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 …