Bai et al. (2026) Persistent and intensifying heat extremes in global deeper soils

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Environmental Research Letters
• Year: 2026
• Date: 2026-02-10
• Authors: Wenhao Bai, Ruifang Guo, . Batunacun, Jiayi Ma, Shizhan Qiu, Xingwang Fan
• DOI: 10.1088/1748-9326/ae4410

Research Groups

Not specified in abstract.

Short Summary

This study investigated global heatwave evolution across near-surface air, land surface, and subsurface soils from 1980–2024, finding that heatwaves have strengthened across all layers, with soils exhibiting greater exposure and severity than air or land surface, implying air temperature alone underestimates heatwave risks to soil ecosystems.

Objective

• To explore the evolution of global heatwaves across near-surface air, land surface, and subsurface soils worldwide during 1980–2024.
• To compare heatwave exposure and severity across different layers (air, land surface, soil) and analyze how peak intensity changes with soil depth.
• To identify factors influencing inter-layer differences in heatwave intensity within soils.
• To assess regional variations in heatwave severity and persistence, and the role of land cover types.
• To evaluate the implications of relying solely on air temperature for heatwave risk assessment, particularly for soil ecosystems.

Study Configuration

• Spatial Scale: Global (worldwide)
• Temporal Scale: 1980–2024

Methodology and Data

• Models used: Not specified in abstract.
• Data sources: Not specified in abstract (data for near-surface air temperature, land surface temperature, and subsurface soil temperature were used).

Main Results

• Heatwaves have strengthened across all layers (near-surface air, land surface, subsurface soils) globally.
• A pronounced acceleration in heatwave strengthening has been observed since the early 21st century.
• Soils generally exhibit greater heatwave exposure and severity compared to near-surface air and land surface.
• Peak heatwave intensity weakens as soil depth increases.
• Inter-layer differences in heatwave intensity are closely linked to soil moisture, clay content, and organic carbon content.
• Northern high latitudes are more prone to events of greater severity, particularly during summer.
• Lower latitudes and the Southern Hemisphere are characterized by events of greater persistence.
• Forests tend to buffer heat extremes.
• Non-forest land covers readily amplify heat exposure.

Contributions

• Provides a comprehensive global assessment of heatwave evolution across multiple Earth surface layers (near-surface air, land surface, and subsurface soils), which is a novel approach compared to studies focusing primarily on air temperature.
• Quantifies the underestimation of heatwave risks to soil ecosystems when solely relying on air temperature, highlighting the critical need for a multi-layer perspective.
• Identifies key soil properties (moisture, clay, organic carbon) as crucial factors influencing heatwave intensity variations with depth.
• Offers detailed regional insights into heatwave characteristics, distinguishing between severity in northern high latitudes and persistence in lower latitudes/Southern Hemisphere.
• Demonstrates the contrasting roles of different land covers (forests buffering, non-forest amplifying) in modulating heat exposure.
• Advocates for the incorporation of soil temperature into future heatwave monitoring and early-warning systems.

Funding

Not specified in abstract.

Citation

@article{Bai2026Persistent,
  author = {Bai, Wenhao and Guo, Ruifang and Batunacun, . and Ma, Jiayi and Qiu, Shizhan and Fan, Xingwang},
  title = {Persistent and intensifying heat extremes in global deeper soils},
  journal = {Environmental Research Letters},
  year = {2026},
  doi = {10.1088/1748-9326/ae4410},
  url = {https://doi.org/10.1088/1748-9326/ae4410}
}