How well do integrated assessment models simulate climate change?

Publication

Integrated assessment models (IAMs) are regularly used to evaluate different policies of future emissions reductions. Since the global costs associated with these policies are immense, it is vital that the uncertainties in IAMs are quantified and understood. We first demonstrate the significant spread in the climate system and carbon cycle components of several contemporary IAMs.

We then examine these components in more detail to understand the causes of differences, comparing the results with more complex climate models and earth system models (ESMs), where available. Our results show that in most cases the outcomes of IAMs are within the range of the outcomes of complex models, but differences are large enough to matter for policy advice. There are areas where IAMs would benefit from improvements (e.g. climate sensitivity, inertia in climate response, carbon cycle feedbacks). In some cases, additional climate model experiments are needed to be able to tune some of these improvements. This will require better communication between the IAM and ESM development communities.

Authors

D.P. van Vuuren, J. Lowe, E. Stehfest, L. Gohar, A. Hof, C. Hope, R. Warren, M. Meinshausen, G. Plattner

Specifications

Publication title
How well do integrated assessment models simulate climate change?
Publication date
11 December 2009
Publication type
Publication
Magazine
Climatic Change (published online)
Product number
92427