CHENNIMALAI, India – There is river and beach sand aplenty in Tamil Nadu. At 130,000 square kilometers (50,200 square miles), the state is about the same size as Nicaragua and has 95 rivers with sandy bottoms and a long Bay of Bengal shoreline. Or did. For almost all of its thousand-year history, the state of Tamil Nadu took all that sand for granted. No longer.

“A lack of U.S. government support for the Paris climate agreement will mean that the United States will further isolate itself from international collaboration and cooperation on multiple fronts. It will affect U.S. security, the provision of jobs; U.S. business operations, and U.S. diplomatic efforts. The agreement, because it has a broad basis of support, will continue with or without the United States.”

In a recent article for New Security Beat, Colin Walch made the case that the abandonment of some communities in Mali to deal with climate change on their own has created “fertile ground” for jihadist recruitment. In a similar argument, Katharina Nett and Lukas Rüttinger in a report for adelphi asserted last month that “large-scale environmental and climatic change contributes to creating an environment in which [non-state armed groups] can thrive and opens spaces that facilitate the pursuit of their strategies.”

In 1981, Nobel Laureate Amartya Sen noted that “starvation is the characteristic of some people not having enough food to eat. It is not the characteristic of there being not enough food to eat.” Sen was referring to the idea that hunger is not always related to food supply; even in places where ample food exists, many people do not have regular access to it. Yet, more than three decades later, research into the effects of agriculture on armed conflict is still focused much more on the former than the latter.

The epicenter of violence in the unstable country of Mali has historically been in the north, a contested region from where Touareg separatist and jihadist armed groups launched an insurgency against the state in 2012. But over the last two years, there has been a marked shift in communal and anti-state violence to the central region, and climate change may have played a role.

Almost three decades ago, at a conference at the Woods Hole Institute, oceanographer John Martin said with “a half a tanker of iron…I will give you the next ice age.”

Terrorist groups such as the Islamic State and Boko Haram have been dominating the headlines since 2013.  Both groups have gained international notoriety for their ruthless brutality and their rise is posing new challenges for national, regional, and international security. Such non-state armed groups (NSAG) are not a new phenomenon. Today, however, we can observe an increasingly complex landscape of violent actors with a range of hybrid organizational structures and different agendas that set them apart from “traditional” non-state actors and result in new patterns of violence.