1 August 2013 (Last updated at 19:34 ET)

 

By Rebecca Morelle, Science reporter, BBC World Service

 

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The researchers believe that war and personal conflicts are links to shifts in climate

Shifts in climate are strongly linked to increases in violence around the world, a study suggests.

 

US scientists found that even small changes in temperature or rainfall correlated with a rise in assaults, rapes and murders, as well as group conflicts and war.

 

The team says with the current projected levels of climate change, the world is likely to become a more violent place.

 

The study is published in Science.

 

Marshall Burke, from the University of California, Berkeley, said: "This is a relationship we observe across time and across all major continents around the world. The relationship we find between these climate variables and conflict outcomes are often very large."

 

The researchers looked at 60 studies from around the world, with data spanning hundreds of years.

 

They report a "substantial" correlation between climate and conflict.

 

Their examples include an increase in domestic violence in India during recent droughts, and a spike in assaults, rapes and murders during heatwaves in the US.

 

The report also suggests rising temperatures correlated with larger conflicts, including ethnic clashes in Europe and civil wars in Africa.

 

Biological root?

 

Mr Burke said: "We want to be careful, you don't want to attribute any single event to climate in particular, but there are some really interesting results."

 

The researchers say they are now trying to understand why this causal relationship exists.

 

"The literature offers a couple of different hints," explained Mr Burke.

 

"One of the main mechanisms that seems to be at play is changes in economic conditions. We know that climate affects economic conditions around the world, particularly agrarian parts of the world. And there is lots of evidence that changes in economic conditions affect people's decisions about whether or not to join a rebellion, for example."

 

But he said there could also be a physiological basis, because some studies suggest that heat causes people to be prone to aggression.

 

"It is a major priority for future research to distinguish between what is going on in each particular situation."

 

The scientists say that with the current projected levels of climate change the world is likely to become a more violent place.

 

They estimate that a 2C rise in global temperature could see personal crimes increase by about 15%, and group conflicts rise by more than 50% in some regions.

 

However, other researchers have questioned whether climate breeds conflict.

 

Work published in the Proceedings of the National Academy of Sciences suggested that this environmental factor was not to blame for civil war in Africa.

 

Instead, the conflict was more highly correlated with other factors, such as high infant mortality, proximity to international borders and high local population density.

 

'13-08-02, 01:28   Charles Chandler Baltimore, MD

Re: Rise in violence 'linked to climate change'   I really don't like the sound of this. The whole issue of global warming is arguably just one big political agenda. I thought that they just wanted to blame rising energy costs on the Arabs, so fewer people would think to ask why energy taxes keep increasing. Now they're saying that global warming will also increase violence. There are other causes for violence, such as economic hardships, which usually have more to do with politics than the environment. They apparently think that global warming can be used to hide any political problem they want. The frightening part of this is that they're telling us to expect more violence. They cite "a spike in assaults, rapes and murders during heatwaves in the US", and then tell us that a 2 °C global increase in temperature will trigger a 15% increase in personal violence, and a 50% increase in group conflicts. A heatwave is a lot more than 2 °C above normal, and the "spikes" that result are a lot less than 15%. So that's ridiculous, but the part of it that is real is that they're telling us to expect it, which means that they expect it, and plan to blame it on global warming. So why do they expect it? They know something that we don't. And whatever that is, it cannot possibly be good.

'13-08-14, 19:08   Lloyd St. Louis area

Re: Rise in violence 'linked to climate change' The global warming scare seems to be part of a major trend toward a fascist police state as outlined at Major Trends, Good & Bad. And my partial answer to that is Total Solution: Concerns-Based Consensus.