By Alister Doyle
OSLO (Reuters) - Multi-ethnic nations are vulnerable to armed conflicts after weather disasters such as heatwaves and droughts in a trend that could worsen with global warming, scientists said on Monday.
The outbreak of 23 percent of armed conflicts in ethnically diverse countries, a group that includes Afghanistan and Somalia, since 1980 coincided in the same month with such weather disasters, the study said.
By contrast, only 9 percent of all conflicts worldwide in the same period overlapped with such a calamity, it said. That suggests that nations with pre-existing faultlines of many ethnic groups are particularly vulnerable to extreme weather events that may get more severe with global warming, it said.
"Our results imply that (environmental) disasters might act as a threat multiplier in several of the world's most conflict-prone regions," they wrote in the U.S. Journal Proceedings of the National Academy of Sciences (PNAS).
Conversely, cuts in greenhouse gas emissions to limit global warming, or measure to adapt such as drought-resistant crops, could reduce risks in nations with many ethnic divisions such as in north and central Africa or central Asia, the study said.
"Our study adds evidence of a very special co-benefit of climate stabilization: peace," Hans Joachim Schellnhuber, one of the authors and head of the Potsdam Institute for Climate Impact Research, wrote in a statement.
Juergen Scheffran of the University of Hamburg, one of the reviewers of the PNAS study, welcomed it as "one step in understanding the complex relationships" between climate change and conflict.
However, many researchers are wary of linking climate change and conflict, saying it is hard to isolate warming from factors such as poverty, sectarian divides or social injustice.
Jonathan Donges, one of authors at the Potsdam Institute, told Reuters that the study found that disasters did not directly trigger armed conflict in multi-ethnic societies, but clearly raised risks. The study drew on a data of environmental disasters by insurer Munich Re.
Jan Selby, a professor of international relations at the University of Sussex, told Reuters in an e-mail: "I don't find the paper at all persuasive." He said it did not examine the proportion of weather disasters that were not followed by conflict.
In 2013, a panel of U.N. scientists said climate change could "indirectly increase risks of violent conflicts by amplifying well-documented drivers of these conflicts such as poverty and economic shocks".
Some U.S. Republicans, doubting that climate change is stoked by man-made greenhouse gases, denounced that conclusion as an effort to harness fears over public safety to drive an unrelated climate agenda.
(Reporting by Alister Doyle; Editing by Alison Williams)