An influential and controversial paper asserting that recent warming in the Northern Hemisphere was probably unrivaled for 1,000 years was endorsed on Thursday by a panel convened by the nation’s pre-eminent scientific body. The panel said that a statistical method used in the 1999 study was not the best and that some uncertainties in the work ‘have been underestimated,’ and particularly challenged the authors’ conclusion that the 1990s were the warmest decade in a millennium. But in a 155-page report, the 12-member panel convened by the National Academies said ‘an array of evidence’ supported the main thrust of the paper. Disputes over details, it said, reflected the normal intellectual clash that takes place as science tests new approaches to old questions. The study, led by Michael Mann, a climatologist at Pennsylvania State University, was the first to estimate widespread climate trends by stitching together a grab bag of evidence, including variations in ancient tree rings and temperatures measured in deep holes in the earth. It has been repeatedly attacked by Republican lawmakers and some industry-financed groups as built on cherry-picked data meant to create an alarming view of recent warming and play down past natural warm […]