* U.S. public not ready for radical climate action
* Copenhagen climate deal may agree a framework only
* Saving Greenland ice cap is defining climate cause
By Gerard Wynn
OXFORD, England, Sept 28 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 metres 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 Sept. 30 a new draft climate bill for the Senate to vote on. [ID:nN24465551]
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.
Pledges so far would take overall reductions by all industrialised nations to a maximum of 15 percent, Reuters calculations show. U.S. President Barack Obama aims to return U.S. emissions to 1990 levels by 2020. [ID:nL8211693]
"We are not even near the reductions that are necessary," said Schellnhuber.
Delegates from about 190 nations were meeting in Bangkok on Monday to try to speed up the U.N.-led negotiations to replace the Kyoto Protocol after 2012. [ID:nLS243569]
Schellnhuber did not expect individual countries to sign up to ambitious targets in Copenhagen but hoped for agreement on an ambitious long-term framework, for later negotiation.
Schellnhuber was speaking on the sidelines of a conference at Oxford University where scientists detailed how a 4 degrees Celsius hotter planet might look. [ID:nLP228193]
He expected most or all coral reefs to disappear in a 2 degrees hotter world, and the Greenland ice sheet to melt more rapidly at 4 degrees, potentially fuelling further warming and disrupting water supplies to more than 1 billion people.
"If we save Greenland we save the planet." (Reporting by Gerard Wynn; Editing by Charles Dick)