LONDON, June 9 (Thomson Reuters Foundation) - Food shortages caused by climate shocks like drought or floods could exacerbate violence and riots in politically unstable countries, researchers say.

Fragile states that are poor and depend heavily on agriculture are most at risk of violent uprisings since they struggle to cope with climate change, according to a study published this week in the Journal of Peace Research.

“We’ve already started to see climate change as an issue that won’t just put the coasts under water, but as something that could cause food riots in some parts of the world,” said study co-author Bear Braumoeller from The Ohio State University.

The last time the world saw a severe food crisis was in 2007 and 2008, when extreme weather events hit major grain producing regions the year earlier, causing spikes in the demand and cost of food.

The higher prices led to social and political unrest in Morocco, Bangladesh, Tunisia and Indonesia, according to a 2016 report by Global Footprint Network and United Nations Environment Programme.

Drought is becoming more frequent and severe in places like eastern and southern Africa, and that – combined with the recent El Nino phenomenon – is taking a heavy toll on rural lives and economies.

Last April, a rice farmer in the Philippines was killed during protests demanding government assistance after drought linked by some to El Nino hit hundreds of thousands of hectares of farmland.

El Nino, a warming of ocean surface temperatures in the eastern and central Pacific that typically occurs every few years, is linked to crop damage, fires and flash floods.

Moreover, the US-based Center for Climate and Security on Friday said factors like global water shortages, displacement or migration caused by climate change, and rising sea levels also posed serious threats to international security.

Braumoeller said having a stable government was key to placating growing civil unrest and violence in the face of food shortages caused by climate change.

“A capable government is even more important to keeping the peace than good weather,” he said in a statement. “Less vulnerable countries can better handle the problems that droughts or food price fluctuations create.”

Braumoeller said fragile states needed to address instability and invest in sustainable, “greener” industries to increase their economic growth, in order to cope with food shortages due to climate change.

"Development aid is important now and it is likely to be even more important in the future as we look for ways to increase climate resilience," he said. (Reporting by Lin Taylor @linnytayls, Editing by Ros Russell; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters that covers humanitarian issues, conflicts, global land and property rights, modern slavery and human trafficking, women's rights, climate change and resilience. Visit news.trust.org to see more stories)