"The United States is... climate illiterate"

OXFORD (Reuters) U.S. wavering on climate commitment could undermine action to save the planet, the director of Germany's Potsdam Institute for Climate Impact Research said on the sidelines of a conference on Monday.

Preserving the Greenland ice cap was the defining action needed to prevent several meters of sea level rise and warming which would threaten the world's food and water supplies, Hans Schellnhuber told reporters.

The doubts of many Republican U.S. senators over the practicality of a draft, domestic carbon-cutting law undermined the chances of strong global action soon, he said.

"It's a deeper problem in the United States, if you look at global polls about what the public knows about climate change, even in Brazil, China you have more people who know the problem, who think that deep cuts in emissions are needed," he said.

"The United States is in a sense climate illiterate still. If you look at what people in the Republican party think about this problem it's very unlikely you come up with something."

Democrat senators are due to unveil on September 30 a new draft climate bill for the Senate to vote on.

Most analysts doubt Congress will back that bill before countries meet in Copenhagen in December to try to clinch a new global climate pact.

Schellnhuber described that as "the most important meeting in the history of the human species." "We're simply talking about the very life support system of this planet."

The United States is the world's biggest contributor to climate change and many other countries demand it takes a big step before they follow in cutting emissions.

A U.N. panel of climate experts in 2007 outlined cuts of between 25 and 40 percent by 2020 -- compared with 1990 levels -- required by rich nations to avoid the worst climate effects...