El Niño Raises the Risk of Violent Conflicts

E360 Digest

May 12, 2026

A study of hundreds of armed conflicts around the world finds that severe drought raises the risk of violent clashes. The study is the latest addition to a growing body of evidence showing that climate shocks spark conflict. 

The research uses El Niño, the warm phase of the Pacific Ocean, as a kind of natural experiment. Every three to seven years, the climate phenomenon alters rainfall across much of the world, fueling heavier downpours in some regions and more arid weather in others. 

When researchers analyzed 555 armed conflicts from 1950 to 2023, they found that, during El Niño, the risk of conflict grew. The risk was greatest, however, in places such as Central America and southern Africa, where El Niño gives rise to drought. The study is not the first to find that El Niño raises the risk of armed conflict, but it takes a more detailed view than prior research, authors say.

The study also looked at the effect of the Indian Ocean Dipole, sometimes called the “Indian Niño,” which can alternately fuel severe rainfall and intense drought in parts of Asia and Africa. The study found that both extremes raised the risk of conflict in Southeast Asia and the Horn of Africa. 

Coauthor Sylvia Dee, a climate scientist at Rice University, noted that the Indian Ocean Dipole “can shift rapidly, creating climate ‘whiplash’ that may disrupt already vulnerable regions.” 

Authors say the findings, published in the Proceedings of the National Academy of Sciences, could help governments and humanitarian groups think about when and where climate shocks may raise the risk of conflict. They note that an El Niño is expected to take shape this summer, and according to some forecasts, it may be one of the strongest ever recorded.

Global and regional climate modes modulate armed conflict risk

Tyler E. Bagwell https://orcid.org/0009-0002-7910-6192 tyler.e.bagwell@rice.edu, Sylvia G. Dee, Xinyue Luo https://orcid.org/0000-0001-6048-3145, +5 , and Justin S. Mankin https://orcid.org/0000-0003-2520-4555Authors Info & Affiliations

Edited by B. L. Turner II, Arizona State University, Tempe, AZ; received November 18, 2025; accepted April 1, 2026

May 11, 2026

Significance

Climate variability can alter the risk of armed conflict. Leveraging empirical modeling on a dataset of armed conflicts and the natural experiments provided by the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), we offer insights about climate variability and conflict: First, El Niño is known to heighten conflict risk, but we show its effect does not scale smoothly with a region’s climatological connection to ENSO, but may exhibit threshold behavior. Second, conflict risk rises primarily through El Niño’s dry, rather than wet, teleconnections. Last, we show that the IOD, whose effects are regional, can alter regional conflict risk. Our results provide essential details on the climate–conflict relationship, with implications for managing climate risks.

Abstract

Because of their impacts on droughts, famines, and floods, modes of climate variability can shape patterns of social instability. Yet the mechanisms linking climate variability to armed conflict remain contested, especially relative to the myriad sociopolitical and economic determinants of conflict. A key challenge is that most studies rely on coarse, state-level data and treat climatic teleconnections as invariant. As such, it is unknown whether there are distinct climate hazards that select for conflict risk; whether conflict scales with climate hazard exposure; and whether such associations exist for more regional forms of climate variability. Here we leverage empirical modeling using a high-resolution gridded dataset of armed conflicts and the natural experiment afforded by two major climate modes—the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD)—to clarify how systematic hydroclimatic anomalies influence conflict emergence. Our results reveal the following: First, conflict risk heightens during El Niño, but ENSO-associated risk does not scale linearly with teleconnection strength; and, evidence for threshold behavior varies with spatial aggregation. Second, El Niño-related increases in conflict risk arise through its dry teleconnections, with limited evidence for wet teleconnections. Finally, the more regionally confined IOD also influences conflict, with both positive and negative phases elevating risk in strongly teleconnected regions, namely the Horn of Africa and Southeast Asia. These results reveal that modes of climate variability can differentially shape conflict risk, offering insight into societies’ vulnerabilities to natural climate fluctuations and, by extension, anthropogenic climate change.