Steinfeld, H., Gerber, P., Wassenaar, T., Castel, V., Rosales, M., & De Haan, C. (2006). Livestock’s long shadow (p. 392). Rome: FAO.
The single most wide-ranging source of information on the issue, this report is an important and comprehensive source work on the connection between animal agriculture and its wide ranging environmental impacts. Note: some of the numbers used in this report are out of date (for greenhouse gas emission in particular). This paper (citation below) is a good supplement to Livestock’s Long Shadow and a helpful source of up-to-date facts.