November 30, 2009. Copyright 2009, Graphic News. All rights reserved Copenhagen Climate conference -- United States By Joanna Griffin LONDON, November 30, Graphic News: The U.S. may have been overtaken by China as the world's biggest polluter, but as far as tackling climate change goes, it's still the number one laggard. At the COP15 President Barack Obama is expected to announce the U.S. will commit to a 17 percent cut in carbon emissions by 2020 -- it's something, but still less than the EU minimum pledge for the same period. That pledge should at least allow him to wriggle out of accusations that -- on the environment -- he has merely spouted a lot of hot air. And he is clearly preferable to George W. Bush, who killed off Kyoto, and Bill Clinton, who watered it down. Obama faces resistance to his green plans from across the U.S., where no fewer than 25 states produce coal. But, if ever we needed global leadership, it is now -- and the EU has been putting pressure on Obama to step up to the plate. After all, the U.S. owes the rest of the world a debt on climate change and who better than Obama - who'll also be stopping off in Oslo to collect his Nobel peace prize - to start repaying it?