Page "United Nations Framework Convention on Climate Change" Paragraph 91

The emissions reductions required to stabilize the atmospheric concentration of CO < sub > 2 </ sub > can be contrasted with the reductions required for methane.

Unlike CO < sub > 2 </ sub >, methane has a well-defined lifetime in the atmosphere of about 12 years.

Lifetime is defined as the time required to reduce a given perturbation of methane in the atmosphere to 37 % of its initial amount.

Stabilizing emissions of methane would lead, within decades, to a stabilization in its atmospheric concentration.