The ISIMIP2b scenarios are designed to elicit the contribution of climate change to impacts arising from low-emissions climate-change scenarios. Pre-industrial control runs are included to facilitate statistical comparison with a no-climate-change case.

The ISIMIP2b protocol covers several new sectors, including tropical cyclones, temperature-related mortality and lakes.

The scientific rationale for the scenario design is documented in a GMD discussions paper by Frieler, et al.

Important information about preparing your simulation files

  • Please read the Terms of Use and additional information in the Modellers' Dashboard. If you're not an ISIMIP participant, check how to join ISIMIP.
  • Information about which input data are available in ISIMIP2b, can be found here.
  • Basic analysis of global-mean-temperature levels in the ISIMIP2b climate data can be found here.

ISIMIP2b Protocol Changes

Aug. 8, 2019

The variables Total water demand (=potential water withdrawal) (ptotww) and Total potential water consumption (ptotuse) have been added.

Aug. 8, 2019

The thermal stratification and lake ice cover will be reported in the binary variables strat and ice, resp., for a given grid cell. The variables stratstart, stratend and stratdur were removed.

Aug. 8, 2019

The variables icestart, iceend, and icedur have been deleted. Since there are already the daily variables lakeicefrac and icethick, there is no need to add another variable, because the start, end, and duration of ice cover can be derived from those daily variables.

Aug. 8, 2019

For depth-varying variables, data should be provided either as fully-resolved vertical profiles, or, if that is not possible, as a mean of the epilimnion or mixed layer (“mean epi”), and mean of the hypolimnion (“mean hypo”).

Aug. 8, 2019

In the biomes sector, the variables Total carbon mass in Soil Poll (soilc) and Carbon loss due to peat burning (somcfire) have been added. Values for evaporation from canopy (interception), water evaporation from soil and transpiration should be provided at pft-level if the model allows it.