From the WMO: The amount of greenhouse gases in the atmosphere reached a new record high in 2011, according to the World Meteorological Organization. Between 1990 and 2011 there was a 30% increase in radiative forcing – the warming effect on our climate – because of carbon dioxide (CO2) and other heat-trapping long-lived gases... Carbon dioxide is the single most important greenhouse gas emitted by human activities. It is responsible for 85% of the increase in radiative forcing over the past d