WASHINGTON (AP) — Scientists have found another thing to blame on the
climate demon El Nino: civil strife in poor tropical countries.
A new study released Wednesday finds a significant increase in unrest during
the years of an El Nino, which is a regular climatic event that tends to
warm up and dry out tropical regions.
“When people get warm and uncomfortable, they get irritable, they are more
prone to fight,” said Mark Cane, a professor of Earth and climate sciences
at Columbia University and co-author of the study.
"People do like to fight and El Nino conditions help.”
The flip side of El Nino, a La Nina, is also the most peaceful time for
these tropical countries, the research found. Meteorologists predict the
world is heading into another La Nina.
The researchers say the increase in civil unrest during an El Nino is so
noticeable that there is more than just a link, but a partial cause. They
say that El Nino influenced 48 of 234 civil wars or uprisings between 1950
For example, they point to internal strife in Chad, Congo, Eritrea,
Indonesia, Rwanda, Myanmar and Niger during a strong El Nino in 1997.
The weather effects of an El Nino, which warms the central Pacific Ocean,
are felt the most in about half the world, chiefly in the tropics, not
including the United States or Europe. And it’s in those mostly poor nations
where the scientists noticed El Nino’s affect on internal conflict.
In those affected countries, an El Nino makes the weather significantly
warmer and drier, according to the study in the journal Nature. La Nina
tends be cooler and slightly wetter in those regions.
Using internationally accepted figures for civil unrest, the study authors
calculated that the annual risk of conflict during an El Nino year is 6
percent in the affected tropical countries. During a La Nina year, it is
only 3 percent. For countries not in the affected region, the annual
conflict risk is steady at 2 percent.
There are exceptions and they seem to be related to a country’s economic
health. For example, Australia gets major El Nino impacts, but it doesn’t
have a jump in internal conflicts, said lead author Solomon Hsiang, an
international affairs and environmental policy researcher at Princeton
“We’re not trying to explain all the conflicts in the world. What we are
trying to show is that the global climate does play a major role where
previously people didn’t believe that,” Hsiang said.
Historian Thomas Homer-Dixon of Canada’s University of Waterloo said the
research makes sense, noting there are classic cases in ancient history
where weather was a factor in wars and downfalls of civilizations. He wrote
the book, “Environment, Scarcity and Violence.”
Homer-Dixon, who wasn’t part of this study, said the new statistics-based
analysis jibes with his own firsthand research into causes of internal
violence in countries in the past 20 years.
Although this study looks back and is about El Nino, there are lessons to be
learned for the future with man-made global warming, Cane and Homer-Dixon
“It’s frankly difficult to see why (the climate link with conflicts) won’t
carry over into a world that is disrupted by global warming,” Cane said.