claim: ...Livestock are responsible for 18 per cent of the  greenhouse gases that cause global warming, more than cars, planes and  all other forms of transport put together.
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.