Effects of Climate Change and Viarability on the Agricultural Production Systems provides an integrated assessment of global climate changes impact on agriculture at the farm level, in the context of farm level adaptation decisions. Ten agricultural areas in the Upper Midwest region - the heart of the United States corn belt - were subjected to climate change and changing climate variability scenarios through simulations of future climate using results from general circulation models. Crop growth models, calibrated to the study sites, were used to simulate yields under varying climate conditions. Farm level production and economic analyses were performed to determine what adaptation strategies might be best utilized to maintain production and profitability for producers under conditions of global climate change and changing climate variability. Similar integrated analyses from Australia and Argentina provide comparisons from different regions.