On the relation between complex and simple climate models

Within the context of the IPCC assessments little attention has been paid to a systematic study of methodological problems in climate science. The second IPCC Technical Paper "An introduction to simple climate models used in the IPCC Second Assessment Report" (1997) can be regarded as a first attempt by the climate science community to deal with the methodological questions of climate model complexity (although this was not the first aim of that paper). However, the second IPCC Technical Paper does not get any further than pointing out that pragmatic use is made of both complex and simple climate models in the scientific climate assessment practice. We claim that it would be better if simple climate models received more recognition, since their epistemic value is currently underestimated. At the current stage of climate science both simple and complex climate models are needed in the study of the climate system. A collaboration of climate scientists, philosophers of science, and social students of science in discussions concerning the methodology of climate simulation is called for, since the policy relevance of these discussions is large.