Exports are down this year because of higher natural gas prices and a colder-than-average winter at home. When measuring progress on global warming, countries count only pollution from burning fossil fuels. Analyses suggest U.S. exports could be reducing by half or wiping out completely the pollution savings in the U.S. from switching power plants from coal to natural gas. Despite pleas from the governors of Washington and Oregon, the Obama administration has so far refused to evaluate the global impact of those additional exports. A 2010 White House guidance aimed at clarifying how broadly agencies should evaluate greenhouse gas emissions for major projects is still being reviewed.