China and the US, the biggest sources of the greenhouse gas emissions heating the planet, have stood in the way of an international climate treaty for almost as long as there have been efforts to craft one. The US never ratified the 1997 Kyoto Protocol partly because the pact didn’t compel China and other developing economies to lower emissions. Now, the two countries may be moving toward agreement on how to rein in the 40 per cent of the world’s carbon dioxide pollution that comes from their cars, factories and power plants. Chinese and US officials on July 28 pledged to cooperate on clean-energy technology. US Secretary of State Hillary Clinton lauded the memorandum of understanding for giving direction to ongoing negotiations between the two countries ahead of a meeting of 192 nations in December in Copenhagen that’s supposed to produce a successor to the Kyoto pact. ‘There is a good chance at the end of the day that we’re going to be able to find an accommodation with China,’ says Todd Stern, the State Department’s special envoy for climate change. Bilateral discussions are making progress, Stern says, while cautioning that there have been no ‘breakthroughs.’ […]