THE ECONOMIC IMPACTS of climate change are the net costs or benefits from such climatic change on the global economy relative to a prior world with constant climate. Economic impacts are usually measured relative to a pre-industrial average climate (1750–1850). Climate change will directly and indirectly affect peoples lives, the physical environment, as well as the economic growth of developing and developed countries. The economically most significant physical changes brought on by climate change are shifted temperature, rainfall, and radiation patterns, because these factors serve as inputs to production and affect human well-being directly or indirectly through socioeconomic and ecological systems. The largest effects are likely to occur through impacts on the global water balance, the food production system, human health, land, and ecosystems. In ...