摘要：持续数日的山火仍在美国加州南部肆虐。如今，野火的肆虐已成为常态，尤其是在美国西部，加州等地的火灾愈加频繁和猛烈。这场火灾的背后，除了自然环境的变化外，还有什么问题。为什么山火这么难被扑灭？

持续数日的山火仍在美国加州南部肆虐。如今，野火的肆虐已成为常态，尤其是在美国西部，加州等地的火灾愈加频繁和猛烈。这场火灾的背后，除了自然环境的变化外，还有什么问题。为什么山火这么难被扑灭？

It was just a Fireball and traveled so fast.

那只是一个火球，而且它移动的速度极快。

I just saw flames all up on the hill behind my house.

我刚刚看到我家后面的山上到处都是火。

It was Armageddon, I'll tell you, the fire coming in and burning all around us.

我跟你说，那简直就是世界末日，大火席卷而来，在我们周围熊熊燃烧。

Alaska, Arizona, California, Montana, Oregon, Australia, Brazil, Canada, Greece, Russia.

阿拉斯加，亚利桑那，加利福尼亚，蒙大拿，俄勒冈州，澳大利亚，巴西，加拿大，希腊，俄罗斯。

These are just some of the places where in recent years, wildfires have raged out of control.

这些只是近年来野火肆虐失控的一些地方。

NASA satellites detect more than a million large fires worldwide every year.

美国国家航空航天局的卫星每年在全球范围内探测到100多万起大火。

The Western United states, for example, has seen larger fires in each of the last several years and more intense burning, and many times as fire spread faster, making them more difficult to put out and more dangerous for the communities who live in that vicinity.

例如，美国西部，在过去的几年里，每年都有更大的火灾和更猛烈的燃烧，很多时候，当火势蔓延得更快时，它们将更难以被扑灭，对居住在附近的群体来说也更危险。

In many cases, the blazes are set by human activity, but sometimes policy fuels the flames too.

在许多情况下，大火是由人类活动引起的，但有时政策也火上浇油。

Consider California, the state's forests are overgrown in part because of past federal policies of putting out wildfires rather than letting them burn.

以加州为例，该州的森林植物茂盛，部分原因是过去的联邦政策是扑灭野火，而不是让它们燃烧。

Some of these policies were enacted in response to a devastating fire in 1910, in which millions of acres burned more than 80 people died.

其中一些政策是为了应对1910年的一场毁灭性的火灾而通过的，在那场火灾中，数百万英亩的土地被烧毁，80多人死亡。

Years passed and suppression became the go to strategy for dealing with fire.

多年过去了，镇压火势成了对付火灾的首选策略。

Ignition. It only takes a minute to wipe out a century.

起火。只需要一分钟就能毁灭一个世纪。

Initiatives like Smokey Bear urged Americans to help prevent forest fires.

像黑熊斯莫奇这样的倡议敦促美国人帮助防止森林火灾。

Only you can prevent forest fires.

只有你能防止森林火灾。

In 1974, Congress passed the Federal Fire Prevention and Control Act in an effort to save lives, and that plan worked.

1974年，为了拯救生命，国会通过了联邦防火控制法案，而这个计划成功了。

Around that time according to the act fires of all types killed more than 12,000 people each year.

根据该法案，在那个时候，每年有超过1.2万人死于各种类型的火灾。

Today, according to the U.S Fire Administration, the death toll is lower, but...

今天，根据美国消防局的数据，死亡人数有所下降，但是……

Part of the reason we see increasing fuels and increasing extreme fire behavior is that we have a legacy of putting fires out and allowing fuels to grow, permitting fires when they do start to get out of control.

我们观察到越来越多的可燃物和越来越多的极端火势，部分原因是我们有扑灭火灾的传统，允许可燃树木的生长，当火灾发生时，导致火势失控。

Overgrown forests have an abundance of small and medium trees known as Ladder fuels, which can make fires more dangerous.

植物蔓延的森林里有大量被称为阶梯式燃料的中小型树木，这会使火灾更加危险。

Ladder fuels would allow a surface fire burning often slowly along the ground to transition into the canopy, or it can spread more rapidly.

阶梯式燃料可以让地面燃烧的火焰慢慢地沿着地面蔓延至树冠，或者它可以使火灾蔓延得更快。

And when those trees are burning, the embers that are blown by the wind can ignite the neighboring trees, they can also be spread further downwind.

当这些树木燃烧时，被风吹来的余烬会点燃邻近的树木，它们还会进一步顺着风蔓延。

That's part of the story of California's 2018 fire season.

这就是加州2018年火灾季节的一部分故事。

The deadly campfire was fed by dry weather, fast winds and ladder fuels.

干燥的天气、疾风和阶梯式燃料助长了致命的篝火。

According to recent research, 20 million acres of forest land, or nearly 20% of California would benefit from what's known as fuel treatments.

根据最近的研究，2000万英亩的林地，或者说将近20%的加州将受益于燃料处理。

Land managers can limit the fuels that could create large, fast moving fires in several ways, including getting out vegetation, think logging or clearing brush, prescribed burns where small fires are set deliberately, or letting natural wildfires in unpopulated areas run their course under the watch of local firefighters.

土地管理者可以通过几种方式限制可能引发大规模、快速蔓延火灾的燃料，包括清除植被，例如伐木或清理灌木丛，进行规定火烧（即有计划地点燃小规模火灾），或在当地消防员的监督下，让无人区的自然野火自行燃烧。

But clearing out brush can be expensive and labor-intensive.

但是清理灌木丛既费钱又费力。

First since many of these trees are small in diameter, so they don't have commercial value as timber and there's little financial incentive to remove them.

首先，由于这些树木中的许多直径较小，所以它们作为木材没有商业价值，因此几乎没有经济动机去移除它们。

And federal policies have historically favored putting out fires as soon as they start, to keep people safe.

联邦政策历来倾向于在火灾刚刚开始时就将其扑灭，以确保人们的安全。

Maintaining that balance of different ecosystem types in different fire frequencies is more difficult when we move into areas with more dense human populations.

当我们处于人口更密集的地区时，在不同的火灾频率下保持不同生态系统的平衡就更加困难了。

And so the wild land urban interface is really where these two challenges meet, where people are living in communities against landscapes that historically have had fire activity.

所以，荒野和城市的交界区实际上是这两个挑战相遇的地方，在那里，人们居住的地区紧挨着历史上有曾有火灾活动的风景区。

Those are landscapes that are very difficult to protect when fires do start.

当火灾发生时，我们很难保护这些风景区。

One of the factors affecting California's wildfire season is new housing construction in fire prone areas.

影响加州野火季节的因素之一是易发火灾地区的新住房建筑。

Climate change is adding to the problem too.

气候变化也加剧了这个问题。

Where fuels are abundant today and where climate change is leading to warmer and drier conditions, we are already seeing more extreme fire behavior.

在今天可燃物丰富的地区，在气候变化导致气候变暖变干燥的地区，我们已经看到了更极端的火势。

According to recent Federal Data, the last decade was the warmest on record.

根据最近的联邦数据，过去十年是有记录以来最热的十年。

During the summer of 2020 fires burned in the Arctic, as parts of Siberia broke the record for the highest temperature ever recorded above the Arctic circle.

2020年夏天，北极地区发生了大火，西伯利亚部分地区打破了北极圈内有记录以来的最高温度记录。

They're almost always too cold and too wet to burn.

这些地区几乎总是太冷太湿而不能燃烧。

So as those landscapes, which are warming three times faster than the rest of the planet, continue to warm and dry, we certainly expect to see more fires in those remote landscapes directly in response to climate change.

因为这些地区的变暖速度是地球其他地区的三倍，如果气候继续变得温暖干燥，我们肯定会在这些偏远地区看到更多的火灾，这是对气候变化的直接反映。

In August of 2020, wildfires most of them sparked by lightning raged out of control across California.

2020年8月，大部分由闪电引发的野火在加州肆虐。

Earlier in the year, state officials had warned of high fire danger caused by a dry winter and warm spring.

今年早些时候，州政府官员警告过，干燥的冬天和温暖的春天会引发高度的火灾隐患。

It's a pattern scientists generally attribute to climate change.

科学家通常把这种现象归因于气候变化。

In May, the mountain snowpack in California, Sierra Nevada was just 13% of normal, and it's not just 2020, half of California's 20 most destructive wildfires have happened since 2015.

在五月份，加利福尼亚内华达山脉上的积雪只有正常水平的13%，且不仅仅是2020年，加州20场最具破坏性的野火中有一半发生在2015年之后。

Across the forests of Southeast Australia, NASA mapped more fires between 2019 and 2020 than they had in the last 16 years.

穿过澳大利亚东南部的森林，美国国家航空航天局在2019年至2020年期间绘制的火灾地图比过去16年间绘制的都要多。

The fires were fueled by extreme heat and drought, hotter, drier weather sucks moisture out of the trees, grasses, and other fuels making them more flammable.

极端的高温和干旱助长了火势，炎热干燥的天气吸收了树木、草和其他燃料的水分，使它们更易燃。

And this is making fire management all the more complicated.

而这使得火灾管理变得更加复杂。

So as conditions that allow wildfires to spread are lasting longer across the United States and elsewhere, there's a shorter and shorter window where active management could happen under conditions that wouldn't risk fires escaping and spreading into lands as a wildfire.

因此，在美国和其他地区，随着允许野火蔓延的条件持续时间越来越长，在不冒着让火势失控变成野火蔓延到土地的情况下，进行主动管理的时间窗口就越来越短了。

That means fighting fire with fire might not be an option for certain regions anymore.

这意味着以火攻火的方式可能不再是某些地区的选择了。

So to help with wildfires, researchers are working on algorithms to improve forecasting.

因此，为了帮助扑灭野火，研究人员正在努力精进预测火灾的算法。

If we can anticipate the timescales and the locations where fires are most likely, we have the best chance of trying to mobilize and prepare resources to anticipate fires and make up more timely decision about which fires to put out and which to let burn.

如果我们能预测时间段和最可能发生火灾的地点，我们才有最好的机会调动和准备资源来预测火灾，并更及时地决定扑灭哪些火，让哪些火继续燃烧。

来源：英语东