Ronald F. Follett & John M. Kimble 
Potential of U.S. Grazing Lands to Sequester Carbon and Mitigate the Greenhouse Effect [PDF ebook] 

Grazing lands represent the largest and most diverse land resource-taking up over half the earth’s land surface. The large area grazing land occupies, its diversity of climates and soils, and the potential to improve its use and productivity all contribute to its importance for sequestering C and mitigating the greenhouse effect and other condition