TY - JOUR A1 - Harmsen, Mathijs A1 - Kriegler, Elmar A1 - van Vuuren, Detlef P. A1 - van der Wijst, Kaj-Ivar A1 - Luderer, Gunnar A1 - Cui, Ryna A1 - Dessens, Olivier A1 - Drouet, Laurent A1 - Emmerling, Johannes A1 - Morris, Jennifer Faye A1 - Fosse, Florian A1 - Fragkiadakis, Dimitris A1 - Fragkiadakis, Kostas A1 - Fragkos, Panagiotis A1 - Fricko, Oliver A1 - Fujimori, Shinichiro A1 - Gernaat, David A1 - Guivarch, Céline A1 - Iyer, Gokul A1 - Karkatsoulis, Panagiotis A1 - Keppo, Ilkka A1 - Keramidas, Kimon A1 - Köberle, Alexandre A1 - Kolp, Peter A1 - Krey, Volker A1 - Krüger, Christoph A1 - Leblanc, Florian A1 - Mittal, Shivika A1 - Paltsev, Sergey A1 - Rochedo, Pedro A1 - van Ruijven, Bas J. A1 - Sands, Ronald D. A1 - Sano, Fuminori A1 - Strefler, Jessica A1 - Arroyo, Eveline Vasquez A1 - Wada, Kenichi A1 - Zakeri, Behnam T1 - Integrated assessment model diagnostics BT - key indicators and model evolution JF - Environmental research letters N2 - Integrated assessment models (IAMs) form a prime tool in informing about climate mitigation strategies. Diagnostic indicators that allow comparison across these models can help describe and explain differences in model projections. This increases transparency and comparability. Earlier, the IAM community has developed an approach to diagnose models (Kriegler (2015 Technol. Forecast. Soc. Change 90 45–61)). Here we build on this, by proposing a selected set of well-defined indicators as a community standard, to systematically and routinely assess IAM behaviour, similar to metrics used for other modeling communities such as climate models. These indicators are the relative abatement index, emission reduction type index, inertia timescale, fossil fuel reduction, transformation index and cost per abatement value. We apply the approach to 17 IAMs, assessing both older as well as their latest versions, as applied in the IPCC 6th Assessment Report. The study shows that the approach can be easily applied and used to indentify key differences between models and model versions. Moreover, we demonstrate that this comparison helps to link model behavior to model characteristics and assumptions. We show that together, the set of six indicators can provide useful indication of the main traits of the model and can roughly indicate the general model behavior. The results also show that there is often a considerable spread across the models. Interestingly, the diagnostic values often change for different model versions, but there does not seem to be a distinct trend. KW - diagnostics KW - integrated assessment models KW - climate policy KW - Assessment Report IPCC KW - renewable energy KW - migration KW - AR6 Y1 - 2021 U6 - https://doi.org/10.1088/1748-9326/abf964 SN - 1748-9326 VL - 16 IS - 5 PB - IOP Publishing CY - Bristol ER - TY - JOUR A1 - Wilson, Charlie A1 - Guivarch, Céline A1 - Kriegler, Elmar A1 - van Ruijven, Bas A1 - van Vuuren, Detlef P. A1 - Krey, Volker A1 - Schwanitz, Valeria Jana A1 - Thompson, Erica L. T1 - Evaluating process-based integrated assessment models of climate change mitigation JF - Climatic change N2 - Process-based integrated assessment models (IAMs) project long-term transformation pathways in energy and land-use systems under what-if assumptions. IAM evaluation is necessary to improve the models’ usefulness as scientific tools applicable in the complex and contested domain of climate change mitigation. We contribute the first comprehensive synthesis of process-based IAM evaluation research, drawing on a wide range of examples across six different evaluation methods including historical simulations, stylised facts, and model diagnostics. For each evaluation method, we identify progress and milestones to date, and draw out lessons learnt as well as challenges remaining. We find that each evaluation method has distinctive strengths, as well as constraints on its application. We use these insights to propose a systematic evaluation framework combining multiple methods to establish the appropriateness, interpretability, credibility, and relevance of process-based IAMs as useful scientific tools for informing climate policy. We also set out a programme of evaluation research to be mainstreamed both within and outside the IAM community. KW - process-based integrated assessment model KW - IAM KW - evaluation KW - climate mitigation Y1 - 2021 U6 - https://doi.org/10.1007/s10584-021-03099-9 SN - 0165-0009 SN - 1573-1480 VL - 166 IS - 1-2 PB - Springer Science + Business Media B.V. CY - Dordrecht ER -