CONSTRAIN is developing a better understanding of how both natural and human factors will affect the climate in coming decades, and using this knowledge to improve climate projections for the next 20-50 years.



The 2015 Paris Agreement sets out a global action plan to avoid dangerous climate change by limiting global warming to well below 2°C, whilst pursuing efforts to limit warming to 1.5°C. However, predicting how the climate will change over the next 20-50 years, as well as defining the emissions pathways that will set and keep the world on track, requires a better understanding of how several human and natural factors will affect the climate in coming decades. These include how atmospheric aerosols affect the Earth's radiation budget, and the roles of clouds and oceans in driving climate change.

The EU-funded CONSTRAIN project, a consortium of 14 European partners, is developing a better understanding of these variables, feeding them into climate models to reduce uncertainties, and creating improved climate projections for the next 20-50 years on regional as well as global scales. In doing so, CONSTRAIN will take full advantage of existing knowledge from the Sixth Phase of the Coupled Model Intercomparison Project (CMIP6) as well as other Horizon 2020 and European Research Council projects.

IIASA researchers provide scientific input to WP4 and WP5. WP4 will develop two simple climate emulators that capture the behaviour of complex Earth system models for a limited set of variables, but at a much lower computational cost, enabling detailed exploration of both uncertainties and emissions pathways. These tools will translate complex insights from WPs 1-3 into policy-relevant information, to be used by WP5 making assessments of climate change mitigation, impacts and adaptation.

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Last edited: 23 April 2021


Thomas Gasser

Senior Research Scholar Exploratory Modeling of Human-natural Systems Research Group - Advancing Systems Analysis Program

Senior Research Scholar Integrated Assessment and Climate Change Research Group - Energy, Climate, and Environment Program


2019 - 2023


International Institute for Applied Systems Analysis (IIASA)
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