为何美国加州最近的野火成了“常态”？ [美国媒体]

Just a few weeks ago, two large wildfires caused massive destruction and at least 91 deaths in California, the Woolsey fire near Los Angeles and the Camp fire that engulfed the town of Paradise in the north. Residents and firefighters struggled to stop both fires, yet they can expect more like them to come.

就在几周前，两场大火在加州造成了巨大的破坏，造成至少91人死亡，洛杉矶附近的乌尔西大火和席卷北部天堂镇的营地大火。居民和消防队员奋力扑灭了两场大火，但他们预计还会有更多类似的火灾发生。



“What we found is, across nearly all the definitions in nearly all the regions, there was a significant increase in the level of simultaneity in the second time period,” Podschwit said.

波德施韦特说:“我们发现，在几乎所有地区的所有定义中，在第二个时间段的同时性水平都有显着提高。”

For example, in the Southwest, the satellite record revealed only two incidents of wildfires that burned more than 50,000 acres during the first time period. But then 34 separate fires of that size burned in the area in the following 15 years -- including an instance when five blazed simultaneously, in April and May 2011, Cullen and Podschwit found. They’re submitting their study for peer review in the next few weeks.

例如，在美国西南部，卫星记录显示，在第一时间内，只有两起森林大火烧毁了5万多英亩土地。但在接下来的15年里，该地区先后发生了34起这样规模的火灾，包括2011年4月和5月同时发生的5起火灾，卡伦和波德施韦特发现。他们将在未来几周提交他们的研究供同行评审。

Their findings build on those of the federal government's latest National Climate Assessment, released on Nov. 23. The nation’s top climate scientists found that wildfires are growing in frequency, intensity, extent and duration, and we can expect more large wildfires in the next half century, especially in the Western states. Furthermore, the study said that since 1984, climate change caused fires in the West to burn twice the area they would have without it.

他们的发现基于联邦政府11月23日发布的最新国家气候评估。美国顶尖的气候科学家发现，野火发生的频率、强度、范围和持续时间都在增加，我们可以预计，未来半个世纪还会发生更多大型野火，尤其是在西部各州。此外，该研究称，自1984年以来，气候变化导致西部地区的火灾面积是没有气候变化的两倍。



To help people prepare for the next fire, scientists have begun developing “fireshed” maps, analogous to watersheds. These locate the places most likely to ignite and where the fires will likely spread. Such maps could inform where people choose to build -- or where to rebuild after a fire.

为了帮助人们准备下一场火灾，科学家们已经开始开发类似分水岭的“火棚”地图。这些设备可以定位最容易着火的地方，以及火势可能蔓延的地方。这些地图可以告诉人们选择在哪里建造——或者火灾后在哪里重建。



But while people have begun considering retreating from hurricane flood zones or eroding coastlines threatened by sea level rise, discussions about building in fire-prone wildland areas haven't coalesced in the same way. And by their presence, people inevitably start more fires in the wildlands if they live there, too.

但是，当人们开始考虑从飓风洪泛区或侵蚀受海平面上升威胁的海岸线撤退时，关于在火灾多发的野地地区建造房屋的讨论并没有以同样的方式结合在一起。由于他们的存在，如果人们也住在那里，他们不可避免地会在荒地上引发更多的火灾。

“Accidental fires can happen because your car is overheated on the side of the freeway, or somebody throws a cigarette butt out the window, but they can also happen just because someone has a chain hanging out the back end [of their car], and it causes a spark that lands at the wrong time and place, and boom, you have a fire,” said Natasha Stavros, a fire ecologist and engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California.

娜塔莎·斯塔夫罗斯(Natasha Stavros)说：“意外起火可能是因为你的汽车在高速公路一侧过热，或者有人把烟头扔出窗外，但也可能是因为有人在(他们的车)的后端挂着一根链子，它会引发火花，落在错误的时间和地点，然后砰的一声，你就会起火。” 她是加州帕萨迪纳美国宇航局喷气推进实验室的一位火灾生态学家和工程师。

We have a different relationship with fire than with other extreme weather, since for example, no one ever talks about trying to stop a hurricane, she pointed out. “The Camp Fire was burning at 80 acres per minute -- that’s 61 football fields per minute. Why do we think we can control that?”

她指出，我们与火灾的关系不同于与其他极端天气的关系，因为例如，从来没有人谈论过试图阻止飓风。“营火以每分钟80英亩的速度燃烧——也就是每分钟61个足球场。”为什么我们认为我们可以控制它?”