Academic disputes are different from bar fights. At a House hearing last month, someone suggested to Sarah Green that she meet Richard Tol, a climate change economist who had attacked her research moments before in front of a panel of lawmakers. Green declined politely, with a wry smile. Tol, professor of economics at Britain's University of Sussex, had no idea Green was in the hearing room. The two have never met, although they have been tussling in obscure journals.