In 2007, farming contributed to 14% of man made GHGs
"In 2007 the Intergovernmental Panel on Climate Change reported that farming contributes 14 percent of man-made greenhouse gas emissions (GHG)" (CIS 5)
Source: IPCC. 2007a. Climate Change 2007 Synthesis Report: Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Core Writing Team, Pachauri, R.K. and Reisinger, A. (Eds.) IPCC, Geneva, Switzerland, 104, hhttps://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html [verified 4/25/14]