The climate crisis is not just an environmental challenge—it is a profound threat to global stability, touching every aspect of society, from livelihoods and health to governance and peace. As its impacts grow in frequency, intensity, and cost, the links between climate change and security are becoming increasingly clear. Extreme weather events, resource scarcity, and forced displacement are drivers of instability that ripple across borders, affecting human security, national resilience, and international relations. Germany has been at the forefront of efforts to broaden the understanding of security to include the risks posed by climate change. By framing climate impacts as a matter of human, national, and international security, Germany and other European countries aim to galvanize action at all levels (see Germany’s National Security Strategy 2023 and EU 2023). However, this approach has not been without controversy. Some emerging economies have expressed concerns about framing climate change as a security issue, warning of potential unintended consequences such as the marginalization of vulnerable groups or the securitization of climate governance.
This article starts by synthesizing findings from Germany’s National Interdisciplinary Climate Risk Assessment. It then explores critical debates surrounding the securitization of climate change, highlighting both the opportunities and risks of this framing. Finally, it looks toward the future, proposing how Germany and Brazil—two nations with distinct yet complementary roles in global climate policy—can work together to strengthen resilience, foster equitable development, and advance a global response to the intertwined crises of climate and security.
The Global Climate-Security Nexus
We are already living through the climate crisis, and it is set to worsen before it might get better–provided we prioritize ambitious climate policy measures. Global warming is accelerating: while temperatures rose at about 0.18°C per decade from 1970 to 2008, the current rate has increased to approximately 0.3°C per decade (Hausfather 2024). Hence, we find ourselves in uncharted territory. This has given rise to a policy nexus now often dubbed climate, peace and security (UN). Pacific Island countries have been among the most vocal on this issue. Their Boe Declaration on Regional Security unequivocally “reaffirm[s] that climate change remains the single greatest threat to the livelihoods, security and wellbeing of the peoples of the Pacific” (Pacific Island Forum Leaders 2018). The African Union has similarly (and repeatedly) “acknowledged inextricable link between climate change, peace and security in Africa” (AU 2016) and is in the process of finalizing a Common African Position on Climate, Peace and Security ahead of COP 30 (Amani Africa 2025). European countries have pushed this issue in the UN Security Council, where it has gained currency but not consensus, repeatedly becoming a key point of contention among its members (see here for a short history, see here for the key issues).
What security risks do Europeans, and Germany in particular, see emanating from the climate crisis? To explore this, the subsequent paragraphs will summarize Germany’s National Interdisciplinary Climate Risk Assessment, published earlier this year at the Munich Security Conference (Metis Institute et al. 2025). The assessment identifies three national security risks to Germany emanating from the climate crisis: firstly, direct climate impacts in Germany and the EU. Secondly, impacts elsewhere in the world that have direct implications for Germany and the EU. Thirdly indirect impacts that undermine the global system upon whose predictability and stability ultimately rely, as well as Germany’s prosperity and security.
Category 1: Direct Impacts: Germany and the EU Under Pressure. Germany is affected by an increasing amount of extreme weather events. They caused up to 145 billion euros of damage over the first two decades of this century, with some 1,400 deaths per year (Prognos et al. 2022). At the same time, Germany is also increasingly affected by droughts, which harm sectors like agriculture, (fluvial) transport, energy production (from cooling water shortages), and damage ecosystems. Moreover, heat is increasingly becoming a risk for health and productivity even in Germany while global warming drives the expansion of disease vectors such as mosquito and tick species.
Category 2: Global Impacts: Ripple Effects Beyond Borders. While Germany is undoubtedly affected by the climate crisis, the impacts are not as existential as in many other countries, where more severe physical effects and limited adaptive capacity create a vicious cycle of vulnerability and fragility. Intensified competition over natural resources like water and arable land can drive migration and increase the risk of conflict, even if it does not lead to armed conflict directly. According to current mitigation pathways, modellers have calculated that, by the end of the century, between 22 and 39% of humanity will no longer live in a climate that sustains human life (Lenton 2023). The resulting strain on the governments and governance mechanisms should not be underestimated.
Category 3: Systemic Risks: Feedback Loops and Instability.Europe’s historical reliance on fossil fuels has funded autocratic regimes like Russia, undermining its own security—making the energy transition both a climate and strategic priority. However, decarbonization carries risks. It may destabilize fossil fuel-dependent states and spark new conflicts over critical minerals needed for green technologies, particularly in areas where these resources are mined (e.g., the eastern Democratic Republic of the Congo). Control over various stages of production offers significant geopolitical leverage, and the use—or perceived misuse—of this power can easily lead to misinterpretation and heightened tensions.
Domestically, climate policy can affect political cohesion—underperformance may erode legitimacy, while ambitious action can deepen divisions if framed as part of a culture war, a narrative actively promoted by hostile actors like Russia. NATO has accused Russia of being “the main driver of hostile communications in online conversations about the green energy transition on social media and web news media” since its full-scale invasion of Ukraine.
Beyond the many specific pathways in which global environmental change threatens national security, what can we take away? Firstly, the security risks of the climate crisis should not be understood too narrowly, i.e. in terms of direct impacts only. Secondly, not everything is doom and gloom. There are significant opportunities in the green transition, especially when comparing the costs of action to inaction. Germany’s Energiewende, for instance, has created over 300,000 jobs in renewables and pushed clean energy to cover more than half of electricity generation in 2023. (Umweltbundesamt 2025) Yet, while the green transition is often hailed as a panacea for economic and environmental challenges, the reality is of course more complex. The shift has also exposed vulnerabilities in the energy system, including supply chain pressures and intermittency issues, as well as higher upfront costs for businesses and consumers.
At the EU level, the European Green Deal and Fit for 55 package are mobilising vast investments—1 trillion euros by 2030—but not all regions and sectors benefit equally (European Commission 2025). Some communities face job losses in traditional industries, and the transition demands substantial retraining and social support. Nevertheless, there are concrete signs of progress: energy efficiency measures are saving households money, and the clean tech sector continues to attract investment and talent. Germany’s push for green hydrogen and battery innovation is opening new market opportunities, though these technologies are not yet fully mature or accessible at scale.
Ultimately, while the green transition brings undeniable opportunities for economic renewal, public health, and climate resilience, it requires careful management to ensure that the benefits are broadly shared and that no one is left behind. Although policy trade-offs are inevitable, there is no fundamental conflict between the EU’s objectives. Whether it is containing the climate crisis and its impacts or containing hostile powers, the fundamental environmental, economic and security trends align. Therefore, anyone thinking about security must also consider the climate. The assessment identifies four key areas for action. First, Germany and the EU must decarbonize rapidly and equitably to avoid deepening the global crisis and maintain international credibility. Second, Europe should actively support global decarbonization efforts. Third, building resilience at home, where “home” has a European dimension as closer cooperation can reduce adaptation costs and strengthen disaster response – from linking grids to mutually reinforcing disaster response and civil protection. Fourth, adaptation beyond Europe is essential, including efforts to bolster global stability and a resilient multilateral order. Now more than ever, foreign policy is climate policy.
The Climate, Peace and Security Debate
The framing of global environmental change as a threat to peace and security has faced significant criticism. Initially, scientific debates focused on whether environmental change leads to conflict. This debate has arguably shifted from “whether” to questions on “how,” “how much,” and “how relevant” environmental factors are (e.g. Chapter 1 and 10, adelphi research and PIK 2020). The answer, as so often in social science, is a resounding “it depends” and “context matters”: “There is no deterministic thread that automatically links climate change to increased conflict and fragility. Rather, climatic impacts have an effect on security when they interact with a larger web of existing socio-political and economic grievances that affect means and motivations for violence.“(ibid., p.12)
Another criticism from both academia and policy-making concerns the framing of climate change impacts as (national) security risks (rather than, adaptation and development needs). Their worry is that the “securitization” of the topic implies a removal of climate policy-making from the realm of normal (democratic) politics, with exclusionary tendencies (whether by strengthening security sector voices in domestic policy-making, or by moving discussions on climate change from the United Nations Framework Convention on Climate Change (UNFCCC) – to the far more narrowly representative UN Security Council. The fear is that framing climate change as a security issue will take away agency from vulnerable groups and end up strengthening the very power systems that have been facilitating if not been responsible for the climate crisis, among other social ills.
So far, the empirical evidence that the climate crisis is triggering exclusionary responses on a large scale is limited (although this judgment will partly be in the eye of the beholder). No instances come to mind of a military takeover based of insufficient climate action. Concerning the UN Security Council, it has yet to pass any thematic resolution on the issue. The draft resolution that was tabled in December 2021 (and ultimately vetoed by Russia) only modestly requested that the UN to reflect more systematically on the implications of climate change for peace and security (UN 2021). This absence of evidence should not be misinterpreted as evidence of absence. Critics have a point insofar as policies often have unintended consequences, and even well-intentioned policies have already negatively affected vulnerable groups. The introduction of biofuels mandates, for example, has been blamed for contributing to food price rises and even emission increases as a result of land use change (Richards 2022).
However, there is a countervailing risk that currently seems to be more pronounced: the lack of awareness of the scale of environmental threats leads to conspicuous underinvestment into mitigation and adaptation (IPCC). Ultimately, a lot hinges on how we understand securitization theory. Its origins lie in critically examining claims by the powers that certain issues are existential threats which, therefore, require extraordinary measures, justify enormous costs and may bypass normal political and administrative processes. Contemporary US policies on migration provide but one crass example for the relevance and need of this critical tradition. However, such acts of commission have mirror images in acts of omission: not recognizing or acknowledging that some other issues are, in fact, existential threats and, therefore, must not be relegated to third-order significance and regularly disregarded when policy trade-offs emerge. In other words, despite all the stark warnings and evidence, the climate crisis probably (still) suffers from a lack of securitization.
Can these perspectives on the risks of securitization and the lack thereof be reconciled? We would argue that they can: while we need stronger awareness of the security risks of global environmental change, we need to avoid responses that focus primarily on the traditional tools of security policy. Clearly, the security sector will have to play a role (it will need to become green, too, and it represents an important bulwark against instability). Yet, its levers are unlikely to be the key to the economic and social transformation that is needed for attenuating the existential threat of the climate crisis. Thus, collectively we need to truly understand the existential security threat while reaching for other tools to respond, such as those set out above: the right response to this security risk is investment into mitigation, adaptation, and governance for resilience.
This is the global perspective, and the long run. However, for many communities the existential threat from climate change and its second-order impacts is already palpable reality or quickly becoming so. The challenges they face range from urgent adaptation needs (or even compensation for losses and damages that have become unavoidable) to economic development to better governance and conflict resolution. Why, then, put a focus on the peace and security dimension rather than adaptation and development needs? The answer is that the two dimensions blend into each other, to the extent that they may well be the same thing. Within vulnerable settings, resilience to both climate change and fragility is regularly driven by the same factors such as alternative livelihood options, social safety networks and institutions for constructively managing and resolving conflicts that result from competition over resources (whether these be natural resources or access to jobs and public services). In such contexts, the Sustainable Development Goals 13 (Climate Action) and 16 (Peace, Justice and Strong Institutions) are thus mutually reinforcing—or, rather, ought to be (made) as mutually reinforcing as possible.
Yet, there is also a global dimension: whereas the quest for climate justice provides one (moral) impetus for a degree of multilateral solidarity, understanding the implications of inaction on the climate crisis for peace and security adds an important dimension of self-interest. As instability spreads, so do the costs and risks to everyone. Adaptation and development everywhere are hence important to the security and prosperity of everyone, including rich countries. In the current political climate in the West, where so much focus is on protecting societies from seemingly ubiquitous (perceived, relative and absolute) losses, understanding how global environmental changes drive instability that in turn drives risks to everyone’s security and prosperity will hopefully help persuade both decision-makers and broader constituencies that they need to respond ambitiously to both these changes and their second-order impacts.
A Shared Agenda? Strengthening Brazilian-German Cooperation on Climate-Security Gaps
This article presented a European perspective, conscious that perspectives from other parts of the world including Latin America will differ—and that there is a lot of heterogeneity within both continents along national, political and sectoral lines on how to address the challenges outlined above. This being said, however, there are numerous ways in which the climate crisis undermines stability in Latin America (Abdenur and Rüttinger 2020). From the migration crisis in Venezuela to deforestation-driven conflicts in the Amazon to organised crime in Central America, the ripple effects of instability and environmental degradation are felt far beyond national borders. Addressing these challenges is not just about safeguarding peace, stability and development. It is also about ensuring sustainable climate action.
Aligning climate action with peacebuilding and conflict prevention is not just a moral imperative; it is a smarter, more strategic approach. These regions are where climate risks and human vulnerabilities collide, threatening not just local stability but regional and global security. Without targeted interventions, we risk huge losses in human security that simultaneously undermine the fight against both climate change and instability.
How could Brazil and Germany collaborate in trying to address these challenges? An important first step would consist in having a strategic discussion about their perspectives on the interlinkages between the climate crisis and stability risks, and on their respective ideas for addressing these, including those issues where perspectives do not align. There is no need for both countries to reach full consensus on this, but the process will be eased by the fact that both countries (as well as most other countries of the continents they are part of) subscribe to a strong commitment to the multilateral order—even as that order remains an ideal and in need of reform.
Brazil has long been a champion of multilateralism. As Natalie Samarasinghe and Giovanna Kuele wrote a few weeks ago, “Brazil under President Luiz Inacio Lula da Silva stands out for its multilateral ambition […] from re-engaging with the Community of Latin American and Caribbean States, or CELAC, and leading U.N. Security Council efforts on the Israel-Hamas war in 2023, to rebooting the Amazon Cooperation Treaty Organization (ACTO), hosting last year’s G20 Summit and now chairing BRICS and this year’s U.N. COP30 Climate Change Conference” (Samarasinghe and Kuele 2025). This energy and ambition could also benefit the need for bridging the gap between climate action and peacebuilding. Brazil’s leadership in hosting COP30 and advancing global climate diplomacy presents an opportunity to further progress and shape this nexus. Similarly, regional initiatives like ACTO demonstrate how collaboration can drive climate action while addressing the root causes of instability. Below, we outline some possible entry points on how that agenda could be operationalized:
Despite their vulnerability, communities facing instability remain underfunded in global climate action (World Bank 2024). Instead, the majority of funding flows to middle-income countries with stronger institutions and lower risks. This imbalance is shortsighted. Communities where climate action is most urgently needed—and where it can have the greatest impact—are often those facing risks to their human security and stability. For example, investments in climate-resilient agriculture in Guatemala have reduced food insecurity and strengthened community resilience, helping to break cycles of conflict and displacement (Whitaker & Vivekananda 2025). Similarly, renewable energy projects in rural Brazil not only reduce emissions but also create jobs, foster stability, and reduce reliance on illicit economies (Whitaker & Vivekananda 2025).
Smarter climate financing does not just mean more money—it means better-targeted investments. Funding must be long-term, adaptive, and aligned with local priorities. It must also address the structural drivers of instability, from weak governance to social exclusion. For example, promoting inclusive decision-making in water management or land-use planning can reduce resource-based conflicts and strengthen trust between communities and governments.
As the world gears up for COP30 in Brazil in 2025, there is a unique opportunity to bring peacebuilding and conflict prevention to the forefront of global climate discussions. A dedicated “Peace Day” at COP30 could serve as a platform to highlight the intersection of climate action, equitable development, and peace. This focus would not only raise awareness but also drive actionable commitments to address the challenges faced by unstable regions. Such a day could feature high-level dialogues, case studies, and collaborative workshops to explore how climate resilience can foster peace in regions grappling with instability. For instance, discussions could draw on lessons from the Dry Corridor, where climate adaptation projects have reduced tensions, or from the Amazon, where community-led conservation efforts have strengthened social cohesion and reduced vulnerabilities to crime (Rüttinger et al. 2022).
By framing peace as a central theme, COP30 could catalyse international support for targeted interventions in unstable contexts, ensuring they receive the attention and resources they urgently need. To ensure that climate action also benefits the most vulnerable who are exposed to mutually reinforcing climate and conflict risks, we propose four principles that should underpin more ambitious action in fragile contexts: (1) Pivot to Prevention: Early action saves lives and money. For example, investments in flood early warning systems in Brazil have reduced the need for costly humanitarian interventions during extreme weather events. (2) Operationalise the Nexus: Climate action must integrate development, peacebuilding, and humanitarian efforts. This calls for climate security risk analyses to become standard operating practices for all climate initiatives. (3) Flexible, Localised Responses: Diplomacy can enable tailored, context-specific interventions. In the Andes, for instance, partnerships with indigenous communities have strengthened resilience to glacial melting while fostering trust and collaboration (Rüttinger et al. 2022). (4) Regional Cooperation: Instability and climate risks transcend borders. Regional initiatives like ACTO’s efforts in the Amazon basin show how collective action can address shared challenges.
Peacebuilding is the missing link in global climate action. Without targeted interventions in unstable regions, the world risks failing its climate goals—and leaving millions behind. Every dollar invested in climate resilience saves $16 in crisis response (Volz 2020). The international community must act with urgency and foresight. By aligning climate financing with peacebuilding strategies, integrating foreign policy into climate action, and adopting smarter, multidimensional approaches, we can turn instability from a barrier into an opportunity for progress. Integrating peacebuilding into climate action is not just a moral imperative but a strategic necessity. As the host of COP30, Brazil has a unique opportunity to demonstrate leadership by championing policies that link climate resilience with conflict prevention. This means prioritising investments in vulnerable regions, fostering regional cooperation, and ensuring that climate financing reaches those most at risk. The stakes are clear: failure to act will deepen instability and derail global climate goals. The cost of inaction is calculable, and it is far greater than the price of bold, coordinated action today (Kotz et al. 2024).
Further Reading on E-International Relations