Bob I'm sorry I can't let this one go. It's too important. The elephant in the room amongst the world's worst polluters is the United States. China has recently overtaken the USA as the worst offender year on year but if you look at total carbon emissions over all years the USA is alone at the top of the pack. The point is if the USA committed to reducing greenhouse gases to virtually zero it would make a huge difference, not no difference as you stated. Many developing countries including China (leading the way in developing alternative energy sources) have gone beyond promises to put in place carbon reduction strategies. It's not really fair to pick on poorer countries when the USA is back pedalling on the few promises they have made.