Climate change and security

The Intergovernmental Panel on Climate Change (IPCC) has stated global warming is making extreme weather events, such as heatwaves, droughts, and extreme rainfall, more frequent and intense worldwide. This amplifies a variety of potential security risks domestically and overseas, including food, water, and biosecurity risks. 

The security implications of climate change arise due both to its direct impacts and measures taken to address it. Disasters affect critical infrastructure, such as power and food systems, and disrupt global supply chains, which cross borders and amplify risks overseas. Migration and conflict may be exacerbated by climate impacts, and the security outcomes in every case depend on the resilience of the affected societies. Energy transitions create other security risks by changing geopolitical relationships and creating dependencies on different material resources. A new global approach to security is required if effective responses to such interconnected climate risks are to be developed and poorly implemented adaptation measures that can increase climate risks avoided.

However, more effective menagement of the security implications of climate change may present opportunities.  New tools and approaches can be used to identify opportunities and manage risks, including a range of new technologies and risk analysis methods, such as Machine Learning, agent-based modelling and scenario-focused decision analysis. Building general resilience to disruption at home and overseas also reduces climate risks. Reducing overseas risks may require effective international development, which links defence, development and diplomacy. This involves co-creating development measures locally, collaborating across disciplines to understand complex systems, and building trusted institutions. 

Key messages 

• Climate change has impacted health, livelihoods, wildlife, infrastructure, and economies across the world. The globalised economy can propagate these impacts, exacerbating challenges in other regions. 
• Both mitigating and adapting to climate change brings risks and opportunities. For example, transitioning to renewable energy technologies provides opportunities for diplomacy and economic growth. 
• Deep uncertainties in complex risks limits the predictive capacities of new technologies such as Machine Learning. 
• Decision making under uncertainty requires intelligence on local contexts, expert input, and scenario-building exercises. 
• Building general resilience across complex systems reduces these risks. Best practice principles could guide institutional processes and its governance at different levels. 

Acknowledgments

POSTnotes are based on literature reviews and interviews with a range of stakeholders and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:

Members of the POST board* 

Samira Barzin, University of Oxford 

Tugba Basaran, University of Cambridge* 

Tim Benton, Chatham House 

Richard Black, Imperial College London 

Alex Clark, University of Oxford* 

Duncan Depledge, Loughborough University* 

Sherri Goodman, The International Military Council on Climate and Security* 

Weisi Guo, Cranfield University* 

Alexandra Harrington, Lancaster University 

Rowena Hill, Nottingham Trent University 

Scott Hosking, British Antarctic Survey 

Matthew Ince, Ministry of Defence* 

John Ingram, University of Oxford  

Lenny Koh, University of Sheffield* 

Tim Lenton, University of Exeter* 

Sam Loni, University of Oxford* 

Erik Mackie, University of Cambridge 

Neil Morisetti, University College London* 

Max Nathanson, University of Oxford* 

Richard Nugee, Ministry of Defence 

Richard Pickford, Nottingham Trent University 

Edward Pope, Met Office* 

Mark Workman, Imperial College London* 

*denotes people and organisations who acted as external reviewers of the briefing.