日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

   

Global warming to alter California landscape

(Agencies)
Updated: 2007-12-30 11:37

Related readings:
2007 a year of weather records in US
Global warming speeds ice melting
US experts insist global warming not man-made
Penguin species threatened warming
Global warming 'will destroy Amazon'

"They could be wiped out of California depending on how quickly the change happens," said Cameron Barrows, who studies the effects of climate change for the Center for Conservation Biology in Riverside.

Farther north, where wet, cold winters are crucial for the water supply of the entire state, warmer temperatures will lead to more rain than snow in the Sierra Nevada and faster melting in the spring.

Because 35 percent of the state's water supply is stored annually in the Sierra snowpack, changes to that hydrologic system will lead to far-reaching consequences for California and its ever-growing population.

Some transformations already are apparent, from the Sierra high country to the great valleys that have made California the nation's top agricultural state.

The snow line is receding, as it is in many other alpine regions around the world. Throughout the 400-mile-long Sierra, trees are under stress, leading scientists to speculate that the mix of flora could change significantly as the climate warms. The death rate of fir and pine trees has accelerated over the past two decades.

In the central and southern Sierra, the giant sequoias that are among the biggest living things on Earth might be imperiled.

"I suspect as things get warmer, we'll start seeing sequoias just die on their feet where their foliage turns brown," said Nate Stephenson, a US Geological Survey ecologist who is studying the effects of climate change in the Sierra Nevada. "Even if they don't die of drought stress, just think of the wildfires. If you dry out that vegetation, they're going to be so much more flammable."

Changes in the mountain snowpack could lead to expensive water disputes between cities and farmers. Without consistent water from rivers draining the melting snow, farmers in the Central and Salinas valleys could lose as much as a quarter of their water supply.

Any drastic changes to the state's $30 billion agriculture industry would have national implications, since California's fertile valleys provide half the country's fresh fruits, nuts and vegetables, according to the Union of Concerned Scientists' study.

   1 2 3   


Top World News  
Today's Top News  
Most Commented/Read Stories in 48 Hours
主站蜘蛛池模板: 亚洲一区二区美女 | 成人激情视频在线播放 | av手机在线看 | 最新久久 | 国产黄色在线播放 | 久久久综合网 | 污网站在线免费看 | 免费av成人 | 九九久久九九久久 | 自拍偷拍另类 | 亚洲一区二区三区三州 | 九九超碰| 宅男噜噜噜 | 黄网在线观看视频 | 亚洲性欧美 | 91在线视频免费 | 黄色a级片视频 | 湖南良妇3p自拍 | 亚洲久久综合 | 国产在线观看91 | 一区二区三区在线看 | 国产一区二区久久 | 国产剧情自拍 | 婷婷社区五月天 | 欧美成人一级片 | 91性| 男人操女人的视频网站 | www.婷婷.com| 久国产视频 | 国产精品久久久久久久久借妻 | 国内精品一区二区 | 老汉色av | 91国产视频在线观看 | 91精品亚洲 | 伊人免费视频 | 免费av在线网址 | 亚洲三级国产 | 亚洲天堂8 | 久久久午夜影院 | 亚洲一区欧美二区 | 国产视频网站在线观看 |