Climate change and global security: A primer

Climate change poses a significant and evolving threat to global stability and security. Beyond environmental degradation, its cascading impacts undermine economies, governance structures, and social cohesion. This primer examines the interconnections between climate change and global security, addressing its effects on migration, geopolitical relations, infrastructure, and health systems. It concludes with policy recommendations emphasizing scientific leadership, international coordination, and moral governance as essential components of global climate resilience.

Introduction

The climate crisis presents one of the greatest challenges to modern governance and international security systems. Traditionally, security threats have been characterized as kinetic — terrorism, armed conflict, or cyberwarfare. The 21st century requires a broader definition that encompasses nontraditional, slow-onset risks that transcend borders, yet they are increasingly severe and directly influence global stability.

The International Court of Justice recently recognized climate change as an urgent and existential global threat — a common concern of humankind. The United States recently withdrew from the world’s largest climate fund (the Green Climate Fund) and reversed the 2009 “endangerment finding,” which had set limits on greenhouse gas emissions. The Doomsday Clock, as reported in the Bulletin of Atomic Scientists, is now 85 seconds before midnight, partly due to climate change.

Addressing climate change is not solely an environmental or economic issue — it is a strategic and moral imperative for global security.

Background

We are living in a period of profound political and social instability that often distracts from addressing the climate crisis. Across the world, the rise of autocracies and the decline of ethical leadership have undermined coordinated global action. Currently 72 percent of the global population is under autocracy. In the United States, heightened domestic unrest and institutional fragility — masked federal law enforcement, over 200 immigrant prison camps or detention centers, violations of the rule of law, human rights violations including without due process, and other autocratic efforts — further divert attention. While these command our immediate attention and action, they also complicate attention to climate change. Conservative columnist George Will has called this a “sickening moral slum of an administration”.

At the World Economic Forum 2026 in Davos, this global disarray was described as a rupture in multilateral cooperation, a condition that weakens collective capacity for climate action. Meanwhile, climate change continues to generate natural disasters, resource scarcity, forced migration, and social conflict — phenomena that directly threaten international stability. Excellent background material can be found at Alleman1, Alleman2, and a 1982 EXXON Report.

While the complexity and interconnection of Earth’s functions make precise forecasting difficult, the scale of the climate change challenge is so vast, the risks so complex, and so many actors involved, that we have never dealt with such a multifaceted risk before. Moreover, it is an intergenerational issue. The goals set in Paris aren’t just targets — they’re a fragile path through systematic chaos.

This primer does not cover other key climate change impacts to areas such as biodiversity, ecosystems, pollution, poverty, mental health, soils, erosion, landslides, desertification, declining organic matter, and coastal salinization.

Increasing risks

Some scientists classify climate-related effects into three categories: settled and certain, limited evidence and low agreement, and uncertain.

Settled and certain: Rising CO₂ concentrations, global temperature increases, intensifying heat waves, and accelerating sea-level rise.

Limited evidence and low agreement: Increased heavy rainfall, floods, droughts, and wildfires.

Uncertain: Changing tornado frequencies, large-scale ice-sheet collapse, and permafrost carbon release.

While some impacts are uncertain or not fully settled, this does not mean they are unaffected by climate change. Ongoing research continues to clarify and quantify their potential impacts.

The World Economic Forum ranked climate-exacerbated extreme weather events as the world’s most significant risk over both short- and long-term horizons. Seven of nine critical Earth system “tipping points” have also been crossed

In 2024, average global temperatures surpassed 1.5°C (2.7°F) above pre-industrial levels — a milestone that signals escalating danger. Without substantial emissions reductions, global warming could exceed 2°C (3.6°F) before 2050. These projections vary across models, but the scientific consensus underscores the magnitude of the challenge: interconnected, systemic, and unprecedented in human history.

Global security threats

Climate change as a “threat multiplier”

The CNA Military Advisory Board (2007) was one of the first to identify climate change as a threat multiplier, aggravating social, economic, and political vulnerabilities. The Intergovernmental Panel on Climate Change (IPCC, 2023) warns that rising global temperatures will intensify food and water scarcity, exacerbate disasters, and strain governance. These dynamics threaten fragile states and heighten the risk of conflict over essential resources. Climate-related shocks can reduce trust in government, expose corruption, and restrict the government’s ability to deliver basic services. When institutional capacity is limited, local conflicts over land and resources can quickly escalate and spill over borders, affecting regional stability.

The U.S. National Intelligence Estimate on Climate Change (2021) echoed these warnings, projecting rising geopolitical tensions over the energy transition, competition for critical minerals, and the opening of Arctic routes due to sea-ice loss.

Climate-induced migration and border pressures

Climate-induced migration poses increasing challenges for global security. As heat waves, droughts, and sea-level rise make regions uninhabitable, millions may be forced to relocate. The World Bank (2021) projects that, without effective intervention, more than 200 million people could be displaced by 2050.

Historical precedent underscores these risks. The 2015 European migration crisis, largely attributed to conflict in Syria, was worsened by prolonged drought and food insecurity. Such refugee movements reshape regional politics, fuel extremism, and strain migration governance systems. Migration flows often connect with smuggling, trafficking, and other transnational crimes, making response strategies more complex. Meanwhile, public opinion in receiving countries may turn hostile, raising the risk of domestic unrest and xenophobia.

Current international law provides inadequate protection for climate-displaced persons, as the 1951 Refugee Convention does not recognize environmental causes of displacement, leaving climate migrants in legal limbo. Thus, the modernization of legal frameworks is urgent and essential.

Geopolitical implications

Climate change is transforming global power dynamics. The Arctic exemplifies this shift: melting ice is unlocking new maritime routes and exposing untapped energy and mineral reserves. These developments carry implications for trade, energy exploration, and military and civil operations.

As economies transition away from fossil fuels, petrostates — particularly in the Middle East and Central Asia—face potential instability. Uncoordinated transitions could destabilize entire regions reliant on oil revenues to sustain public services and political legitimacy.

Infrastructure and operational disruptions

Climate change degrades critical infrastructure — including roads, bridges, runways, rail lines— and impairs operational readiness. High temperatures can weaken pavements and rail systems, while floods and wildfires threaten energy grids, supply chains, and transportation networks. Increases in ocean acidification and sea-surface temperature changes may require maritime vessels to undergo more frequent maintenance. 

Military and humanitarian operations must adapt to environmental constraints — necessitating civil–military partnerships for disaster response and resilience planning.

Exacerbating existing conflicts

Climate change can heighten geopolitical tensions as countries pursue and defend their interests through societal, economic, and environmental pressures that can worsen or trigger conflicts. These pressures can magnify existing stresses — competition for scarce resources, migration, livelihood disruptions, and governance fragility — and can trigger social unrest and cross-border conflict, particularly in fragile or resource-dependent states.

Public health and disease risk

Rising global temperatures increase cardiovascular and respiratory illness deaths and illnesses, reshape infectious disease patterns, boost pathogens and vectors, and cause malnutrition due to declining agricultural productivity and crop failures. Recent outbreaks of several emerging infectious diseases have caused significant death and illness, and the frequency of these outbreaks is expected to rise because of pathogen, environmental, and population factors influenced by climate change. These combined pressures threaten human security and health.

Food and water insecurity

Climate change undermines global, regional, and local food security by disrupting availability, production, access, supply, and distribution. This can lead to increasingly damaging outcomes, particularly by 2100, with higher global warming. Risks extend beyond agricultural production to other parts of the global food system, including processing, transportation, and consumption. Droughts in the Horn of Africa have devastated crops and livestock, contributing to hunger and recruitment by extremist groups such as al-Shabaab.

Similarly, shifting precipitation patterns and rising demand are worsening global water scarcity. More than 2 billion people now live in water-stressed regions. Decreasing access to freshwater can be a persistent source of domestic and international tension, especially where rival nations share transboundary rivers.

Policy recommendations

Addressing the security implications of climate change requires integrated, science-based policies that link environmental sustainability, economic stability, and peacebuilding.

1. Integrate climate risk into security strategies: Embed environmental risk considerations into doctrines, policies, defense strategies, intelligence assessments, infrastructure planning, supply chains, and the economy.

2. Invest in climate-resilient infrastructure: Strengthen critical systems through sustainable materials, design, practices; renewable energy adoption and resources; protection initiatives to protect against rising sea levels, flooding, wildfires, and heat waves.

3. Enhance interagency and international coordination: Foster cross-sector collaboration — among defense, diplomatic, environmental, intelligence, and development institutions — to address shared vulnerabilities and governance.

4. Expand humanitarian and disaster response capabilities: Improve readiness for climate-related emergencies through pre-positioned supplies, enhanced logistics, and regional response frameworks with local, regional, and international partners.

5. Plan for climate-induced migration: Establish legal and policy frameworks recognizing environmental displacement, with relocation and adaptation assistance. This involves establishing relocation pathways, investing in adaptation efforts for vulnerable communities, and updating asylum policies to address environmental displacement. Local, regional, and international collaboration is crucial to prevent unilateral border closures and humanitarian crises.

6. Develop climate intelligence and early warning systems: Utilize climate-aware intelligence gathering and risk assessment through satellite monitoring, data analytics, and predictive modeling to guide strategic decisions and prevent crises. This information should be shared locally, regionally, and internationally.

7. Lead in decarbonization and sustainable energy practices: Transition to renewable energy sources such as solar and wind, incorporate hybrid or biofuel technologies, and encourage green initiatives to lower vulnerabilities and demonstrate leadership on climate action.

8. Support climate-resilient development in fragile states: Prioritize sustainable agriculture, conflict prevention, and governance reforms to reduce long-term risks of instability. This involves investing in water management, sustainable agriculture, conflict resolution mechanisms, and community-based adaptation. These efforts help lower the risk of state failure.

9. Reinvigorate scientific leadership: Invest in climate science and innovation. As the National Academies (2024) president warned, falling behind in research endangers both environmental and national security. Science is the very foundation of security, understanding, and addressing climate change. Without it, we are adrift, posing increased risks to global security and climate efforts. Reports indicate that 75% of U.S. scientists are now seeking opportunities abroad, likely a result of the United States autocratic trend.

Conclusion

Climate change is a defining security challenge of the 21st century. Its cascading impacts — rising temperatures, mass migrations, and resource scarcity — are destabilizing nations and straining global governance.

While ruptures in global systems are at play, the path forward relies on moral leadership, scientific progress, and sustained local, regional, and international cooperation. Ensuring a livable and secure planet is an ethical duty shared by all nations. 

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