How well do integrated assessment models simulate climate change?

TitleHow well do integrated assessment models simulate climate change?
Publication TypeJournal Article
Year of Publication2011
AuthorsHof, A, Meinshausen, M, Hope, C, Plattner, G-K, Warren, R, van Vuuren, DP, Lowe, J, Stehfest, E, Gohar, L
JournalClimatic Change
Start Page255
ISBN Number01650009
KeywordsCarbon cycles; Climate model; Climate sensitivity, Climate system, Complex model, Development community, Earth system model, Emissions reduction, Integrated assessment models

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. © 2009 Springer Science+Business Media B.V.