tag:theconversation.com,2011:/africa/topics/typhoons-6435/articlesTyphoons – The Conversation2023-08-08T03:20:28Ztag:theconversation.com,2011:article/2107882023-08-08T03:20:28Z2023-08-08T03:20:28ZIn the future, we could snuff out cyclones. But weather control comes with new risks<figure><img src="https://images.theconversation.com/files/541403/original/file-20230807-20-nxav4q.jpg?ixlib=rb-1.1.0&rect=22%2C19%2C2533%2C1682&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">NASA</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Right now, people in coastal China <a href="https://www.bbc.com/news/in-pictures-66400905">are fleeing</a> successive typhoons. Parts of the Philippines are awash. </p>
<p>Typhoons are intense circular storms, which Australians know as tropical cyclones and Americans call hurricanes. Damage from cyclones <a href="https://storymaps.arcgis.com/stories/8df884dbd4e849c89d4b1128fa5dc1d6">has increased sevenfold</a> since the 1980s, even as death tolls <a href="https://public.wmo.int/en/media/press-release/economic-costs-of-weather-related-disasters-soars-early-warnings-save-lives">fell dramatically</a>. In the 2010s, tropical cyclones did A$872 billion worth of damage globally.</p>
<p>Why? Our world has more heat in the oceans and atmosphere, which can <a href="https://news.sciencebrief.org/cyclones-mar2021">supercharge cyclones</a>. A cyclone is a <a href="https://www.nature.com/articles/44287">heat engine</a>, transferring heat from warm ocean water up into colder layers of the atmosphere. More heat in the system means more intense heat engines. </p>
<p>No wonder there’s been renewed interest in Cold War era experiments in weather control. While early efforts had little success, our <a href="https://doi.org/10.1016/j.crm.2023.100535">new research</a> evaluates other methods of weakening these storms by pumping up cold water from the depths or spreading particles in the lower atmosphere to reduce incoming heat and encourage early rainfall. But these techniques could have unexpected – or even dangerous – side effects. </p>
<h2>Why are researchers even looking into this?</h2>
<p>Tropical cyclones are lethal. In 1970, an <a href="http://www.hurricanescience.org/history/storms/1970s/greatbhola/">enormous cyclone</a> struck Bangladesh (then East Pakistan). Meteorologists knew it was coming, but they had no way to communicate to people in its path. The storm killed up to 500,000 people. </p>
<p>Since then, we’ve invested in far better <a href="https://www.nytimes.com/2022/04/08/climate/weather-warnings-climate-change.html">early warning systems</a>. Deaths have <a href="https://phys.org/news/2023-05-early-disaster-deaths-plunging.html">fallen substantially</a> now that people have time to evacuate. </p>
<p>But in developing countries in particular, deaths still happen. And then there’s the damage to farms, houses, roads and livestock. You may well survive the storm only to be forced into poverty. </p>
<p>Scientists are exploring ways of <a href="https://theconversation.com/climate-fuelled-disasters-warning-people-is-good-but-stopping-the-disaster-is-best-here-are-4-possible-ways-to-do-it-194916">preventing natural disasters</a>, from bushfires to floods to hailstorms. So why not cyclones? </p>
<h2>Can we really turn a cyclone into a normal storm?</h2>
<p>It is certainly possible. But it’s not easy. </p>
<p>In the 1960s, the United States explored the use of cloud seeding to stop hurricanes from forming. During <a href="https://www.aoml.noaa.gov/hrd/hrd_sub/stormfury_era.html">Project STORMFURY</a>, planes flew high above cyclones out at sea and sprayed them with silver iodide, a chemical which could encourage water droplets to clump together and fall as rain. This, the theory ran, would disrupt the hurricane from forming. While some seedings seemed to correlate with weaker hurricanes, the link was never adequately found and the project was eventually abandoned. </p>
<p>Instead, researchers are exploring two new options.</p>
<p>Cyclones need hot sea surfaces to form. If we could cool the surface – such as by piping chilled water from depths <a href="https://oceanexplorer.noaa.gov/facts/temp-vary.html#:%7E:text=This%20results%20in%20less%20warming,C%20(39%C2%B0F).">below 200 metres</a> – we could prevent the cyclone from ever forming. </p>
<p>The problem is it’s expensive. Norwegian cyclone-busting startup OceanTherm estimates it <a href="https://www.fastcompany.com/90549749/this-norwegian-startup-thinks-it-can-stop-hurricanes-with-bubbling-underwater-pipes">would cost</a> about A$750 million to develop the technology, and another $105 million every year to keep it going. </p>
<p>And worse, cooling one area of the sea does nothing to stop cyclones from forming elsewhere. <a href="https://phys.org/news/2022-09-artificial-ocean-cooling-weaken-hurricanes.html">Models suggest</a> ocean cooling will, at best, have only a limited dampening effect on cyclones. </p>
<p>There’s a more likely option – aerosol injection. Scientists already know that dust blown from the Sahara into the Atlantic <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014GL059918">reduces cyclone formation</a>. We could use planes or drones to inject hygroscopic (water-attracting) particles into the lower atmosphere, where they would reflect and scatter sunlight and trigger rainfall and energy release. </p>
<p>This method has a stronger scientific pedigree, given it already occurs naturally. But we don’t know what side-effects it would have and we still aren’t sure what happens to energy redistributed by the intervention.</p>
<p>Other research <a href="https://www.eurekalert.org/news-releases/939099">has found</a> aerosols could reduce cyclone intensity while boosting rainfall on the rotating outer edges of cyclones. More intense rain could still cause substantial damage.</p>
<p>As you’d expect, it’s easier and more effective to intervene early in a cyclone’s life, before too much energy builds up. Making the call to try to stop a cyclone means taking decisions early. That’s a challenge, because <a href="https://www.washingtonpost.com/climate-environment/2022/09/29/ian-hurricane-rapid-intensification-climate">cyclones can become stronger</a> faster in a hotter world. </p>
<h2>Difficult politics, difficult policy</h2>
<p>Cyclone control missions might conjure up the image of <a href="https://www.salon.com/2023/07/04/armageddon-is-25-years-old-scientists-agree-this-problematic-blockbuster-aged-like-warm-milk/">Hollywood action heroes</a> off to save the world. </p>
<p>Unfortunately, it’s more complicated than that. </p>
<p>Let’s say the Philippine government spots a extremely dangerous cyclone forming and decides to disrupt it. But the heat doesn’t magically go away. It just moves. Suddenly, another storm reappears, heading straight for China, a country you have a testy relationship with, and who may blame you for weather manipulation. </p>
<p>Far-fetched? Not at all. When Cuban dictator Fidel Castro heard of Project STORMFURY, he <a href="https://www.theatlantic.com/magazine/archive/2007/10/riders-on-the-storm/306177">feared it was an attempt</a> to turn the weather into a weapon. </p>
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<a href="https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="tropical storm dorothy" src="https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=427&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=427&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=427&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=536&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=536&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541436/original/file-20230807-4145-jerwkh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=536&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Project STORMFURY researchers seeded tropical storm Dorothy over the eastern Caribbean in 1970 and believed they had succeeded. But future efforts did not succeed and the project was abandoned.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Tropical_storm_dorothy_recon_(1970).jpg">Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Only three years ago, China’s neighbours sounded the alarm about the Middle Kingdom’s plans to reroute an atmospheric “sky river” to dry northern regions. This, according to nations like India, could <a href="https://www.theguardian.com/world/2020/dec/03/china-vows-to-boost-weather-modification-capabilities">take water away</a> from their rivers. </p>
<p>So who would decide how or when to snuff out a cyclone? How would they decide? Should private companies be allowed to run their <a href="https://www.washingtonpost.com/climate-environment/2023/01/09/make-sunsets-solar-geoengineering-climate/">own field tests</a> or should these large-scale interventions be government-only? Who would be responsible for any side-effects? </p>
<p>There are more thorny questions. If cyclone control is perfected, what would stop a country trying to redirect cyclones towards a rival? Could cyclone technologies be misused, following similar fears with <a href="https://www.sciencedirect.com/science/article/abs/pii/S0959378023000407?via%3Dihub">large-scale geoengineering</a>? Most importantly, are these technological risks worth the potentially reduced risks of cyclones? </p>
<h2>What’s next?</h2>
<p>We’ll need to find answers for questions like these. As cyclones get stronger, we will urgently need new institutions to help tackle scientific uncertainties, develop monitoring capabilities and find ways of making collaborative decisions at speed. That won’t be easy – most international agreements move slowly, and most <a href="https://www.democracywithoutborders.org/23344/most-existing-international-treaties-do-not-work-study-concludes">don’t meet</a> their intended goals. </p>
<p>Technologies like particle injection are promising, but not ready for deployment. As the technology matures, so should our institutions. It’s why we’re researching the science and policy of these interventions. We must hash out how and when to use technologies like these – before we need to respond urgently. </p>
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Read more:
<a href="https://theconversation.com/trying-to-cool-the-earth-by-dimming-sunlight-could-be-worse-than-global-warming-175455">Trying to cool the Earth by dimming sunlight could be worse than global warming</a>
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<img src="https://counter.theconversation.com/content/210788/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jack Miller was formerly employed as a research assistant by the Institute for Climate, Energy & Disaster Solutions at The Australian National University.</span></em></p><p class="fine-print"><em><span>Mark Howden is the Director of the Institute for Climate, Energy & Disaster Solutions at The Australian National University.</span></em></p><p class="fine-print"><em><span>Roslyn Prinsley is the Head of Disaster Solutions at the ANU Institute for Climate, Energy and Disaster Solutions.</span></em></p><p class="fine-print"><em><span>Thao Linh Tran is a Research Fellow at the ANU Institute for Climate, Energy and Disaster Solutions and Research School of Earth Sciences. </span></em></p><p class="fine-print"><em><span>Aaron Tang 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>It may soon be possible to reduce cyclone formation and intensity by spraying particles into the atmosphere above a forming storm. But the technology opens up a can of wormsAaron Tang, PhD Scholar in Climate Governance, Australian National UniversityJack W. Miller, Research assistant, Australian National UniversityMark Howden, Director, ANU Institute for Climate, Energy and Disaster Solutions, Australian National UniversityRoslyn Prinsley, Head, Disaster Solutions, Australian National UniversityThao Linh Tran, Research Fellow, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2069202023-06-20T18:25:21Z2023-06-20T18:25:21ZHurricanes push heat deeper into the ocean than scientists realized, boosting long-term ocean warming, new research shows<figure><img src="https://images.theconversation.com/files/532027/original/file-20230614-23-paym8a.png?ixlib=rb-1.1.0&rect=1182%2C376%2C2629%2C1747&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Satellite data illustrates the heat signature of Hurricane Maria above warm surface water in 2017.</span> <span class="attribution"><a class="source" href="https://climate.nasa.gov/explore/ask-nasa-climate/3181/a-force-of-nature-hurricanes-in-a-changing-climate/">NASA</a></span></figcaption></figure><p>When a hurricane hits land, the destruction can be visible for years or even decades. Less obvious, but also powerful, is the effect hurricanes have on the oceans. </p>
<p>In a <a href="https://doi.org/10.1073/pnas.2301664120">recent study</a>, we show through real-time measurements that hurricanes don’t just churn water at the surface. They can also push heat deep into the ocean in ways that can lock it up for years and ultimately affect regions far from the storm.</p>
<p>Heat is the key component of this story. It has long been known that hurricanes <a href="https://www.whoi.edu/know-your-ocean/did-you-know/how-does-the-ocean-affect-storms/">gain their energy from warm sea surface temperatures</a>. This heat helps <a href="https://youtu.be/wPDoIrGUrEc">moist air near the ocean surface rise</a> like a hot air balloon and form clouds taller than Mount Everest. This is why hurricanes generally form in tropical regions.</p>
<p>What we discovered is that hurricanes ultimately help warm the ocean, too, by enhancing its ability to absorb and store heat. And that can have far-reaching consequences.</p>
<figure class="align-center ">
<img alt="Schematic showing the formation of a hurricane, which gains its energy from warm ocean surface water." src="https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=262&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=262&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=262&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=329&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=329&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531237/original/file-20230611-186962-ohn2oi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=329&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">How hurricanes draw energy from the ocean’s heat.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Hurricane-en.svg">Kelvin Ma via Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
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<p>When hurricanes mix heat into the ocean, that heat doesn’t just resurface in the same place. We showed how underwater waves produced by the storm can push the heat <a href="https://doi.org/10.1073/pnas.2301664120">roughly four times deeper</a> than mixing alone, sending it to a depth where the heat is trapped far from the surface. From there, deep sea currents can transport it thousands of miles. A hurricane that travels across the western Pacific Ocean and hits the Philippines could end up supplying warm water that heats up the coast of Ecuador years later.</p>
<h2>At sea, looking for typhoons</h2>
<p>For two months in the fall of 2018, we lived aboard the research vessel Thomas G. Thompson to record how the Philippine Sea responded to changing weather patterns. As <a href="https://scholar.google.com/citations?user=c9pivSIAAAAJ&hl=en">ocean</a> <a href="https://scholar.google.com/citations?user=kAGkuGgAAAAJ&hl=en">scientists</a>, we study turbulent mixing in the ocean and hurricanes and other tropical storms that generate this turbulence.</p>
<p>Skies were clear and winds were calm during the first half of our experiment. But in the second half, three major typhoons – as hurricanes are known in this part of the world – stirred up the ocean. </p>
<figure class="align-right ">
<img alt="A photo of an instrument being lowered into the ocean. It's a long thin line with sensors attached." src="https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531240/original/file-20230611-22144-y4s1b9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Microstructure profilers are used to measure ocean turbulence. This one is designed and built by the Ocean Mixing Group at Oregon State University.</span>
<span class="attribution"><span class="source">Sally Warner</span></span>
</figcaption>
</figure>
<p>That shift allowed us to directly compare the ocean’s motions with and without the influence of the storms. In particular, we were interested in learning how turbulence below the ocean surface was helping transfer heat down into the deep ocean.</p>
<p>We measure ocean turbulence with an instrument called a microstructure profiler, which free-falls nearly 1,000 feet (300 meters) and uses a probe similar to a phonograph needle to measure turbulent motions of the water. </p>
<h2>What happens when a hurricane comes through</h2>
<p>Imagine the tropical ocean before a hurricane passes over it. At the surface is a layer of warm water, warmer than 80 degrees Fahrenheit (27 degrees Celsius), that is heated by the sun and extends roughly 160 feet (50 meters) below the surface. Below it are layers of colder water. </p>
<p>The <a href="https://youtu.be/H5-ZW8sH9ws">temperature difference</a> between the layers keeps the waters separated and virtually unable to affect each other. You can think of it like the division between the oil and vinegar in an unshaken bottle of salad dressing.</p>
<p>As a hurricane passes over the tropical ocean, its strong winds help stir the boundaries between the water layers, much like someone shaking the bottle of salad dressing. In the process, cold deep water is mixed up from below and warm surface water is mixed downward. This causes surface temperatures to cool, allowing the ocean to absorb heat more efficiently than usual in the days after a hurricane.</p>
<p>For over two decades, scientists <a href="https://news.mit.edu/2010/hurricane-thermostate-0304">have debated</a> whether the warm waters that are mixed downward by hurricanes could heat ocean currents and thereby shape global climate patterns. At the heart of this question was whether hurricanes could pump heat deep enough so that it stays in the ocean for years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Schematic with five stages showing the ocean's warm surface layer mixing during a hurricane, heat continuing to be pushed down after the hurricane passes and remaining there for months." src="https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=206&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=206&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=206&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=258&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=258&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531238/original/file-20230611-82779-r41xfk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=258&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 illustrations show what happens to ocean heat before, during, after and many months after a hurricane passes over the ocean.</span>
<span class="attribution"><span class="source">Sally Warner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>By analyzing subsurface ocean measurements taken before and after three hurricanes, we found that underwater waves transport heat roughly four times deeper into the ocean than direct mixing during the hurricane. These waves, which are generated by the hurricane itself, transport the heat deep enough that it cannot be easily released back into the atmosphere.</p>
<h2>Implications of heat in the deep ocean</h2>
<p>Once this heat is picked up by large-scale ocean currents, it can be transported to distant parts of the ocean. </p>
<p>The heat injected by the typhoons we studied in the Philippine Sea may have flowed to the coasts of Ecuador or California, following current patterns that carry water from west to east across the equatorial Pacific. </p>
<p>At this point, the heat may be mixed back up to the surface by a combination of <a href="https://doi.org/10.1007/s10236-005-0115-1">shoaling currents</a>, <a href="https://oceanservice.noaa.gov/facts/upwelling.html">upwelling</a> and <a href="https://doi.org/10.1038/nature12363">turbulent mixing</a>. Once the heat is close to the surface again, it can warm the local climate and affect ecosystems. </p>
<p>For instance, coral reefs are particularly sensitive to extended periods of heat stress. El Niño events are the typical culprit behind <a href="https://doi.org/10.1016/B978-044451388-5/50020-5">coral bleaching in Ecuador</a>, but the excess heat from the hurricanes that we observed may contribute to stressed reefs and bleached coral far from where the storms appeared.</p>
<figure class="align-center ">
<img alt="Schools of striped tropical fish swim through a coral reef." src="https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531242/original/file-20230611-26322-dj1p3x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Coral reefs are essential habitat for fish and other sea life, but they are threatened by rising ocean temperatures.</span>
<span class="attribution"><a class="source" href="https://www.noaa.gov/education/resource-collections/marine-life/coral-reef-ecosystems">James Watt via NOAA</a></span>
</figcaption>
</figure>
<p>It is also possible that the excess heat from hurricanes stays within the ocean for decades or more without returning to the surface. This would actually have a mitigating impact on climate change. </p>
<p>As hurricanes redistribute heat from the ocean surface to greater depths, they can help to slow down warming of the Earth’s atmosphere by keeping the heat sequestered in the ocean. </p>
<p>Scientists have long thought of hurricanes as extreme events fueled by ocean heat and shaped by the Earth’s climate. <a href="https://doi.org/10.1073/pnas.2301664120">Our findings</a>, published in the Proceedings of the National Academy of Sciences, add a new dimension to this problem by showing that the interactions go both ways — hurricanes themselves have the ability to heat up the ocean and shape the Earth’s climate.</p><img src="https://counter.theconversation.com/content/206920/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Noel Gutiérrez Brizuela receives funding from the Mexican Council for Science and Technology (CONACYT). </span></em></p><p class="fine-print"><em><span>Sally Warner has received funding from the National Science Foundation and the Office of Naval Research.</span></em></p>Currents can carry that deep ocean heat hundreds of miles to surface again at distant shores.Noel Gutiérrez Brizuela, Ph.D. Candidate in Physical Oceanography, University of California, San DiegoSally Warner, Associate Professor of Climate Science, Brandeis UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1646902021-07-23T12:15:09Z2021-07-23T12:15:09ZSurfing makes its Olympic debut – and the waves should be world-class thanks to wind, sand and a typhoon or two<figure><img src="https://images.theconversation.com/files/412283/original/file-20210720-21-1gy3edx.jpg?ixlib=rb-1.1.0&rect=523%2C0%2C2726%2C2418&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hawaiian surfer John John Florence, seen here competing in Portugal, is one of the favorites to win surfing's first Olympic gold. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PortugalSurf/28db9b5fff044e9186c7db8caa8d855f/photo?Query=surfing%20john%20florence&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=18&currentItemNo=0">AP Photo/Francisco Seco</a></span></figcaption></figure><p>For the first time, <a href="https://olympics.com/tokyo-2020/en/sports/surfing/">surfing is on the Olympic stage</a>. </p>
<p>The surfing event will last for three days and has to run within the dates <a href="https://olympics.com/tokyo-2020/en/sports/surfing/">from July 25 to August 1</a>. The reason for this window? Not all waves are created equal, and organizers and surfers will wait for the best day full of the best waves to hold the competition.</p>
<p>As a recreational surfer and <a href="https://www.brandeis.edu/facultyguide/person.html?emplid=6cf46554ff6936fa51d9e22d0414e63798a5c4a1">physical oceanographer</a>, I spend a lot of time thinking about waves. But for many people, this year’s Olympics will be their first time watching the sport. They might be wondering: </p>
<p>What generates the waves that surfers will ride at the Olympics? Where do the waves come from? And why will the new Olympians be surfing at Tsurigasaki Beach?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Lines of waves out to sea with a surfer in the foreground." src="https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/412285/original/file-20210720-13-zkr21h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Winds create waves that organize into an evenly spaced swell before breaking on shore.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/localsurfer/466383547/in/photolist-bFG8Wn-bqWsc-nYKNvM-qkQpqu-7zJw3K-NHDsdt-2kH5rnb-En7DLm-7zPz51-9oqKbr-adansm-ad7y6H-adamqf-dbdGGh-HdkzD-ad7x9r-2icyHFN-dd2HhH-TTfUEC-dbdNFC-dd2He2-dd2HKd-dbdKMn-adan9d-2kybhqL-fqxGi3-2kvamns-77s3b3-dbdKCZ-fjaWba-dbdNLQ-EFEm8-ztEds-5wsctT-6iVhC7-vCNim-zy8vx">Jon Bowen/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Wind creates waves</h2>
<p>Think for a few seconds about what happens when you throw a stone into a serene pond. It creates a ring of waves – depressions and elevations of the water’s surface – that spread out from the center.</p>
<p>Waves in the ocean act similarly by propagating outward from where they are generated. The key difference is that the vast majority of ocean waves are formed by wind. As the wind blows over the surface of the water, some of the energy of the wind is transferred into the water, creating waves. The biggest and most powerful wind-generated waves are produced by <a href="https://doi.org/10.3389/fmars.2019.00361">strong storms</a> that blow for a sustained period of time over a large area of the ocean. </p>
<p>The waves within a storm are usually messy and chaotic, but as they move away from the storm they grow more organized as faster waves outrun slower waves. This <a href="https://doi.org/10.1098/rsta.1948.0005">organization of the waves</a> creates “swell,” or regularly spaced lines of waves. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sunrise over a beach with a Japanese arch in the foreground." src="https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/412288/original/file-20210720-15-1ja01o1.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">Surfers will be competing at Tsurigasaki Beach on the east coast of Japan, where the waves break on sandbars.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:%E9%87%A3%E3%83%B6%E5%B4%8E%E6%B5%B7%E5%B2%B8%E3%81%8B%E3%82%89%E6%9C%9B%E3%82%80%E6%9D%B1%E6%B5%AA%E8%A6%8B%E3%81%AE%E9%B3%A5%E5%B1%85.jpg#/media/File:%E9%87%A3%E3%83%B6%E5%B4%8E%E6%B5%B7%E5%B2%B8%E3%81%8B%E3%82%89%E6%9C%9B%E3%82%80%E6%9D%B1%E6%B5%AA%E8%A6%8B%E3%81%AE%E9%B3%A5%E5%B1%85.jpg">Pullwell/WikimediaCommons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Seafloors break waves</h2>
<p>As waves travel across the ocean, they don’t actually bring water with them – a wave from a storm 1,000 miles away isn’t made of water from 1,000 miles away. Waves are actually just energy moving from water molecule to water molecule. This energy doesn’t just move through the top layer of the ocean, either. Ocean waves extend far below the surface, sometimes as deep as 500 feet. When waves move into shallower water close to shore, they start to “feel” the seafloor as it pulls and drags on them, slowing them down. As seafloor gets shallower, it pushes upwards against the bottoms of waves, but the energy has to go somewhere, so the waves grow taller.</p>
<p>As the waves move toward shore, the water gets ever more shallow and the waves keep growing until, eventually, they <a href="https://youtu.be/5nCcE-jABSo">become unstable and the wave “breaks”</a> as the crest spills over toward shore.</p>
<p>It is only here, after a wave has traveled perhaps thousands of miles, that the surfing starts. To catch a wave, a surfer paddles toward shore until their speed matches that of the wave. As soon as the wave starts to break, the surfer stands up quickly and maneuvers the surf board with their feet and weight to ride the wave just ahead of the crashing lip. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the Earth showing blue to red lines with a dense red area south of Japan and east of China." src="https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=512&fit=crop&dpr=1 754w, https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=512&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/412269/original/file-20210720-17-osib4j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=512&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This map shows the tracks of all the tropical storms, typhoons and hurricanes that formed from 1945 to 2006. Note the hot spot of frequent, powerful storms south of Japan.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Tropical_cyclones_1945_2006_wikicolor.png#/media/File:Tropical_cyclones_1945_2006_wikicolor.png">Citynoise/WikimediaCommons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Waves at the Olympics</h2>
<p>The waves that surfers ride at Tsurigasaki Beach for the Olympics will be generated from one of two different types of wind: trade winds and typhoons. </p>
<p>Trade winds consistently blow around 11 to 15 mph (18 to 24 kph) in a band that stretches across the Pacific Ocean from approximately Mexico to the Philippines. These winds generate small “trade swells” that propagate northward toward the east coast of Japan and are usually <a href="https://magicseaweed.com/Shidashita-Surf-Report/2802/Historic/">a few feet tall when they arrive</a>.</p>
<p>But if the surfers and spectators are lucky, a typhoon with wind speeds greater than 74 mph (119 kph) will be supplying powerful waves for the event. Typhoons are what hurricanes are called in much of Asia and are common near Japan and China during summer and fall. Winds in a typhoon are much stronger than the trade winds. Therefore, they generate much bigger waves. Olympic surfers obviously do not want a typhoon to hit Japan. What they want is for a typhoon to form about 500 to 1,500 miles (800 to 2,400 km) to the southeast of Japan and generate big waves that will hit the coast of Japan after traveling across the ocean for one to three days.</p>
<p>Based on the current weather and surf forecasts, it looks like just such a situation will happen. As of July 22, 2021, weather models are predicting that a tropical cyclone or typhoon will <a href="https://www.surfline.com/surf-news/surf-forecast-tokyo-2020-olympics-tropical-cyclone-swell/126332">almost certainly develop</a> to the southeast of Japan over the next few days, and the winds from this storm will send a powerful swell to the Olympics. Currently, models are predicting that the waves <a href="https://www.surfline.com/surf-news/surf-forecast-tokyo-2020-olympics-tropical-cyclone-swell/126332">could be 7 feet (2.1 m) at Tsurigasaki Beach</a>, just in time for the surfing event to start.</p>
<p>Once the swell from the trade winds or a far-off typhoon reaches Tsurigasaki Beach, it is the seafloor that will determine where the waves break. Tsurigasaki Beach is a “beach break,” which means that the seafloor is sand, rather than rocks or coral reef. There are a series of human-made rock walls, <a href="https://www.nps.gov/articles/groins-and-jetties.htm">called groins</a>, sticking out perpendicularly from the beach. These have been engineered to prevent <a href="https://doi.org/10.1061/9780784400890.097">sand from moving along the beach</a> and are meant to slow erosion. These groins <a href="https://pubs.geoscienceworld.org/sepm/jsedres/article/42/2/401/96528/Coastal-processes-and-nearshore-sand-bars">create shallow sandbars a few hundred yards from shore</a> that incoming waves will break on. This is where the athletes will surf.</p>
<p>When you tune in to watch the surfing competition at the Olympics, marvel at the amazing skills of elite surfers, but remember too the far-off storms and the underwater sandbars that come together to create the beautiful waves.</p>
<p><em>Portions of this article originally appeared in an <a href="https://theconversation.com/what-makes-the-worlds-biggest-surfable-waves-150600">article</a> published on Dec. 3, 2020.</em></p><img src="https://counter.theconversation.com/content/164690/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sally Warner 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>Olympic surfers are coming from around the world to compete in surfing’s Olympic debut. But where will the waves come from?Sally Warner, Assistant Professor of Climate Science, Brandeis UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1340302020-05-14T19:53:48Z2020-05-14T19:53:48ZRebuilding from disaster: it doesn’t end when housing aid projects finish<figure><img src="https://images.theconversation.com/files/334842/original/file-20200513-167753-10pmuiv.jpg?ixlib=rb-1.1.0&rect=0%2C7%2C2592%2C1715&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Residents of Cagayan de Oro survey what's left of their homes the day after Typhoon Washi hit the Philippines in 2011.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Disasters are typically followed by an influx of resources, including <a href="http://documents.worldbank.org/curated/en/290301468159328458/pdf/528390PUB0safe101Official0Use0Only1.pdf">millions of dollars channelled through humanitarian agencies</a> for rebuilding housing. Images of destruction and distressed victims create deep empathy and generosity, generating a “<a href="https://www.amazon.com/Reporting-Disasters-Famine-Politics-Media/dp/1849042888">revolution of giving</a>” to ease suffering and help rebuild shattered lives. For instance, the <a href="https://www.worldbank.org/en/news/feature/2012/12/26/indonesia-reconstruction-chapter-ends-eight-years-after-the-tsunami">Aceh post-tsunami reconstruction received nearly US$7 billion</a> worth of humanitarian aid.</p>
<p>However, this outpouring of support often occurs with limited understanding of the actual conditions of affected people and the support they need. In contrast to the costly implementation of reconstruction projects, very little attention is paid to project evaluation. Non-governmental organisations (NGOs) and other humanitarian agencies often focus on short-term outcomes. </p>
<p>Occasionally, well-paid <a href="https://www.ifrc.org/PageFiles/95751/B.d.03.%20Guidelines%20for%20Post%20Disaster%20Housing%20%20version%201_OXFAM%20GB.pdf">external consultants undertake mid-term project</a> assessment. <a href="https://researchbank.rmit.edu.au/view/rmit:21375">Issues of long-term recovery</a> are less well-examined. </p>
<p>In fieldwork in the Philippines in 2014 and 2019, we explored <a href="https://www.tandfonline.com/doi/pdf/10.3130/jaabe.15.25?needAccess=true">how and why</a> residents have improved the houses first built in 2012 when they were relocated after Typhoon Washi hit the city of Cagayan de Oro. Over the years, these <a href="https://www.sciencedirect.com/science/article/pii/B9780128127117000262">modifications have produced more habitable housing</a>. They have also added colour to otherwise dull and uniform housing units. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=484&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=484&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=484&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=608&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=608&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334578/original/file-20200513-82375-ygjsb9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=608&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334580/original/file-20200513-82366-1jlz058.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334581/original/file-20200513-82375-z4b6qv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The evolution of a Habitat for Humanity block house from completion in 2012 (top) to July 2014 (middle) to December 2019.</span>
<span class="attribution"><span class="source">S. Carrasco 2014, 2019</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our research findings underscore the need to <a href="https://www.sciencedirect.com/science/article/pii/S1877042816300088">consider community views</a> on post-occupancy issues and development opportunities. It is important to understand <a href="https://www.researchgate.net/publication/303393648_Residential_satisfaction_and_housing_modifications_A_study_in_disaster-induced_resettlement_sites_in_Cagayan_de_Oro_Philippines">why resettled residents resort to their own housing renovations</a>. It’s their way of coping with the <a href="https://www.sciencedirect.com/science/article/abs/pii/S221242091630005X">impacts</a> and <a href="https://www.researchgate.net/publication/303393648_Residential_satisfaction_and_housing_modifications_A_study_in_disaster-induced_resettlement_sites_in_Cagayan_de_Oro_Philippines">shortcomings</a> of humanitarian housing projects.</p>
<h2>The case of Cagayan de Oro</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=743&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=743&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=743&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=933&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=933&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334621/original/file-20200513-156679-yvkrk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=933&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Typhoon exposure of the Philippines and the path of Typhoon Washi through Cagayan de Oro (red dot).</span>
<span class="attribution"><span class="source">Carrasco et al. (2016)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The <a href="https://reliefweb.int/sites/reliefweb.int/files/resources/WorldRiskReport-2019_Online_english.pdf">2019 World Risk Index</a> ranked the Philippines among the countries most at risk of disasters in Asia and the ninth in the world. Typhoons are by far the most frequent hazard. The poor and those who live in vulnerable areas are most at risk. </p>
<p>On December 16 and 17 2011, <a href="https://www.sciencedirect.com/science/article/pii/S2225603218300808">Typhoon Washi</a> (locally known as Sendong) devastated most of Cagayan de Oro, a regional centre in Northern Mindanao. Washi displaced more than <a href="https://www.internal-displacement.org/sites/default/files/publications/documents/2013-ap-philippines-DRR-country-en.pdf">250,000 people</a>, almost 40% of the city population. Around <a href="https://reliefweb.int/sites/reliefweb.int/files/resources/PDNA%2520Draft%2520Final%2520Report.pdf">85% of the affected households</a>, mostly poor families, lived in informal settlements near or along the Cagayan River.</p>
<p>After the typhoon, the state-led rehabilitation plan focused on building 11,225 permanent houses. Humanitarian agencies built 86% of these for households in relocation sites. </p>
<p>The government mobilised resources and <a href="https://www.sciencedirect.com/science/article/pii/S1877042816300088">tapped multiple stakeholders</a> to fast-track construction. In April 2012, four months after the disaster, the first families moved in to their new houses. </p>
<p>The new housing sites were 7 to 20 kilometres away from their original homes near the city centre. The former settlements were cleared and declared “<a href="https://www.sciencedirect.com/science/article/pii/S1877042816300088">no-build zones</a>” to prevent relocated residents from returning.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=579&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=579&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=579&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=728&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=728&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334620/original/file-20200513-156645-y7kqvm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=728&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Locations of Cagayan de Oro city and resettlement sites.</span>
<span class="attribution"><a class="source" href="https://www.tandfonline.com/doi/pdf/10.3130/jaabe.15.25?needAccess=true">Carrasco et al. (2017)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>NGOs, volunteer groups and community-based organisations worked with local and national governments to build the new settlements and houses. Each organisation chose the housing type to be built, following minimum standards set by Philippine government agencies. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334585/original/file-20200513-156660-z4bdkr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334583/original/file-20200513-82379-cb4m1z.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334582/original/file-20200513-82375-1vdhmkm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A row house built by the Filipino-Chinese Chamber of Commerce in 2012 (top), July 2014 (middle) and December 2019.</span>
<span class="attribution"><span class="source">S. Carrasco 2014, 2019</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Key considerations included access roads, communal facilities, sanitation, and water and power supply. In many cases however, communal taps or deep wells provided water, while electricity remained unavailable after years of occupation. </p>
<p>Another major concern is the limited floor area of housing units. Housing units of 21 square metres were provided for families of 12. In some units, temporary materials were used. The result was poor living conditions for resettled residents.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334590/original/file-20200513-156641-1ntptz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334589/original/file-20200513-156645-vk9vj5.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=452&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=452&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=452&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=568&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=568&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334587/original/file-20200513-156641-ng89u1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=568&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 row house built by NGO Gawad Kalinga and Shell after completion in 2012 (top), in July 2014 (middle) and in December 2019.</span>
<span class="attribution"><span class="source">S. Carrasco 2014, 2019</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Why residents renovate houses themselves</h2>
<p>In our fieldwork, we saw how residents have progressively improved their houses by undertaking their own renovations. This work depended on their available resources and changing family needs and plans. </p>
<p>For many residents, the most <a href="https://www.tandfonline.com/doi/pdf/10.3130/jaabe.15.25?needAccess=true">relevant factors they considered</a> in housing extensions are: </p>
<ul>
<li><p>their families’ composition and needs</p></li>
<li><p>local economic and socio-cultural factors</p></li>
<li><p>local environment and climatic conditions. </p></li>
</ul>
<p>Livelihoods, for instance, emerge as a critical factor. Many residents have added an extra room or space to operate sari-sari stores (retail shops) and other home-based enterprises. The table below shows other overlapping reasons and motivations for housing modifications.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334573/original/file-20200513-82370-1t1z97t.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.tandfonline.com/doi/pdf/10.3130/jaabe.15.25?needAccess=true">S. Carrasco (2018)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>The <a href="https://www.sciencedirect.com/science/article/abs/pii/S221242091630005X">impacts</a> of the provided housing on the lives of residents affect later investments in housing construction by the residents themselves, or with support from humanitarian groups. </p>
<p>The lack of proper monitoring of the incremental housing modifications could compromise housing safety. <a href="https://www.sciencedirect.com/science/article/abs/pii/S221242091630005X">Unreliable structural quality</a> could leave some residents vulnerable to earthquakes or typhoons. Unregulated construction using makeshift materials also creates fire risks.</p>
<p>Our findings suggest these concerns should be at the centre of discussions on strategies that enable residents to incrementally expand their houses based on their needs and capacity at the time. Evaluation and supervision of incremental housing projects should be an integral aspect of humanitarian housing programs. These <a href="https://www.theigc.org/wp-content/uploads/2016/11/Wainer-et-al-2016-final-report.pdf">processes are as important as the project delivery itself</a>.</p><img src="https://counter.theconversation.com/content/134030/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>Months after Typhoon Washi tore through the Philippines in 2011, relocated residents were moving into newly built housing. They soon began modifying and extending homes that didn’t meet their needs.Sandra Carrasco, Research Fellow, Melbourne School of Design, The University of MelbourneNeeraj Dangol, Research and Teaching Assistant, Melbourne School of Design, The University of MelbourneRedento B. Recio, Postdoctoral Research Fellow – Informal Urbanism (InfUr-) Hub, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1215482019-08-18T12:42:26Z2019-08-18T12:42:26ZMyths about disaster survivors stall the global response to climate change<figure><img src="https://images.theconversation.com/files/288181/original/file-20190815-136199-1f16zbm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5760%2C2267&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In this November 2013, photo, Typhoon Haiyan survivors pass by hundreds of victims in body bags near Tacloban, Philippines. Haiyan left more than 7,300 people dead or missing.</span> <span class="attribution"><span class="source">(AP Photo/David Guttenfelder)</span></span></figcaption></figure><p>The <a href="https://www.ipcc.ch/sr15/">2018 report</a> from the Intergovernmental Panel on Climate Change (IPCC), a United Nations body that assesses climate change science, says the world needs to limit global temperature increases to below 1.5C this century. </p>
<p>Doing so will minimize human suffering from climate-related risks, the IPCC argues, but they won’t be eliminated completely. The report says we also need to implement the UN’s <a href="https://sustainabledevelopment.un.org/?menu=1300">Sustainable Development Goals</a>, particularly in eradicating poverty and bridging socio-cultural, political and economic inequalities. </p>
<p>This is even more important in the Asia Pacific region, where a number of countries, including the Philippines, are suffering significantly from <a href="https://germanwatch.org/sites/germanwatch.org/files/Global%20Climate%20Risk%20Index%202019_2.pdf">extreme weather events</a>. </p>
<p>Disasters, as forms of crisis, can offer opportunities to more sharply focus on historical and ongoing inequalities. What lessons can we learn from large-scale disaster responses and how can we apply them in the face of intensifying and more frequent extreme weather events? </p>
<p>Drawing on <a href="https://www.tandfonline.com/eprint/K5FU9BBUIGTWGSCHWBHF/full?target=10.1080/0966369X.2019.1635997">our research</a> in the aftermath of the 2013 Typhoon Haiyan disaster in Eastern Visayas, Philippines, we found that few meaningful lessons were drawn from Haiyan because the recovery of survivors <a href="https://odihpn.org/blog/bayanihan-after-typhoon-haiyan-are-we-romanticising-an-indigenous-coping-strategy/">had been romanticized</a> and distorted. While resilience and stories of the communities “<a href="https://plan-uk.org/blogs/building-back-better-after-typhoon-haiyan">building back better</a>” has become the legacy of Haiyan, those on the ground says it’s actually more like “<a href="http://www.newmandala.org/build-back-bitter-five-lessons-five-years-after-typhoon-haiyan/">building back bitter</a>.”</p>
<p>We found that after almost six years, there are now worrying signs in the telling and re-telling of the disaster, and the recovery that occurred afterwards, especially for the hardest-hit communities. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288187/original/file-20190815-136208-1helh8t.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">In this November 2013 photo, Typhoon Haiyan survivors walk through the ruins in the streets of Tacloban, Philippines.</span>
<span class="attribution"><span class="source">(AP Photo/David Guttenfelder)</span></span>
</figcaption>
</figure>
<p>Non-governmental humanitarian agencies, governments and the media tell us that Typhoon Haiyan-affected communities aren’t just surviving, <a href="https://publications.iom.int/books/typhoon-haiyan-portraits-recovery">they are thriving</a>. Poor households, in particular, are resilient and resourceful. They were even referred to as “<a href="https://www.brookings.edu/wp-content/uploads/2016/06/Resolving-PostDisaster-DisplacementInsights-from-the-Philippines-after-Typhoon-Haiyan-June-2015.pdf">the happiest beneficiaries</a>” seen by international responders. In fact, five years after Haiyan, Tacloban City branded itself as “<a href="https://www.facebook.com/watch/?v=806463926204558">Home of the Happiest People in the World</a>” in an attempt to attract tourism. This is aligned with other forms of myth-making that took place after Haiyan.</p>
<h2>Myth 1: Resilience is innate</h2>
<p>National media and international humanitarian coverage of the Haiyan post-disaster recovery strongly drew upon narratives of survival and highlighted stories of communities joining together against all odds. </p>
<p>The recovery was attributed to the innate resilience of Filipinos represented by <em><a href="http://vovworld.vn/en-US/cultural-rendezvous/bayanihan-housemoving-tradition-of-the-philippines-559494.vov">bayanihan</a></em>, a traditional custom of mutual assistance. </p>
<p>Yet we found evidence — based on a survey of local residents and from secondary sources, including official humanitarian and evaluation reports — that <em>bayanihan</em> was short-lived. Community well-being was secondary or regarded as a positive side-effect to securing self-interest or family welfare in the immediate aftermath of the disaster. </p>
<p>Respondents noted how recovery has been uneven and that mutual assistance did not always mean mutual trust. Indeed, women have specific motivations to be skeptical of relying upon community altruism in the broader post-Haiyan context because <a href="https://pennpoliticalreview.org/2014/03/typhoon-haiyan-women-in-the-wake-of-natural-disasters/">of reports</a> that sexual and gender-based violence, especially in <a href="https://www.journals.uchicago.edu/doi/abs/10.1086/695318?mobileUi=0&journalCode=signs">displacement sites</a>, took place as the crisis unfolded. </p>
<p>And so promoting the idea of resilience in the absence of addressing community tensions and inequalities worsens rather than enhances post-disaster recovery.</p>
<h2>Myth 2: The poor are endlessly resourceful</h2>
<p>We found through our research that despite the devastation, social welfare and community work were grossly undervalued when it came to physically rebuilding devastated communities. This particularly affected women social workers and volunteers. Even worse, women volunteers often have to use their own personal resources to do their jobs.</p>
<p>The myth that the poor are resourceful is one that strategically relies on gender roles due to a bias that women will make do with whatever is available. This further adds “proof” that resources are always plentiful in impoverished communities, thereby relinquishing responsibility from governments to redistribute resources adequately. </p>
<p>The myth of resourcefulness glorifies the capacity of female disaster victims to not just overcome the daily struggles of poverty and post-disaster survival, but to even “thrive,” “innovate” or take the initiative to stretch available resources. This erases all the gendered sacrifices, including physical and emotional stress, from intensified care obligations.</p>
<h2>Myth 3: Overseas migrant remittances</h2>
<p>In times of disasters and crises, a growing body of research has started to focus on the role of global households and money sent back home. In the case of the Haiyan response, <a href="https://www.alnap.org/system/files/content/resource/files/main/philippines-iahe-final-report.pdf">the humanitarian evaluation report</a> by the Inter-Agency Standing Committee (IASC) concluded that “the diaspora played possibly the most direct and important role for many affected communities … remittances to the Philippines rose by $600 million in the first three months following Haiyan.”</p>
<p>The surge of remittances after the disaster isn’t surprising given that the Philippines was the <a href="https://www.tandfonline.com/eprint/K5FU9BBUIGTWGSCHWBHF/full?target=10.1080/0966369X.2019.1635997">third largest recipient of remittances</a> in the world in 2017. But remittances on their own cannot change the pre-existing inequalities that compound the impact of a disaster; they simply mitigate them. </p>
<p>Our findings caution against overstating the importance and contribution of remittances to post-disaster recovery. Unlike long-term development assistance and investments in social welfare, they typically augment daily household provisions and rely on the <a href="https://www.tandfonline.com/eprint/K5FU9BBUIGTWGSCHWBHF/full?target=10.1080/0966369X.2019.1635997">unending altruism</a> of mostly women migrant workers abroad. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/typhoon-haiyan-a-perfect-storm-of-corruption-and-neglect-20149">Typhoon Haiyan: a perfect storm of corruption and neglect</a>
</strong>
</em>
</p>
<hr>
<p>Haiyan-affected households with limited or no access to remittances were not able to rebuild fully. They remain exposed and even more vulnerable when the next typhoon strikes.</p>
<p>Based on our research, we argue that long-term global climate change response is at risk when accounts of resilience, resourcefulness and remittance are mythologized and eventually cemented as truths in the aftermath of disasters.</p>
<p>The Haiyan disaster is a cautionary case for climate adaptation and mitigation because it demonstrates the seductiveness of survival myths. </p>
<p>These idealized narratives ultimately do more harm than good because they prevent the identification of specific conditions that make households and communities particularly vulnerable to disasters, as well as the tremendous gendered inequalities that are often exacerbated in their aftermath. </p>
<p>[ <em>Deep knowledge, daily.</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/121548/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yvonne Su receives funding from SSHRC, IDRC and OGS. She is affiliated with the Samara Centre for Democracy. </span></em></p><p class="fine-print"><em><span>Maria Tanyag 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>The Haiyan Typhoon disaster is a cautionary case for climate adaptation and mitigation because it demonstrates the seductiveness of survival myths.Yvonne Su, PhD Candidate, International Development and Political Science, University of GuelphMaria Tanyag, Lecturer, International Relations, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/673422016-10-19T17:43:21Z2016-10-19T17:43:21ZVanishing Mekong? Shifting tropical storms threaten a great river delta<figure><img src="https://images.theconversation.com/files/142390/original/image-20161019-20308-jiamqs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Elena Ermakova / shutterstock</span></span></figcaption></figure><p>Recent changes in the patterns of tropical storms are threatening the future of the Mekong River delta in Vietnam. This is one of the world’s great deltas. It is home to more than 20m people and the rice that is grown on its fertile land underpins food security across South-East Asia. </p>
<p>Working with colleagues from the UK, US and Finland, we’ve just published a paper in <a href="http://nature.com/articles/doi:10.1038/nature19809">Nature</a>, which shows that fewer tropical storms have been hitting the Mekong catchment in recent years. This in turn results in much less mud and sand reaching the delta. We’re worried that this could have dramatic effects on the delta’s sustainability in the medium and longer term due to the adverse impacts on flooding and reduced agricultural productivity. </p>
<p>The world’s deltas are facing a sustainability crisis: 28 of the 33 largest are at <a href="http://www.nature.com/ngeo/journal/v2/n10/abs/ngeo629.html">risk of “drowning”</a> as a result of rising relative sea-levels. Deltas naturally sink slowly under their own weight, but under normal conditions the sediments supplied from the rivers that feed them are deposited, maintaining the delta surface above sea-level. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=687&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=687&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=687&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=864&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=864&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142398/original/image-20161019-20313-1mnhod8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=864&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 Mekong flows from Tibet to Vietnam.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Mekongbasin.jpg">Shannon1 / wiki</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>However, the rate of sea-level rise is accelerating as a consequence of climate change warming the oceans, and drilling for oil and gas or the “mining” of groundwater is causing rapid subsidence. Meanwhile, the sediment loads in many rivers are declining as a result of human activities upstream – the large-scale development of dams being a particular issue in many river systems.</p>
<p>The Mekong faces many of these challenges – and the IPCC has recognised it (along with the Ganges-Brahmaputra and Nile deltas) as one of the <a href="https://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter6.pdf">three most vulnerable to climate change</a>. The sustainability of the delta is critical to the lives and livelihoods of local residents, many of whom are poor. River sediment represents a critical resource for building delta lands, reducing flooding and maintaining fertile soils.</p>
<h2>How we know sediment is declining</h2>
<p>Our work had two main components. First we carried out an extensive programme of fieldwork to quantify the Mekong’s sediment load under varying conditions (including, in September 2013, during one of the largest floods on record, which itself was generated by a typhoon), so that we could link water and sediment flows. </p>
<p>The second aspect of our work traced the frequency and location of tropical storms that have tracked over the Mekong basin in the past 30 years or so. Working with our colleagues in Finland we used this information to run a computer model of the flows of water through the whole Mekong catchment, taking into account scenarios “with” and “without” tropical storms. </p>
<p>Our results showed just how crucial tropical storms are in maintaining the Mekong delta. Only around 5% of the catchment area’s total annual rainfall is sourced from storms, but because this heavy and sudden rainfall is so effective at washing mud and sand into the river, the storms are responsible for more than 30% of the sediment that reaches the delta.</p>
<p>Future climate models predict that tropical storms, such as the so-called <a href="https://weather.com/storms/typhoon/news/super-typhoon-haima-lawin-philippines-china-forecast">“Super Typhoon” Haima</a> which, at the time of writing, is tracking towards the Philippines, are going to get stronger and more frequent as oceans warm up. However, these models also project that their typical track locations will <a href="http://link.springer.com/article/10.1007/s00382-014-2450-8">shift north and eastwards</a> towards China, so that in the future it is likely that fewer storms will cross the Mekong’s catchment. </p>
<p><a href="http://www.sciencedirect.com/science/article/pii/S0169555X14003560">Sand mining</a> is already reducing the sediment being delivered to the Mekong delta and further reductions are anticipated as a result of <a href="http://www.sciencedirect.com/science/article/pii/S0169555X06003229">future damming</a> upstream. Therefore, if the storm projections are correct and even less sediment is washed downstream, the delta’s prospects look bleak. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142406/original/image-20161019-20298-bmt099.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">The Mekong Delta is on shaky foundations.</span>
<span class="attribution"><span class="source">Jim Best</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our study is the first to show the significant role tropical storms can have in the delivery of sediment to large river deltas. This has implications for a range of other major rivers, such as the Ganges in Bangladesh, the Yangtze in China, and the Mississippi in the US. All of these have catchments that are regularly struck by tropical storms. Some 500m people live and work in the world’s major river deltas – and our work shows we can’t evaluate their future vulnerability to sea-level rise without also considering changes in the storms that feed the deltas.</p>
<hr>
<p><em>Chris Hackney, Andrew Nicholas, Rolf Aalto, Matti Kummu and Jim Best also contributed to this research.</em></p><img src="https://counter.theconversation.com/content/67342/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Darby receives funding from the UK Natural Environment Research Council (NERC), the UK Economic and Social Research Council and the UK Department for International Development, as well as the EU Framework 7 programme. The research described in this article was supported by award NE/JO21970/1 from NERC.</span></em></p><p class="fine-print"><em><span>Daniel Parsons receives funding from UK NERC and EPSRC and the EU Framework 7.</span></em></p><p class="fine-print"><em><span>Julian Leyland receives funding from the UK Natural Environment Research Council (NERC) and the UK Engineering and Physical Sciences Research Council (EPSRC). The research described in this article was supported by award NE/JO21970/1 from NERC.</span></em></p>The Mekong Delta is gradually being washed away, as less sediment is delivered downstream.Stephen Darby, Professor of Physical Geography, University of SouthamptonDaniel Parsons, Professor of Process Sedimentology and Associate Dean for Research (Science and Engineering), University of HullJulian Leyland, Lecturer in Physical Geography, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/445942015-08-18T20:33:41Z2015-08-18T20:33:41ZWeather forecasting is about to get even better<p>While some people might still joke about the reliability of weather forecasts, meteorologists are likely to nominate weather prediction as one of the great success stories of modern science – a crowning achievement of collaboration across many scientific and technological fields.</p>
<p>And now Australian weather forecasts are about to become even better, thanks to a new satellite and supercomputer.</p>
<p>Most of us simply take it for granted that weather can be forecast with some accuracy several days ahead. As measured by maximum and minimum temperature predictions for the next day, over 95% of forecasts issued by the Australian Bureau of Meteorology are verified as accurate to within 3 degrees Celsius, reflecting a steady improvement in science, weather observations, and computing power over the past 30 years.</p>
<p>But it’s not just about getting the maximum temperature right. Our ability to forecast important weather features has also improved dramatically over the past three decades. </p>
<p>For example, the recent <a href="http://www.abc.net.au/news/2015-07-13/new-south-wales-snow-damaging-roofs-felling-trees-ses/6614290">snowfalls in New South Wales</a>, which stretched into southeast Queensland, were highlighted nearly a week ahead by our weather models. And the wind change that was so influential on the fire behaviour on Black Saturday was predicted several days in advance. Such foresight would have been impossible over a decade ago. </p>
<h2>A brief history of weather forecasting</h2>
<p>In the pre-satellite era, the forecaster’s ability to analyse weather systems was limited by the availability of surface observations from weather stations. There were huge data gaps, such as over the Southern Ocean. Weather charts were hand-drawn, including the position of high and low pressure systems and cold fronts. High-impact weather events could catch communities by surprise.</p>
<p>In the early 1970s, the first weather satellites dramatically changed this, sending vital new information back to Earth that improved our understanding of Southern Hemisphere’s weather patterns. </p>
<p>At the same time, as supercomputing became cheaper and more powerful, numerical models began to replace the entirely manual analysis of early forecasters. </p>
<p>A forecast model solves fundamental equations of fluid dynamics and heat transfer to compute the evolution of the atmosphere with time (or “the weather”, in other words). While the basic formulae for doing this, based on Newtonian physics, have been known for almost a century, we had to wait for the growth in computing power to apply this knowledge to weather prediction.</p>
<p>The role of the forecaster continues to evolve as numerical prediction skill improves further and extra, more frequent, observations become available. </p>
<p>Ironically, rather than being challenged by limited information, modern forecasting techniques grapple with how best to assimilate the terabytes of data that flood in from all manner of observation sources and models.</p>
<h2>Our region’s next-generation satellite is now in orbit</h2>
<p>Modern meteorology is underpinned by satellites, providing real-time situational awareness, such as the position of a tropical cyclone, and the major initial input into weather models.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92228/original/image-20150818-12389-10awnk1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Monitoring typhoons is a crucial job for weather satellites.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AHaiyan_2013-11-07_0120Z.jpg">NASA/Wikimedia Commons</a></span>
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<p>The main source of data comes from the polar orbiting satellites. These operate about 700 km above the Earth, roughly twice the height of the International Space Station. At these heights, the satellite observations are able to extract a vertical cross-section of the atmosphere, revealing such things as moisture, winds and temperatures.</p>
<p>Polar orbiting satellites scan the same area of the planet only twice a day which, if you are concerned about developing severe weather, is not frequent enough. For more frequent updates forecasters rely on satellites in a geostationary orbit.</p>
<p>At an altitude of 35,786 km above the Equator, a geostationary satellite has the same orbital period as the rotation of the Earth, and there is effectively no relative motion between the satellite and the ground. </p>
<p>For weather applications, this allows continuous monitoring of the area visible to the satellite, equating to roughly 40% of Earth’s surface. Visible and infra-red images of cloud cover from these satellites are familiar to most people, being routinely shown on television weather bulletins and on the Bureau of Meteorology’s <a href="http://www.bom.gov.au/australia/satellite/">website</a>.</p>
<p>In October last year, the Japanese Meteorological Agency launched the 3.5-tonne Himawari-8 satellite into geostationary orbit above the western Pacific region, the first of a new generation of advanced meteorological satellites. </p>
<p>It provides a significant increase in the spatial and temporal resolution of satellite images, increasing the spatial resolution to 500m and increasing the frequency to every ten minutes, giving forecasters rapid updates on developing meteorological conditions, particularly in areas without radar coverage. </p>
<p>A key benefit will be the ability to observe thunderstorm formation. Other benefits will be seen in the detection of tropical cyclone genesis, detection and tracking of bushfire movements using hotspot algorithms, improved observation of fog, and faster detection and analysis of volcanic eruptions.</p>
<p>From September 2015 the <a href="http://himawari8.nict.go.jp/">imagery from Himawari-8</a> will be available on the Bureau’s website.</p>
<h2>Improvements in Numerical Weather Prediction</h2>
<p>One of the biggest contributors to improved weather forecasts is the increase in supercomputing power. The Bureau’s new supercomputer – to be built by CRAY, costing A$77 million and funded by the Federal Government – will be the fastest in Australia when it becomes operational in mid-2016. </p>
<p>But it’s not a case of simply upgrading to new hardware – improved forecasts are dependent on taking advantage of the increased computing power. Over the next few years, the Bureau will use the supercomputer to implement a next-generation high-resolution weather forecasting model.</p>
<p>Weather forecasts start in the real world with data about what’s actually happening at the start of the forecast period. The data – including temperature, humidity, surface pressure and wind — collected from a variety of sources – are fed into models in a process known as data assimilation. </p>
<p>As the models improve, and more data becomes available, techniques for data assimilation must also be updated. </p>
<p>In the Southern Hemisphere, satellite data can make up more than 95% of the observational data fed into forecasting models.</p>
<p>Recently the Bureau tested a prototype forecast model in New South Wales with a resolution of 1.5 km and hourly updates. This type of high-resolution model can assimilate 10-minute data from Himawari-8, and allows us to capture thunderstorms and sea breezes that are too fine in scale for current forecast systems.</p>
<p>The forecast model takes all available observations and essentially evolves the simulated atmosphere forward in time to create the actual weather forecast.</p>
<p>The models do this by breaking the atmosphere up into small grid boxes or cells. The current regional model has cells that are 12 km wide - too large to represent individual clouds, which are typically hundreds of metres across. The model thus estimates these “sub-grid-scale” processes using physics. </p>
<p>As the resolution of the models increases, the sub-grid-scale physics has to evolve. This is both a boon and a challenge for forecasting. </p>
<h2>Get ready for new weather services</h2>
<p>Taken collectively, with the advent of the new satellite, supercomputer and advancing science, the public can expect a step change in weather forecasting services over the next decade. Improvements can be expected in near-real-time information for unfolding weather events, and improvements in lead times for forecasts that assist our warning, response and recovery efforts for severe weather.</p>
<p>As with all advances in technology, it is impossible to predict what some of the new service opportunities will be, as they connect with advances in communication and technology, but we know they’ll continue to evolve and excite, for both meteorologists and the public.</p><img src="https://counter.theconversation.com/content/44594/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>Moaning about weather forecasts is almost an Australian national pastime. But weather predictions have improved a lot, and with a new satellite and supercomputer, they are about to get even more reliable.Paul Gregory, BOM, Australian Bureau of MeteorologyAnthony Rea, Assistant Director, Observing Strategy and Operations, Australian Bureau of MeteorologyGary Dietachmayer, Atmospheric Modelling Team Leader, Australian Bureau of MeteorologyKarl Braganza, Manager, Climate Monitoring Section, Australian Bureau of MeteorologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/447322015-08-05T03:20:33Z2015-08-05T03:20:33ZExplainer: why volcanoes erupt<p>Some people believe volcanic eruptions are caused by fate. Others believe a volcanic eruption is a sign that a mountain is upset because residents living nearby have sinned. </p>
<p>But science has another explanation.</p>
<p>Volcanoes are channels that transfer underground molten rock called <a href="http://education.nationalgeographic.com/encyclopedia/magma/">magma</a> from Earth’s crust up to Earth’s surface. These channels have shapes like cones, shields or calderas. Beneath a volcano lies a magma chamber, a reservoir of a single large body of molten rock. </p>
<p>It is increased magma movement within a volcano that causes an eruption. These movements are triggered by different processes that happen below, inside, and above the magma chamber. </p>
<h2>Below the magma chamber</h2>
<p>Volcanoes that are located in <a href="https://en.wikipedia.org/wiki/Subduction">subduction zones</a> – where Earth’s moving plates collide, causing one plate to sink under the other – receive a steady injection of new molten rock into the magma chamber. </p>
<p>Under the magma chamber, the heat of Earth’s core partially melts existing rocks into new magma. This fresh molten rock will eventually enter the magma chamber. When the chamber, already filled with a certain volume, cannot contain the new magma, the excess will be ejected through eruptions. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=796&fit=crop&dpr=1 600w, https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=796&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=796&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1000&fit=crop&dpr=1 754w, https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1000&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/90239/original/image-20150730-22660-1ltcqf9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1000&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<p>This process usually occurs in cycles, so it’s possible to predict eruptions caused by it. West Java’s <a href="https://en.wikipedia.org/wiki/Mount_Papandayan">Mount Papandayan</a>, which sits atop the meeting of the Eurasian and Indo-Australian Plates, has a 20 yearly cycle and may next erupt in 2022. It last erupted in 2002. </p>
<p>The time period between eruptions depends on how fast the rock melts, which is influenced by the speed of the sinking plate. The Earth has several subduction zones and the subducting plates generally move at a constant speed of up to 10 centimetres per year. For Papandayan, the speed of the Indo-Australian Plate that subducts under the Eurasian Plate is around 7cm per year. </p>
<h2>Inside the magma chamber</h2>
<p>Activities inside the magma chamber can also cause eruptions. Inside the chamber, magma crystallises due to decreasing temperature. The crystalised magma, which is heavier than the semi-fluid molten rocks, descends to the chamber floor. This pushes the rest of the magma up, adding pressure to the chamber lid. An eruption happens when the lid can no longer hold the pressure. This also happens in cycles and can be predicted. </p>
<p>Another important process inside the magma chamber is when magma mixture mixes with surrounding rocks. This process is called assimilation. When magma moves, it interacts with rocks on the lining of the chamber. </p>
<p>Sometimes, volcanoes have pathways for the magma to flow out to the surface. But if the pathway doesn’t exist, then magma will force itself to an area that has less pressure. This can cause the walls surrounding the chamber to collapse. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=584&fit=crop&dpr=1 754w, https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=584&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/90240/original/image-20150730-22679-1lvjlz9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=584&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<p>Imagine dropping a brick into a bucket full of water. The first thing that would happen is water splashing out from the bucket. </p>
<p>The splashing of magma caused by the collapsing chamber wall will cause an eruption. Eruptions from this process are hard to predict. </p>
<h2>Above the magma chamber</h2>
<p>Eruptions can also happen due to loss of pressure above the magma chamber. This can be caused by various things, such as a decrease in density of rocks above the chamber or the melting of ice atop a volcano. A typhoon that passes a volcano in critical condition can exacerbate the strength of an eruption too. </p>
<p>Rocks that cover the magma chamber can gradually soften due to changes in mineral composition. A decrease in the density of covering rocks eventually makes them unable to hold in pressure from the magma. </p>
<p>What causes this mineralogical change? Sometimes, volcanoes have cracks on the surface that allow water to seep in and interact with magma. When this happens, hydrothermal alterations of rocks occur, resulting in eruptions. </p>
<p>Where the magma exits the volcano is also important. If lava or <a href="http://www.geology.sdsu.edu/how_volcanoes_work/Tephra.html">pyroclastic rocks</a> come out through the side of a volcano, gravity can cause that section of the volcano to collapse, causing a sudden loss of covering pressure. Big eruptions usually happens moments after a sector collapse. </p>
<h2>Glacial melting</h2>
<p>Global warming may cause more eruptions by causing glaciers atop volcanoes to melt. When large volumes of ice on top of volcanoes melt, the pressure above the magma chamber decreases. Magma will ascend to find a new state of balance and cause an eruption. </p>
<p><a href="http://icelandmag.visir.is/article/icelands-melting-glaciers-could-result-more-frequent-volcanic-eruptions">A study</a> has shown the huge eruption of Eyjafjallajökull in Iceland in 2010 was triggered by this. Iceland is losing an estimated 11 billion tons of ice each year, so there might yet be more. </p>
<p>In 1991, Mount Pinatubo in the Philippines had a big eruption when typhoon Yunya struck the volcano and its surroundings. Pinatubo was already rumbling, but the typhoon exacerbated the strength of explosion. </p>
<p>The high speed of the typhoon caused the area around it to lose significant pressure. As a consequence, the air column above the volcano was swept into the typhoon’s path. Mount Pinatubo experienced a change of pressure and a big eruption was inevitable. </p>
<p>Given the important role magma plays in triggering volcanic eruptions, studying magma more closely can help predict these spectacular natural events.</p><img src="https://counter.theconversation.com/content/44732/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mirzam Abdurrachman 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>What happens beneath the surface before a volcano erupts? Can we predict when one will blow? And how can typhoons and melting glaciers contribute to big eruptions?Mirzam Abdurrachman, Lecturer at Department of Geology, Faculty of Earth Sciences and Technology, Institut Teknologi BandungLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/425362015-05-29T20:58:42Z2015-05-29T20:58:42ZIncreased typhoon intensity linked to ocean warming<figure><img src="https://images.theconversation.com/files/83427/original/image-20150529-15228-1gfphm0.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More like these? Typhoon Haiyan in 2013. </span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p><em>This article is part of The Conversation’s series this month on hurricanes. You can read the rest of the series <a href="https://theconversation.com/us/topics/hurricanes-2015">here</a>.</em></p>
<p>Every year, typhoons over the western North Pacific – the equivalent to hurricanes in the North Atlantic – cause considerable damage in East and Southeast Asia. </p>
<p>Super Typhoon Haiyan of 2013, one of the strongest ocean storms ever recorded, devastated large portions of the Philippines and killed at least <a href="https://web.archive.org/web/20141006091212/http://www.ndrrmc.gov.ph/attachments/article/1177/Update%20Effects%20TY%20YOLANDA%2017%20April%202014.pdf">6,300 people</a>. It set records for the strongest storm at landfall and for the highest sustained wind speed over one minute, hitting 315 kilometers (194 miles) per hour when it reached the province of Eastern Samar.</p>
<p>The situation may get even worse. </p>
<p>Our new study of what controls the peak intensity of typhoons, published in the journal <a href="http://advances.sciencemag.org/content/1/4/e1500014-0"><em>Science Advances</em></a>, suggests that under climate change, storms like Haiyan could get even stronger and more common by the end of this century.</p>
<h2>Disentangling factors in typhoon peak intensity</h2>
<p>The lifetime peak intensity of a typhoon is the maximum intensity the storm reaches during its entire lifetime. It results from an accumulation of intensification, which is equivalent to speed being an accumulation of acceleration.</p>
<p>To better understand the variability and changes in typhoon peak intensity, we employed a novel approach by decomposing the peak intensity (akin to speed) into two components: intensification rate (akin to acceleration) and intensification duration (akin to time). These two components vary independently from each other from one year to another. We then separately explored the climate conditions that were most strongly associated with the year-to-year variations in these two components.</p>
<p>We examined various atmospheric and oceanic variables that might influence the rate of cyclone intensification. </p>
<p>We looked at atmospheric pressure, <a href="http://www.wunderground.com/education/shear.asp">vertical wind shear</a>, or the change in wind speed in one direction, and <a href="http://www.met.tamu.edu/class/ATMO151.hold/tut/hurr3.html">vorticity</a>, or the spin of the atmosphere. Surprisingly, we found that compared to those factors, ocean temperature most strongly correlated to the rate of cyclone intensification.</p>
<p>Specifically, how strongly and quickly a cyclone can grow depends on two oceanic factors: pre-storm sea surface temperature and the difference in temperature between the surface and subsurface. </p>
<p>A warmer sea surface generally provides more energy for storm development and thus favors higher intensification rates. </p>
<p>A large change in temperature from the surface to subsurface (ie, cooling with depth), however, can disrupt this flow of energy. That’s because strong winds drive turbulence in the upper ocean, which brings cold water up from below and cools the sea surface. Therefore, a smaller difference between surface and subsurface ocean temperature favors higher intensification rates.</p>
<p>On the other hand, the variations in the duration of typhoon intensification can be connected to sea surface temperatures associated with the naturally occurring phenomena known as El Nino-Southern Oscillation/Pacific Decadal Oscillation (ENSO/PDO). This is because in a positive phase of ENSO/PDO, warmer-than-normal sea surface temperatures over the central equatorial Pacific produce favorable atmospheric conditions for cyclone genesis near the equator and dateline. This allows developing typhoons to grow for a longer period of time over the warm water before reaching land or cold water.</p>
<p>In sum, our analyses reveal that the upper-ocean temperatures over the low-latitude western North Pacific influence typhoon intensification rates, and that sea surface temperatures over the central equatorial Pacific influence typhoon intensification duration. </p>
<p>We then quantified the relationships between typhoon peak intensity and these identified climatic factors – that is, local upper ocean temperatures and ENSO/PDO indices. </p>
<p>We concluded that the strong rise in typhoon peak intensity over the past 35 years or so (about five meters per second; equivalent to half a category in typhoon strength) can be mostly attributed to unusual local upper-ocean warming rates.</p>
<h2>Projecting typhoon peak intensity in a warming climate</h2>
<p>We analyzed the ocean temperature changes simulated by models from the fifth phase of the <a href="http://cmip-pcmdi.llnl.gov/">Coupled Model Intercomparison Project</a> (CMIP5), a model for studying interactions between ocean and the atmosphere. </p>
<p>We found that by year 2100, the temperature of the upper ocean will be more than 1.6 degrees Celsius higher than the baseline average of the 50-year period from 1955-2005 even under a moderate future scenario of greenhouse gas emissions. </p>
<p>The continued ocean warming provides more “fuel” for storm intensification. Using the statistical relationships built from observations, we projected that the intensity of typhoons in the western North Pacific will increase as much as 14% – nearly the equivalent to an increase of one category – by century’s end.</p><img src="https://counter.theconversation.com/content/42536/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wei Mei received funding from NASA Headquarters under the NASA Earth and Space Science Fellowship Program.</span></em></p>New analysis shows that warmer ocean temperatures in the Pacific are creating more intense typhoons.Wei Mei, Postdoctoral Scholar at Scripps Institution of Oceanography, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/210512013-12-04T06:31:17Z2013-12-04T06:31:17ZMangroves, nature’s shield against typhoons and tsunami<figure><img src="https://images.theconversation.com/files/36834/original/z27tqrkh-1386097247.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Natures flood defences.</span> <span class="attribution"><span class="source">Gerald Herbert/AP</span></span></figcaption></figure><p>Following <a href="http://www.bbc.co.uk/news/world-24901032">typhoon Haiyan</a>, the Philippines’ Department for Environment and Natural Resources <a href="http://www.gov.ph/2013/11/27/denr-sets-aside-p347m-for-coastal-forest-rehabilitation-in-eastern-visayas/">has earmarked around US$8m</a> to fund efforts to replant much of the affected coastal zone with mangrove forests. Reforesting these coasts with 19m trees, particularly the extensively damaged islands of <a href="http://www.philstar.com/headlines/2013/11/17/1257616/aid-delivery-leyte-samar-speeding">Leyte and Samar</a>, is a key part of bolstering the first line of defence against future storms. Reports suggest up to 80% of the money is likely to be channelled to residents to engage them in tree planting activities as part of the country’s cash-for-work programme.</p>
<p>Why trees and not, say, concrete? Mangrove forests grow along the coast in fine, salty sediments across the tropics and sub-tropics. Recent research has revealed that mangroves, along with salt marshes and other wetlands, can sequester carbon much <a href="http://www.nature.com/ngeo/journal/v4/n5/full/ngeo1123.html">more permanently and effectively</a> than terrestrial forests, offering an important means to mitigate global climate change.</p>
<p>But more importantly in this case is their <a href="http://www.sciencedirect.com/science/article/pii/S0272771407003915">role in coastal protection</a> – something that will grow in importance if storms the magnitude of Haiyan <a href="http://www.theguardian.com/environment/blog/2013/nov/29/climate-change-extreme-weather-philippines-typhoon-haiyan">become more frequent</a> with the effects of climate change. The extent to which mangroves reduce the damage caused by typhoons (as well as tsunami) is still debated, but the evidence suggests that mangroves provide an effective natural buffer against storms, flooding, coastal erosion and strong waves.</p>
<h2>The value of vanishing mangroves</h2>
<p>The global economic value that can be extracted from mangrove forests <a href="http://na.unep.net/geas/getUNEPPageWithArticleIDScript.php?article_id=103">is estimated by the UNEP</a> at US$1.6 billion per year. Many millions of dollars have been invested in replanting efforts in several of the <a href="http://data.unep-wcmc.org/datasets/22">more than 100 countries</a> with mangroves – as this value has become more widely recognised, and with the effects of storms such as Haiyan. These multi-million dollar investments haven’t always been successful though – it’s not as straightforward as just planting trees.</p>
<p>Replanting damaged areas will depend on the nature of damage caused, the geography, and extent of infrastructure development in the area. It will also depend on how the financial and practical aspects of planting and replanting are addressed, and how local communities are involved. Similar considerations apply in devising ways to protect the remaining mangrove areas, already drastically <a href="http://www.cserge.uea.ac.uk/sites/default/files/gec_1996_06.pdf">reduced by more than a third</a> of their global extent. This is largely due to land clearance for agriculture and fish farming, major coastal development, rapid urbanisation, and pollution.</p>
<h2>A Vietnamese case study</h2>
<p>Having just returned from a study of mangrove forests in Vietnam, we found those living alongside the mangroves use them as a source of food (fish, crabs, clams, worms, octopus, shrimps, jellyfish), either subsisting from them or using their natural resources as a safety net when other food supplies fail. The communities use various formal and informal rules and practices to govern and manage the mangroves.</p>
<p>The formal institutions and governance structures that many of the current restoration and replanting efforts operate through ignore these. They frequently reinforce existing power relations and inequalities, and fail to take into account the importance of community buy-in that can make or break ecological rehabilitation initiatives.</p>
<p>Some groups (often the poor and those with limited livelihood options) are more dependent on certain areas of the mangrove forests, and planting replacement mangroves elsewhere could change or remove how they can access those essential forest benefits. It’s important to develop a clear picture of who, what for, and how the mangroves are used and governed, as a pre-requisite to large-scale planting.</p>
<p>Efforts to plant and replant more mangroves, such as those planned in the Philippines, are laudable. But a clear understanding is needed of the mangrove forests’ role in underpinning the livelihoods of some of the poorest people living along the coast. If the long-term sustainability of any replanting investment is to be assured, then it is vital to understand how the mangroves will be used once the short-term cash to communities for assisting replanting is gone, so that the new forests are not exploited unsustainably.</p>
<p>Finally, detailed consideration needs to be given to the scale and distribution of costs and benefits linked to mangrove restoration and rehabilitation, not just in the Philippines, but globally. Mangroves certainly offer a means to mitigate climate change, conserve biodiversity, and provide a wide range of goods and services as well as protecting coasts against erosion and storm surges. But unless planted and managed carefully, those who depend most upon the mangroves for their survival could lose out.</p><img src="https://counter.theconversation.com/content/21051/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lindsay Stringer receives funding from the Economic and Social Research Council through the Centre for Climate Change Economics and Policy (CCCEP).</span></em></p><p class="fine-print"><em><span>Steven Orchard receives funding through an Economic and Social Research Council (ESRC) scholarship.</span></em></p>Following typhoon Haiyan, the Philippines’ Department for Environment and Natural Resources has earmarked around US$8m to fund efforts to replant much of the affected coastal zone with mangrove forests…Lindsay C. Stringer, Professor in Environment and Development, Director, Sustainability Research Institute, University of LeedsSteven Orchard, PhD Candidate, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/201872013-11-13T01:01:35Z2013-11-13T01:01:35ZInside Typhoon Haiyan and a year of weird weather<figure><img src="https://images.theconversation.com/files/35059/original/35fnd53h-1384302079.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Typhoon Haiyan as seen from space on November 9 by NASA astronaut Karen L. Nyberg.</span> <span class="attribution"><span class="source">http://twitter.com/AstroKarenN</span></span></figcaption></figure><p>Even before <a href="https://theconversation.com/topics/typhoon-haiyan">Typhoon Haiyan</a> struck the Philippines with <a href="http://www.abc.net.au/news/specials/typhoon-haiyan-photos-before-after/">such devastating force</a>, weather watchers around the world had been tracking this year’s typhoon season with intense interest.</p>
<p>Typhoon Haiyan has been seen as significant among meteorologists for several reasons - particularly because it has been part of such a strange season. </p>
<p>The 2013 tropical cyclone season in the Northwest Pacific started quite slowly and gradually accelerated, eventually setting a few records. </p>
<p>From January to September this year, we saw 23 <a href="http://www.bom.gov.au/cyclone/about/">tropical cyclones</a> form in the Northwest Pacific. Those cyclones involve low pressure systems forming over warm tropical waters, with sustained gale force winds of 63 km/h or more.</p>
<p>Yet during that same time in the Northwest Pacific, we only saw five <a href="http://www.bom.gov.au/faq/">typhoons</a> with sustained winds of more than 118 km/h, when in an average season we would have seen around 12 typhoons by the end of September.</p>
<p>But then last month, the tropical cyclone activity accelerated, particularly when it came to the strength or intensity of the storms. </p>
<p>Seven typhoons formed in the Northwest Pacific in October; a new record for the month. </p>
<p>And then came the November impact of Haiyan, which has been a sobering exclamation mark at what is typically the end of the season.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/w6p9KbVK97w?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Newly released footage showing Typhoon Haiyan blanketing the Philippines, shot with external cameras on the International Space Station. Source: NASATelevision, YouTube.</span></figcaption>
</figure>
<h2>The rise and deadly fall of a super typhoon</h2>
<p>Haiyan was the eighth typhoon to form in the Northwest Pacific since the start of October this year. It formed near 6°N on 3 November, possibly in association with an Equatorial Rossby wave — a westward moving atmospheric wave near the equator that can trigger convergence in the lower levels of the atmosphere.</p>
<p>On November 4, Haiyan first reached tropical cyclone strength, defined as winds greater than 63 km/h, and then it continued to strengthen. </p>
<p>As a typhoon, the winds around Haiyan reached a maximum sustained wind strength of 232 km/h on November 7. </p>
<p>To date, Typhoon Haiyan is the strongest storm of the 2013 season and among the strongest on record for the Northwest Pacific. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/02lNiAdVfGU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Tracking Haiyan, with an animation of its flood potential. Source: NASAgovVideo, YouTube.</span></figcaption>
</figure>
<p>Because the system made landfall in a highly populated and vulnerable part of the world coinciding with its peak intensity, <a href="http://www.abc.net.au/news/2013-11-13/typhoon-haiyan-death-toll-likely-lower-than-feared/5087698">its impact was devastating</a> for the communities it hit.</p>
<p>The coincident peak wind speeds occurring at landfall also helped produce a significant storm surge, a phenomenon that leads to higher than normal tides and waves along coastal areas. <a href="http://www.bom.gov.au/cyclone/about/stormsurge.shtml">Storm surges</a> are the single biggest threat to life in coastal areas from these events. </p>
<p>Haiyan is likely to have produced a storm surge of around 5 to 6 metres above the normal tide level, causing significant damage and loss of life along the coastal fringe of affected areas. </p>
<p>When the slightly less intense 1970 <a href="http://www.hurricanescience.org/history/storms/1970s/greatbhola/">Bhola cyclone</a> hit Bangladesh, up to 500,000 people died, mainly because of the associated storm surge. </p>
<p>When <a href="http://www.bom.gov.au/cyclone/history/monica.shtml">Severe Tropical Cyclone Monica</a> hit western Arnhem Land in 2006 with a similar intensity and storm surge to Haiyan, there were fortunately no fatalities because the point of landfall was sparsely populated.</p>
<p>Analysis after the event will no doubt refine estimates of Typhoon Haiyan’s maximum wind speed, storm surge, and other vital statistics. </p>
<p>But there’s no doubting it will be assessed as one of the worst tropical cyclones at landfall in recorded history. It is a strong reminder to us all that continued improvements in forecasting accuracy, warning response, and community resilience will help save lives on the ground.</p><img src="https://counter.theconversation.com/content/20187/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The Bureau of Meteorology provides Australians with environmental intelligence for their safety, sustainability, well-being and prosperity. Our weather, climate and water services include observations, alerts, warnings and forecasts for extreme events. Joel Lisonbee and Todd Smith do not consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and have no relevant affiliations.</span></em></p><p class="fine-print"><em><span>Todd Smith 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>Even before Typhoon Haiyan struck the Philippines with such devastating force, weather watchers around the world had been tracking this year’s typhoon season with intense interest. Typhoon Haiyan has been…Joel Lisonbee, Climatologist for the Bureau of Meteorology at the Northern Territory Climate Services Centre in Darwin, Australian Bureau of MeteorologyTodd Smith, Manager of Weather Services, Northern Territory, Australian Bureau of MeteorologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/200482013-11-08T15:11:02Z2013-11-08T15:11:02ZEyewitness: Typhoon Haiyan strikes the Philippines<figure><img src="https://images.theconversation.com/files/34793/original/zrqndb86-1383916865.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Path of destruction: Haiyan makes landfall.</span> <span class="attribution"><span class="source">AP Photo/Nelson Salting</span></span></figcaption></figure><p>The rain is ricocheting off the roads here in Manila. Early on Friday, our car’s tyres dragged in the deep puddles. Basketball courts - remnants of bygone American rule, and a staple of every district - are already flooding. </p>
<p>During a typhoon, flooding is one of the major causes of death in Philippine cities, the streaming water wreaking havoc. Missing manhole covers, sometimes stolen to sell for scrap metal, create lethal traps beneath the streams. One of the city’s landfills, which goes by the name of “Smokey Mountain” and is seven storeys high, is surrounded by thousands of dwellers who burn the trash for charcoal to sell. When the water comes, the trash flows with it. More than once before, parts of the mountain have <a href="http://abcnews.go.com/International/story?id=83209&page=1">collapsed</a> under the volume of water.</p>
<p>According to <a href="http://www.theguardian.com/world/2013/nov/08/typhoon-haiyan-hits-philippines">news reports</a>, Typhoon Haiyan is the <a href="https://theconversation.com/super-typhoon-haiyan-hits-philippines-with-devastating-force-20016">worst storm ever</a> to make landfall, with near 200mph winds in some areas. But because it is so enormous - 600km across - Haiyan’s impact on the country is lopsided; Manila is being spared the worst this time, experiencing a category 2 storm as opposed to the dreaded category 5 that has struck further south. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/34801/original/33ct9vbm-1383924644.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Haiyan as viewed by Japan’s MTSAT satellite today.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Many Filipinos here in the capital have families on the worst-hit islands. This morning, one woman said her relatives in the Visayas were sheltering in a church after the roof was torn from their house. For the most part, the Philippines is devoutly Catholic, and this was their last place of refuge and hope as the storm hit. </p>
<h2>A disastrous year</h2>
<p>The typhoon could not have come at a worse time. Badly hit areas in the southern islands, like the cities of Cebu and Bohol, were still recovering from last month’s 7.2 magnitude earthquake. Many homes had not yet been rebuilt, and even if they had, those with corrugated iron roofs - of which there are many - had the metal ceilings lifted away by the wind. Millions of Filipinos live in poor housing, with as many as <a href="http://www.homeless-international.org/our-work/where-we-work/philippines">22.8 million</a> in high-density slum conditions that make them all the more vulnerable to disaster.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=467&fit=crop&dpr=1 600w, https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=467&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=467&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=587&fit=crop&dpr=1 754w, https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=587&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/34796/original/dg2jszfb-1383919257.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=587&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human cost: evacuation underway in Albay Province.</span>
<span class="attribution"><span class="source">AP Photo/Nelson Salting</span></span>
</figcaption>
</figure>
<p>And Haiyan is just the latest in a string of catastrophes: besides the recent earthquake, it has been an especially bad year for natural disasters in the Philippines. Floods and storms (there have been 25 typhoons this year alone) have returned again and again, wrecking homes and destroying lives. I’m told that after one major flood in August, many employees from affected areas still turned up for work in the following days. They did so because they had nothing left, and nowhere else to go.</p>
<p>As the storm passes tomorrow morning, the rebuilding will begin. Filipinos have a well-deserved reputation for resilience, and communities here are very strong - especially at Christmas. In Manila, decorations are already up and Christmas carols have been playing in malls since early October. This year more than any, it is a time for coming together. A time for goodwill. A time for family.</p><img src="https://counter.theconversation.com/content/20048/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Kucharski 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>The rain is ricocheting off the roads here in Manila. Early on Friday, our car’s tyres dragged in the deep puddles. Basketball courts - remnants of bygone American rule, and a staple of every district…Adam Kucharski, Research Fellow in Mathematical Epidemiology, London School of Hygiene & Tropical MedicineLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/200162013-11-08T01:31:39Z2013-11-08T01:31:39ZSuper Typhoon Haiyan hits Philippines with devastating force<figure><img src="https://images.theconversation.com/files/34737/original/qrz2yxk2-1383879427.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Super Typhoon Haiyan hits the islands at the mouth of the Leyte Gulf in the Philippines. </span> <span class="attribution"><span class="source">NASA/NOAA</span></span></figcaption></figure><figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/34716/original/6qn9rtwc-1383872183.jpg?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"></a>
<figcaption>
<span class="caption">Super Typhoon Haiyan hits the islands at the mouth of the Leyte Gulf in the Philippines.</span>
<span class="attribution"><span class="source">NASA/NOAA</span></span>
</figcaption>
</figure>
<p>With sustained winds of more than 310 km/h, or 195 mph, as it approached the Philippines, Super Typhoon Haiyan has hit land in the past few hours with terrifying force. This makes it the strongest tropical cyclone to make landfall in history.</p>
<p>Haiyan was earlier reported to be the most intense tropical storm in this area since <a href="http://journals.ametsoc.org/doi/pdf/10.1175/1520-0493%281980%29108%3C1915%3AAAOSTT%3E2.0.CO%3B2">Super Typhoon Tip</a> (1979), and may even have exceeded the force of Tip. It had already been recognised to be one of the four most intense storms on modern record. </p>
<p>Preliminary satellite estimates of the central pressure at the eye of the storm have been reported at around 860 mbar, which if confirmed would make Haiyan the strongest storm ever recorded. Its intensity is recorded as Category 5 (maximum) on the scale for tropical storms and 8.0 (maximum) on the Dvorak scale of intensity.</p>
<p>The US National Oceanic and Atmospheric Administration <a href="http://www.nnvl.noaa.gov/MediaDetail2.php?MediaID=1452&MediaTypeID=1">reports</a>:</p>
<blockquote>
<p>The intensification of Super Typhoon Haiyan is being fuelled by “ideal” environmental conditions – namely low wind shear and warm ocean temperatures. Maximum sustained winds are currently at 195 mph, well above the Category 5 classification used for Atlantic and East Pacific hurricanes.</p>
</blockquote>
<p>Tropical storms such as Haiyan are known as typhoons in the Pacific, but are the same as the storms labelled hurricanes or cyclones elsewhere. Haiyan is the strongest tropical storm since <a href="http://www.wunderground.com/hurricane/atlantic/1980/Major-Hurricane-Allen">Hurricane Allen</a> (1980) which hit the Caribbean. It appears to have surpassed <a href="http://www.nhc.noaa.gov/outreach/history/#camille">Hurricane Camille</a> (1969) in making landfall with wind speeds at Category 5 level.</p>
<p>Already, the reasons for such extreme weather are being scrutinised. The surface water, as well as deeper water, temperatures of the Western Pacific have provided huge amounts of energy for the storm to absorb, fuelling Haiyan’s intensification. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/34724/original/f88yqtdd-1383873798.jpg?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"></a>
<figcaption>
<span class="caption">Deep, warm water fuels Haiyan.</span>
<span class="attribution"><span class="source">NOAA</span></span>
</figcaption>
</figure>
<p>Along with devastating storms, the typhoon will bring a deluge of rain and storm surge, threatening coastal areas of the Philippines with flood and destruction. As the storm progresses across the islands it is expected to weaken and dissipate, tracking towards Vietnam.</p>
<p>The recent <a href="http://www.climatechange2013.org/">IPCC report on climate change</a> highlighted the risks associated with changes in the patterns and frequency of extreme weather events. While individual storms such as Haiyan cannot be directly attributed to such changes, the statistics of such storms will help build a picture of how climate change is affecting the planet. Climatologists are keen to develop models that provide accurate risk factors for tropical cyclones. </p>
<p>As the planet and particularly the oceans heat, simple physics indicates that the energy stored is likely to increase the intensity and frequency of devastating storms like Haiyan, at great cost to coastal communities.</p><img src="https://counter.theconversation.com/content/20016/count.gif" alt="The Conversation" width="1" height="1" />
With sustained winds of more than 310 km/h, or 195 mph, as it approached the Philippines, Super Typhoon Haiyan has hit land in the past few hours with terrifying force. This makes it the strongest tropical…Simon Redfern, Professor in Earth Sciences, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/160942013-07-16T05:45:08Z2013-07-16T05:45:08ZAvoiding annual typhoon catastrophes<figure><img src="https://images.theconversation.com/files/27480/original/ch3cv77s-1373890553.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Typhoon Soulik on 12th July 2013 as the storm approaches the coast of Taiwan.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>Typhoon Soulik struck Taiwan at the beginning of the weekend, killing two people before moving on into Guangdong in southern China, where <a href="http://www.bbc.co.uk/news/world-asia-23310512">300,000 people</a> have already been evacuated. Classed as a category 3 tropical storm according to the <a href="http://www.nhc.noaa.gov/aboutsshws.php">Saffir Simpson Scale</a>, Soulik’s maximum peak sustained wind speed reached 145mph, into the realms of an “Extreme” or Category 4 storm.</p>
<p>Soulik is the seventh tropical storm in the Western North Pacific ocean basin this year, the most active tropical cyclone spawning region in the world. Nearly every year they havoc with agriculture, fisheries and transportation in China, Taiwan, the Philippines, Vietnam, Korea and Japan. Must it always be like this?</p>
<h2>Predicting typhoons</h2>
<p>The number of tropical cyclones in the Western North Pacific each year varies widely, from 19 tropical storms in 1969 to 43 in 1996. Early prediction can help warn the public of the severity of the typhoon hazard, reducing the risk of catastrophe and assisting emergency planning.</p>
<p>Seasonal forecasting of tropical cyclones has been under development for 20 years by experts at <a href="http://tropical.atmos.colostate.edu/forecasts/">Colorado State University</a>, <a href="http://www.tropicalstormrisk.com/">University College London</a>, <a href="http://weather.cityu.edu.hk/tc_forecast/forecast.htm">City University of Hong Kong</a> and the <a href="http://www.noaanews.noaa.gov/stories2013/20130523_hurricaneoutlook_atlantic.html">National Oceanic Atmospheric Administration</a>, covering different ocean basins from the Atlantic to the Pacific.</p>
<p>Several atmospheric and ocean phenomena, for exmaple <a href="http://www.education.noaa.gov/Weather_and_Atmosphere/El_Nino.html">El Nino</a>, the Sea Surface Temperature, and the <a href="http://www.britannica.com/EBchecked/topic/323172/quasi-biennial-oscillation">Quasi-biennial Oscillation</a> found in the tropical stratosphere are watched as indicators for tropical storms. Nevertheless, accurate <a href="http://www.tropicalstormrisk.com/docs/LeaSaunders2006.pdf">seasonal forecasting</a> that predicts where storms will land is far from perfect - though the assessment of how many can be expected is reasonably accurate.</p>
<p>Forecasting far ahead of typhoon season is unreliable, but the five-day forecast of typhoons due to make landfall and their “<a href="http://www.nhc.noaa.gov/aboutcone.shtml">cone of uncertainty</a>” - the area a moving typhoon is predicted to cover - are quite trustworthy. But the typhoons of the Western North Pacific are capricious, often moving abruptly and unexpectedly in any direction, and this complicates forecasts.</p>
<h2>Every season is typhoon season</h2>
<p>The Western North Pacific is known as the “warm pool”, and is the only ocean basin in which cyclones can form in any month of the year due to the warmth of the sea, at 26°C.</p>
<p>Typhoon catastrophes in this region are not necessarily because they are more frequent but because they are larger and more severe in intensity. For example, <a href="http://www.scientificamerican.com/article.cfm?id=earths-strongest-most-massive-storm-ever">Super Typhoon Tip</a> in 1979 had a central pressure of 870 millibars, a peak wind speed of 190mph and diameter of approximately 1,380 miles. Shallow coastal areas can be devastated by severe <a href="http://www.comet.ucar.edu/nsflab/web/hurricane/313.htm">storm surge</a>, flash flooding and landslides caused by heavy rain.</p>
<p>Existing studies of the region have shown a significant decreasing trend of cyclonic activity, but an increased number of high-intensity cyclones, with an increase of precipitation of around 20% within 100km of the storm’s centre under global warming scenarios.</p>
<p>A super typhoon in Asia (such as <a href="http://www.telegraph.co.uk/news/worldnews/asia/japan/8778079/The-worlds-deadliest-typhoons.html">Vera in 1959 or Nina in 1975</a>) could kill between 1000s and 100,000s of people. And even as the death toll has declined in recent years, the financial losses from typhoon catastrophes have increased. In Taiwan in 2012, typhoon Tembin killed only eight people but caused $8 million damage; typhoon Saola killed six but caused $27 million damage. Typhoon Morakot was the most expensive typhoon ever, devastating Taiwan to the cost of $2.3 billion damages in 2009.</p>
<h2>Early warnings reduce vulnerability</h2>
<p>Tropical cyclones build slowly. Continuous surveillance and monitoring via satellites, radar, aircraft reconnaissance, weather probes and automatic weather stations are undertaken. Information is gathered and shared at a regional level, such as through the <a href="http://www.usno.navy.mil/JTWC/">Joint Typhoon Warning Centre</a> and at national level, such as China’s <a href="http://english.nmefc.gov.cn/HomeSeverlet.do">National Marine Environmental Forecasting Centre</a>. Each issues warnings on cyclone formation, intensity, speed and direction.</p>
<p>With early warning, people can evacuate from the path of approaching typhoons or take protective measures for themselves and buildings. Whether people choose to act in the face of a typhoon threat can be affected by many factors, including economic vulnerability, social norms, cultural preferences, and religious reasons.</p>
<p>In Asia, the real problem is building vulnerability. In China, rapid and unregulated property development in coastal cities exacerbates the problem. Those who live in low coastal areas may have buildings on stilts, or levees in front of their buildings. Construction deficiencies from weak builds or insufficiently deep piles driven into the ground leave buildings vulnerable. Levees can be overtopped or even destroyed by high storm surges generated by super-typhoons, particularly those occurring with high tides. Natural barriers such as salt marshes have been used to weaken the strength of storm surges, but they are not impassible.</p>
<h2>Catastrophe modelling is the solution</h2>
<p>Disaster management for typhoons lies on the assessment of potential damages. Sharing the risk through insurance may be the solution for those living with typhoons.</p>
<p>Hurricane catastrophe models have in development for decades, such as <a href="http://www.air-worldwide.com/Home/AIR-Worldwide/">AIR Worldwide</a>, <a href="http://www.eqecat.com/">EQECAT</a>, <a href="http://www.rms.com/">RMS</a>, and public-private collaborations such as the <a href="http://www.cis.fiu.edu/hurricaneloss/">Public Hurricane Loss Projection Model</a> based in Florida International University. Unfortunately such models for typhoons in the Western North Pacific ocean basin are still at an early stage, and more improvement is needed before they are comparable.</p><img src="https://counter.theconversation.com/content/16094/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Norman K.W. Cheung 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>Typhoon Soulik struck Taiwan at the beginning of the weekend, killing two people before moving on into Guangdong in southern China, where 300,000 people have already been evacuated. Classed as a category…Norman K.W. Cheung, Senior Lecturer in environmental hazards and disaster management, Kingston UniversityLicensed as Creative Commons – attribution, no derivatives.