Climate change, Indian Ocean Dipole, compounding natural hazards and high vulnerability: increased severity of flooding in the Horn of Africa

The study finds that human-induced climate change and a positive phase of the Indian Ocean Dipole (IOD) contributed approximately equally to the magnitude of extreme rainfall in the Horn of Africa during the 2023 OND season. While the IOD is a natural oscillation, the warming of 1.2C from fossil fuel combustion approximately doubled the rainfall magnitude. The researchers report high confidence that climate change increased rainfall intensity, though they have low confidence in the specific quantification due to limited model correlation and short records. The impact was compounded by previous droughts, unsustainable land management, and systemic challenges in early warning systems, leading to over 300 deaths and the displacement of more than one million people in Kenya and Somalia.

• The 2023 OND rainy season saw exceptional precipitation, with 2023 recording either the highest or second highest events on record across various timescales from 1-day to 30-day rainfall.
• Human-induced climate change and the positive phase of the Indian Ocean Dipole (IOD) were roughly equal contributors to the magnitude of the rainfall event. Specifically, the 1.2C of warming caused by fossil fuel combustion approximately doubled the rainfall magnitude, and the positive IOD phase similarly doubled the intensity compared to a neutral IOD year.
• The researchers have very high confidence that climate change increased the intensity of heavy rainfall in the OND season in the Horn of Africa, although they have low confidence in the specific quantification (which estimates an increase by up to a factor of two) due to a low number of models and short observed records.
• The severity of the flooding impacts was exacerbated by compounding factors, including a preceding drought that caused livestock deaths and crop failure, as well as unsustainable land management and failures in implementing early warning early action (EWEA) protocols.
• The floods resulted in more than 300 reported deaths and the displacement of over one million people specifically within Kenya and Somalia.

APA

World Weather Attribution (2023). Climate change, Indian Ocean Dipole, compounding natural hazards and high vulnerability: increased severity of flooding in the Horn of Africa. https://www.worldweatherattribution.org/climate-change-indian-ocean-dipole-compounding-natural-hazards-and-high-vulnerability-increased-severity-of-flooding-in-the-horn-of-africa/

Chicago

World Weather Attribution. Climate change, Indian Ocean Dipole, compounding natural hazards and high vulnerability: increased severity of flooding in the Horn of Africa. 2023. https://www.worldweatherattribution.org/climate-change-indian-ocean-dipole-compounding-natural-hazards-and-high-vulnerability-increased-severity-of-flooding-in-the-horn-of-africa/.

Wikipedia

{{cite report |author=World Weather Attribution |title=Climate change, Indian Ocean Dipole, compounding natural hazards and high vulnerability: increased severity of flooding in the Horn of Africa |date=7 December 2023 |url=https://www.worldweatherattribution.org/climate-change-indian-ocean-dipole-compounding-natural-hazards-and-high-vulnerability-increased-severity-of-flooding-in-the-horn-of-africa/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2023climate, author = {{World Weather Attribution}}, title = {{Climate change, Indian Ocean Dipole, compounding natural hazards and high vulnerability: increased severity of flooding in the Horn of Africa}}, institution = {World Weather Attribution}, year = {2023}, month = dec, url = {https://www.worldweatherattribution.org/climate-change-indian-ocean-dipole-compounding-natural-hazards-and-high-vulnerability-increased-severity-of-flooding-in-the-horn-of-africa/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }