extract greenhouse gases from the air, a U.N. report said on Sunday. solar or nuclear power was affordable and would shave only about 0.06 percentage point a year off world economic growth. Edenhofer, co-chair of a Berlin meeting of the Intergovernmental Panel on Climate Change (IPCC). "I'm not saying it's costless. I'm not saying climate policy is a free lunch. But it's a lunch worthwhile to buy," he said. The report, endorsed by governments, is meant as the main scientific guide for nations working on a U.N. late 2015 to rein in world greenhouse gas emissions that have hit repeated highs, led by China's industrial growth. warming. percent from 2010 levels by 2050, and then close to zero by 2100, to keep temperatures below 2C. Such cuts are far deeper than most governments are planning.