Observational determination of surface radiative forcing by CO2 from 2000 to 2010

Observationally based evidence of clear-sky CO2 surface radiative forcing that is directly attributable to the increase, between 2000 and 2010, of 22 parts per million atmospheric CO2 is presented, confirming theoretical predictions of the atmospheric greenhouse effect due to anthropogenic emissions, and providing empirical evidence of how rising CO2 levels are affecting the surface energy balance.