The World Meteorological Organization’s annual Greenhouse Gas Bulletin shows that between 1990 and 2012 there was a 32% increase in radiative forcing – the warming effect on our climate – because of carbon dioxide (CO2) and other heat-trapping long-lived gases such as methane and nitrous oxide. Carbon dioxide, mainly from fossil fuel-related emissions, accounted for 80% of this increase. The atmospheric increase of CO2 from 2011 to 2012 was higher than its average growth rate over the past ten years, according to the Greenhouse Gas Bulletin.