Climate change is increasingly becoming a cause of armed conflict. That is the central finding of research by Mehdi Shiva, to be presented at the Royal Economic Society''s annual conference in Brighton in March 2016.

His study finds that regions where the temperature has risen by 1oF over the last 30 years are 1.6% more likely to see violence and conflict. This effect is twice as strong when looking just at countries that experienced at least one conflict between 1961 and 2011.

The research also examines other causes of strife and finds that rising incomes only make violence less likely in countries that are already fairly stable; otherwise, it is possible that insurgents end up with enough money to afford to rebel. This suggests that severe misery – that might be brought about by climate change – actually discourages rebellion.


• Climatic factors have a causal effect on armed conflicts.
• The effect of climate change is larger if the country experienced a conflict before or has an unfavourable climate.
• Severe misery – that might be caused by climate change – could discourage rebellion.

There is solid evidence that our planet is getting warmer, and this affects not only our surrounding environment, but also us as human beings. This study uses a wide range of controls and approaches to argue that climatic factors – especially temperature – have a causal effect on armed conflicts.

A 1oF positive increase in temperature''s deviation from its past 30 years'' average and its growth from the previous year increases the chance of getting into a conflict by 1.6% and 0.79% respectively. Limiting the study to countries that experienced at least one conflict during the period 1961-2011, the effects double – to 3.3% and 1.5%.

Considering that 1oF higher annual temperature is associated with a 0.23% higher risk, an instant change in temperature has a larger effect on the probability of an onset compared to a general one. This may be due to an adaptation mechanism that could improve people''s resilience over time.

Furthermore, these effects are approximately 6.2% and 2.5% larger in hot and mild areas compared with cold ones, respectively. Also, 1000mm fall in annual rainfall – compared to average climate – would rise the chances of getting into a conflict by 3.3% in average, and 6.6% if the country experienced a conflict in the past. Such results suggest that there is a higher risk of getting into a conflict for vulnerable countries – in terms of climatic conditions or a history of past conflicts.

Moreover, a rise in average incomes only lowers the probability of conflicts in countries with relatively stable governments. Otherwise, it could really escalate the chances of getting into one; for example, insurgents could afford to rebel when they have enough money to overcome basic needs. This is different from the usual ''Opportunity cost'' models linking economic prosperity and conflicts, which denotes that participation in rebellion should decrease as income rises.

There is a ''Flight Theory'' in psychology, which could be adopted here by considering an oppressed society instead of an individual, where people are under so much pressure that they cannot afford to rebel. Based on these results, severe misery could deter rebellion.

Furthermore, there is evidence supporting grievance motives, spillover effects and relevance of perceived heat with armed conflicts; for example, a 50% higher chance of getting into a conflict if your neighbour is at one already.

In the end, not only the annual value of temperature and precipitation matters, but also their deviation and growth. These findings are robust to a large range of political, geographic and spatial controls as well as different methodologies. Clearly, this work does not suggest that climate is the only or even the dominant reason for any of the past conflicts, but neither is any other factor by itself.

In the author''s opinion, targeted financial assistance to the vulnerable regions should be a priority – as we know that climate change and its consequences would not be homogenous around the globe and some regions would get affected more than the others. But we should not forget that the damage could spread easily from more affected regions to the rest, through different mechanisms such as migration.