China was one of several nations to praise US pledges to do more to combat global warming, Reuters reported. Washington delegates started an 11-day series of climate talks in Bonn on Sunday by announcing plans to cut US emissions of greenhouse gases by 16-17% – or back to 1990 levels – by 2020. Yu Qingtai, China’s climate ambassador, said Beijing welcomed “this positive change in attitude and approach” by the Obama administration. He said China, widely thought to have overtaken the US to become the world’s largest emitter of greenhouse gases, would curb the growth of its emissions by 2020. This is part of a UN pact set to be agreed in Copenhagen at the end of the year. Yu also stressed that poorer nations such as China have to put economic growth before global warming. “We have the option of leaving our people in the darkness without electricity, leaving the factories idle and people unemployed, or building up the necessary infrastructure to allow our economy to grow,” he said.