claim: By that time CO2 emissions had already risen from the expanded use  of coal that had powered the industrial revolution, and emissions only  increased slowly from 3.5gigatonnes in 1910 to under 4gigatonnes by the  end of the Second World War.
evidence: The IPCC (Intergovernmental Panel on Climate Change) has estimated that agriculture (including not only livestock, but also food crop, biofuel and other production) accounted for about 10 to 12 percent of global anthropogenic greenhouse gas emissions (expressed as 100-year carbon dioxide equivalents) in 2005 and in 2010.Cows produce some 570 million cubic metres of methane per day, that accounts for from 35 to 40% of the overall methane emissions of the planet.