claim: And their wind and manure emit more than one third of  emissions of another, methane, which warms the world 20 times faster  than carbon dioxide.
evidence: While the lifetime of atmospheric methane is relatively short when compared to carbon dioxide, with a half-life of about 7 years, it is more efficient at trapping heat in the atmosphere, so that a given quantity of methane has 84 times the global-warming potential of carbon dioxide over a 20-year period and 28 times over a 100-year period.