Global water availability and its distribution under the Coupled Model Intercomparison Project Phase Six scenarios

Abstract

Changes in the hydrological cycle have widespread consequences and remain uncertain under climate change. We analyse the changes in major water components of the hydrological cycle, that is, precipitation (P), runoff (Q), evapotranspiration (E), precipitation minus evapotranspiration (P − E), and terrestrial water storage (S), and quantify the uncertainties across the 21st century with Phase Six of the Coupled Model Intercomparison Project (CMIP6) simulations. The multimodel ensemble based on over 10 GCMs shows that P − E and Q share similar trends with P, with increases expected in northern high latitudes of Eurasia and North America, South Asia, and eastern Africa, and decreases expected in Central America, the Mediterranean, and the Amazon. The seasonal changes in S at mid and high latitudes are behind the large seasonal shifts in Q while changes in P − E are dominantly affected by P. The equatorial regions are expected to have the largest changes and intermodel variability. From low emission scenario SSP1‐2.6 to high emission scenario SSP5‐8.5, the spatial patterns for future changes remain consistent while more drastic and more widespread changes are expected globally over time with warming for all water components. Larger intermodel variability is also found under higher emission scenarios. The study provides a comprehensive perspective on the assessment of annual and seasonal changes in all water components within the hydrological cycle as well as the associated uncertainty with the latest CMIP6 simulations under three representative scenarios, providing the most updated climate information for formulating appropriate mitigation and adaptation.

Intercomparison and evaluation of ten global ET products at site and basin scales

“…This dataset has been applied to global hydrology, climate and other field studies (e.g., R.-J. Wu, Lo, and Scanlon 2021;Lehmann, Vishwakarma, and Bamber 2022;X. Li and Li 2022).…”

Precipitation Sensitivity to Soil Moisture Changes in Multiple Global Climate Models

“…In this context, we build upon prior studies that have already shed light on certain identified issues within these model frameworks. For instance, MERRA-2 has shown a robust land-atmosphere coupling [41], ERA5 has exhibited P overestimation in specific regions [42], and certain biases have been identified in CMIP6 soil moisture and precipitation variables, particularly in high latitude regions [43,44]. While these recognized issues have been observed at regional scales, their global consistency remains uncertain.…”

Evaluation of bias correction techniques for generating high-resolution daily temperature projections from CMIP6 models

“…Secondly, most of the previous studies assessed bias correction methods using global climate outputs from CMIP5 or its previous generations (Switanek et al, 2017). CMIP6 models have a higher climate sensitivity than previous generations, where hotter temperature projections are expected (Forster et al, 2020;Gettelman et al, 2019;Li and Li, 2022).…”