Climate reveals war risk study

Wars and civil conflicts are twice as likely to occur during years affected by the El Nino climate-warming phenomenon, a study suggests.

The naturally recurring weather system, which boosts temperatures and cuts rainfall over a broad swathe of the globe every three to seven years, doubles the risk of civil wars across many countries in the tropics, a remarkable statistical analysis by American scientists shows.

The researchers suggest El Nino may help account for a fifth of worldwide conflicts during the past half-century although the exact mechanism remains unclear.

The study, in the journal Nature, claims to be the first demonstration that the stability of modern societies relates strongly to the global climate. Its implication, in the context of continuing man-made climate change, is that the world may be facing more turbulent times still.

At its heart is El Nino, the periodic warming of the waters of the eastern tropical Pacific, given its name - "the Christ child" in Spanish - because its onset is often observed just before Christmas.

El Nino leads to warmer conditions and droughts across many parts of the tropics including Africa, the Middle East, India, Southeast Asia, Australasia and the Americas.

It is one half of the Southern Oscillation, the other half being La Nina, which conversely is a cooling phenomenon marked by more plentiful rainfall over the areas affected; the two together are known as Enso (El Nino-Southern Oscillation).

The researchers, from Columbia University in New York, compared more than half a century of Enso data with the history of conflicts in the tropics from 1950 to 2004 which killed more than 25 people in a given year. The data included 175 countries and 234 conflicts, more than half of which each caused more than 1000 battle-related deaths.

For nations whose weather is controlled by Enso, they found that during La Nina, the chance of civil war breaking out was about 3 per cent, whereas during El Nino, the chance doubled, to 6 per cent. (Countries not affected by the cycle remained at 2 per cent.) Overall, the team calculated that El Nino may have played a role in 21 per cent of civil wars worldwide over the past 50 years, although they stressed the study does not show that wars are started by weather alone.

"But if you have social inequality, people are poor, and there are underlying tensions, it seems possible that climate can deliver the knockout punch," said Dr Solomon Hsiang, the study's lead author.

"When crops fail, people may take up a gun simply to make a living."

Poorer countries appear to be tipped into chaos more easily by bad weather; that of rich Australia, for instance, is controlled by Enso, but the country has never seen a civil war. But on the other side, at least two countries, said Hsiang, "jump out of the data".

In 1982, a powerful El Nino struck impoverished highlands Peru, destroying crops, and simmering guerrilla attacks by the revolutionary Shining Path turned into a 20-year civil war that is still sputtering today.

Similarly, forces in southern Sudan were facing off with the domineering north, when warfare broke out in the El Nino year of 1963.

The insurrection flared again in 1976, another El Nino year. Then, in 1983 came a major El Nino and the cataclysmic outbreak of more than 20 years of fighting which killed two million.

Hsiang said other countries where festering conflicts have tended to blow up during El Ninos include El Salvador, the Philippines and Uganda (1972); Angola, Haiti and Myanmar (1991); and Congo, Eritrea, Indonesia and Rwanda (1997).

WEATHER LINK

La Nina:
Cool, rainy
3pc chance of civil war

El Nino:
Warm, dry
6pc chance of civil war

Countries not affected by the cycle:
2pc chance of civil war.

- Independent