Kongo et al. (2025) The 2023 drought in West Africa and associated vulnerability to food insecurity

Identification

• Journal: Scientific Reports
• Year: 2025
• Date: 2025-10-07
• Authors: Vincent Ondima Kongo, Nkongho Ayuketang Arreyndip
• DOI: 10.1038/s41598-025-18940-9

Research Groups

• African Institute for Mathematical Science (AIMS), Cape Town, South Africa
• Department of Environmental Sciences, Informatics, and Statistics, Ca’ Foscari University of Venice, Mestre, Venezia, Italy
• Economic Analysis of Climate Impacts and Policy Division, CMCC Foundation - Euro-Mediterranean Center on Climate Change, Venice, Venezia, Italy

Short Summary

This study analyzes the changes in local climate variables during the 2023 planting season in West Africa and their potential consequences for agricultural productivity. It found significant shifts in rainfall patterns, increased temperatures, and vegetation loss, leading to reduced crop yields, while attributing a weak direct influence to El Niño, suggesting other factors like global mean temperature are more dominant drivers.

Objective

• To analyze the changes in local climate variables (precipitation, air temperature, relative humidity, NDVI, drought, soil moisture) during the 2023 planting season in West Africa.
• To assess the potential consequences of these changes for agricultural productivity and vulnerability to food insecurity in the region.
• To investigate the link between the 2023 El Niño event and these observed climate impacts, particularly during the planting season.

Study Configuration

• Spatial Scale: West Africa (20°W – 16°E and 1°N – 20°N).
• Temporal Scale: Focus on the 2023 planting season (March to August), with anomalies calculated against a 30-year climatology period (1991–2020). Data sources span from 1940 to present (ERA5), 1979 to present (SPEI), and 1981 to present (NDVI).

Methodology and Data

• Models used: Not applicable; the study primarily used reanalysis data and indices.
• Data sources:
  • ERA5 (Copernicus Climate Data Store): Monthly and hourly mean data for Total Precipitation, Surface Temperature, Sea Surface Temperature (SST), Soil Moisture, and Dew Point Temperature. Horizontal resolution: 0.25° × 0.25°. Relative humidity was derived from ERA5 data.
  • Normalized Difference Vegetation Index (NDVI) (NOAA): Gridded daily NDVI derived from Surface Reflectance Climate Data Record. Global grid resolution: 0.05° × 0.05°.
  • Standardized Precipitation Evaporation Index (SPEI) (Global Drought Crops Monitoring - GDCM): Global drought indices.
  • FAOSTAT: Normalized crop yield and harvest area data for maize, rice, wheat, and soybeans.
  • United States Department of Agriculture (USDA): Crop calendar data for West Africa.

Main Results

• The year 2023 recorded the warmest Sea Surface Temperature (SST) on record, with El Niño present from March (Niño 3.0 dominating) and strengthening through June (Niño 3.4) and August (Niño 4.0).
• During the critical planting season (April to June) in West Africa, the study observed abnormally high surface temperatures, low precipitation, and a loss of vegetation compared to climatology.
• Soil moisture was significantly low from April to June but increased in July and August.
• A significant drop in maize yield was observed in West Africa in 2023, even with an increased harvest area, followed by wheat and soybeans. Rice yield was less affected, likely due to its reliance on irrigation.
• The Sahel region, Nigeria, Benin, Togo, Northern Ghana, Ivory Coast, and the Niger Delta region were identified as most severely impacted by vegetation loss, precipitation deficits, or drought.
• Statistical analysis showed a very weak correlation (Pearson r = 0.05) between Niño 3.4 SST and local precipitation in West Africa, suggesting El Niño is not the sole or primary driver of the observed drought conditions.
• Regional surface temperature (a subset of global mean surface temperature) showed a strong correlation with precipitation, indicating it might be a major driver of droughts in West Africa.

Contributions

• Provides the first comprehensive assessment of the agricultural impacts of the 2023 El Niño climate year in the rain-fed agricultural region of West Africa, specifically focusing on the planting season.
• Quantifies the spatio-temporal anomalies of key climate variables (temperature, precipitation, humidity, soil moisture, NDVI, drought) in West Africa during 2023 relative to a 30-year climatology.
• Demonstrates that while El Niño was present, its direct influence on West African precipitation and local climate variables in 2023 was weak, suggesting other factors like global mean surface temperature play a more significant role in regional drought.
• Offers practical adaptation strategies for farmers and policymakers in West Africa, such as efficient irrigation, drought-resistant crops, early warning systems, bio-stimulants, and adjusted planting dates, to mitigate future climate extreme impacts.

Funding

• European Union (Grant Agreement No. 945361) through the Marie Skłodowska-Curie Actions COFUND scheme
• Next Generation EU

Citation

@article{Kongo20252023,
  author = {Kongo, Vincent Ondima and Arreyndip, Nkongho Ayuketang},
  title = {The 2023 drought in West Africa and associated vulnerability to food insecurity},
  journal = {Scientific Reports},
  year = {2025},
  doi = {10.1038/s41598-025-18940-9},
  url = {https://doi.org/10.1038/s41598-025-18940-9}
}