Recent Greenhouse Gas Concentrations

This tabular data set provides pre-1750 tropospheric and recent tropospheric greenhouse gas concentrations of carbon dioxide, methane, nitrous oxide, tropospheric ozone, CFC-11, CFC-12, CFC-113, HCFC-22, HCFC-141b, halon 1211, halon 1301, HFC-134a, carbon tetrachloride, methyl chloroform, sulfur hexafluoride, and other halons. Also provided are the Global Warming Potential (GWP) (100-yr time horizon), atmospheric lifetime (years), and increased radiative forcing (W/m^2) for these gases. Gases typically measured in parts per million (ppm), parts per billion (ppb) or parts per trillion (ppt) by volume are presented separately to facilitate comparison of numbers. Sources of the current concentrations are given in the footnotes to the table. The concentrations given are mostly derived from data available via the CDIAC Web pages; many corresponding links are given in the footnotes. These data are contributed to CDIAC by various investigators. The table is updated annually.