ISIMIP3b simulation round simulation protocol - Terrestrial biodiversity

Introduction
Scenarios & Experiments
- Scenario definitions
- Experiments
Input data
Output data
- Output variables
Reporting model results
References

Introduction

General concept

The Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) provides a framework for the collation of a consistent set of climate impact data across sectors and scales. It also provides a unique opportunity for considering interactions between climate change impacts across sectors through consistent scenarios.

ISIMIP is intended to be structured in successive rounds connected to the different phases of the climate model intercomparison CMIP (ISIMIP Mission & Implementation document).

The main components of the ISIMIP framework are:

A common set of climate and other forcing data which will be distributed via a central database;
A common modelling protocol to ensure consistency across sectors and scales in terms of data, format and scenario set-up;
A central archive where the output data will be collected and made available to the scientific community.

ISIMIP3b

GCM-based simulations assuming fixed 2015 direct human influences for the future

The ISIMIP3b part of the third simulation round is dedicated to a quantification of climate-related risks at different levels of climate change and socio-economic conditions. The group 1 simulations refer to the pre-industrial and historical period of the CMIP6-based climate simulations. Group 2 covers all future projections assuming fixed 2015 levels of socio-economic forcing and different future projections of climate (SSP126, SSP37 and SSP585). Group3 simulations account for future changes in socio-economic drivers and are intended to be started in summer 2021.

You can find the ISIMIP3a protocol, which is is dedicated to impact model evaluation and improvement and detection and attribution of observed impacts, here.

Simulation protocol

In this protocol we describe the scenarios & experiments in ISIMIP3b simulation round, the different input datasets, the output variables, and how to report model results specifically for Terrestrial biodiversity. An overview of all sectors can be found at protocol.isimip.org.

Throughout the protocol we use specifiers that denote a particular scenario, experiment, variable or other parameter. We use these specifiers in the tables below, in the filenames of the input data sets, and ask you to use the same specifiers in your output files. More on reporting data can be found at the end of this document.

Model versioning

To ensure consistency between ISIMIP3a and ISIMIP3b as well as the different experiments within a simulation round, we require that modelling groups use the same version of an impact model for the experiments in ISIMIP3a and ISIMIP3b. If you cannot fulfill this, please indicate that by using a suffix for your model name (e.g. simple version numbering: MODEL-v1, MODEL-v2 or following semantic versioning: MODEL-2.0.0, see also reporting model results).

This versioning does not only apply to changes in the computational logic of the model, but also to input parameters, calibration or setup. If model versions are not reported, we will name them according to the simulation round (e.g. MODEL-isimip3a). We require the strict versioning to ensure that differences between model results are fully attributable to the changes in model forcings.

Scenarios & Experiments

Scenario definitions

Table 1: Climate scenario specifiers (`climate-scenario`).
Scenario specifier	Description
picontrol	Pre-industrial climate as simulated by the GCMs.
historical	Historical climate as simulated by the GCMs.
ssp126	SSP1-RCP2.6 climate as simulated by the GCMs.
ssp370	SSP3-RCP7 climate as simulated by the GCMs.
ssp585	SSP5-RCP8.5 climate as simulated by the GCMs.

Table 2: Socio-economic scenario specifiers (`soc-scenario`).
Scenario specifier	Description
1850soc	Fixed year-1850 direct human influences (e.g. land use, nitrogen deposition and fertilizer input, fishing effort). Please label your simulations `1850soc` if they do not at all account for historical changes in direct human forcing, but they do represent constant year-1850 levels of direct human forcing for at least some direct human forcings.
histsoc	Varying direct human influences in the historical period (e.g. observed changes in historical land use, nitrogen deposition and fertilizer input, fishing effort). Please label your model run `histsoc` even if it only partly accounts for varying direct human forcings while another part of the the direct human forcing is considered constant or is ignored.
2015soc	Fixed year-2015 direct human influences (e.g. land use, nitrogen deposition and fertilizer input, fishing effort). Please label your simulations `2015soc` if they do not at all account for historical changes in direct human forcing, but they do represent constant year-2015 levels of direct human forcing for at least some direct human forcings.
nat	No direct human influences (naturalized run). Please only label your model run `nat` if it does not at all account for any direct human forcings, including e.g. human land use.

Table 3: Sensitivity scenario specifiers (`sens-scenario`).
Scenario specifier	Description
default	For all experiments other than the sensitivity experiments.
2015co2	CO₂ concentration fixed at 2015 levels.

General note regarding sensitivity experiments

The sensitivity experiments are meant to be "artificial" deviations from the default settings. So for example if your model does not at all account for changes in CO₂ concentrations (no option to switch it on or off) the run should be labeled as default in the sensitivity specifier of the file name even if the run would be identical to the 1850co2 sensitivity setting.

The particular sensitivity scenario for an experiment is given in the experiments table below. For most experiments no sensitivity scenario is given, so the default label applies.

Experiments

Table 4: Experiment set-up: Each experiment is specified by the climate forcing (CF) and the Direct Human Forcing (DHF).
Experiment	Short description	Pre-industrial 1601-1849	Historical 1850-2014	Future 2015-2100
pre-industrial control histsoc 1st priority	CF: no climate change, pre-industrial CO₂ fixed at 1850 levels	picontrol	picontrol	picontrol
pre-industrial control histsoc 1st priority	DHF: varying management before 2015, then fixed at 2015 levels thereafter	1850soc	histsoc	2015soc
pre-industrial control 2015soc 1st priority	CF: no climate change, pre-industrial CO₂ fixed at 1850 levels	does not have to be simulated as the following year already provide a large sample of years with stable climate and constant (2015soc) / no (nat) DHF for period	picontrol	picontrol
pre-industrial control 2015soc 1st priority	DHF: fixed at 2015 levels for all periods		2015soc	2015soc
pre-industrial control nat 2nd priority	CF: no climate change, pre-industrial CO₂ fixed at 1850 levels	does not have to be simulated as the following year already provide a large sample of years with stable climate and constant (2015soc) / no (nat) DHF for period	picontrol	picontrol
pre-industrial control nat 2nd priority	DHF: No direct human influences		nat	nat
RCP2.6 histsoc 1st priority	CF: Simulated historical climate and CO₂ in historical period, then SSP1-RCP2.6 climate & CO₂	"histsoc" version of the pre-industrial period of the pre-industrial control experiment	historical	ssp126
RCP2.6 histsoc 1st priority	DHF: varying management before 2015, then fixed at 2015 levels thereafter		histsoc	2015soc
RCP2.6 2015soc 1st priority	CF: Simulated historical climate and CO₂ in historical period, then SSP1-RCP2.6 climate & CO₂	"2015soc" version of the pre-industrial period of the pre-industrial control experiment	historical	ssp126
RCP2.6 2015soc 1st priority	DHF: fixed at 2015 levels for all periods		2015soc	2015soc
RCP2.6 nat 2nd priority	CF: Simulated historical climate and CO₂ in historical period, then SSP1-RCP2.6 climate & CO₂	"nat" version of the pre-industrial period of the pre-industrial control experiment	historical	ssp126
RCP2.6 nat 2nd priority	DHF: No direct human influences		nat	nat
RCP7 2015soc 1st priority	CF: SSP3-RCP7 climate & CO₂	"2015soc" version of pre-industrial of pre-industrial control experiment runs	"2015soc" version of the historical period of the RCP2.6 experiment	ssp370
RCP7 2015soc 1st priority	DHF: fixed at 2015 levels for all periods			2015soc
RCP7 nat 2nd priority	CF: SSP3-RCP7 climate & CO₂	"nat" version of pre-industrial of pre-industrial control experiment runs	"nat" version of the historical period of the RCP2.6 experiment	ssp370
RCP7 nat 2nd priority	DHF: No direct human influences			nat
RCP8.5 2015soc 1st priority	CF: SSP5-RCP8.5 climate & CO₂	"2015soc" version of pre-industrial of pre-industrial control experiment runs	"2015soc" version of the historical period of the RCP2.6 experiment	ssp585
RCP8.5 2015soc 1st priority	DHF: fixed at 2015 levels for all periods			2015soc
RCP8.5 nat 2nd priority	CF: SSP5-RCP8.5 climate & CO₂	"nat" version of pre-industrial of pre-industrial control experiment runs	"nat" version of the historical period of the RCP2.6 experiment	ssp585
RCP8.5 nat 2nd priority	DHF: No direct human influences			nat

Note regarding models requiring spin-up

For models requiring spin-up, please use the pre-industrial control data and CO₂ concentration and DHF fixed at 1850 levels for the spin up as long as needed. Please note that the "pre-industrial control run" from 1601-1849 is part of the regular experiments that should be reported and hence the spin-up has to be finished before that.

Input data

The base directory for input data at DKRZ is:

/work/bb0820/ISIMIP/ISIMIP3b/InputData/

Further information on accessing ISIMIP data can be found at ISIMIP - getting started.

Some of the datasets are tagged as mandatory. This does not mean that the data must be used in all cases, but if your models uses input data of this kind, we require to use the specified dataset. If an alterntive data set is used instead, we cannot consider it an ISIMIP simulation. If the mandatory label is not given, you may use alternative data (please document this clearly).

Climate forcing

The climate forcing input files can be found on DKRZ using the following pattern:

climate/atmosphere/bias-adjusted/global/daily/<climate-scenario>/<climate-forcing>/<climate-forcing>_<ensemble-member>_<bias-adjustment>_<climate-scenario>_<climate-variable>_global_daily_<start-year>_<end-year>.nc

Table 5: Climate and climate-related forcing data (`climate-forcing`).
Title	Specifier	Institution	Native resolution	Ensemble member	Priority
GFDL-ESM4	gfdl-esm4	National Oceanic and Atmospheric Administration, Geophysical Fluid Dynamics Laboratory, Princeton, NJ 08540, USA	288x180	r1i1p1f1	1
UKESM1-0-LL	ukesm1-0-ll	Met Office Hadley Centre, Fitzroy Road, Exeter, Devon, EX1 3PB, UK	192x144	r1i1p1f2	2
MPI-ESM1-2-HR	mpi-esm1-2-hr	Max Planck Institute for Meteorology, Hamburg 20146, Germany	384x192	r1i1p1f1	3
IPSL-CM6A-LR	ipsl-cm6a-lr	Institut Pierre Simon Laplace, Paris 75252, France	144x143	r1i1p1f1	4
MRI-ESM2-0	mri-esm2-0	Meteorological Research Institute, Tsukuba, Ibaraki 305-0052, Japan	320x160	r1i1p1f1	5

Note on climate forcing priority

The priority for the different climate forcing datasets is from top to bottom. If you cannot use all climate forcing datasets, please concentrate on those at the top of the table.

Table 6: Climate forcing variables for ISIMIP3b simulations (`climate-variable`).
Variable	Variable specifier	Unit	Resolution	Models
Atmospheric variables mandatory
Near-Surface Relative Humidity	hurs	%	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Near-Surface Specific Humidity	huss	kg kg-1	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Precipitation	pr	kg m-2 s-1	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Snowfall Flux	prsn	kg m-2 s-1	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Surface Air Pressure	ps	Pa	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Surface Downwelling Longwave Radiation	rlds	W m-2	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Surface Downwelling Shortwave Radiation	rsds	W m-2	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Near-Surface Wind Speed	sfcwind	m s-1	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Near-Surface Air Temperature	tas	K	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Daily Maximum Near-Surface Air Temperature	tasmax	K	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0
Daily Minimum Near-Surface Air Temperature	tasmin	K	0.5° grid daily	GFDL-ESM4 UKESM1-0-LL MPI-ESM1-2-HR IPSL-CM6A-LR MRI-ESM2-0

Other climate datasets

Table 7: Other climate datesets for ISIMIP3b simulation round.
Variable	Variable specifier	Unit	Resolution	Datasets
Atmospheric composition mandatory
Atmospheric CO2 concentration	`climate/atmosphere_composition/co2/<climate-scenario>/co2_<climate-scenario>_annual_<start_year>_<end_year>.txt`
Atmospheric CO2 concentration	co2	ppm	global annual	Meinshausen, Raper, & Wigley (2011) for 1850-2005 and 2016-2100 and Dlugokencky & Tans (2019) from 2006-2015

Socioeconomic forcing

Table 8: Socioeconomic datasets for ISIMIP3b simulation round.
Dataset	Included variables (specifier)	Covered time period	Resolution	Reference/Source and Comments
Land use mandatory
Landuse totals	`socioeconomic/landuse/<soc_scenario>/<soc_scenario>_landuse-totals_annual_<start_year>_<end_year>.nc`
	share of the total cropland (cropland_total) all of the rainfed cropland (cropland_rainfed) all of the irrigated cropland (cropland_irrigated) share of managed pastures or rangeland (pastures)	1850-1900 1901-2018	0.5° grid annual	Based on the HYDE 3.2 data set (Klein Goldewijk, 2016), but harmonized by Hurtt et al. (LUH2 v2h data set, see Hurtt, Chini, Sahajpal, Frolking, & et al. (2020), see also https://luh.umd.edu). For further information on the land use data refer to https://www.isimip.org/gettingstarted/input-data-bias-correction/details/82/.
Downscaling to 5 crops	`socioeconomic/landuse/<soc_scenario>/<soc_scenario>_landuse-5crops_annual_<start_year>_<end_year>.nc`
	share of rainfed/irrigated C4 annual crops (c4ann_rainfed, c4ann_irrigated) share of rainfed/irrigated C3 perennial crops (c3per_rainfed, c3per_irrigated) share of rainfed/irrigated C3 N-fixing crops (c3nfx_rainfed, c3nfx_irrigated) share of rainfed/irrigated C4 annual crops (c4ann_rainfed, c4ann_irrigated) share of rainfed/irrigated C4 perennial crops (c4per_rainfed, c4per_irrigated)	1850-1900 1901-2018	0.5° grid annual	Based on the HYDE 3.2 data set (Klein Goldewijk, 2016), but harmonized by Hurtt et al. (LUH2 v2h data set, see Hurtt, Chini, Sahajpal, Frolking, & et al. (2020), see also https://luh.umd.edu).
Downscaling to 15 crops	`socioeconomic/landuse/<soc_scenario>/<soc_scenario>_landuse-15crops_annual_<start_year>_<end_year>.nc`
	share of rainfed/irrigated maize (maize_rainfed, maize_irrigated) share of rainfed/irrigated rice (rice_rainfed, rice_irrigated) share of rainfed/irrigated oil crops (groundnut) (oil_crops_groundnut_rainfed, oil_crops_groundnut_irrigated) share of rainfed/irrigated oil crops (rapeseed) (oil_crops_rapeseed_rainfed, oil_crops_rapeseed_irrigated) share of rainfed/irrigated oil crops (soybean) (oil_crops_soybean_rainfed, oil_crops_soybean_irrigated) share of rainfed/irrigated oil crops (sunflower) (oil_crops_sunflower_rainfed, oil_crops_sunflower_irrigated) share of rainfed/irrigated pulses (pulses_rainfed, pulses_irrigated) share of rainfed/irrigated temperate cereals (temperate_cereals_rainfed, temperate_cereals_irrigated) share of rainfed/irrigated temperate roots (temperate_roots_rainfed, temperate_roots_irrigated) share of rainfed/irrigated tropical cereals (tropical_cereals_rainfed, tropical_cereals_irrigated) share of rainfed/irrigated tropical roots (tropical_roots_rainfed, tropical_roots_irrigated) share of rainfed/irrigated C3 annual crops not covered by the above (others_c3ann_rainfed, others_c3ann_irrigated) share of rainfed/irrigated C3 N-fixing crops not covered by the above (others_c3nfx_rainfed, others_c3nfx_irrigated) share of rainfed/irrigated C3 perennial crops (c3per_rainfed, c3per_irrigated) share of rainfed/irrigated C4 perennial crops (c4per_rainfed, c4per_irrigated) share of pastures, both managed and rangeland (pastures)	1850-1900 1901-2018	0.5° grid annual	The C4 perennial crops are not further downscaled from the "5 crops" data set and currently only include sugarcane. Similarly, the C3 perennial crops are not downscaled either. The data is derived from the "5 crops" LUH2 data, and the crops have been downscaled to 15 crops according to the ratios given by the Monfreda data set (Monfreda, Ramankutty, & Foley, 2008).
Managed pastures and rangeland	`socioeconomic/landuse/<soc_scenario>/<soc_scenario>_landuse-pastures_annual_<start_year>_<end_year>.nc`
	share of managed pastures (managed_pastures) share of rangeland (rangeland)	1850-1900 1901-2018	0.5° grid annual	Based on the HYDE 3.2 data set (Klein Goldewijk, 2016), but harmonized by Hurtt et al. (LUH2 v2h data set, see Hurtt, Chini, Sahajpal, Frolking, & et al, in review., see also https://luh.umd.edu).
Urban areas	`socioeconomic/landuse/<soc_scenario>/<soc_scenario>_landuse-urbanareas_annual_<start_year>_<end_year>.nc`
	share of urban areas (urbanareas)	1850-1900 1901-2018	0.5° grid annual	Based on the HYDE 3.2 data set (Klein Goldewijk, 2016), but harmonized by Hurtt et al. (LUH2 v2h data set, see Hurtt, Chini, Sahajpal, Frolking, & et al. (2020), see also https://luh.umd.edu).
N-fertilizer mandatory
Nitrogen deposited by fertilizers on croplands	`socioeconomic/n-fertilizer/<soc_scenario>/<soc_scenario>_n-fertilizer-5crops_annual_<start_year>_<end_year>.nc`
	deposition of N through fertilizer on cropland with C3 annual crops (fertl_c3ann) C3 perennial crops (fertl_c3per) C3 N-fixing crops (fertl_c3nfx) C4 annual crops (fertl_c4ann) C4 perennial crops (fertl_c4per)	1850-1900 1901-2018	0.5° grid annual (growing season)	Based on the LUH2 v2h data set (see Hurtt, Chini, Sahajpal, Frolking, & et al. (2020), see also https://luh.umd.edu). For further information refer also to https://www.isimip.org/gettingstarted/input-data-bias-correction/details/28/.
N-deposition
Reduced nitrogen deposition	`socioeconomic/n-deposition/<soc_scenario>/ndep-nhx_<soc_scenario>_monthly_<start_year>_<end_year>.nc`
	NHx deposition (nhx)	1850-1900 1901-2016	0.5° grid monthly	Simulated by NCAR Chemistry-Climate Model Initiative (CCMI) during 1850-2014. Nitrogen deposition data was interpolated to 0.5° by 0.5° by the nearest grid. Data in 2015 and 2016 is assumed to be same as that in 2014 (Tian et al. 2018). For further information refer also to https://www.isimip.org/gettingstarted/input-data-bias-correction/details/24/.
Oxidized nitrogen deposition	`socioeconomic/n-deposition/<soc_scenario>/ndep-noy_<soc_scenario>_monthly_<start_year>_<end_year>.nc`
	NOy deposition (noy)	1850-1900 1901-2016	0.5° grid annual	Simulated by NCAR Chemistry-Climate Model Initiative (CCMI) during 1850-2014. Nitrogen deposition data was interpolated to 0.5° by 0.5° by the nearest grid. Data in 2015 and 2016 is assumed to be same as that in 2014 (Tian et al. 2018). For further information refer also to https://www.isimip.org/gettingstarted/input-data-bias-correction/details/24/.
Reservoirs & dams
Reservoirs & dams	`socioeconomic/reservoir_dams/reservoirs-dams_1850_2015.xls`
	Unique ID representing a dam and its associated reservoir corresponding to GRanD/KSU IDs (ID) name (DAM_NAME) original location (LON_ORIG, LAT_ORIG) location adjusted to the DDM30 routing network (LON_DDM30, LAT_DDM30) upstream area in DDM30 (CATCH_SKM_DDM30) upstream area in GRanD (CATCH_SKM_GRanD) maximum storage capacity of reservoir (CAP_MCM) year of construction/commissioning (YEAR) flag to indicate that the year of dam construction has been artificially set to 1850 if not existing (FLAG_ART=1, otherwise 0) alternative year may indicate a multi-year construction or secondary dam (ALT_YEAR) flag of correction if relocation was applied (FLAG_CORR) river name which the dam impounds (RIVER) height of dam (D_Hght_m) maximum inundation area of reservoir (R_Area_km2) main purpose(s) of dam (PURPOSE) source of information (SOURCE) other notes (COMMENTS)	1850-2015	0.5° grid and original coordinates (degree) annual	Lehner et al. (2011a, https://doi.org/10.7927/H4N877QK), Lehner et al. (2011b, https://dx.doi.org/10.1890/100125), and Jida Wang et al. (KSU/Kansas State University, personal communication, data starting in 2016). Because the data from KSU is yet unpublished, modeling teams using it are asked to offer co-authorship to the team at KSU on any resulting publications. Please contact info@isimip.org in case of questions.
Water abstraction
Water abstraction for domestic and industrial purposes	`socioeconomic/water_abstraction/[domw\|indw][w\|c]_<soc_scenario>_annual_<start-year>_<end-year>.nc`
	domestic and industrial water withdrawal and consumption (domww, domwc, indww, indwc)	1850-1900 1901-2014	0.5° grid annual	For modelling groups that do not have their own representation, we provide files containing the multi-model mean of domestic and industrial water withdrawal and consumption generated by WaterGAP, PCR-GLOBWB, and H08. This data is based ISIMIP2a varsoc simulations for 1901-2005, and on RCP6.0 simulations from the Water Futures and Solutions project (Wada et al., 2016, http://www.geosci-model-dev.net/9/175/2016/) for after 2005. Years before 1901 have been filled with the value for year 1901.
Population mandatory
Population 5' grid	`socioeconomic/pop/<soc_scenario>/population_<soc_scenario>_5arcmin_annual_<start-year>_<end-year>.nc`
	total number of people (popc) rural number of people (rurc) urban number of people (urbc)	1850-1900 1901-2014	5' grid annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 2000 have been linearly interpolated in time.
Population 0.5° grid	`socioeconomic/pop/<soc_scenario>/population_<soc_scenario>_30arcmin_annual_<start-year>_<end-year>.nc`
	total number of people (popc) rural number of people (rurc) urban number of people (urbc)	1850-2014	0.5° grid annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 2000 have been linearly interpolated in time. Aggregated to 0.5° spatial resolution
Population national	`socioeconomic/pop/<soc_scenario>/population_<soc_scenario>_national_annual_<start-year>_<end-year>.csv`
	total number of people per country	1850-2014	national annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 1950 have been linearly interpolated in time.
Population density 5' grid	`socioeconomic/pop/<soc_scenario>/population-density_<soc_scenario>_5arcmin_annual_<start-year>_<end-year>.nc`
	total number of people per square kilometer (popc) rural number of people per square kilometer (rurc) urban number of people per square kilometer (urbc)	1850-1900 1901-2014	5' grid annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 2000 have been linearly interpolated in time.
Population density 0.5° grid	`socioeconomic/pop/<soc_scenario>/population-density_<soc_scenario>_30arcmin_annual_<start-year>_<end-year>.nc`
	total number of people per square kilometer (popc) rural number of people per square kilometer (rurc) urban number of people per square kilometer (urbc)	1850-2014	0.5° grid annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 2000 have been linearly interpolated in time. Aggregated to 0.5° spatial resolution
Population density national	`socioeconomic/pop/<soc_scenario>/population-density_<soc_scenario>_national_annual_<start-year>_<end-year>.csv`
	total number of people per square kilometer	1850-2014	national annual	HYDE v3.2.1 (Klein Goldewijk et al., 2017). For 1950-2014, data are based on the 2008 Revision of the United Nations World Population Prospects, which transits from estimates to projections in 2010. Decadal data prior to year 1950 have been linearly interpolated in time.
GDP mandatory
GDP	`socioeconomic/gdp/<soc_scenario>/<soc_scenario>_gdp_annual_<start-year>_<end-year>.nc`
	GDP PPP 2005 USD (gdp)	1850-2014	country-level annual	Historic country-level GDP data are an extension of the historical data provided by Geiger, 2018 (https://www.earth-syst-sci-data.net/10/847/2018/essd-10-847-2018.html). They are derived mainly from Penn World Tables (PWT) for recent decades, and from the Maddison Project database (2018 version, https://www.rug.nl/ggdc/historicaldevelopment/maddison/releases/maddison-project-database-2018) for earlier periods where no PWT data is available. Gaps were filled using World Bank data (WDI). No interpolation to SSPs is performed for this historical dataset.

Static geographic information

Table 9: Geographic data and information for ISIMIP3b simulation round.
Dataset	Included variables (specifier)	Resolution	Reference/Source and Comments
Land/Sea masks
landseamask	`geo_conditions/landseamask/landseamask.nc`
	land-sea mask (mask)	0.5° grid	This is the land-sea mask of the W5E5 dataset (Cucchi et al., 2020; Lange et al., 2021). Over all grid cells marked as land by this mask, all climate data that are based on W5E5 (GSWP3-W5E5 as well as climate data bias-adjusted using W5E5) are guaranteed to represent climate conditions over land. For further information see also https://www.isimip.org/gettingstarted/input-data-bias-correction/details/41/.
landseamask_no-ant	`geo_conditions/landseamask/landseamask_no-ant.nc`
	land-sea mask (mask)	0.5° grid	Same as landseamask but without Antarctica.
landseamask_water-global	`geo_conditions/landseamask/landseamask_water-global.nc`
	land-sea mask (mask)	0.5° grid	This is the generic land-sea mask from ISIMIP2b that is to be used for global water simulations in ISIMIP3. It marks more grid cells as land than landseamask. Over those additional land cells, the climate data that are based on W5E5 (GSWP3-W5E5 as well as climate data bias-adjusted using W5E5) are not guaranteed to represent climate conditions over land. Instead they may represent climate conditions over sea or a mix of conditions over land and sea.
Soil
gswp3_hwsd	`geo_conditions/soil/gswp3_hwsd.nc`
	Soil texture (soiltexture)	0.5° grid	One fixed pattern to be used for all simulation periods. Upscaled Soil texture map (30 arc sec. to 0.5°x0.5° grid) based on Harmonized World Soil Database v1.1 (HWSD) using the GSWP3 upscaling method A (http://hydro.iis.u-tokyo.ac.jp/~sujan/research/gswp3/soil-texture-map.html)
hwsd_soil_data_all_land	`geo_conditions/soil/hwsd_soil_data_all_land.nc`
	USDA soil texture class dominant HWSD on cropland (texture_class) domiant HWSD soil mapping unit within dominant USDA soil texture class on cropland (mu_global) Topsoil pH(H2O) (soil_ph) Topsoil Calcium Carbonate (soil_caco3) Topsoil Bulk Density (bulk_density) Topsoil Cation Exchange Capacity (soil) (cec_soil) Topsoil Organic Carbon (oc) depth of Obstacles to Roots (ESDB) (root_obstacles) depth of Impermeable Layer (ESDB) (impermeable_layer) Available Water Content (awc) Topsoil Sand Fraction (sand) Topsoil Silt Fraction (silt) Topsoil Clay Fraction (clay) Topsoil Gravel Content (gravel) Topsoil Salinity (ece) Topsoil Base Saturation (bs_soil) flag for valid soils (issoil)	0.5° grid	GGCMI Phase 3 soil input data set for usage in ISIMIP/GGCMI Phase 3 simulations, data aggregated by dominant soil profile (MU_GLOBAL) within dominant soil texture class from HWSD on all land.
hwsd_soil_data_on_cropland	`geo_conditions/soil/hwsd_soil_data_on_cropland.nc`
	USDA soil texture class dominant HWSD on cropland (texture_class) domiant HWSD soil mapping unit within dominant USDA soil texture class on cropland (mu_global) Topsoil pH(H2O) (soil_ph) Topsoil Calcium Carbonate (soil_caco3) Topsoil Bulk Density (bulk_density) Topsoil Cation Exchange Capacity (soil) (cec_soil) Topsoil Organic Carbon (oc) depth of Obstacles to Roots (ESDB) (root_obstacles) depth of Impermeable Layer (ESDB) (impermeable_layer) Available Water Content (awc) Topsoil Sand Fraction (sand) Topsoil Silt Fraction (silt) Topsoil Clay Fraction (clay) Topsoil Gravel Content (gravel) Topsoil Salinity (ece) Topsoil Base Saturation (bs_soil) flag for valid soils (issoil)	0.5° grid	GGCMI Phase 3 soil input data set for usage in ISIMIP/GGCMI Phase 3 simulations, data aggregated by dominant soil profile (MU_GLOBAL) within dominant soil texture class from HWSD on current cropland (MIRCA2000 at 5 arc-minutes).

Output data

ISIMIP output variables are usually reported with the dimensions (time,lat,lon). For variables with a number of levels (e.g. layers or depth), an alternative set of dimensions is given in the comment column in the table below. More information about level dimensions can be found here and here on the ISIMIP webpage.

Please note that unless otherwise defined, the variables in ISIMIP should be reported relative to the grid cell land area.

Output variables

Table 10: Output variables for Terrestrial biodiversity (`variable`).
Variable long name	Variable specifier	Unit	Resolution	Comments
Species probability of occurrence
Amphibian Species Probability of Occurrence	amphibianprob	Probability of occurrence per cell	0.5° grid 30year-mean	Results from individual SDMs assuming no dispersal.
Terrestrial Bird Species Probability of Occurrence	birdprob	Probability of occurrence per cell	0.5° grid 30year-mean	Results from individual SDMs assuming no dispersal.
Terrestrial Mammal Species Probability of Occurrence	mammalprob	Probability of occurrence per cell	0.5° grid 30year-mean	Results from individual SDMs assuming no dispersal.
Summed probability of occurrence
Amphibian Summed Probability of Occurrence	amphibiansumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Terrestrial Bird Summed Probability of Occurrence	birdsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Terrestrial Mammal Summed Probability of Occurrence	mammalsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Endemic summed probability of occurrence
Summed Probability of Endemic Amphibian Species	endamphibiansumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Summed Probability of Endemic Terrestrial Bird Species	endbirdsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Summed Probability of Endemic Terrestrial Mammal Species	endmammalsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Threatened summed probability of occurrence
Summed Probability of Threatened Amphibian Species	thramphibiansumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Summed Probability of Threatened Terrestrial Bird Species	thrbirdsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Summed Probability of Threatened Terrestrial Mammal Species	thrmammalsumprob	Summed probability of occurrence per cell	0.5° grid 30year-mean	Aggregated results from individual SDMs assuming no dispersal.
Species richness
Amphibian Species Richness	amphibiansr	Estimated number of species (species richness) per cell	0.5° grid 30year-mean	Results from macroecological richness models
Terrestrial Bird Species Richness	birdsr	Estimated number of species (species richness) per cell	0.5° grid 30year-mean	Results from macroecological richness models
Terrestrial Mammal Species Richness	mammalsr	Estimated number of species (species richness) per cell	0.5° grid 30year-mean	Results from macroecological richness models

Reporting model results

The specification on how to submit the data, as well as further information and instructions are given on the ISIMIP website at:

https://www.isimip.org/protocol/preparing-simulation-files

It is important that you comply precisely with the formatting specified there, in order to facilitate the analysis of your simulation results in the ISIMIP framework. Incorrect formatting can seriously delay the analysis. The ISIMIP Team will be glad to assist with the preparation of these files if necessary.

File names consist of a series of identifier, separated by underscores. Things to note:

Report one variable per file.
In filenames, use lowercase letters only.
Use underscore (_) to separate identifiers.
Variable names consist of a single word without hyphens or underscores.
Use hyphens (-) to separate strings within an identifier, e.g. in a model name.
If no specific sens-scenario is given in the experiments table, use default.
Data model is NETCDF4_CLASSIC with minimum compression level of 5.
NetCDF file extension is .nc.
The relative time axis' reference year for ISIMIP3b is 1601.
for daily data use standard, proleptic_gregorian, 366_day, 365_day or 360_day calendar depending on the temporal resolution of your model and the 360_day calendar for non-daily data.

Please name the files in the Terrestrial biodiversity sector according to the following pattern:

<model>_<climate-forcing>_<bias-adjustment>_<climate-scenario>_<soc-scenario>_<sens-scenario>_<variable>_<region>_<time-step>_<start-year>_<end-year>.nc

and replace the identifiers with the specifiers given in the tables of this document. Examples would be:

lpjml_gfdl-esm4_w5e5_picontrol_histsoc_default_qtot_global_annual_2001_2010.nc
lpjml_ukesm1-0-ll_w5e5_ssp585_2015soc_2015co2_yield-mai-noirr_global_annual_2006_2010.nc

The following regular expression can be used to validate and parse the file name for the terrestrial biodiversity sector:

(?P<model>[a-z0-9-+.]+)_(?P<climate_forcing>[a-z0-9-]+)_(?P<bias_adjustment>[a-z0-9-]+)_(?P<climate_scenario>[a-z0-9-]+)_(?P<soc_scenario>[a-z0-9-]+)_(?P<sens_scenario>[a-z0-9-]+)_(?P<variable>[a-z0-9]+)_(?P<region>(global))_(?P<time_step>[a-z0-9-]+)_(?P<start_year>\d{4})_(?P<end_year>\d{4}).nc

For questions or clarifications, please contact info@isimip.org or the data managers directly (isimip-data@pik‐potsdam.de) before submitting files.

References

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ISIMIP3b simulation round simulation protocol - Terrestrial biodiversity

Introduction

General concept

ISIMIP3b

GCM-based simulations assuming fixed 2015 direct human influences for the future

Simulation protocol

Model versioning

Scenarios & Experiments

Scenario definitions

General note regarding sensitivity experiments

Experiments

pre-industrial control

pre-industrial control

pre-industrial control

RCP2.6

RCP2.6

RCP2.6

RCP7

RCP7

RCP8.5

RCP8.5

Note regarding models requiring spin-up

Input data

Climate forcing

Note on climate forcing priority

Other climate datasets

Socioeconomic forcing

Static geographic information

Output data

Output variables

Reporting model results

References