Reuters: Senior advisers to presidential candidates Barack Obama and John McCain debated how the United States should tackle climate change at a conference in New York on Monday. The debate between Dan Esty, an Obama adviser and an environmental law professor Yale University, and Douglas Holtz-Eakin, a McCain adviser and a former director of the Congressional Budget Office, focused on the auctioning of permits for the right to pollute greenhouse gases. Both candidates support a cap and …