Earth’s Future Farms (page 62)

In November 2009, the prestigious Worldwatch magazine published a striking critique of the seminal report Livestock’s Long Shadow, in which the authors conclude that the global warming impact of livestock is not 18% of GHGs by 51%. They make a lot of valid points, but two of their big ones are very questionable. To Livestock’s Long Shadows estimate of 7.5 Gt of annual GHGs they add 8.8 Gt for livestock respiration, which the IPCC discounts as invalid because all respiration is, by definition, carbon neutral. They also ask “what if all land used for livestock was growing forest instead?” and add 2.6 Gt of CO₂, but this seems to assume that all grasslands would become forest, which is ecologically not true, and ignores the enormous potential of grasslands to store carbon if we change the way cattle graze (see Solution #43)

Source: Worldwatch Magazine, Nov 2009