their skin with freshly oxygenated water. This would enhance their ability to “breathe” through their skin. </p>
<p>Alternatively, movement may be necessary for turtles as they look for micro-climates within their environment that have higher concentrations of oxygen or preferred temperature and depth profiles. In doing so, map turtles may be able to better need their physiological needs and oxygen requirements through the entirety of winter. </p>
<p>Much of what we know about reptiles in temperate regions is based on research done during the months which they are conspicuous. We are thus missing out on a big chunk of their annual cycle. As global temperatures continue to change, it is increasingly important to understand the winter part of a reptile’s lifecycle so we can plan how climate change may impact these animals.</p><img src="https://counter.theconversation.com/content/195050/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jessica Robichaud received funding from Carleton University, Natural Sciences and Engineering Research Council (NSERC), the Canadian Foundation for Innovation and the Ontario Research Fund Small Infrastructure Fund.</span></em></p>Freshwater turtles in Canada survive the cold, harsh winters by remaining under ice and conserving their energy. Northern map turtles however, move around constantly beneath the ice.Jessica Robichaud, PhD Student, Aquatic ecology, Carleton UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2106932023-08-01T00:22:59Z2023-08-01T00:22:59ZWhy is Australia having such a warm winter? A climate expert explains<figure><img src="https://images.theconversation.com/files/540096/original/file-20230731-17-nj0u87.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6669%2C3138&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>If you’ve been out and about the past few days, you may have noticed Australia is experiencing an unseasonably warm winter. It’s been t-shirt weather across many parts of the country’s east, including Sydney where <a href="https://www.theguardian.com/environment/2023/jun/08/australia-ski-season-no-snow-skiing-snowboarding-resorts-closed-warm-weather">temperatures topped 25°C</a> on Sunday.</p>
<p>Meanwhile, at high altitudes, the cover at some snowfields remains <a href="https://twitter.com/Cam_Walker/status/1685525535521402880">lacklustre</a>, even after warm conditions forced <a href="https://www.abc.net.au/news/2023-06-09/nsw-resorts-postpone-ski-snowboarding-kings-birthday-lack-snow/102456510">a delay</a> to the start of the traditional ski season.</p>
<p>All this comes after the world experienced its hottest month since reliable records began. July brought <a href="https://qz.com/hottest-days-month-ever-recorded-july-2023-1850685494">an incredible 21 of the warmest 30 days</a> ever recorded – prompting the United Nations to declare a new era of “<a href="https://www.theguardian.com/science/2023/jul/27/scientists-july-world-hottest-month-record-climate-temperatures">global boiling</a>”. </p>
<p>So what’s going on with the weather in Australia? Should we just enjoy the pleasant conditions, or is it a troubling sign of what’s to come under climate change? </p>
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<h2>The nice weather, explained</h2>
<p>Australia’s unseasonably warm conditions are the result of both natural drivers of our weather and continued global warming.</p>
<p>Since early July, warmer and drier conditions have dominated, due to a high pressure system sitting stubbornly over Australia at the moment. The clear conditions are leading to warmer daytime conditions. </p>
<p>For example, daytime temperatures in Canberra in July – historically known for its cold winters – were <a href="https://www.9news.com.au/national/canberra-on-track-for-warmest-july-max-temps-on-record/1d0b9683-7dda-4cc0-b6a6-1e32bfa51407">the warmest on record</a>, despite frequent frosty mornings. Sydney has just experienced its <a href="https://www.theguardian.com/australia-news/2023/jul/31/australia-weather-august-warmth-heat-winds-tasmania#:%7E:text=Sydney%27s%2023.5C%20was%20enough,Hill%20goes%20back%20to%201858.">warmest July</a> on record, too.</p>
<p>The high pressure has caused the air over the continent’s interior to warm. When cold fronts move across the south of Australia they push this warm air ahead of them, bringing warm and windy conditions to southern coastal areas. This is similar to the weather pattern we see in summer when cities such as Adelaide and Melbourne experience their hottest days.</p>
<p>On Thursday, an approaching cold front is forecast to lift temperatures ahead of it to about 23°C in Adelaide, 20°C in Melbourne and 18°C in Hobart. These are very warm temperatures in these locations for early August.</p>
<p>And what about the oceans? Around Australia, oceans are a bit cooler than average in some places including <a href="http://www.bom.gov.au/products/IDYOC053.Global.SSTAnomaly.shtml">to the northwest of the continent</a>. </p>
<p>But as the image below shows, ocean temperatures are currently above normal in many places around the world, including the west Indian Ocean and the central and eastern tropical Pacific. This indicates a developing El Niño and positive Indian Ocean Dipole – two natural climate drivers that affect Australia’s weather patterns.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=364&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=364&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=364&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=458&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=458&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540054/original/file-20230730-191965-434fnd.png?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"></a>
<figcaption>
<span class="caption">Across most of the world’s oceans, temperatures remain well above normal.</span>
<span class="attribution"><span class="source">National Oceanic and Atmospheric Administration</span></span>
</figcaption>
</figure>
<p>This difference in ocean temperatures reduces the amount of atmospheric moisture over southern and eastern Australia. It also makes low pressure systems weaker and less frequent, reducing rainfall over the region.</p>
<p>Over the coming months, warm and dry weather is expected to continue. For the rest of winter and spring, it’s expected to be <a href="http://www.bom.gov.au/climate/outlooks/#/rainfall/summary">drier than normal</a> in the southwest of Western Australia and much of the east of the continent. And the whole of Australia is predicted to be <a href="http://www.bom.gov.au/climate/outlooks/#/temperature/summary">warmer than normal</a> during this period. Of course, this doesn’t rule out occasional cool, wet spells.</p>
<p>So is climate change a factor here? Yes. Australia’s land areas have <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/factsheets/IPCC_AR6_WGI_Regional_Fact_Sheet_Australasia.pdf">already warmed by 1.4°C</a> since pre-industrial times. This is the result of humans burning fossil fuels and releasing greenhouse gases.</p>
<p>The record winter warmth is part of a <a href="https://theconversation.com/australias-record-breaking-winter-warmth-linked-to-climate-change-83304">long-term upward trend</a> in Australian winter temperatures. </p>
<p>As I’ve written <a href="https://theconversation.com/australias-record-breaking-winter-warmth-linked-to-climate-change-83304">previously</a>, there has been at least a 60-fold increase in the likelihood of a very warm winter that can be attributed to human-caused climate change. </p>
<p>And we’re likely to see more record warm winters as the planet continues to warm.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/global-warming-to-bring-record-hot-year-by-2028-probably-our-first-above-1-5-c-limit-205758">Global warming to bring record hot year by 2028 – probably our first above 1.5°C limit</a>
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<h2>Looking north</h2>
<p>Of course, Australia’s spell of warm weather seems harmless compared to the Northern Hemisphere’s weird and wild summer. </p>
<p>There, simultaneous extreme heatwaves have struck all four continents in recent weeks. Ocean temperatures are well <a href="https://www.washingtonpost.com/weather/2023/07/28/ocean-temperature-maps-heat-records/">above previous record highs</a> for this time of year. Last week, <a href="https://edition.cnn.com/2023/07/25/weather/canadian-wildfire-us-air-pollution/index.html">1,000 wildfires burned</a> in Canada alone.</p>
<p>The planet’s warmest average temperatures typically happen in July. That’s because the Northern Hemisphere’s large land masses heat up more quickly than the oceans, in response to the high amounts of radiation from the sun. Still, the heat of the last few weeks has been unprecedented.</p>
<p>The heatwaves are <a href="https://theconversation.com/a-climate-expert-explains-the-northern-hemispheres-weird-wild-summer-and-what-it-means-for-australia-209862">linked to</a> high-pressure weather systems that are “blocking” or deflecting oncoming low-pressure systems (and associated clouds and rain). On top of this, human-caused global warming is greatly increasing the chance of record-breaking extreme heat events and concurrent heatwaves across many regions.</p>
<p>Worryingly, a <a href="https://www.worldweatherattribution.org/extreme-heat-in-north-america-europe-and-china-in-july-2023-made-much-more-likely-by-climate-change/">rapid analysis</a> by international experts suggests the extreme heat should not be viewed as unusual, given the effects of climate change. For example, it says China’s recent <a href="https://www.smh.com.au/world/asia/china-logs-52-2-celsius-as-extreme-weather-rewrites-records-20230718-p5dp1v.html">record-breaking heatwave</a> should now be expected about once in every five years, on average. </p>
<p>Not all extreme weather events can be attributed to human-caused climate change. But the study found climate change significantly contributed to the recent heatwaves in China, North America and Europe.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1684185665322332163"}"></div></p>
<h2>A sign of what’s to come</h2>
<p>The Northern Hemisphere’s heatwaves are very alarming. But Australia’s temperatures are also unusually high for winter – and this is also cause for concern.</p>
<p>Warm winters in Australia can negatively affect some parts of the economy, including the ski industry. It also disrupts flora and fauna and increases the chance of “<a href="https://theconversation.com/flash-droughts-can-dry-out-soil-in-weeks-new-research-shows-what-they-look-like-in-australia-161286">flash droughts</a>” – where drier-than-normal conditions turn into severe drought in the space of weeks. </p>
<p>The warm, dry conditions may also lead to an <a href="https://www.theguardian.com/cities/2018/aug/15/sydneys-bushfire-season-starts-in-winter-we-may-have-to-rethink-how-we-live">earlier start</a> to the fire season in Australia’s southeast. </p>
<p>So while we may appreciate warm winter weather, we mustn’t forget what’s driving it – and how urgently we need to stabilise Earth’s climate by slashing greenhouse gas emissions.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/two-trillion-tonnes-of-greenhouse-gases-25-billion-nukes-of-heat-are-we-pushing-earth-out-of-the-goldilocks-zone-202619">Two trillion tonnes of greenhouse gases, 25 billion nukes of heat: are we pushing Earth out of the Goldilocks zone?</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/210693/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the National Environmental Science Program. </span></em></p>What’s going on with the weather in Australia? It’s partly the result of natural drivers of our weather – and partly due to global warming.Andrew King, Senior Lecturer in Climate Science, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2094162023-07-31T17:08:53Z2023-07-31T17:08:53ZWhy we need to reuse waste energy to achieve net-zero heating systems<figure><img src="https://images.theconversation.com/files/539953/original/file-20230728-23-6n3k7n.jpg?ixlib=rb-1.1.0&rect=26%2C0%2C3000%2C1985&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Just generating heat is not enough. We must also capture, store, and utilize waste heat year-round and especially in the winter months.</span> <span class="attribution"><span class="source">(AP Photo/David J. Phillip)</span></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/why-we-need-to-reuse-waste-energy-to-achieve-net-zero-heating-systems" width="100%" height="400"></iframe>
<p>As we move toward a cleaner energy future, there is a growing push to electrify everything, from cars to home heating. While that sounds ideal, it is also much more than a matter of simply plugging in.</p>
<p>The <a href="https://www.cbc.ca/news/politics/power-grid-demand-electric-vehicles-1.6440595">grid is nowhere near ready to satisfy our carbon-free energy needs</a>, especially as more and more Canadians switch to electric vehicles and we wait for more carbon-free sources of electricity to supply the growing demand.</p>
<p>We’re <a href="https://www.scientificamerican.com/article/spikes-in-air-conditioning-use-with-warming-could-tax-electric-grid/">already pushing the system on the hottest days of the year to keep our electric air conditioning running</a>, mainly by supplementing with inefficient carbon-producing natural gas or coal power plants during peak demand periods.</p>
<p>If we were all relying on electrical forms of heating, electricity demand would be substantially higher on the coldest days of the year and overwhelm the grid. The solution to this problem, however, lies not in the heat we generate but the heat we reuse. </p>
<h2>The importance of heating</h2>
<p>Heating systems keep many of us alive.</p>
<p>In a cold-climate country such as Canada it takes far, far more energy to heat homes in winter than to cool them in summer. To compare the overall energy required for heating and cooling buildings we look at <a href="https://www.degreedays.net/">heating degree days (HDD) versus cooling degree days (CDD)</a>.</p>
<p>In Toronto, for example, heating degree days outnumber cooling degree days about 7-1. Consumers may not be aware of this huge disparity, since most home heating comes from burning natural gas, while most cooling comes from electricity, but if we moved all that demand to the grid, it would become apparent all too quickly.</p>
<figure class="align-center ">
<img alt="A chart representing heating degree days and cooling degree days by various key urban areas." src="https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538570/original/file-20230720-27-9p0mm9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chart representing heating degree days and cooling degree days by various key urban areas.</span>
<span class="attribution"><span class="source">(James S. Cotton)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Air conditioning already pushes the electrical grid when cooling indoor spaces to 23 C when it is above 35 C outside, but warming our indoor spaces to 20 C when it is -40 C outside means covering a 60-degree gap.</p>
<p>If we were to move all our heating demands to the electrical grid, even with <a href="https://doi.org/10.1016/j.joule.2019.11.011">the most modern, efficient air-source heat pumps</a>, <a href="https://www.pollutionprobe.org/future-hold-natural-gas-report">peak demand would be about four to five times what it is today</a>, and that’s not a problem anyone can solve quickly.</p>
<h2>Utilize everything</h2>
<p>Fortunately, there is another option that can keep us warm without burning additional fuel. By storing the heat generated from all sources, including waste heat, and drawing from it through the coldest months of the year, our research shows we can <a href="https://www.sciencedirect.com/science/article/abs/pii/S0306261923006554">use discarded waste heat</a>.</p>
<p>A huge amount of heat generated today is simply dissipated into our surroundings and wasted, and when it’s cold outside, we use new energy to make fresh heat. That doesn’t make sense.</p>
<p>A typical pizza restaurant produces <a href="https://patents.google.com/patent/US10094553B2/en?oq=14%2f791980">enough leftover heat</a> every year to heat <a href="https://www.cga.ca/natural-gas-statistics/natural-gas-facts/">seven family homes</a>. A <a href="https://www.sciencedirect.com/science/article/abs/pii/S0378778821004540">hockey arena creates huge amounts of heat</a> in the process of making ice and keeping it frozen. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chart showing the different demands of heating versus cooling systems at peak demand." src="https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=269&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=269&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=269&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=338&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=338&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538571/original/file-20230720-21-61nj78.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=338&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 chart showing the different demands of heating versus cooling systems at peak demand.</span>
<span class="attribution"><span class="source">(James S. Cotton)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Same for a grocery store and its many freezers and refrigerators, a factory running industrial-scale production equipment, and any large building running commercial air-conditioners. Today <a href="https://www.sciencedirect.com/science/article/abs/pii/S0196890423004971">we dump all that heat into the air instead of holding onto it for when we need it</a>, leading to unnecessary greenhouse gas emissions.</p>
<p>We need to start seeing the heat we make as a readily recoverable, carbon-free resource and do much more to harness it. There is already technology that can harvest and store such heat for months in <a href="https://www.sciencedirect.com/science/article/pii/S1364032121000290">underground thermal batteries</a> until it is needed.</p>
<h2>Integrated heat harvesting systems</h2>
<p>We can recover the heat by piping water through hot underground batteries and running those pipes into nearby buildings, like a big boiler-and-radiator system, except the boiler is <a href="https://energy.mcmaster.ca/icepick">actually an underground battery</a> charged not with electricity, but with heat.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/a-21st-century-reinvention-of-the-electric-grid-is-crucial-for-solving-the-climate-change-crisis-173631">A 21st-century reinvention of the electric grid is crucial for solving the climate change crisis</a>
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<p>McMaster University is preparing to put replacement back-up generators into play, <a href="https://dailynews.mcmaster.ca/articles/new-electric-boilers-will-reduce-campus-carbon-emissions-23-per-cent">which will supplement grid power during peak times</a>.</p>
<p>When demand is critical on the hottest days of the year, the gas-powered generators will create the extra electricity needed to operate the campus—including sensitive labs and research facilities. If we were to capture and store the waste heat produced and tie into it in the winter, <a href="https://www.sciencedirect.com/science/article/abs/pii/S2210670723001518">we could halve their net carbon emissions into the atmosphere</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram overviewing the ICE-Harvest plan." src="https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=441&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=441&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538828/original/file-20230723-192659-grm0uz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=441&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The Modular Integrated Community Energy and Harvesting System has the potential to provide winter-long heat at considerable carbon savings.</span>
<span class="attribution"><span class="source">(James S.Cotton)</span>, <span class="license">Author provided</span></span>
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<p>McMaster leads a wider research co-operative demonstration project called <a href="https://www.gridsmartcity.com/partners-sponsors-in-motion/innovation/mcmaster-ice/">Integrated Community Energy and Harvesting</a>, or ICE-Harvest, with 30 municipalities and 19 industrial partners taking part.</p>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S0306261923006554">In a new paper in the journal <em>Applied Energy</em></a>, we show how such localized systems use the same energy twice.</p>
<h2>Heat batteries already exist</h2>
<p>Capturing, saving and using leftover heat is an efficient solution that can be managed by localized microthermal networks. Think of it this way: the Canadian chain Pizza Pizza is <a href="https://www.ngif.ca/harvest-systems-successfully-demonstrates-waste-heat-recovery-from-pizza-pizza-ovens/">piloting a system</a> that uses heat recovered from its ovens to heat its own hot water. The chain can then sell what is left over. In the same way an arena can sell its heat to a retirement home across the street; a grocery store to a neighbouring school, and so on.</p>
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Read more:
<a href="https://theconversation.com/a-tenth-of-all-electricity-is-lost-in-the-grid-superconducting-cables-can-help-199001">A tenth of all electricity is lost in the grid. Superconducting cables can help</a>
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<p>This solution would require <a href="https://www.sciencedirect.com/science/article/abs/pii/S2210670723001518">new infrastructure</a>, including buried pipes to circulate heat from source to storage and from storage to user. That would be expensive to set up, but such costs could readily be spread out over decades, as previous generations did to build highways, hydro lines and gas pipelines.</p>
<p>Existing and emerging technology can measure and regulate the gathering, sharing and distribution of heat in a system where the accounts of heat producers are credited as they add to the supply and end users are charged when they draw from the supply. It is just a matter of time before industrial, commercial and institutional players realize there is value in their cooling towers.</p>
<p>These are not far-fetched ideas. They are practical and available to be implemented now and are a realistic climate action strategy. Here in the northern hemisphere, heat is a valuable resource that’s already there waiting to be tapped, and we can no longer afford to waste it.</p><img src="https://counter.theconversation.com/content/209416/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James (Jim) S. Cotton works for and owns shares in Harvest Systems Inc. He receives funding from Natural Sciences and Engineering Research Council of Canada (CRDPJ 401203143 - 2018) and the Ministry of Research and Innovation and Science administered by Ontario Centre of Innovation (27851-2018), Canada Foundation for Innovation (CFI) and Ontario Research Fund - Research Infrastructure. The author would also like to acknowledge the McMaster Energy Research Cooperative partners for their contributions: HCE Energy Inc., GridSmartCity LDC Cooperative (Brantford Power, Burlington Hydro, Energy+, ENWIN, ERTH Power, Essex Power Lines, Halton Hills Hydro, Kingston Hydro, Kitchener Wilmot Hydro, Milton Hydro, Niagara Peninsula Energy, Oakville Enterprises Corp., Waterloo North Hydro, Welland Hydro Electric Systems Corp.), Alectra Utilities, Enbridge Gas, S2e Technologies, Geosource Energy and Siemens Canada Limited</span></em></p>As the drive towards electrification advances, one fact seems clear: it is far easier to reuse waste heat for our homes and businesses than it is to generate it anew.James (Jim) S. Cotton, Professor, Department of Mechanical Engineering, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2088552023-07-26T00:32:56Z2023-07-26T00:32:56ZRSV is everywhere right now. What parents need to know about respiratory syncytial virus<figure><img src="https://images.theconversation.com/files/538668/original/file-20230721-21-8jb0lp.jpg?ixlib=rb-1.1.0&rect=1%2C4%2C997%2C661&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/newborn-baby-weakened-bronchitis-getting-oxygen-1022883532">Shutterstock</a></span></figcaption></figure><p>This winter, we’re having to get our heads around another respiratory virus – RSV.</p>
<p>It’s less well known than COVID or flu, but it’s also responsible for unplanned visits to the GP or emergency department, and days off school, childcare and work.</p>
<p>It’s the <a href="https://pubmed.ncbi.nlm.nih.gov/31383776/">most common</a> cause of hospitalisation in infants. Most children have at least one RSV infection by the age of three years and yet, many Australians have not heard of RSV or know little about this potentially serious winter virus.</p>
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Read more:
<a href="https://theconversation.com/mondays-medical-myth-you-can-catch-a-cold-by-getting-cold-2488">Monday's medical myth: you can catch a cold by getting cold</a>
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<h2>What is RSV?</h2>
<p>RSV stands for respiratory syncytial (pronounced sin-CITY-al) virus. This common respiratory virus usually causes a mild cold with symptoms such as a fever, runny nose, coughing, decreased appetite and a wheeze. </p>
<p>Adults can be infected with RSV but usually recover in a few days.</p>
<p>But in young babies RSV can cause more severe respiratory illnesses such as <a href="https://www.rch.org.au/kidsinfo/fact_sheets/pneumonia/">pneumonia</a> or <a href="https://www.rch.org.au/kidsinfo/fact_sheets/bronchiolitis/">bronchiolitis</a>. These cause babies to breathe rapidly, stop breathing for a few seconds (apnoeas) and/or feed poorly. RSV in infancy can also potentially affect a child’s long-term health, increasing their risk of asthma, wheezing and allergies. </p>
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<p>In Australia, a wave of RSV infections typically begins in late autumn (April-May) and peaks in June-July. Cases are <a href="https://nindss.health.gov.au/pbi-dashboard/">starting to decline</a> in Australia now.</p>
<p>Because health staff have to report cases of RSV, we can keep track of <a href="https://nindss.health.gov.au/pbi-dashboard/">known cases</a>. But we suspect most go unreported as they are mild and/or doctors don’t always test for the virus.</p>
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Read more:
<a href="https://theconversation.com/heard-of-kindy-flu-theres-no-such-thing-but-kids-are-at-risk-this-flu-season-for-one-simple-reason-207825">Heard of 'kindy flu'? There's no such thing. But kids are at risk this flu season for one simple reason</a>
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<h2>Who’s most at risk?</h2>
<p>Both young and old people are most at risk of severe disease. </p>
<p>For children, those <a href="https://adc.bmj.com/content/107/4/359.long">most at risk</a> of severe disease include babies under two months old, premature infants, those with other medical conditions, or ones infected with another virus at the same time. First Nations children are <a href="https://pubmed.ncbi.nlm.nih.gov/31066061/">three to six times</a> more likely to be hospitalised with bronchiolitis caused by RSV than non-First Nations children.</p>
<p>Otherwise healthy children under 12 months old (usually under six months old) are the ones most often admitted to hospital. Of children admitted to hospital, <a href="https://pubmed.ncbi.nlm.nih.gov/35168504/">about a quarter</a> (26%) will be admitted to intensive care.</p>
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<a href="https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C994%2C667&q=45&auto=format&w=1000&fit=clip"><img alt="Male toddler with oxygen mask over face in hospital bed" src="https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C994%2C667&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538662/original/file-20230721-28237-d8ek9e.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>
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<span class="caption">Young children and the elderly are most at risk.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/2-years-old-asian-toddler-boy-1163046754">Shutterstock</a></span>
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<h2>Why are we seeing so many cases now?</h2>
<p>RSV is spread via coughing and sneezing so it’s easy to see how the virus can spread among children inside during winter months.</p>
<p>But measures earlier in the COVID pandemic limited the spread of RSV.</p>
<p>There was very little RSV circulating in 2020 during the harshest lockdowns. However, in New South Wales and Western Australia (in late 2020) and in Victoria (early 2021) there was an <a href="https://www.nature.com/articles/s41467-022-30485-3">out-of-season re-emergence</a> of RSV, overwhelming hospitals and health-care facilities.</p>
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<p>In 2022, RSV settled back into the usual winter peak. However, many states are experiencing a winter surge in cases and hospitalisations attributed to it this year – bigger than before the pandemic.</p>
<p>This may relate to <a href="https://www.health.gov.au/diseases/respiratory-syncytial-virus-rsv-infection">new reporting requirements</a> for RSV and more testing for it.</p>
<p>However, reduced immunity in young infants due to lower maternal and infant exposure may have contributed to the record number of cases.</p>
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Read more:
<a href="https://theconversation.com/ive-had-covid-and-am-constantly-getting-colds-did-covid-harm-my-immune-system-am-i-now-at-risk-of-other-infectious-diseases-188899">I've had COVID and am constantly getting colds. Did COVID harm my immune system? Am I now at risk of other infectious diseases?</a>
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<h2>Is there a vaccine?</h2>
<p>There are no vaccines to protect against RSV in Australia.</p>
<p>Australia’s only currently available preventative medicine is <a href="https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Palivizumab_for_at-risk_patients/">palivizumab</a>, which is a long-acting monoclonal antibody given monthly during the RSV season. Due to its cost, it is reserved for infants at highest risk for severe RSV infection and is usually given in hospital. </p>
<p>However, several new preventative agents are in the pipeline. </p>
<p><a href="https://www.fda.gov/news-events/press-announcements/fda-approves-first-respiratory-syncytial-virus-rsv-vaccine">In May this year</a>, the US Food and Drug Administration approved the RSV vaccine Arexvy for people aged 60 and over. It is being <a href="https://www.tga.gov.au/resources/prescription-medicines-under-evaluation/arexvy-glaxosmithkline-australia-pty-ltd">considered for use</a> in Australia.</p>
<p>Results from clinical trials for RSV vaccines given to pregnant women to protect their baby for the first six months are promising. The maternal Pfizer vaccine <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa2216480">has demonstrated</a> greater than 80% effectiveness against severe lower respiratory tract illness in their infants for the 90 days after birth.</p>
<p>However, safety data is being closely examined, including a <a href="https://www.bmj.com/content/381/bmj.p1021">potential risk</a> of premature birth. </p>
<p>The long-acting monoclonal antibody nirsevimab, (given as a single injection at the beginning of the RSV season) has regulatory approval in Europe and the US. It is currently <a href="https://www.tga.gov.au/resources/prescription-medicines-under-evaluation/beyfortus-astrazeneca-pty-ltd">being considered</a> for Australian children.</p>
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Read more:
<a href="https://theconversation.com/fdas-approval-of-the-worlds-first-vaccine-against-rsv-will-offer-a-new-tool-in-an-old-fight-4-questions-answered-205111">FDA's approval of the world's first vaccine against RSV will offer a new tool in an old fight – 4 questions answered</a>
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<h2>How can I protect my children in the meantime?</h2>
<p>Parents can minimise the risk of RSV by using many of the measures we’ve been using during the COVID pandemic. Encourage children to cover their mouths and noses when coughing or sneezing, and regularly wash their hands.</p>
<p>Ensuring kids stay away from school, childcare or other children when sick helps prevent the spread of many viruses, including RSV.</p>
<p><a href="https://www.rch.org.au/kidsinfo/fact_sheets/Respiratory_syncytial_virus_RSV/">Viral symptoms</a> to watch out for include difficulty feeding, cough, irritability and/or rapid breathing. If parents notice these signs or are worried about their child they should seek urgent medical assessment and not delay.</p><img src="https://counter.theconversation.com/content/208855/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jane Tuckerman is an investigator on a project grant sponsored by Industry. Her institution has received funding from Industry (GSK) for investigator led research. She does not receive any personal payments from Industry. </span></em></p><p class="fine-print"><em><span>Ashleigh Rak receives funding from NHMRC and the Victorian Government.</span></em></p><p class="fine-print"><em><span>Danielle Wurzel receives funding from NHMRC, MRFF and has received honoraria and/or consultancy fees from MSD, Sanofi, GSK which have been paid into her research fund.</span></em></p><p class="fine-print"><em><span>Margie Danchin receives funding from NHMRC, MRFF, WHO, DFAT and the Victorian Government. She is chair, Australian Regional Immunisation Alliance. </span></em></p>Even otherwise healthy children can end up in hospital with this winter respiratory virus.Jane Tuckerman, Senior Research Officer, Murdoch Children's Research InstituteAshleigh Rak, Research Nurse Coordinator, Murdoch Children's Research InstituteDanielle Wurzel, Paediatric Respiratory Physician, and Honorary Fellow Manager, Murdoch Children's Research InstituteMargie Danchin, Paediatrician at the Royal Childrens Hospital and Associate Professor and Clinician Scientist, University of Melbourne and MCRI, Murdoch Children's Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2081822023-06-21T02:42:02Z2023-06-21T02:42:02ZWhy is it so damn cold right now? A weather researcher explains<p>If you woke up this morning and thought “Gosh, it’s a bit brisk!”, you’re not alone. </p>
<p>Temperatures plummeted across southeast Australia this week, with Weatherzone <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">reporting</a> Canberra’s low of -7.2ºC was “its lowest temperature since 2018 and the lowest for June since 1986.”</p>
<p>Sydney experienced its <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">coldest June morning</a> today since 2010, with a temperature of 5.2ºC. In Victoria, temperatures of -7.2ºC were <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">recorded</a>.</p>
<p>So what’s going on? Here’s what you need to know.</p>
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Read more:
<a href="https://theconversation.com/flash-droughts-can-dry-out-soil-in-weeks-new-research-shows-what-they-look-like-in-australia-161286">'Flash droughts' can dry out soil in weeks. New research shows what they look like in Australia</a>
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<h2>A big pool of Antarctic air</h2>
<p>It started off at the beginning of the week, when a low-pressure system saw a big cold front come through southeastern Australia on Sunday night. This basically means a lot of very cold air came from higher latitudes close to Antarctica, and swept across southeastern Australia. </p>
<p>So everywhere from Melbourne to Sydney to South Australia was getting this big pool of incredibly cold air at the start of the week.</p>
<p>Even though that cold front has now moved off over the Tasman Sea, it has left behind it a really big high-pressure system sitting over the southeast of Australia. </p>
<p>This has led to calm conditions, where winds are very light and the skies are clear with not a lot of cloud during the day or night. </p>
<p>So it’s getting really, really cold in the early mornings because there are no clouds to act as an insulating blanket for the Earth and trap the heat that the planet radiates to space overnight. </p>
<p>The result, in many places, has been very cold temperatures before sunrise, often with a lot of frost.</p>
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<h2>Remind me, what’s a low-pressure system? And what’s a high-pressure system?</h2>
<p>The air above the Earth’s surface has mass, but it’s not uniform everywhere. The way the atmosphere is moved around by what’s going on at upper levels will mean the mass of the atmosphere is redistributed. That transmits down to the surface where we live and causes low- and high-pressure systems. </p>
<p>At some points the pressure is lower because there’s not as much mass of air above that point over the Earth. This is what we call a low-pressure system. Air rises in a low, reducing the pressure at the surface.</p>
<p>The winds around the low are clockwise in the Southern Hemisphere. So when that low is approaching Australia, the winds on the western side are bringing air from near Antarctica. That’s why a low-pressure system in Australia often means cooler conditions. </p>
<p>At some points above the Earth, the pressure is higher because the mass of air above that area is greater. This is what we call a high-pressure system. Air descends in a high, raising the surface pressure.</p>
<p>High-pressure systems tend to mean very calm weather; the wind isn’t very strong, the skies tend to be clear and there’s little to no cloud.</p>
<p>In summer, that means the sun is baking down all day onto Earth with no protection from cloud. So a high-pressure system in summer can mean a heatwave.</p>
<p>In winter, the lack of cloud in a high-pressure system means that much of the heat the Earth has absorbed during the day just re-radiates out to space again, as the cloud isn’t there to act as a blanket and keep all that heat in. </p>
<p>That’s why a high-pressure system can mean very cold weather in winter, especially when there are lower levels of sunlight coming in to warm up the Earth in the first place.</p>
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<strong>
Read more:
<a href="https://theconversation.com/4-ways-to-understand-why-australia-is-so-cold-right-now-despite-global-warming-184834">4 ways to understand why Australia is so cold right now despite global warming</a>
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<img src="https://counter.theconversation.com/content/208182/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tess Parker receives funding from the ARC Centre of Excellence for Climate Extremes (CE170100023).</span></em></p>Temperatures plummeted across southeast Australia this week, with Canberra experiencing its lowest temperature since 2018 and the lowest for June since 1986. What’s going on?Tess Parker, Research Fellow, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.