Are we getting more cranky and fractious as the planet heats up? It certainly seems so. The US is only warmer by just a few degrees on average over the last 30 years, and yet the culture seems to have become a lot angrier than thirty years ago. But that’s just one person’s subjective sense of what’s happening.
To see if there is a connection between rising temperatures and rising bellicosity, an interdisciplinary team of researchers at Columbia University’s Earth Institute counted tropical conflicts and compared the timing to the El Niño warming cycles.
Coauthor Mark Cane, a climate scientist at Columbia’s Lamont-Doherty Earth Observatory, was among the earliest to predict the rhythm of El Niño/El Niña cycles, in the 1980s. That discovery is now used by organizations around the world to plan agriculture and relief services.
The higher temperatures during El Niño years double the risk of civil wars across 90 affected tropical countries, the authors found. Their paper appears in the current issue of the leading scientific journal Nature.
In recent years, scientific evidence has accumulated that past societies suffered and fell due in connection with extreme droughts that damaged agriculture and shook governments. This is the first study to make the case for such destabilization in the present day, using statistics to link global weather observations and well-documented outbreaks of violence.
“The most important thing is that this looks at modern times, and it’s done on a global scale,” said Solomon M. Hsiang, the study’s lead author, a graduate of the Earth Institute’s Ph.D. in sustainable development. “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 the El Niño years from 1950 to 2004 and correlated them 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 where the chance of civil war breaking out was about 3 percent; during El Niño, the chance doubled, to 6 percent. Countries not affected by the cycle remained at 2 percent no matter what.
Some examples of festering conflicts they counted that began and flared up during El Niños include Southern Sudan where intense warfare broke out in 1963, and flared up again in 1973 and 1983. El Salvador, the Philippines and Uganda also broke out in conflicts in 1972-73; and Peru’s guerrilla Shining Path movement also began during the 1982-83 El Niño. Angola, Haiti and Myanmar flared into civil war in the 1991 El Niño; and Congo, Eritrea, Indonesia and Rwanda in 1997.
Climate scientists do expect the natural weather cycles of El Niño-El Niña will become more extreme with a warming climate, but the researchers do not directly address the issue of long-term climate change.
“No one should take this to say that climate is our fate” said Cane. “Rather, this is compelling evidence that it has a measurable influence on how much people fight overall. It is not the only factor–you have to consider politics, economics, all kinds of other things.”
Poorer countries seem to be more vulnerable to the effect. Rich Australia, for instance, has never seen a civil war despite its El -driven extreme drought and flood cycles.
“But if you have social inequality, people are poor, and there are underlying tensions, it seems possible that climate can deliver the knockout punch,” Hsiang added.
Sounds like America could be in for rough times.
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