ISI-MIP RD1

ISI-MIP is a community-driven modelling effort with the goal of providing cross-sectoral global impact assessments, based on the newly developed climate [Representative Concentration Pathways (RCPs)] and socio-economic [Shared Socio-Economic Pathways (SSPs)] scenarios. Based on common background scenarios (climate and socio-economic), a quantitative estimate of impacts and uncertainties for different sectors and from multiple impact models will be derived. From this, policy relevant and society-focused metrics will be deducted. This initiative, coordinated by a team at PIK with support from IIASA and backing from the IPCC Working Groups II and III (letters of support WG II and WG III), aims to provide fast-track outcomes for the IPCC's Fifth Assessment Report (AR5). Further it hopes to initiate a longer-term coordinated impact assessment effort driven by the entire impact community. A large number of studies of mitigation pathways and strategies have shown that achieving a 2grad world is much more ambitious and costly than a 3grad world. Therefore there is a great need for comprehensive understanding and quantification of the differences between multiple levels of global warming in terms of impacts from climate change. However, currently 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 impact emulators. These have the ability to enhance integrated assessment studies with the impact and adaptation dimensions.

This effort is aimed to be driven by the impact community. We collaborate with existing model comparison efforts like AgMIP and WaterMIP and believe in the strong synthesis effects and benefits this will generate.