ABSTRACT
The National Academy of Science is trying to outline a research plan for the US Global Change Program. A group composed of natural scientists went through an exercise in which they tried to focus on the intersections among the classic disciplinary areas of research. The scientists identified things that result from land use change in general and agricultural activity in particular. The first thing one does is to identify the set of greenhouse gases and ask which are mediated by land-use transformation activities. Carbon dioxide, one of the major greenhouse gases, is certainly affected by land-use changes, primarily through direct forest clearing. The second is methane coming out of agricultural activities. The next major category is the water budgets of the earth; that is, the land-atmosphere fluxing of water, turns out to be very strongly mediated by the vegetation cover. This has been one of the areas left out of the first generation of global climate models.
