INTERVIEW-China should halve its emissions by 2050-US envoy

BARCELONA, Spain, Nov 5 (Reuters) - China should roughly halve its greenhouse gas emissions by 2050 to keep the world on a safe climate path, the head of the U.S. delegation at U.N. climate talks in Barcelona said on Thursday.

Leading industrialised countries say that the world must halve greenhouse gases by 2050 to avoid the worst effects of climate change, and have committed to lead by cutting their own emissions by 80 percent.

China should cut by about 50 percent, leaving space for poorer countries to grow their economies, Jonathan Pershing told Reuters.

"If you put China in there at a 50 percent reduction, if we're a bit higher, that gives lesser developed countries a bit lower. If they are in that middle band, plus or minus some percentage, that seems about right."

China would be on course to meet that goal if it repeated its present energy efficiency five-year plan into the future, he added. "They're doing pretty well," he said. (Reporting by Gerard Wynn and Alister Doyle; Editing by Charles Dick)