A first of its kind study has laid convincing evidence for the possibility that natural global climate cycles have the potential to increase the likelihood of civil warfare.
The researchers posit that the El Niño-Southern Oscillation, or ENSO, has the tendency to increase the risk of civil war or violence across those countries it directly influences, and may in fact help account for a fifth of the worldwide conflicts during the past 50 years.
The paper, written by an interdisciplinary team at Columbia University’s Earth Institute, was published in the current issue of the journal Nature and authored by Solomon M. Hsiang, a graduate of the Earth Institute’s Ph.D. in sustainable development, and Mark Cane, a climate scientist at Columbia’s Lamont-Doherty Earth Observatory, who was one of the first to explain the mechanisms of El Niño and showing in the 1980s that ENSO could be predicted.
The study follows on from previous work which has posited the downfall of various civilisations can, at least in part, be laid at the feet of the climate of the times. However this is the first study to make the case for such an case happening in the present day, by studying global weather observations with well-documented outbreaks of violence.
No blame is placed on ENSO, or more specifically the El Niño phase, but the study does raise questions about the possibility that in a warmer world where El Niño could become more extreme, will it have a corollary effect on civil unrest and violence?
“The most important thing is that this looks at modern times, and it’s done on a global scale,” said Hsiang, the study’s lead author.
“We can speculate that a long-ago Egyptian dynasty was overthrown during a drought. That’s a specific time and place, that may be very different from today, so people might say, ‘OK, we’re immune to that now.’ This study shows a systematic pattern of global climate affecting conflict, and shows it right now.”
The scientists tracked ENSO from 1950 to 2004 and correlated it with the onset of civil conflicts which took the lives of more than 25 people in a given year, which amounted to 175 countries and 234 conflicts, of which more than half caused a thousand deaths or more.
For nations whose weather is directly controlled by ENSO, Hsiang and Cane found that during La Niña, the chance of civil war breaking out was approximately 3 percent, while during El Niño, the chance doubled to 6 percent. Those countries not affected by El Niño remained at 2 percent no matter what.
In the end, Hsiang and Cane calculated that El Niño may have been in part responsible for 21 percent of civil wars worldwide.
Cane said that the study does not show that weather alone starts wars.
“No one should take this to say that climate is our fate. Rather, this is compelling evidence that it has a measurable influence on how much people fight overall,” he said. “It is not the only factor–you have to consider politics, economics, all kinds of other things.”
The authors did not attempt to explain why climate feeds conflict, but Hsiang noted that “if you have social inequality, people are poor, and there are underlying tensions, it seems possible that climate can deliver the knockout punch.”
There are dissenters, however, to the idea that climate directly influences civil unrest. Halvard Buhaug, a political scientist with the Peace Research Institute Oslo in Norway who studies the issue said that “the study fails to improve on our understanding of the causes of armed conflicts, as it makes no attempt to explain the reported association between ENSO cycles and conflict risk. Correlation without explanation can only lead to speculation.”
Another expert, economist Marshall Burke of the University of California, Berkeley, said the authors gave “very convincing evidence” of a connection. But, he said, the question of how overall climate change might play out remains. “People may respond differently to short-run shocks than they do to longer-run changes in average temperature and precipitation,” he said. He called the study “a useful and illuminating basis for future work.”