Skip navigation

The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP)

ISI-MIP is a community-driven modelling effort with the goal of providing cross-sectoral global impact assessments, based on the newly developed climate scenarios (RCPs: Representative Concentration Pathways) and socio-economic scenarios (SSPs: Shared Socio-Economic Pathways), and was featured in a recent issue of the journal Nature (Schiermeire Q. 2012. “Models hone picture of climate impacts.” Nature 482 (7385), p. 286).

Based on these common background scenarios, quantitative estimates of impacts and uncertainties for different sectors and from multiple impacts models are being derived. From this, policy relevant and society-focused metrics are being calculated.

This project, coordinated by PIK in Potsdam, Germany, with support from IIASA, near Vienna, Austria, and with backing from the IPCC Working Groups I and II, is providing fast-track results for the IPCC’s Fifth Assessment Report (AR5). It will also provide the basis for longer-term coordinated impact assessments efforts.

Figure 1


A large number of studies of mitigation pathways and strategies have shown that achieving a 2° world is much more ambitious and costly than a 3° world. Therefore there is a great need for a comprehensive understanding and quantification of the differences between multiple levels of global warming in terms of impacts from climate change.

However uncertainties in, and fragmentation of, knowledge on impacts are large. A global, cross-sectoral, quantitative synthesis of climate impacts, including consistent estimates of uncertainties, is missing so far.

Furthermore a better, quantitative understanding of impacts will enable the derivation of efficient emulators. These have the ability to enhance integrated assessment studies with respect to impacts and adaptation.

Figure 2


The timeline is dominated by the deadline for Working Group II for the IPCC AR5. Around 18 impact modelling teams from the agricultural, water, ecosystems, infrastructure, and health sectors have been provided with pre-processed input data (i.e. climate and socio-economic data, based on CMIP5, using a wide range of scenarios). Results are being uploaded to servers in Germany for analysis by coordinating teams. Dr Andrew Friend of the Department of Geography is leading the analysis of the terrestrial ecosystem responses.

A Special Feature of PNAS in 2013 will contain a number of sectoral and synthesis articles arising from this project. An international impacts conference in May 2013 will evaluate ISI-MIP and the state of the art in impacts research, and be used to stimulate further long-term efforts (

The Department of Geography has received funding from the German BMBF for participation in ISI-MIP.