By Kate Roff
Today's wars are often attributed to ethnic conflict or extremism, but environmental factors could also be behind tensions.
South Sudan's conflict has raised fears of genocide, with over 1.6 million refugees fleeing the country, but the region has also faced increased temperatures and a lack of rainfall. The UN has recently declared the country a famine zone.
It's not the only conflict zone battling environmental extremes, and growing research suggests there's a link. Water shortages in Yemen have been blamed for tension there, and severe drought is believed to have contributed to Syria’s war.
One study found that for each 1 standard deviation change in climate - towards warmer temperatures or more extreme rainfall - caused the frequency of inter-group conflict to rises by 14%. Last year, another group of scientists showed that climate disasters like heat-waves or droughts enhance the risk of armed conflicts in countries with high ethnic diversity. With the Earth's temps expected to increase 7.2 deg F (4 deg C) this century, this could pose a serious threat to peace around the world.
Linking climate and conflict is a controversial issue. Some scholars warn that inflating the links between conflict and climate change could be damaging to both areas of study. However, evidence on the ground appears to be increasing.
"The stories we get in America, or in New Zealand, I suppose - tend to have more to do with the melting of the ice caps, to do with climate change,” said Timothy Fadgen, from World Vision.
“One of the biggest things I have found, through review of my reports, has been the disruptions to subsistence farming, caused by droughts," he said.
"So it's critical that normal rain patterns exist in order for people to even have enough to grow to eat, never mind to grow to trade."
For post-conflict communities, scarce resources can also re-ignite fighting.
"If you have a large number of people that are in the process of being re-socialized, from having basically been part of an organization that would go and loot, and rob, and kill to get what it wants - you know, it's a battle," Mr Fadgen said.
"When people are extremely poor, and pushed to the brink, things happen that you wish wouldn't, and we are in a position now to do our best to ensure that it doesn't happen," he said.