Climate change exacerbated heavy rainfall leading to large scale flooding in highly vulnerable communities in West Africa

The report attributes the 2022 West African floods to a combination of anthropogenic climate change, which significantly increased the likelihood and intensity of rainfall in the Lake Chad and Lower Niger basins, and systemic vulnerabilities including poor water management, rapid unplanned urbanization, and socioeconomic instability. In the Lake Chad region, climate change made the seasonal rainfall event approximately 80 times more likely and 20% more intense. In the Lower Niger basin, the 7-day maximum rainfall event became about twice as likely and 5% more intense. The human toll was exacerbated by the release of the Lagdo Dam in Cameroon and the proximity of settlements to floodplains.

• Climate change made the 2022 seasonal rainfall over the Lake Chad region approximately 80 times more likely and roughly 20% more intense.
• For the 7-day maximum rainfall over the lower Niger Basin, climate change increased the likelihood of the event by about twofold and the intensity by approximately 5%.
• The 2022 flooding was influenced by the release of the Lagdo Dam in Cameroon, which is part of a river management system that lacked a planned complementary dam in Nigeria.
• The floods in Nigeria and Niger were among the deadliest in their history, with Nigeria seeing 34 of 36 states affected and over 3.2 million people impacted, including 1.5 million displaced.
• In Chad, the 2022 floods affected over 1.1 million people, with 442,000 displaced and 22 deaths reported across 18 of 23 provinces.
• Human vulnerability was intensified by high poverty rates, gender and age-based socioeconomic factors, and the construction of informal settlements on floodplains, particularly in the Niger River basin.
• The floods triggered disease outbreaks, including cholera, which killed 256 people in Nigeria between January and September 2022, and later spread to the borderlands of Nigeria, Niger, Chad, and Cameroon.
• Climate models suggest that in a world 2°C warmer than preindustrial times, rainfall intensity will increase further, though the trend may be less strong than that observed in the last 30 years due to changes in aerosol pollution and atmospheric dynamics.
• The 2022 events are not considered rare in the current climate, with return times of approximately 1 in 10 years for seasonal rain over the Lake Chad Basin and 1 in 5 years for the 7-day maximum over the lower Niger Basin.

APA

Zachariah, M., Barnes, C., Wainwright, C., Balogun, R. A., Vondou, D. A., Adefisan, E. A., Olaniyan, E., Lawal, K. A., Brouillet, A., Sultan, B., Philip, S., Kew, S., Vautard, R., Koren, G., Wolski, P., Vahlberg, M., Singh, R., Kane, C., van Aalst, M., ... Otto, F. E. L. (n.d.). Climate change exacerbated heavy rainfall leading to large scale flooding in highly vulnerable communities in West Africa. World Weather Attribution. https://www.worldweatherattribution.org/wp-content/uploads/Nigeriafloods_scientific-report.pdf

Chicago

Zachariah, Mariam, Clair Barnes, Caroline Wainwright, Richard Ayodeji Balogun, Derbetini A. Vondou, Elijah Adesanya Adefisan, Eniola Olaniyan, et al. Climate change exacerbated heavy rainfall leading to large scale flooding in highly vulnerable communities in West Africa. World Weather Attribution, n.d. https://www.worldweatherattribution.org/wp-content/uploads/Nigeriafloods_scientific-report.pdf.

Wikipedia

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BibTeX

@techreport{zachariahndclimate, author = {Zachariah, Mariam and Barnes, Clair and Wainwright, Caroline and Balogun, Richard Ayodeji and Vondou, Derbetini A. and Adefisan, Elijah Adesanya and Olaniyan, Eniola and Lawal, Kamoru Abiodun and Brouillet, Audrey and Sultan, Benjamin and Philip, Sjoukje and Kew, Sarah and Vautard, Robert and Koren, Gerbrand and Wolski, Piotr and Vahlberg, Maja and Singh, Roop and Kane, Cheikh and van Aalst, Maarten and Thalheimer, Lisa and Li, Sihan and Otto, Friederike E. L.}, title = {{Climate change exacerbated heavy rainfall leading to large scale flooding in highly vulnerable communities in West Africa}}, institution = {World Weather Attribution}, url = {https://www.worldweatherattribution.org/wp-content/uploads/Nigeriafloods_scientific-report.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }