Methane emissions from livestock measured by novel spectroscopic techniques

Methane (CH4) is a greenhouse gas with the second largest radiative forcingafter CO2- its global warming potential (GWP) is 25 times that of CO2 over a100 year time span. CH4 mixing ratio varied in the atmosphere over the last 650kyr, from approximately 320 ppb to 800 ppb until around 1750, after whichmethane mixing ratio increased dramatically to approximately 1770 ppb in 2005.During this period, more than half of the methane emissions to the atmospherewere from human activities. Ruminant livestock is the main source of methane