Livestock industry biggest source of methane

 From Annie Leymarie

Methane is 80 times as potent a greenhouse gas as CO2 over 20 years.  The good news is that it decays to CO2 over 12 years.  And so, if we cut our emissions, this would have a rapid effect on temperatures, as the increase in atmospheric methane is responsible for 1/3 of the rise in temperatures since 1850-1900.