In an approximate 5 year cycle the warming of the surface water in the tropical eastern Pacific Ocean during the El Niño-Southern Oscillation causes changes in weather including shifts in rainfall and temperatures. For 90 affected tropical countries these climate changes cause societal stress that up the risk of civil war.
In the first study of its kind, researchers have linked a natural global climate cycle to periodic increases in warfare. The arrival of El Niño, which every three to seven years boosts temperatures and cuts rainfall, doubles the risk of civil wars across 90 affected tropical countries, and may help account for a fifth of worldwide conflicts during the past half-century, say the authors. The paper, written by an interdisciplinary team at Columbia University's Earth Institute, appears in the current issue of the leading scientific journal Nature.
These authors worry that anthropogenic global warming will cause in a more sustained fashion the same food shortages and higher prices that trigger civil wars during El Nino. My guess is global warming won't be needed for that outcome.
In recent years, historians and climatologists have built evidence that past societies suffered and fell due in connection with heat or 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 study does not blame specific wars on El Niño, nor does it directly address the issue of long-term climate change. However, it raises potent questions, as many scientists think natural weather cycles will become more extreme with warming climate, and some suggest ongoing chaos in places like Somalia are already being stoked by warming climate.
In a less globalized world with less transportation food shortages were a more local phenomenon. Today with a global food market that's changed.
"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."
Climate changes cause changes in food supplies, and therefore in food prices. Higher food prices are probably the biggest mechanism by which civil war risks are stoked. But I do not yet think that global warming as caused by carbon dioxide emissions is a major factor driving civil wars. High food prices have other causes.
Marco Lagi, Karla Z. Bertrand and Yaneer Bar-Yam of New England Complex Systems Institute have published a paper showing the 2007-2008 food price spike and the 2010-2011 food price spike both are highly correlated with civil unrest and food riots. See the graph on the 3rd page (or here and here). Arab Spring a result of social networking web sites bringing down big meanie dictators? Nope. It is about people suddenly pressured to get money for their next meal. The authors predict a shift toward higher long term food prices with prices staying above the threshold for unrest by 2012 or 2013. So we could be at the beginning of a long term uptick in the frequency of of wars and revolutions.
A persistence of global food prices above this food price threshold should lead to persistent and increasing global unrest. Given the sharp peaks of food prices we might expect the prices of food to decline shortly. However, underlying the peaks in Fig. 1, we see a more gradual, but still rapid, increase of the food prices during the period starting in 2004. It is reasonable to hypothesize that when this underlying trend exceeds the threshold, the security of vulnerable populations will be broadly and persistently compromised.
If we really are heading into an era of sustained higher food prices then future food price spikes will start from higher base prices and the spikes will cause even greater political upheavals.
The price spikes and long term trend of rising food prices are driven by Asian economic development, rising energy and fertilizer costs, and population growth. Population growth lower the ratio of land to people. Bigger populations use more water and leave less for agriculture. The people of the poorer countries might find themselves unable to compete for food with large industrialized populations. The recent spikes in civil wars and uprisings might be more than a temporary blip.
|Share |||Randall Parker, 2011 August 25 11:42 PM Trends Human Conflict|