simulations. The simulations reported upon here 1. Introduction were conducted during 1991 and 1992. In all cases the models comprise an atmospheric GCM coupled The potential enhancement of the natural to a simplified upper ocean sub-model. The greenhouse effect has caught the attention of the enhanced greenhouse gas results are derived from public, scientists, policymakers and industrialists experiments in which an instantaneous increase of worldwide. It is now well known that the trace gases was imposed and the model climate concentrations of greenhouse gases in the atmosphere have been increasing since the allowed to come into equilibrium. Summary Industrial Revolution and current concern is that information on the models, the results and these increased concentrations of gases could result experiments are included in Table 1. Further in global and regional climatic changes. The impacts detailed descriptions of the models may be obtained from the MECCA CD prototype (Henderson-Sellers, of this enhanced greenhouse are not yet fully understood and may depend upon both the degree McGuffie et al. , 1994) and more explanatory and the speed of climatic change. Attempts to information about climate models can be found in improve understanding include numerical simulations Henderson-Sellers and McGuffie (1987). using Global Climate Models (GCMs): extensive computer programs that simulate the main The Climate Change Atlas is a means of visually atmospheric physical processes determining both representing, comparing and communicating the voluminous numerical results derived from current today's climate and also possible future climates.