ABSTRACT
This chapter reviews the understanding of the role of the human activities associated with raising crops and livestock, silviculture, and land-use change in relation to the emission of greenhouse gases. Although agriculture is usually thought of as potentially harmed by changes in CO2 levels and/or climate, it is itself a significant source of greenhouse-gas emissions to the atmosphere. The principal agriculture and land-use-related sources of emissions are the production of rice and ruminant livestock and land-use change. The dominant human activities associated with N2O emissions are related to agriculture and energy production. J. M. Reilly explored the implication of a quadratic damage function and an allowance for a CO2-fertilization effect and obtained a trace-gas index, which, like the greenhouse-warming potential coefficient, is indexed relative to CO2. Roughly 40% of total atmospheric CH4 emissions are estimated to come from agriculture and land-use change.
