http://www.worldwatch.org/agriculture-and-...gas-emissions-0 Worldwatch Institute World Watch nel 2012 37 percent of agricultural greenhouse gas emissions http://www.worldwatch.org/agriculture-and-...gas-emissions-0 third largest Worldwatch Institute generator of greenhouse gases Worldwatch Institute Worldwatch Institute generator of greenhouse gases Worldwatch Institute 37% of agricultural greenhouse gas emissions Worldwatch Institute greenhouse gas emissions Worldwatch Institute Worldwatch Institute Worldwatch