In its most recent Greenhouse Gas Bulletin, the World Meteorological Organization provides some of the most contemporaneous data on the status of long-lived greenhouse gases in the atmosphere, as well as providing some excellent charts for lectures and presentations on climate science.
Among the key findings in the publication:
- Radiative forcing by long-lived greenhouse gases increased by 36% between 1990 and 2014, with carbon dioxide accounting for approximately 80% of this increase;
- Carbon dioxide levels reached 143% of pre-industrial levels in 2014 and is responsible for 83% of the the increase in radiative forcing over the past decade. Global atmospheric concentrations reached 397.7ppm in 2014, with an average annual growth rate of 2.06ppm over the past decade, with last year’s growth rate over 2013 of 1.9ppm
- Approximately 44% of anthropogenic carbon dioxide emissions reached the atmosphere in the past decade, with the remaining 56% removed by oceans and the terrestrial biosphere
- Methane concentrations in the atmosphere reached 254% of pre-industrial levels in 2014, contributing 17% of the radiative forcing of long-lived greenhouse gases. Atmospheric concentrations were 1833 ppb in 2014;
- Nitrous oxide levels reached 327 ppb in 2014, up 21% above pre-industrial levels. Nitrous oxide accounts for 6% of radiative forcing by long-lived greenhouse gases;
- Chlorofluorocarbons and minor halogenated gases account for 12% of radiative forcing by long-lived greenhouse gases, though their production is declining due to international treaty regulation. While potent greenhouse gases hydrochlorofluorocarbons and hydrofluorcarbons are increasing in production at a substantial clip, their atmospheric concentrations remain low, in the parts per trillion currently.
The Bulletin also provides a concise explanation of the anthropogenic greenhouse effect, including an excellent chart explaining radiative forcing.