Arboleda et al. (2025) Joint evolution of irrigation, the water cycle and water resources under a strong climate change scenario from 1950 to 2100 in the IPSL-CM6

Identification

• Journal: Earth System Dynamics
• Year: 2025
• Date: 2025-12-10
• Authors: Pedro Arboleda, Agnès Ducharne, Frédérique Cheruy, Joséfine Ghattas
• DOI: 10.5194/esd-16-2201-2025

Research Groups

• Laboratoire METIS (UMR 7619, Sorbonne Université, CNRS, EPHE), Paris, France
• Institut Pierre Simon Laplace (FR 636, Sorbonne Université, CNRS), Paris, France
• Laboratoire de Météorologie Dynamique-IPSL, CNRS/Sorbonne Université/École Normale Supérieure-PSL Université/École Polytechnique-Institut Polytechnique de Paris, Paris, France

Short Summary

This study investigates the coupled evolution of irrigation, the water cycle, and water resources from 1950 to 2100 under a strong climate change scenario using the IPSL-CM6 model, revealing increased irrigation, intensified water depletion, and identifying regions vulnerable to water stress.

Objective

• To investigate the coupled evolution of irrigation activities, the water cycle, and water resources from 1950 to 2100 under a strong climate change scenario (SSP5-RCP8.5) using the IPSL-CM6 model.
• To assess how irrigation rates are expected to evolve and its influence on hydroclimate variables.
• To identify regions where future hydroclimate conditions may limit irrigation growth or increase tensions over water use.

Study Configuration

• Spatial Scale: Global (all continental areas except Greenland and Antarctica), with a model resolution of approximately 1.41° × 0.71° (256 × 256 grid cells).
• Temporal Scale: 1950–2100 (150 years), with historical (1950–2000) and future (2050–2100) periods analyzed.

Methodology and Data

• Models used:
  • IPSL-CM6 (Institut Pierre Simon Laplace Climate Model 6)
  • LMDZOR model (coupling of LMDZ atmospheric model and ORCHIDEE land surface model)
  • LMDZ6A atmospheric model
  • ORCHIDEE 2.2 land surface model with a global irrigation scheme
• Data sources:
  • CMIP6 (Coupled Model Intercomparison Project phase 6)
  • Historical dataset (1950–2014) and SSP5-RCP8.5 dataset (2015–2100) for atmospheric radiative forcing, land use, and irrigated areas (from ScenarioMIP and LUHv2).
  • AMIP dataset for prescribed sea surface temperature/sea ice content (SST/SIC) during spin-up.
  • Bias and variance-corrected SST/SIC dataset (Beaumet et al., 2019) for simulations.
  • Land Use Harmonization 2 (LUHv2) for land use and irrigated area fractions.
  • Siebert et al. (2010a) map for the fraction of irrigated area equipped with surface water (fixed to year 2000 conditions).
  • AQUASTAT for reported irrigation values (around year 2000) for comparison.
  • Flow direction map from Vörösmarty et al. (2000) and Oki et al. (1999) for the routing scheme.
  • USDA soil texture map from Zobler (1986).

Main Results

• Climate Change Impacts: Between 1950–2000 and 2050–2100, the simulations show strong global warming (+5.6 °C over land with irrigation) and precipitation increases (+8.1 % over land with irrigation).
• Irrigation Evolution: Global irrigation is projected to increase by 76 % in 2050–2100 compared to 1950–2000, reaching a volume of 3280 cubic kilometers per year (km³/year) in the future period.
• Evapotranspiration (ET) Influence: The influence of irrigation on ET in irrigated areas increases from +8 % in 1950–2000 to +12 % in 2050–2100. ET also increases in non-irrigated areas near irrigated zones due to increased precipitation.
• Precipitation (P) Influence: Irrigation increases average land P by approximately 1 % under both historical and future climates, with remote impacts observed in non-irrigated areas such as the Sahelian band and Central Asia.
• Water Resources Depletion: Water depletion due to irrigation intensifies in the future. Groundwater storage (GWS) in irrigated areas decreases by 7 % historically and 14 % in the future due to irrigation. Stream storage (Stream S) in irrigated areas decreases by 8 % historically and 12 % in the future due to irrigation.
• River Discharge: In heavily irrigated river basins (e.g., Nile, Indus, Ganges), irrigation activities decrease discharge values by 4 % to 51 % in the future. In some modestly irrigated African basins (e.g., Congo, Senegal), irrigation can lead to slightly higher discharge values due to increased precipitation in non-irrigated areas.
• Hydroclimate Limits: Approximately one-third of irrigated areas (including the Mediterranean basin, California, and Southeast Asia) are identified as regions where future hydroclimate conditions may limit irrigation or increase tensions over water use due to water resource depletion or overexploitation.

Contributions

• Provides the first coupled simulations using the IPSL-CM6 model to explore the joint evolution of irrigation, the water cycle, and water resources under a strong future climate change scenario (SSP5-RCP8.5) from 1950 to 2100.
• Quantifies the increasing influence of irrigation on evapotranspiration and water depletion in irrigated areas under future climate conditions.
• Demonstrates remote impacts of irrigation on precipitation and water resources in nearby non-irrigated areas, highlighting atmospheric feedback loops.
• Identifies specific global regions where irrigation growth may be hydroclimatically limited or lead to increased water use tensions, offering crucial insights for adaptation policies in the water-food nexus.
• Underlines the importance of integrating irrigation into climate change projections for comprehensive water resource assessments.

Funding

• Belmont Forum, BLUEGEM project (grant no. ANR-21-SOIL-0001)

Citation

@article{Arboleda2025Joint,
  author = {Arboleda, Pedro and Ducharne, Agnès and Cheruy, Frédérique and Ghattas, Joséfine},
  title = {Joint evolution of irrigation, the water cycle and water resources under a strong climate change scenario from 1950 to 2100 in the IPSL-CM6},
  journal = {Earth System Dynamics},
  year = {2025},
  doi = {10.5194/esd-16-2201-2025},
  url = {https://doi.org/10.5194/esd-16-2201-2025}
}