Do El Niño and La Niña Play a Role in Conflict and Peacebuilding?

May 23, 2024 | Marisa O. Ensor

Earlier this month – May 9^th – the U.S. National Oceanic and Atmospheric Administration (NOAA) reported a substantial weakening of the current El Niño, predicting a 60 percent chance that a La Niña phase will develop between June and August 2024. El Niño and La Niña represent opposite extremes in El Niño Southern Oscillation (ENSO). ENSO is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation which, in turn, influences temperature and precipitation across the globe. Research suggests that El Niño-related weather systems bring more intense and frequent cyclones along the Pacific, while resulting in higher temperatures and below-average rainfall in Southern Africa from November to April. La Niña, on the other hand, is associated with higher chances of a more active hurricane season in the Atlantic. While some studies have proposed a causal link between ENSO and heightened insecurity, other experts see collaborative preventative action in response to ENSO-related challenges as peacebuilding opportunities. These diverse possible outcomes have more severe consequences on already vulnerable populations and are deeply gendered.

El Niño and La Niña as Environmental Phenomena

The El Niño episode which is currently waning started in June of 2023, and has been among the strongest ever experienced. El Niño represents the warm phase of the ENSO cycle. It refers to the above-average sea-surface temperatures that periodically develop across the east-central equatorial Pacific. It results from a change in the “trade winds” that circle the Earth and normally blow west along the equator, carrying warm water west from South America toward Asia. During El Niño, trade winds weaken, and warm water is pushed back east, toward the west coast of the Americas. Fishermen in Peru first identified the occurrence of warmer-than-usual waters in the Pacific during the 1600s.  They called this pattern El Niño de Navidad, after the baby Jesus, since the unusually warm currents tended to arrive around Christmas. La Niña – meaning thegirl child – represents the cold phase of the ENSO cycle. It refers to the periodic cooling of sea-surface temperatures across the east-central equatorial Pacific. During La Niña, trade winds intensify pushing warm water towards Asia while colder water rises to the surface off the coast of the Americas. Each set of conditions come with their own consequences and risks.

Globally, ENSO is associated with a higher prevalence of weather extremes. More precipitation is expected in some places, while others may receive none at all.  While El Niño and La Niña both have the greatest impact on countries around the equator, other regions are also affected in different ways depending on their location on the globe – e.g., people in Indonesia and Australia typically associate El Niño with drought, while people in Peru connect El Niño with floods. This variability is often quite pronounced even within the same continent. Northern Europe generally experiences colder and drier conditions during winters influenced by El Niño, while southern Europe receives increased rainfall due to the shifting of the jet stream. In the UK, El Niño summers tend to be hotter and drier than usual, as reported by the Met Office. It is also worth noting that El Niño and La Niña events are becoming stronger and more frequent. As concluded in a recent study, “this amplified cycle translates into more extreme and frequent ENSO-linked droughts, floods, heat waves, wildfires and severe storms.” ENSO, like other aspects of the climate crisis, is not "gender neutral". El Niño and La Niña can amplify existing gender inequalities, posing gender-differentiated threats to the livelihoods, health, and safety of those affected.

El Niño and La Niña as Harbingers of Insecurity

While the relationship between ENSO and climate change is still being explored, the impact of ENSO-related fluctuations is expected to worsen as climate change intensifies both the frequency and severity of ENSO occurrences. Global warming represents an additional difficulty, as “cool” La Niña years are now hotter than most El Niño years from 20 years ago. Drivers specifically related to extreme heat include disruptions to livelihoods, food price increases, displacement, and heightened competition for scarce resources, such as water and pasture. In many regions, women bear a disproportionate responsibility for securing food, water, and fuel. While there is considerable variation across regions, the UN Food and Agricultural Organization (FAO) concludes that the global labor burden of rural women likely exceeds that of men. When extreme heat dries water sources and affects food production, women’s workloads increase even more, as they must walk longer distances in the sweltering sun to find food and water, exacerbating pre-existing vulnerabilities. A cross-sectional study based on the demographic and health surveys in Sub-Saharan Africa revealed that increases in round-trip time to water sources were associated with increased intimate partner violence across 26 countries in Africa.

The potential link between ENSO and heightened insecurity is being further investigated. As noted in a previous post, a growing body of evidence shows that rapid global warming can – and is – increasing violent behavior. The consequences are particularly devastating in at-risk regions that are least prepared to respond to the impacts of extreme temperatures. A study by climate economist Solomon Hsiang concluded that conflicts are associated with the ENSO cycle.  Hsiang and his colleagues at the Climate Impact Lab examined whether countries in tropical latitudes were more or less likely to erupt into violence during El Niño years than they were during the cooler, wetter La Niña phase of ENSO. Their results indicate that the probability of new conflicts breaking out doubles when the global climate changed from La Niña to El Niño. The additional conflicts that occur during El Niño years tend to happen between June and December — the months when El Niño dominates. Based on these findings, they calculated that the onset of one in five civil conflicts in these countries since 1950 was indeed influenced by ENSO. The study also found that a country’s sensitivity to the effects of ENSO on conflict is strongest for poor countries where resource scarcity or weak government institutions exacerbates the impacts of environmental extremes. The extreme weather events and other drivers of conflict and insecurity associated both El Niño and La Niña affect women and girls in particular ways that must be understood and incorporated into humanitarian, climate adaptation, and peacebuilding interventions.

The Way Forward: ENSO as a Peace-Building Opportunity

When conflicts do occur, they can vastly increase people’s exposure to environmental extremes and undermine their coping capacities. The destruction of shelter and damage to life-sustaining health and water systems that often accompany conflicts – particularly in urban environments – dramatically increases the risks associated with ENSO-related episodes. A recent report from SIPRI concludes that mutually reinforcing dynamics between food insecurity, climate- and environment-related pressures, and violent conflict can trap people, communities, and countries in a downward spiral. Women and girls, particularly those living in low-income regions, are at greater risk of violence, early marriage, teenage pregnancy, malnutrition, and other health issues during crises like those associated with ENSO. At the same time, the intrinsic linkages between these interrelated factors “offer the opportunity to turn vicious circles into virtuous ones, where food security is enhanced, climate- and environment-related stress reduced, conflict managed, and peace promoted.” Advances in predictive modelling make it now possible to forecast strong ENSO events up to two years in advance, while the widespread use of information and communication technologies (ICT) facilitate the rapid communication of such early warnings to populations across large geographic regions. By guiding the development of protection and empowerment strategies that are people-centered, comprehensive, context-specific and prevention-oriented, environmental peacebuilding represents an opportunity to build resilience and robust conflict prevention measures. Underscoring human security, environmental peacebuilding thus provides an effective framework for responding to complex climate change- and ENSO-related security challenges.  Additionally, nature-based solutions can help build more resilient systems that can withstand the extreme weather associated with ENSO and climate change.

Our shared future is one in which recurring and extreme weather events will bring more severe environmental and security-related impacts. The synergistic effects of climate change and ENSO have wide-range implications from the global to the individual level. Integrated approaches help ensure that individuals, communities, and countries have the mitigation, adaptation, coping strategies, and response mechanisms in place to reduce the intensity of impacts, and safeguard livelihoods and peacebuilding gains in future cycles. A holistic, gender-sensitive approach is vital to both address these disproportionate challenges and leverage any related opportunities.

Dr. Marisa O. Ensor is an applied environmental and legal anthropologist currently based at the Georgetown Institute for Women, Peace and Security (GIWPS) where she leads the portfolio on climate security.  She is also the current Chair of the Environmental Peacebuilding Association’s Gender Interest Group (“EnPAx-GIG”).