Swain et al. (2026) Human-induced temperature rise is driving Africa towards drought-prone climatic conditions

Identification

• Journal: Scientific Reports
• Year: 2026
• Date: 2026-01-03
• Authors: Basudev Swain, Marco Vountas, Rui Song, Aishwarya Singh, Vittal Hari, Md Saquib Saharwardi, Akshaya Nikumbh, Adrien Deroubaix, Pritanjali Shende, Luca Lelli, Richard Alawode, Sachin S. Gunthe
• DOI: 10.1038/s41598-025-34010-6

Research Groups

• Department of Physics, Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK
• Institute of Environmental Physics, University of Bremen, Bremen, Germany
• School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States
• Department of Environmental Science and Engineering, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, India
• Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
• Department of Climate Studies, Indian Institute of Technology Bombay, Maharashtra, India
• Max-Planck-Institut für Meteorologie, Hamburg, Germany
• Indian Institute of Tropical Meteorology, Pune, India
• Remote Sensing Technology Institute, German Aerospace Centre (DLR), Wessling, Germany
• Leipziger Institut für Meteorologie, Leipzig University, Leipzig, Germany
• Centre for Atmospheric and Climate Sciences, Indian Institute of Technology Madras, Chennai, India

Short Summary

This study identifies human-induced factors as the primary drivers of surface air temperature (SAT) rise and subsequent drought intensification across Africa, attributing a 0.8 to 1.06 °C warming above pre-industrial levels mainly to greenhouse gases and land-use changes, which has shifted the continent towards significantly drier conditions.

Objective

• To isolate human influences on surface air temperature (SAT) over Africa and assess their role in increasing drought risk.
• To quantify the contributions of specific anthropogenic forcings (greenhouse gases, land-use changes, aerosols) and natural forcings to SAT changes and their causal impact on the Standardized Precipitation Evapotranspiration Index (SPEI).

Study Configuration

• Spatial Scale: Continental Africa.
• Temporal Scale: Historical period (1850-2005, with focus on pre-industrial 1850-1900 and industrial 1955-2018), and future projections (2006-2100).

Methodology and Data

• Models used: Coupled Model Intercomparison Project 5 (CMIP5) simulations (22 models, 158 simulations), including specific forcing experiments for Greenhouse Gas emissions (GHG), anthropogenic aerosols (Aaer), human-driven land use (LU), and natural forcings (NAT).
• Data sources: HadCRUT5 observational dataset for surface air temperature, CMIP5 model outputs for SAT and precipitation, Global Standardized Precipitation Evapotranspiration Index (SPEI) dataset.

Main Results

• Human-induced factors have contributed to a surface air temperature (SAT) increase ranging from 0.8 to 1.06 °C above pre-industrial benchmarks over Africa during the industrial period.
• Greenhouse gases (GHGs) are the primary driver of this warming (0.47 to 0.92 °C), followed by land-use (LU) changes (0.47 to 0.63 °C).
• Anthropogenic aerosols (Aaer) exert a cooling effect (-1.82 to -1.36 °C) on SAT, while natural forcings (NAT) have a minimal effect (-0.03 to 0.06 °C).
• SAT anomalies during the industrial period have significantly contributed to the intensification of drought-prone climatic conditions, shifting the average Standardized Precipitation Evapotranspiration Index (SPEI) from 0.54 (mildly wet) in the pre-industrial period to -0.73 (mildly dry) in the industrial period.
• Future projections under Representative Concentration Pathways (RCP) 4.5 and 8.5 suggest that SAT over Africa could rise by approximately 2 °C and 5 °C, respectively, by the end of the century.
• Spatially, northern and southern Africa show rapid SAT increases driven by LU (0.13 °C/decade) and GHG (0.26 °C/decade) forcings during the industrial period, aligning with increasing dryness (lower SPEI values).

Contributions

• Provides a comprehensive analysis of various natural and anthropogenic forcings (GHG, Aaer, LU, NAT) contributing to SAT increase across Africa, utilizing HadCRUT5, CMIP5 models, and the Regularized Optimal Fingerprinting (ROF) method, which is novel for African climate studies.
• Explores the causal influence of rising SAT and individual forcings on the Standardized Precipitation Evapotranspiration Index (SPEI) and extends future projections under RCP scenarios, offering a multidimensional view of climate change impacts, particularly drought, in Africa.
• Fills a critical gap in climate literature by focusing on Africa's unique climate dynamics and human-climate interactions, distinct from more industrialized regions, providing insights vital for tailored adaptation strategies.

Funding

• Open Access funding enabled and organized by Projekt DEAL.

Citation

@article{Swain2026Humaninduced,
  author = {Swain, Basudev and Vountas, Marco and Song, Rui and Singh, Aishwarya and Hari, Vittal and Saharwardi, Md Saquib and Nikumbh, Akshaya and Deroubaix, Adrien and Shende, Pritanjali and Lelli, Luca and Alawode, Richard and Gunthe, Sachin S.},
  title = {Human-induced temperature rise is driving Africa towards drought-prone climatic conditions},
  journal = {Scientific Reports},
  year = {2026},
  doi = {10.1038/s41598-025-34010-6},
  url = {https://doi.org/10.1038/s41598-025-34010-6}
}