{"id":1134,"date":"2018-11-20T13:47:01","date_gmt":"2018-11-20T13:47:01","guid":{"rendered":"http:\/\/waims.co.in\/?p=1134"},"modified":"2018-11-20T13:47:01","modified_gmt":"2018-11-20T13:47:01","slug":"is-climate-change-fanning-megafires","status":"publish","type":"post","link":"https:\/\/waims.co.in\/index.php\/2018\/11\/20\/is-climate-change-fanning-megafires\/","title":{"rendered":"Is climate change fanning megafires?"},"content":{"rendered":"<p>The biggest fire in California history ignited shortly after noon on July 27, 2018, and burned until mid-September. Called the Mendocino Complex Fire, its twin infernos started at the same time. They also burned close to one another and quickly blazed across forested lands. Together, they charred more than 1,800 square kilometers (700 square miles) \u2014 an area nearly half the size of the state of Rhode Island. Ninety crews of firefighters worked to contain it. They used hundreds of fire engines, 20 helicopters, 76 bulldozers and other tools. One firefighter died and four were injured. More than 150 homes burned, and smoke from the fire spread through the sky to nearby states.<\/p>\n<aside class=\"floating-sidebar floating-sidebar-right clearfix\">\n<h4><a href=\"https:\/\/www.sciencenewsforstudents.org\/article\/explainer-how-and-why-fires-burn\">Explainer: How and why fires burn<\/a><\/h4>\n<\/aside>\n<p>Six of the state&#8217;s worst fires blazed in 2017 and 2018. A wildfire that burned through Napa Valley in October 2017 was particularly bad. Before it ignited, people who lived in the area described incredible winds that could knock a person over. Once the fire started, witnesses saw fires jump across roads, rip through vast fields of grapes and hop over hills. During more than three weeks, the fire claimed 22 lives, destroyed more than 5,000 structures and burned more than 146 square kilometers (56 square miles). That\u2019s an area as big as one-and-a-half Disney Worlds. By year end, 2017 became California\u2019s worst wildfire year on record.<\/p>\n<p>Many areas across the world have seen a rise in extreme fires in recent years. Those include western U.S. states and southern Europe. They also include places you might not expect.<\/p>\n<p>For example, wildfires used to be uncommon on Alaska\u2019s North Slope. This\u00a0region borders the Arctic Ocean and is home to the largest U.S. oil field. Now, however, fires are igniting there more frequently. The same is true in other Arctic regions. In July, for instance, people had to evacuate cities in northern Sweden as wildfires swept through them.<\/p>\n<p>Some reasons for the rise in destructive fires are clear. People have been building homes on the edge of forests that face a high risk of fire. Periods of heavy rainfall can also spur a massive growth in vegetation. If that same area later experiences a drought \u2014 and California has suffered from many droughts in recent years \u2014 that new vegetation may dry out and become tinder that burns easily.<\/p>\n<p>\u201cThe Napa Valley fires were a good example of this,\u201d said Timothy Brown. He spoke during an online press briefing in August 2018. (It had been organized by a science communication project called SciLine.) During the briefing, experts talked about climate and weather. \u201cExtreme precipitation in the winter and spring allowed for extensive [vegetation] growth,\u201d he noted. \u201cThen, when that dried later in the fall, it became very flammable and susceptible to ignition.\u201d Brown is a climate scientist at the Desert Research Institute in Reno, Nev.<\/p>\n<h4><strong>The signal of climate change<\/strong><\/h4>\n<p>Has climate change made wildfires worse and megafires more likely? That\u2019s what Brown and other climate scientists want to know. More importantly, they worry that more intense fires could become the new normal.<\/p>\n<p>Studies have long predicted that warmer temperatures, due to climate change, make droughts and heat waves more likely. Many areas hit by recent fires had suffered through extreme droughts and heat waves.<\/p>\n<p>But connecting individual fires to climate change is complicated. That\u2019s partly because fire is complicated. Blaming climate change for any single fire is too simple. It ignores the natural conditions that make fire possible. But hotter days and warmer nights, caused by changes in the climate, do likely boost the risk of fire.<\/p>\n<p>Scientists are still trying to agree on what makes a blaze ignite and spread. A wildfire has three main ingredients. First, it needs a spark. This can come from lightning or a downed power line. It can also come from negligent or malicious people who set fires by accident or on purpose. Brown points out that people start four out of every five wildfires. Second, a fire needs fuel to burn. This can be the trees in the forest or the dead \u201clitter\u201d \u2014 leaves, twigs and grass \u2014 on or near the forest floor. Finally, a fire needs weather conditions, like wind and no rain, to help it spread.<\/p>\n<p>Many studies predict that climate change will boost the number of droughts and heat waves. Fire-ravaged areas, including California and Sweden, have had extreme droughts and extreme heat in recent years. Some scientists point to these weather events as proof that climate change makes wildfires worse.<\/p>\n<p>But it\u2019s even more complicated than that, says Janice Coen.<\/p>\n<h4><strong>Fires can make their own weather<\/strong><\/h4>\n<aside class=\"floating-sidebar floating-sidebar-right clearfix\">\n<h4><a href=\"https:\/\/student.societyforscience.org\/article\/explainer-what-computer-model\" target=\"_blank\" rel=\"noopener\">Explainer: What is a computer model?<\/a><\/h4>\n<\/aside>\n<p>Coen is a meteorologist at UCAR. That\u2019s the University Corporation for Atmospheric Research in Boulder, Colo. Testing\u00a0<em>hypotheses<\/em>\u00a0about fire is difficult, she explains. After all, scientists can\u2019t go out and start a megafire. But she can make a\u00a0<em>computer model<\/em>\u00a0to test various ideas about the conditions that play a role in them. And that is exactly what Coen and her team did.<\/p>\n<p>California\u2019s 2014 King Fire burned for 27 days. During that time, it destroyed 12 homes. It was started by a man who recorded a selfie of himself right afterward. (He\u2019s now in jail.) Coen wanted to know why the blaze raced so quickly through a forest canyon. To find out, she recreated the fire with a computer program. It used math to study how air particles move. It included data about temperature, humidity, air pressure and wind speeds. Those measurements had been collected by satellites, weather stations\u00a0and special planes with onboard sensors.<\/p>\n<div class=\"dnd-widget-wrapper context-sdl_editor_representation type-image atom-align-right\">\n<div class=\"dnd-atom-rendered\">\n<div class=\"image\"><img loading=\"lazy\" decoding=\"async\" class=\"image-style-none\" title=\"a sattelite image showing smoke from the King Fire in September 2014\" src=\"https:\/\/www.sciencenewsforstudents.org\/sites\/default\/files\/scald-image\/350_King_Fire_California.png\" alt=\"a sattelite image showing smoke from the King Fire in September 2014\" width=\"350\" height=\"438\" \/><\/div>\n<\/div>\n<div class=\"dnd-caption-wrapper\">\n<div class=\"sns-scald-image-caption\">\n<div>Smoke from the King Fire can be seen in this September 17, 2014 satellite image of the border between California and Nevada.<\/div>\n<\/div>\n<div class=\"sns-scald-image-credit\">\n<div>NASA\/Wikimedia Commons<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>These data helped her team explore why the King fire behaved as it did. Laws of physics \u201ctell us what the answer ought to be,\u201d she explains. Those answers can then help scientists predict how future fires will behave.<\/p>\n<p>Some ecologists said the King fire burned so fast and so intensely because it had so much fuel. No fires had burned in that area for years. As a result, leaves and other plant debris had built up on the forest floor. Other researchers blamed the drought. But Coen found yet another culprit: the atmosphere. She reported her findings in the May\u00a0<em>Ecological Applications<\/em>.<\/p>\n<p>As a fire burns, it releases heat and water vapor, a gas. As that hot air rises, cooler air is drawn in at the bottom. This process creates a column of rising air. It also creates wind. In the case of the King Fire, those local winds drove the fire into new vegetation \u2014 more fuel, Coen\u2019s team reported. As the fire grew, it created more wind, which made the fire more intense. That phenomenon, combined with the shape of the canyon, led to the fire\u2019s rapid spread.<\/p>\n<p>\u201cWeather directs the fire,\u201d she says. \u201cThe fire, in turn, can change the weather.\u201d When she ran the\u00a0<em>simulated<\/em>\u00a0fire without drought conditions, the blaze behaved almost the same way. That suggests the long drought and heat wave had not worsened the fire. Instead, the canyon\u2019s shape and local weather conditions had boosted its intensity.<\/p>\n<p>The terrible fires that have ravaged California in 2018 arose from a complex mix of ingredients. These included the Santa Ana winds, which blow hot and dry through the state every fall. They also included a lack of the rain that usually develops in the cooler months. Less rain may be due to a\u00a0<em>La Ni\u00f1a<\/em>\u00a0event (a natural phenomenon that affects weather patterns worldwide). Some of those ingredients may have been worsened by climate change. But as Coen&#8217;s study points out, finding some clear fingerprint of climate change in wildfires is not easy.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The biggest fire in California history ignited shortly after noon on July 27, 2018, and burned until mid-September. Called the Mendocino Complex Fire, its twin infernos started at the same time. They also burned close to one another and quickly blazed across forested lands. Together, they charred more than 1,800 square kilometers (700 square miles) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"class_list":["post-1134","post","type-post","status-publish","format-standard","hentry","category-current-story"],"_links":{"self":[{"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/posts\/1134","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/comments?post=1134"}],"version-history":[{"count":1,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/posts\/1134\/revisions"}],"predecessor-version":[{"id":1136,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/posts\/1134\/revisions\/1136"}],"wp:attachment":[{"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/media?parent=1134"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/categories?post=1134"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/waims.co.in\/index.php\/wp-json\/wp\/v2\/tags?post=1134"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}