Climate Change Indicators: Greenhouse Gases // United States Environmental Protection Agency, 16 December 2015. Carbon dioxide’s lifetime cannot be represented with a single value because the gas is not destroyed over time, but instead moves among different parts of the ocean–atmosphere–land system. Some of the excess carbon dioxide is absorbed quickly (for example, by the ocean surface), but some will remain in the atmosphere for thousands of years, due in part to the very slow process by which carbon is transferred to ocean sediments.
Understanding methane emissions // International Energy Agency. The concentration of methane in the atmosphere is currently over two-and-a-half times greater than its pre-industrial levels
