This chart from the Intergovernmental Panel on Climate Change (IPCC) 2011 report shows the relative importance of different factors in driving climate change — through their influence on the atmosphere’s radiative forcing, an index of the amount of incoming heat from the sun that is absorbed by the Earth rather than radiated back out into space. Carbon dioxide (top bar) is the greatest factor. The second bar includes methane (CH4), nitrous oxide (N2O), and halocarbons, such as chlorofluorocarbons (CFCs). Other factors have weaker effects.
Image from the 2014 Intergovernmental Panel on Climate Change (IPCC) Synythesis Report
