Jia et al. (2025) How vegetation greening mitigates climate-driven aridification in mid-latitude Asia

Identification

• Journal: Advances in Climate Change Research
• Year: 2025
• Date: 2025-10-30
• Authors: Xiaojing Jia, QianJia Xie, Wei Dong, Qifeng Qian
• DOI: 10.1016/j.accre.2025.10.006

Research Groups

• Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou, China
• Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion, Yunnan University, Kunming, China
• Zhejiang Institute of Meteorological Science, Hangzhou, China

Short Summary

This study investigates the spatiotemporal characteristics and drivers of drought variability across mid-latitude Asia from 1982 to 2018, revealing a biogeophysical dichotomy where climate-driven aridification intensifies in the central-western sector, while vegetation greening mitigates drought in the southeastern regions through hydrological and land-atmosphere interactions.

Objective

• To investigate why drought trends in mid-latitude Asia exhibit notable spatial heterogeneity.
• To determine the role of vegetation greening and related climate feedback in drought events.

Study Configuration

• Spatial Scale: Mid-latitude Asia, specifically divided into central-western (e.g., Xinjiang, Mongolia) and southeastern (e.g., North China, Northeast China) sectors.
• Temporal Scale: Observational analysis from 1982 to 2018. Numerical model simulations spanned 30 days.

Methodology and Data

• Models used:
  • Linear Baroclinic Model (LBM) for numerical experiments.
  • DoWhy test for causal inference, employing linear regression within the backdoor criterion.
  • Pearson correlation, linear regression, partial regression, and Student’s t-test for statistical analysis.
• Data sources:
  • Global Land Surface Satellite (GLASS) AVHRR product (Fractional Vegetation Cover (FVC), Leaf Area Index (LAI), Evapotranspiration (ET)) at 0.05° spatial resolution.
  • Climate Research Unit (CRU, version TS4.08) (surface temperature, precipitation, Standardized Precipitation-Evapotranspiration Index (SPEI), total cloud cover (TCC), potential evaporation (PE)) at 0.5° × 0.5° spatial resolution.
  • ECMWF reanalysis (ERA5) (geopotential heights, horizontal winds, surface net solar radiation, surface net thermal radiation, top atmosphere net solar radiation, top atmosphere net thermal radiation, sensible heat (SH), latent heat (LH), relative humidity (RH), volumetric 0-7 cm soil water (SM), convective rain rate, convective available potential energy (CAPE), vertical integral of water vapor flux) at 1° × 1° spatial resolution.
  • NOAA’s National Geophysical Data Center (ETOPO2v2) (Topography data) at 0.1° × 0.1° spatial resolution.

Main Results

• Mid-latitude Asia experienced significant, spatially coherent surface warming from 1982 to 2018, with a distinct 'wet-southern and dry-northern' precipitation pattern.
• The central-western sector showed significant aridification (SPEI trend: Xinjiang: -0.016 per year, Mongolia: -0.017 per year, p < 0.05), while the southeastern regions maintained relatively stable drought conditions.
• Vegetation greening was pronounced in the southeastern region (FVC trend: North China: 0.15 per year, Northeast China: 0.08 per year, p < 0.05), with minimal changes in central-western areas.
• Intensified aridification in central-western mid-latitude Asia is attributed to rising surface temperatures and declining precipitation, mediated by a persistent high-pressure anomaly over the northwestern Mongolian Plateau. This system reduces cloud cover, increases net radiation, enhances evaporation, and suppresses water vapor transport.
• In contrast, the southeastern region benefits from weaker climatic anomalies and pronounced vegetation greening. Enhanced evapotranspiration related to greening lowers surface temperature, creating an atmospheric cold source that feedbacks into land and water cycles, thereby mitigating drought.
• Causal analysis (DoWhy test) confirmed a persistent causal relationship between vegetation and drought, demonstrating vegetation's independent mitigating effect even after accounting for climatic confounding factors.
• Numerical experiments using the Linear Baroclinic Model (LBM) showed that vegetation-induced cooling generates a low-pressure cyclone anomaly, enhancing oceanic moisture advection and convergence, which further mitigates aridification.

Contributions

• Reveals a biogeophysical dichotomy in drought responses across mid-latitude Asia, advancing mechanistic understanding of dryland ecosystem resilience under global warming.
• Provides a comparative investigation into the formation mechanisms underlying the spatial heterogeneity of aridity patterns across mid-latitude Asia, addressing a critical knowledge gap.
• Elucidates the specific feedback pathways and regulatory role of vegetation greening in drought events, primarily through evapotranspiration-atmospheric moisture modulation processes.
• Offers a scientific basis for targeted land management and climate adaptation policies in vulnerable regions of mid-latitude Asia.

Funding

• National Key R&D Program of China (2024YFF0808401)
• National Natural Science Foundation of China (42205020)
• Zhejiang Provincial Natural Science Foundation (LQ23D050003)

Citation

@article{Jia2025How,
  author = {Jia, Xiaojing and Xie, QianJia and Dong, Wei and Qian, Qifeng},
  title = {How vegetation greening mitigates climate-driven aridification in mid-latitude Asia},
  journal = {Advances in Climate Change Research},
  year = {2025},
  doi = {10.1016/j.accre.2025.10.006},
  url = {https://doi.org/10.1016/j.accre.2025.10.006}
}