The heatwaves, droughts and other natural disasters expected to increase because of global warming are helping to push countries into armed conflict, particularly those already split along ethnic lines

Heatwaves, droughts and other severe weather events are increasing the risk of wars breaking out across the world, scientists say they have proved.

The researchers carried out a statistical analysis of the outbreak of armed conflicts and climate-related natural disasters between 1980 and 2010.

Their findings – that nearly one in four conflicts in ethnically divided countries coincided with “climatic calamities” – suggest that war should be added to the usual list of problems likely to be caused by global warming, such as sea level rise, crop failures, water shortages and floods.

Environmentalists have warned that if temperatures rise significantly over the next century, large areas of the planet could become uninhabitable, forcing millions of people to migrate elsewhere and significantly increase the risk of conflicts breaking out.

But the new research, by academics in Germany, found there was already a statistical link between outbreaks of widespread violence and extreme weather events.