... acidity, integrated pest management, double-cropping, and crop Livestock’s role in climate change and air pollution rotations including green manure and cover crops Increasing crop yields result in ... 2000) Overgrazing is the greatest cause of degradation of grasslands and the overriding humaninfluenced factor in determining their soil carbon Livestock’s role in climate change and air pollution ... the decline of ruminant livestock in relative terms, and the overall trend towards higher productivity in ruminant production, it is unlikely Livestock’s role in climate change and air pollution...