A sample of global economic and social system models are examined to ascertain how they might be utilized for climate impact analysis. General values and difficulties of global models as tools for climate impact are discussed. Special note is made of two models whose relatively strong biophysical basises appear to make them particularly compatible with climatological thinking. These and other global models are explored in terms of their time horizon, methods, and substantive focus. Possible contributions toward understanding climate in relation to agriculture, energy, demography, and politics are described. It is concluded that, despite the large number of difficulties with global models, models of some sort are required to investigate quantitative interrelationships of the global system, and that useful results could be extricated from existing models given imagination, critical awareness, and good scientific practice