The United Nations climate-change panel is under fire for wrongly linking rising global temperatures to an increase in the severity of natural disasters such as floods and hurricanes. The panel’s claim was based on an unpublished report that had not been peer-reviewed and whose authors later retracted—despite warnings from scientific advisers that the evidence was too weak. The supposed link was central to the debate in the Copenhagen climate summit last month; developing nations demanded $100 billion from wealthier nations blamed for emitting global-warming gases. Many global leaders, including Barack Obama, have urged action based on the claim. The report was eventually published in 2008, with the authors saying, "We find insufficient evidence to claim a statistical relationship between global temperature increase and catastrophe losses." But the U.N. panel failed to issue a clarification ahead of the Copenhagen summit.