Despite mounting evidence that global warming has already begun to exact steep tolls on the environment, the Bush administration told Congress yesterday that it needs up to five years of additional scientific research before it will be ready to formulate a plan to address climate change. Speaking in front of the House Science Committee, Commerce Assistant Secretary James Mahoney said the administration was ready to “move into a new time of differentiation and strategy evaluation” extending for the next two to five years. Some committee members responded by expressing frustration about the White House’s lack of a coherent climate change policy; using somewhat clearer language than Mahoney’s, Rep. Mark Udall (D-Colo.) said, “We really don’t have a policy [on climate change]. There’s a lot of rhetoric and not a lot of action.”