Winners of Tyler environmental prize...( Two scientists who found warning sig...)

Two scientists who found warning signs of climate change in the upper atmosphere and in the deepest ice sheets will share the 2009 Tyler Prize for Environmental Achievement.

The award, consisting of a $200,000 cash prize and gold medals, will go to Richard Alley, professor of geosciences at Penn State University, and Veerabhadran (Ram) Ramanathan, professor of atmospheric and climate sciences in the Scripps Institution of Oceanography at the University of California, San Diego.

On Friday, April 24, at 7 p.m., the Tyler Prize Executive Committee and the international environmental community will honor the recipients at a banquet and ceremony at the Four Seasons Hotel in Beverly Hills.

The prize committee recognized the two "for their scientific contributions that advanced understanding of how human activities influence global climate, and alter oceanic, glacial and atmospheric phenomena in ways that adversely affect planet Earth."

Alley is widely credited with showing that Earth has experienced abrupt climate change in the past, and likely will again. He based his work on a meticulous study of ice cores from Greenland and West Antarctica. Up to two miles thick, the ice sheets contain a unique record of Earth's climate history.

"Among climate scientists he is a recognized as an outstanding example of a superlative researcher who has found a way to balance his passion for discovery with his duty to inform nonscientists of the crises that are looming," geophysicist Garry Clarke of the University of British Columbia wrote in support of Alley's nomination.

"His wonderful book 'The Two-Mile Time Machine' (on the climate record from Greenland ice cores and its implications for humankind) combines good science with a serious message and succeeds, equally, with novices and experts."

One of the world's leading atmospheric scientists, Ramanathan was the first to show that ozone-depleting aerosols could aggrava
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