Natural global climate cycles increase insurgence of warfare. It’s the main finding of an interdisciplinary team at Columbia University’s Earth Institute, which appears in the current issue of the leading scientific journal Nature.
First of its kind, the Earth Institute’s uses statistics to link global weather observations and well-documented outbreaks of violence. Focus has been put on natural events like El Niño, the periodic warming and cooling of the tropical Pacific Ocean. Coming with a three to seven years cycle, ENSO – as this phenomenon is also known, from El Niño-Southern Oscillation – boosts temperatures and cuts rainfall, doubles the risk of civil wars across 90 affected tropical countries, and may help account for a fifth of worldwide conflicts during the past half-century. This affects weather patterns across much of Africa, the Mideast, India, southeast Asia, Australia, and the Americas, where half the world’s people live.
The study does not blame specific wars on El Niño, nor does it directly address the issue of long-term climate change. However, it raises potent questions, as many scientists think natural weather cycles will become more extreme with warming climate, and some even suggest ongoing chaos in places like Somalia are already being stoked by warming climate.
The team’s scientists tracked ENSO from 1950 to 2004 and correlated it with onsets of civil conflicts that killed more than 25 people in a given year. The data included 175 countries and 234 conflicts, over half of which each caused more than 1,000 battle-related deaths. For nations whose weather is controlled by ENSO, they found that during El Niño the chance of a civil war breaking out was about 6 percent, or twice as much as in normal, non-El Niño conditions. Overall, the team calculated that El Niño may have played a role in 21 percent of civil wars worldwide — and nearly 30 percent in those countries affected by El Niño.
The idea that extreme environment fuels violence has gained popularity in the past decade. Some scientists and historians remain unconvinced of connections between climate and violence.