Simulation Protocols


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.

Please read the data and co-authorship policy and register your model for ISIMIP2b here.

Below you will always find the latest version of the simulation protocol. Changes compared to previous versions will be recorded in the change log.

  • Important information about preparing your simulation files can be found here.
  • Names of all files to be delivered for ISIMIP2b experiments can be found here.
  • Information about downloading the input data here.

  • Information about which input data are available can be found here.

  • Basic analysis of global-mean-temperature levels in the ISIMIP2b climate data can be found here.

ISIMIP2b Protocol Changes

June 25, 2018

To resolve potential double harvests within one year, crop yields should be reported per growing and not per calendar year. The unit of the time dimension of the NetCDF v4 output file is thus “growing seasons since YYYY-01-01 00:00:00”. Cumulative growing season variables as, e.g., actual evapotranspiration or precipitation are to be accumulated ..

June 25, 2018

The time horizons for which simulations on terrestrial biodiversity are to be run have been updated. Additionally, the interpretation of output variables may be different in runs based on the MaxEnt algorithm.

June 25, 2018

Descriptions of human-influence and land-use scenarios in crop simulations were updated to avoid potential misunderstandings. Crop-model simulations should be provided as pure crop runs (i.e., assuming that each crop grows everywhere). Yet, if a models contains different varieties of the same crop (e.g.

June 25, 2018

We standardized the forest site names within the protocol. Now, all spaces and underscores have been replaced by hyphens. Site names will be written in lower case and do not contain special characters (Hyytiälä -> Hyytiala).


The simulation protocol contains all information necessary to run climate-impacts simulations consistent with other models participating in the current ISIMIP simulation round, ISIMIP2a. Here you will find the protocol for ISIMIP2a. Click on the link below for information about the ISIMIP Fast Track.

Information about accessing and transferring using the DKRZ server

Important information about preparing your simulation files

The protocol is divided into 7 chapters: chapters 1-6 contain important information for modellers in all sectors. Chapter 7 provides sector-specific instructions (can be downloaded separately below).  For any queries, get in touch.

See the table below for an up-to-date list of protocol changes.

ISIMIP2a Protocol Changes

March 5, 2018

The file-naming conventions for output file has been updated to include a tag to indicate the target climate data set for the bias correction. The standard file name now has the form: <modelname>_<obs>_<bias-correction><clim_scenario>­_<socio-econ-scenario>_<sens-scenarios>_<variable>_<region>_&..

March 5, 2018

To maintain consistency with other sectors, the "man" and "nat" scenarios for forest sectors have been  renamed to "nosoc" and "varsoc" respectively.

June 13, 2017

References for the four observational climate data sets for ISIMIP2a have been added to table 3.

May 22, 2017

Changes include updates to the management schedules (table 26) and correction of the definition of output variables.

ISIMIP Fast Track

FT protocol image

Complete Protocol

Last updated on 11 March, 2013.

See here for more information about the ISIMIP Fast Track.

ISIMIP-FT Protocol Changes

March 5, 2018

The definition of the agriculture-sector output variables pirrww and pirruse have been updated to match those in the ISIMIP2b protocol.pirrww: Irrigation water withdrawal, assuming unlimited fresh-water availability and no water losses during conveyance and application. While the latter assumption has no implications for crop growth, it helps to ..