We are happy to announce that the first package of input data to start the ISIMIP4b-simulations based on the first CMIP7-ScenarioMIP simulations from EC-Earth! Many thanks to the EC-Earth team for giving us early access to the data!
The experiments cover the picontrol, historical, H (High) and VL (Very Low) scenarios considered within CMIP7-ScenarioMIP. Compared to the last AR6-Fast Tracks, we have now managed to bias-adjust the climate data (many thanks do Dánnell Quesada). In addition, we pre-processed the core Direct Human Forcings (DHF) from the Integrated Assessment Models (GCAM for H and Remind-MAgPIE for VL). This not only allows for impact projections assuming fixed present-day socio-economic conditions (2021soc, ISIMIP4b, group II) but also enables future impact projections accounting for changes in these forcings in response to mitigation measures and socio-economic development (ISIMIP4b, group III, ‘no adaptation’). Experiment set-ups and related forcing data are further detailed in the ISIMIP4b protocol (many thanks to Jochen Klar).
Below, we highlight some improvements on the DHFs compared to ISIMIP3b:
We now provide the SSP-based populations, GDP, and asset data at different resolutions and without jumps from the historical to the future period (Many thanks to Dominik Paprotny et al.).
The disaggregation of the land use / irrigation data was extended to distinguish winter and spring wheat from other temperate cereals using GGCMI phase-3 data from Jonas Jägermeyr, and crop composition was refined using CROPGRIDS (Tang et al., 2024) (many thanks to Jonas Jägermeyr, Paul Kühnel and Sebastian Ostberg!).
We also use new crop-specific data (Nguyen et al., 2024) to distribute the fertilizer input within each crop functional type, briefly described here; application rates are bounded at 500 kg N ha⁻¹ yr⁻¹, following the bound used in the LUH harmonization (many thanks to Paul Kühnel and Sebastian Ostberg).
The future dam locations were updated based on the new projections of hydropower demand from GCAM and Remind-MAgPIE, respectively (many thanks to Stefanie Heinicke for the future projections and Jan Volkholz for the extension of the historical reported data)
As for the ISIMIP4a data, this data has been generated very recently. We want to immediately share it with you to not lose time in the face of the AR7 submission deadline expected in May 2027. However, that means that we also build on you regarding testing the data. Please let us know any problems swiftly. We will also continue checking in parallel, but from our experience your models are most effective in finding errors and artefacts.
We will continue the work on adding:
- additional GCMs: We already know that the UKESM runs are finished, and we hope to be able to add them, along with runs from other upcoming GCMs, to the ISIMIP4b package as soon as possible
- rural/urban populations, national age / sex classes, and mortality / survival rates
synthetic tropical cyclone tracks by Kerry Emanuel - Please let us know if you have any questions (info@isimip.org or isimip-data@isimip.org)!
