研究:气候变暖或引发更多野火

 　　A warmer planet is helping¹ to fuel more wildfires in the United States, according to a new study.

　　Environmental scientists at Harvard University predict that by 2050, wildfire seasons will be three weeks longer, up to twice as smoky, and will burn a wider area in the western part of the country.

　　Fires in the Western United States have gotten worse since the 1970s. Scientists at Harvard University School of Engineering and Applied² Sciences looked at past weather conditions and wildfires to find out why.

　　“In some regions, like the Rocky Mountains, really temperature is the driving force, but elsewhere variables like relative humidity can play a role," said Loretta Mickley, an atmospheric³ chemist and co-author of the study. "If one year is particularly moist, for example, in the Great Basin, Nevada, Utah area, then that will foster a lot of vegetation growth and then the following year all that vegetation can feed wildfires and their spread.”

　　The scientists then turned to a suite⁴ of 15 climate models based on the conclusions of the Intergovernmental Panel on Climate Change, the leading international body for the assessment⁵ of global warming. On average, the models predicted increases between 2 and 2.5 degrees Celsius⁶ by 2050.

　　“The finding for rainfall, which can diminish fire activity, and for relative humidity, we found only small changes, with some models predicting small increases and some models predicting small decreases in those variables," Mickley said. "So we found as in the past, temperature is really driving the changes that we predict for the future.”

　　The calculations suggest the probability of large wildfires would increase by factors of two or three, and that by 2050, the more than four-month fire season would be three weeks longer.

　　“If we just look at one month in the future for example, the area burned in the very forested Rockies could quadruple," Mickley said. "If we look at the whole fire season, we see increases more on the order of say 20 or 30 percent to 100 percent.”

　　While air quality in the United States has greatly improved in recent decades in response to federal laws, Mickley says air pollution is an unexpected consequence of longer lasting⁷, widespread wildfires.

　　“These increases in wildfires could totally disrupt our efforts to clean the air," she said. "Last weekend, there was an area the size of some states in the eastern U.S. blanketed with unhealthy air over California and Nevada. And we call this increase in smoke an important climate penalty on air quality.”

　　That penalty would be air that is twice as smoky as it is today. These findings, Mickley says, underscore the need for better forest management. But also she adds, they send a signal to policy makers⁸ and the public to reduce fossil fuel emissions⁹ that are warming the planet.

1 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

2 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

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 suite   

n.一套(家具)；套房；随从人员

参考例句：

• She has a suite of rooms in the hotel.她在那家旅馆有一套房间。
• That is a nice suite of furniture.那套家具很不错。

5 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

6 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。

7 lasting   

adj.永久的，永恒的；vbl.持续，维持

参考例句：

• The lasting war debased the value of the dollar.持久的战争使美元贬值。
• We hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。

8 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

9 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。