A security threat assessment of global climate change: How likely warming scenarios indicate a catastrophic security future

This report is a first of its kind, bringing together a panel of security professionals to analyze the security implications of two future warming scenarios (near term: 1-2°C and medium-long term: 2-4+°C). It identifies major threats, including heightened social and political instability, and risks to U.S. military missions and infrastructure, as well as security institutions, at both warming scenarios and across all regions of the world. Key findings and recommendations include:

Key findings

1. A near-term scenario of climate change, in which the world warms 1-2°C/1.8-3.6°F over pre-industrial levels by mid-century, would pose ‘High’ to ‘Very High’ security threats. A medium-to-long term scenario in which the world warms as high as 2-4+°C/3.6-7.2°F would pose a ‘Very High’ to ‘Catastrophic’ threat to global and national security. The world has already warmed to slightly below 1°C compared to pre-industrial temperatures. 

2. At all levels of warming (1-4+°C/1.8-7.2+°F), climate change will pose significant and evolving threats to global security environments, infrastructure, and institutions. 

3. While at lower warming thresholds, the most fragile parts of the world are the most at risk, all regions of the world will face serious implications. High warming scenarios could bring about catastrophic security impacts across the globe.

4. These threats could come about rapidly, destabilizing the regions and relationships on which U.S. and international security depend. 

5. Climate change will present significant threats to U.S. military missions across all of its geographic areas of responsibility (AORs), as well as to regional security institutions and infrastructure that are critical for maintaining global security.

Key recommendations

1. Mitigating these risks requires quickly reducing and phasing out global greenhouse gas emissions. This is a call for the world to achieve net-zero global emissions as soon as possible in a manner that is ambitious, safe, equitable, and well-governed, in order to avoid severe and catastrophic security futures.

2. The world must also “climate-proof” environments, infrastructure, institutions, and systems on which human security depends, and so this report calls for rapidly building resilience to current and expected impacts of climate change. With future-oriented investments in adaptation, disaster response, and peacebuilding

3. In the United States, it is needed a renewed efforts to prioritize, communicate, and respond to climate security threats, and to integrate these considerations across all security planning.