VOA慢速英语--科学家称美国西部高温天气加剧野火

Scientists Say Hotter Weather Worsens Wildfire in Western US

As temperatures rise in the western part of the United States, wildfires grow in size as well.

The Associated Press has studied information on weather and wildfires from the last 35 years. The media group’s findings¹ show that the years in which wildfires burned the highest number of hectares were also years with the hottest weather.

The report said the amount of land burned in wildfires has more than doubled.

Fires need something to cause them to start. They also require oxygen and fuel to keep them going. The report says global warming increases the supply of fuel by drying trees and other plants.

Mike Flannigan, a fire scientist with the University of Alberta in Edmonton, Canada, spoke² to the Associated Press.

“Hotter, drier weather means our fuels are drier, so it’s easier for fires to start and spread and burn more intensely,” Flannigan said.

The period of April to September is fire season in the U.S. The National Interagency Fire Center is the governmental group responsible for organizing the country’s efforts to fight wildfires. The National Oceanic and Atmospheric³ Administration⁴, or NOAA, studies weather conditions.

Data from the two agencies⁵ demonstrates⁶ that higher air temperatures are severely⁷ affecting conditions during fire season. Since 1983, the five hottest fire seasons in the western U.S. produced fires that, on average, burned more than 35,000 square kilometers.

That is three times the average for the five coldest fire seasons.

So far this summer, temperatures in the western United States have reached more than 1.7 degrees Celsius⁸ above the 20th century average. In July, California recorded its hottest month in 124 years of record-keeping.

The Associated Press examined the federal⁹ fire data from the last 35 years. It found that the fire seasons that had the largest fires were in years that temperatures reached several degrees hotter than the 20th century average.

Tim Brown is the western regional climate center director for NOAA. He said the fuel wetness levels in California and Oregon are close to record lows.

Jennifer Balch is a University of Colorado fire scientist. She said that reduced wetness in the air is “the key driver of wildfire spread.” She predicted the western U.S. soon will start to see wildfires of over 400,000 hectares.

Long-time Colorado firefighter Mike Sugaski used to consider 4,000 hectare fires big. Now he fights fires 10 times that size and more.

“You kind of keep saying, ‘How can they get much worse?’ But they do,” Sugaski said.

The number of U.S. wildfires has not changed much over the last few decades, but the size of areas burned has greatly increased.

Randy Eardley is chief spokesman¹⁰ for the National Interagency Fire Center. He pointed¹¹ to the year 2000 as “some kind of turning point,” in wildfires.

From 1983 to 1999, the United States had less than 26,000 square kilometers burned each fire season. Since then, there have been 10 years in which more than 26,000 square kilometers have burned. The largest burns took place in 2017, 2015 and 2006. The wildfires in each of those years burned more than 38,000 square kilometers.

Some people who reject climate science point to data that seems to show far more land burned in the 1930s and 1940s. But Eardley said data before 1983 is not dependable.

Nationally, more than 23,050 square kilometers have burned this year. That is already 28 percent more than the 10-year average and fire season continues.

Scientists generally avoid blaming global warming for any given extreme event without extensive¹² research. But fire and weather scientists have done those extensive examinations¹³ of wildfires.

John Abatzgolou of the University of Idaho looked at forest fires and dry conditions in the western United States. The data covered from the years 1979 to 2015. He compared that data to computer-based models of what would be expected with no human-caused climate change. He concluded that global warming was partly to blame for an extra 42,000 square kilometers of forests burning since 1984.

The 2015 Alaska fire season is the second biggest on record. A similar comparison¹⁴ with a computer-based model found that human-based climate change increased the fire risk by 34 to 60 percent.

One 2015 study said worldwide fire seasons are about 18.7 percent longer since 1979. Another study that year said climate change is increasing extreme wildfire risk in California, where wildfires already are year-round.

Also, insects and a lack of water have killed 129 million trees in California since 2016, creating more fuel.

Interior¹⁵ Secretary Ryan Zinke recently told Breitbart radio that “what’s driving” increased wildfires is an increase in fuel. He said the government has “been held hostage¹⁶ by environmental terrorist¹⁷ groups.” These groups oppose clearing dead trees that they say act as homes for animals.

However, Zinke did admit that climate change did play a part in worsening wildfires.

I’m Anna Matteo. And I’m Pete Musto.

Words in This Story

century – n. a period of 100 years

regional – adj. describing a part of a country or of the world that is different or separate from other parts in some way

key – adj. extremely important

decade(s) –n. a period of 10 years

extensive – adj. very full or complete

conclude(d) – v. to decide something after a period of thought or research

held hostage – idm. held against one’s will

1 findings   

n.发现物( finding的名词复数 )；调查（或研究）的结果；（陪审团的）裁决

参考例句：

• It behoves us to study these findings carefully. 我们理应认真研究这些发现。
• Their findings have been widely disseminated . 他们的研究成果已经广为传播。

2 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

3 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

4 administration   

n.经营，管理；行政，行政机关，管理部门

参考例句：

• Who is in charge of the administration of your company?你们公司的行政工作由谁负责？
• The teachers are responsible to the school administration.教师向学校行政负责。

5 agencies   

n.代理( agency的名词复数 )；服务机构；（政府的）专门机构；代理（或经销）业务（或关系）

参考例句：

• There are many specialized agencies in the United Nations. 联合国有许多专门机构。 来自《简明英汉词典》
• The project is funded by the World Bank and other multilateral agencies. 这项计划由世界银行和其他多国机构资助。 来自《简明英汉词典》

6 demonstrates   

举行示威游行（或集会）( demonstrate的第三人称单数 )； 示范。展示； 显示； 论证

参考例句：

• I hope this message demonstrates my feelings to the students. 我希望这个祝词能表达出我对学生们的感情。
• I hope this demonstrates to you how I feel. 我希望这能向你表明我的感受。

7 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

8 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

9 federal   

adj.联盟的；联邦的；(美国)联邦政府的

参考例句：

• Switzerland is a federal republic.瑞士是一个联邦共和国。
• The schools are screaming for federal aid.那些学校强烈要求联邦政府的援助。

10 spokesman   

n.发言人，代言人

参考例句：

• The government spokesman gave a quick briefing to the reporters.政府发言人向记者们作了情况简介。
• They drew lots to decide who should be their spokesman.他们抽签决定谁是他们的发言人。

11 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

12 extensive   

adj.广泛的，广阔的，广大的

参考例句：

• The story had an extensive popularity among American readers.这本小说在美国读者中赢得广泛的声望。
• The museum offers extensive facilities for study.这个博物馆提供了许多供研究的设备。

13 examinations   

n.检查( examination的名词复数 )；考试；考查；试题

参考例句：

• He had been forced to incriminate himself in cross-examinations. 他在盘问中被迫受到牵连。 来自《简明英汉词典》
• Examinations are hanging over her head—that's why she can't sleep at nights. 她大脑里想的都是考试，所以晚上无法入睡。 来自《简明英汉词典》

14 comparison   

n.比较，对照；比拟，比喻

参考例句：

• They make a comparison of New York to a beehive.他们把纽约比作一个蜂巢。
• This dress is really cheaper by comparison.比较起来，这件衣服确实便宜。

15 interior   

adj.在内的，内部的，内地的，国内的；n.内部

参考例句：

• There is water in the interior of the cave.在山洞的内部有水。
• They went into the interior room.他们进了内室。

16 hostage   

n.人质，抵押品

参考例句：

• One group claimed to have executed the American hostage.一个组织声称已经处决了那名美国人质。
• Have you read the article about the rescue of the hostage?你看了关于营救人质的文章了吗？

17 terrorist   

n.恐怖主义者，恐怖分子

参考例句：

• Without the gun,I'm a sitting duck for any terrorist.没有这支枪，我就成了恐怖分子下手的目标了。
• The district was put on red alert during a terrorist's bomb scare.这个地区在得到恐怖分子炸弹恐吓后作了应急准备。