Climate change poses “immediate risks” to national security and will have broad and costly impacts on the way the US military carries out its missions, the Pentagon said in a new report on the impact of climate change released on 13 October.

The Defense Department said in the report, described as a “Climate Change Adaptation Roadmap," that it has begun to boost its "resilience" and ensure mission readiness is not compromised in the face of rising sea levels, increasing regularity of natural disasters, and food and water shortages in the developing world.

In a statement, US Defence Secretary Chuck Hagel called global warming a “threat multiplier,” saying rising seas and increasing numbers of severe weather events could exacerbate the dangers posed by threats ranging from infectious disease to terrorism:

In two months, the United Nations will convene countries from around the world here in Peru to discuss climate change. Defense leaders must be part of this global discussion. We must be clear-eyed about the security threats presented by climate change, and we must be pro-active in addressing them.

Christiana Figueres, UNFCCC Executive Secretary, said in response to the report:

There is no doubt that runaway climate change threatens the long term national security of many countries as well as the overall stability of the world.

Military leaders will be faced with ever more tough decisions in terms of providing humanitarian assistance in the face of extreme weather events and disruptions to their own supply chains while coping with declining defense budgets in many parts of the globe.  It is therefore critical that military leaders become aware of the risks and start to engage in providing solutions.  I welcome the clear statement to this effect from Secretary Hagel.

Read the report

Read speech by US Secretary of Defense Chuck Hagel

The Center for Climate and Security, a policy institute with an advisory board of retired senior military officers and national security experts, said in a statement it concurred with the roadmap's assessment and urged policymakers to follow the military's lead.

In November 2013, Defense Secretary Hagel also released a new Defense Department strategy for the Arctic, identifying climate change and rising seas as key issues in changes there.

In May, the CNA Military Advisory Board issued a report highlighting the accelerating risks of climate change for national security. This was an update of the Board's 2007 report, the first major study to draw the link between climate change and national security. The report’s authors said the biggest change in the seven years between the two studies was the increase in scientific certainty about global warming, and of the link between global warming and security disruptions.

In September, heads of State and Government attending the Wales Summit of the North Atlantic Council (NAC), the principal political decision-making body of NATO, declared that climate change and increasing energy needs will shape the Organization's future security environment and could significantly affect its planning and operations.

Institutions such as the OSCE and the IES are also addressing the issue. According to experts like Rear Admiral Neil Morisetti, the former UK Foreign Secretary's Special Representative for Climate Change, the impact of climate change needs to be considered far more of a mainstream issue, and the implications factored into security and economic strategies in the same way that other threats to prosperity and stability are.

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UN Secretary-General Ban Ki-moon has also been vocal on the subject of climate change and security. In a speech at the 50th Munich Security Conference held in January in the Bavarian capital, he said that "Climate change is every much a security threat as an armed group bent on plunder". 

Read UN security council statement on security and climate change

Speech by UNEP Executive Director Achim Steiner at security council debate

Main photo by Roger Wollstadt

Hornet fighter photo by Greg Bishop