Associated Press: The next report by the Intergovernmental Panel on Climate Change should deal with the "frightening" possibility that both Antarctic and Greenland ice sheets start melting at the same time, the chief U.N. climate scientist said Tuesday. The panel, which shared the 2007 Nobel Peace Prize with former Vice President Al Gore, has released four climate assessment reports, including summaries for policymakers that are approved by government representatives. Though there are …