Cui et al. (2026) Historical deforestation drives strong rainfall decline across the southern Amazon basin

Identification

• Journal: Nature Communications
• Year: 2026
• Date: 2026-01-13
• Authors: Jiangpeng Cui, Shilong Piao, Chris Huntingford, Tao Wang, Dominick V. Spracklen
• DOI: 10.1038/s41467-026-68361-z

Research Groups

• State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
• Institute of Carbon Neutrality, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
• U.K. Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK
• School of Earth and Environment, University of Leeds, Leeds, UK

Short Summary

This study combines satellite observations and an atmospheric moisture tracking model to quantify how historical deforestation has driven a strong rainfall decline across the southern Amazon basin, revealing that current climate models significantly underestimate this sensitivity.

Objective

• To explain observed precipitation changes across the Amazon basin and investigate their linkage to direct forest cover change (deforestation) over the past four decades (1980-2019).

Study Configuration

• Spatial Scale: Entire Amazon basin, with a focus on contrasting northern and southern regions, and upwind areas across South America. Analyses performed at 1° × 1° grid resolution.
• Temporal Scale: 1980-2019 for precipitation trends; 1982-2016 for forest cover and related analyses; future projections to the end of the 21st century (2081-2100).

Methodology and Data

• Models used:
  • Water Accounting Model-2layers (WAM-2layers) for atmospheric moisture tracking.
  • Water balance-based method for calculating basin-average evapotranspiration (ET_wb).
• Data sources:
  • Precipitation: Global Precipitation Climatology Project (GPCP) v.2.3 (merged satellite, rain-gauge, sounding observations); Global Precipitation Climatology Centre (GPCC) (gauge-based).
  • Evapotranspiration: Global Land Evaporation Amsterdam Model (GLEAM) v3.5a (satellite, model-with-measurements); OAFlux (ocean evaporation).
  • Forest Cover: Global Land Change dataset (satellite-derived optical observations).
  • Solar Radiation: National Tibetan Plateau Data Center (TPDC) (satellite-derived).
  • Discharge: Global Runoff Data Centre (GRDC).
  • Terrestrial Water Storage (S): GRACE-REC.
  • Reanalysis Data: ECMWF ERA5 (vertical specific humidity, zonal and meridional wind speeds, surface pressure, Convective Available Potential Energy (CAPE)).
  • Future Scenarios: Land-Use Harmonization 2 (LUH2) project (CMIP6) for future forest cover (primary forested land 'primf', secondary forested land 'secdf'); 29 CMIP6 climate models for surface wind speed evaluation.

Main Results

• A pronounced, statistically significant precipitation reduction of 3.9 to 5.4 mm yr⁻¹ per year was observed in the southern Amazon basin (1980-2019), corresponding to an 8-11% decline in annual precipitation over the period.
• This reduction is primarily driven by a decline in terrestrial recycled precipitation (3.6 to 4.1 mm yr⁻¹ per year), accounting for 76-92% of the observed negative trend in the southern basin.
• Historical deforestation, both local and upwind, is responsible for 52-72% of the observed precipitation decline in the southern Amazon basin.
• Deforestation reduces precipitation by suppressing evapotranspiration, increasing atmospheric stability (21% decrease in CAPE), and increasing moisture outflow (4% increase in transport distance, 19% reduction in local moisture fraction).
• Climate models significantly underestimate the sensitivity of precipitation to forest cover loss (observed 0.32% reduction per percentage point forest loss vs. modeled mean 0.16%).
• Under a high-deforestation scenario (SSP2-4.5 "primf"), annual precipitation in the southern Amazon could decrease by up to 202.4 mm yr⁻¹ (10.6% of current annual precipitation) by the end of the 21st century. Conversely, reforestation (SSP2-4.5 "primf+secdf") could limit this reduction to -22.3 mm yr⁻¹.

Contributions

• Provides a robust, observation-based quantification of the impact of historical deforestation on regional precipitation in the Amazon basin, including the role of inter-regional atmospheric moisture transport.
• Introduces and validates a "weighted forest cover" (FC_w) metric that comprehensively accounts for both local and upwind deforestation impacts on local precipitation.
• Reveals a significant underestimation by current climate models of the precipitation response to deforestation, suggesting that Amazon tipping points may be reached sooner than projected.
• Offers detailed insights into the atmospheric and land-surface mechanisms (evapotranspiration suppression, increased atmospheric stability, increased moisture outflow) through which deforestation reduces rainfall.
• Highlights the critical role of forest conservation and reforestation as a mitigation strategy to buffer against climate change impacts and reduce the risk of Amazon forest dieback.

Funding

• National Natural Science Foundation of China (42522506 and 42471113)
• Second Tibetan Plateau Scientific Expedition and Research (STEP) program (2024QZKK0301)

Citation

@article{Cui2026Historical,
  author = {Cui, Jiangpeng and Piao, Shilong and Huntingford, Chris and Wang, Tao and Spracklen, Dominick V.},
  title = {Historical deforestation drives strong rainfall decline across the southern Amazon basin},
  journal = {Nature Communications},
  year = {2026},
  doi = {10.1038/s41467-026-68361-z},
  url = {https://doi.org/10.1038/s41467-026-68361-z}
}