大学英语六级仔细阅读练习题（四）_大学英语阅读

大学英语六级仔细阅读练习题（四）

　　The study points to a gradual increase of Katrina-like events. The warming experienced over the 20th century doubled the number of such debilitatingstorms. But the ongoing warming of the planet into the 21st century could increase the frequency of the worst kinds of storms by 700 percent, threatening coastlines along the Atlantic Ocean with muitiple Category 5 storms every year.

　　Our results support the idea that changes in regional sea surface temperatures is the primary cause of hurricane variability, said Aslak Girnstead, a researcher with the Center for Ice and Climate at the University of Copenhagen. The large impact of small sea-surface temperature increases was more than Girustead and his colleagues had anticipated. The entire study was published in the Proceedings of the National Academy of Sciences.

　　Global temperatures have steadily increased, making the past decade the warmest on record. Earlier this year, climate researchers reported that the Earths temperatures have risen faster in the last century than at any point since the last ice age, 11,300 years ago. The primary cause, a couseusus of scientists has said, is the rising emissions of greenhouse gases like carbon dioxide and methane.

　　Past hurricanes have supported the studys finding that global temperature rise is linked to more destructive storms. According to the National Center for Atmospheric Research, while the frequency of storms doesnt appear to have increased, the percentage of strong ones has risen sharply over the past few decades. The trend may be similar further back in time, but comprehensive hurricane data doesnt exist.