A dispute about whether climate change will cause more wars in Africa heated up last week with the publication of a study that pours cold water on the link.
"The primary causes of civil war are political, not environmental," said Halvard Buhaug, a political scientist from the Peace Research Institute Oslo, Norway, whose study, published in Proceedings of the National Academy of Sciences yesterday, challenges theories that increasing pressure on food and water security caused by climate change would lead to social disorder and violent conflicts.
But Marshall Burke, an economist at the University of California, Berkeley, and the author of a paper claiming the opposite — published in the same journal last year — said: "We think he's made some serious econometric mistakes that undermine his results."
Burke's paper found a 50 per cent increase in armed conflict in warmer years between 1981 and 2002, and predicted that global warming would impede the growth of democracy and the eradication of poverty in Africa.
Buhaug countered that it is Burke's team that has skewed its findings by cherry-picking the evidence.
Roger Pielke, a political scientist and climate policy expert at the University of Colorado, Boulder, said: "The climate signals are small in the context of the broader social factors. This does not at all diminish the importance of responding to climate change, but it does offer a stark warning about trying to use overly simplistic notions of cause and effect to advocate for such actions".
Nature doi:10.1038 (2010)