The recent breakthrough in climate finance at COP29 in Baku, which committed to mobilizing USD 1.3 trillion annually by 2035, appears both promising and precarious.Footnote 1 While climate donors have demonstrated willingness to make ambitious financial commitments for general climate action, they remain notably hesitant to fund migration-related projects due to political sensitivities and uncertainty about effective approaches.Footnote 2 Traditional humanitarian and environmental protection frames are unlikely to mobilize sufficient funding, particularly as conservative governments express growing skepticism toward both immigration and climate action.
The challenge of financing climate mobility requires blending moral duties with pragmatic investment considerations. This essay argues that wealthy nations have compelling reasons to fund climate mobility on both historical responsibilities and forward-looking investment logic. As Melissa Johns writes, the first step toward inclusive climate finance is making the business case.Footnote 3 To demonstrate feasibility, I examine successful historical examples of responsibility sharing, which involves not just pooling finances but also accepting displaced people, developing multilateral frameworks rather than bilateral ones, and establishing legally binding commitments instead of mere declarations of principles.
As we transition from traditional refugee protection frameworks to addressing climate displacement, three considerations must guide our approach. First, unlike political persecution where refugees might eventually return home after regime changes, climate change creates permanent uninhabitability in certain regions and sometimes in entire states. Second, unlike refugee situations which sometimes arise suddenly due to unexpected violence and require immediate temporary settlements, climate displacement often involves gradual onset but ever-worsening disaster cycles. Third, the overlap between political persecution and climate vulnerability suggests a priority focus on doubly vulnerable populations, such as the tens of thousands of stateless Rohingya relocated to the cyclone-prone, man-made island of Bhasan Char.
The Duty-Based Perspective and Its Limits
Traditionally, the case for financing climate mobility has not been a forward-looking, investment logic, but instead, a duty-based perspective to remedy past harms. The duty case for financing climate mobility rests, in turn, on two distinct normative foundations—one well-established but poorly implemented, the other more novel and controversial. First is the familiar principle that wealthy nations bear special responsibilities as the primary historical contributors to climate change. Having generated the vast majority of greenhouse gas emissions that drive climate displacement, developed countries have an ethical obligation to support those forced to migrate due to climate impacts they largely caused. While this principle has gained rhetorical acceptance, as seen in the recent COP29 agreement in Baku to increase climate finance, actual implementation has consistently fallen short of promises.
A second, more controversial framework comes from Tendayi Achiume’s innovative argument that imperial domination and intervention create enduring duties for wealthy nations.Footnote 4 In her view, states should view migration within former imperial networks—for instance, movement within the Commonwealth—not as discretionary but as imperative given these historical bonds. Furthermore, countries like the United States, which may not have been formal colonizers but have intervened heavily in regions including Central America, also bear responsibilities under this framework. Achiume’s analysis of U.S. policies, such as the Temporary Protected Status (TPS) granted to Salvadorans, illustrates how both historical intervention and contemporary need compel obligations.Footnote 5 Her framework can be straightforwardly extended to create an even stronger case for duty when people are forcibly displaced by climate change within these imperial networks. This more radical perspective challenges traditional notions of state sovereignty and suggests deeper obligations than conventional climate finance approaches.
Whereas these principles are well-theorized, it is challenging to establish legal obligations on wealthy governments to take affirmative and proactive steps to realize the rights of non-residents. Some narrow but well-established affirmative duties include the concept of the duty to rescue at sea. It is a fundamental principle of international law, codified in treaties like the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and reflected in customary international law.Footnote 6 This duty has been applied directly to the rescue of migrant boats in distress in the Mediterranean. However, as Iris Goldner Lang and Boldizsár Nagy note, practices such as pushbacks and border obstructions have posed serious challenges to these obligations.Footnote 7 Scholars such as Jean-François Durieux have sought to extend this principle further to suggest that, in extreme circumstances, states should proactively retrieve refugees from danger zones.Footnote 8 This represents an important shift from reactive to proactive measures in international refugee law. What is missing, however, is an affirmative duty to implement earlier-stage actions to mitigate displacement.
Extending existing affirmative obligations of all states to reduce statelessness is a promising way to expand and develop doctrinal solutions to climate displacement. Two groups in particular should be prioritized using this doctrinal extension approach: citizens of small island states at risk of complete submersion (such as Kiribati, Tuvalu, the Marshall Islands, and the Maldives, all with average elevations below three meters above sea level), and stateless persons and refugees resettled in extraordinarily climate-vulnerable locations. Particularly concerning is the situation of the Rohingya, who constitute one in seven stateless persons globally, with the vast majority of those who fled Myanmar now living in precarious conditions in Bangladesh’s low-lying, flood-prone districts like Cox’s Bazar and Bhasan Char Island, where rising sea levels and intensifying cyclones threaten their already fragile existence. At the end of the day however, as Iris Goldner Lang and Maroje Lang flag in this volume, the affirmative duties of all states not to turn back refugees and stateless persons do not extend to many people displaced by climate change, so additional perspectives are needed.Footnote 9
The Security Perspective
While duty-based approaches to climate mobility financing anchor obligations in historical responsibility, security and investment frameworks focus on managing future risks and opportunities. The recent geopolitical competition with China has made security framing particularly resonant with current policy priorities. However, experience suggests important limitations to security narratives. As Jeroen Warner and Ingrid Boas demonstrate in their analysis of UK and Dutch climate securitization efforts, apocalyptic security framings often backfire by triggering skepticism or defensive reactions from key audiences.Footnote 10 For example, the UK Foreign Office’s attempts to leverage security concerns to promote climate action met resistance from emerging powers who viewed it as deflecting Western responsibilities, while the Dutch Delta Commission’s extreme climate scenarios provoked scientific criticism that undermined its credibility.Footnote 11 Rather than leaning exclusively on security logic, effective climate mobility financing likely requires combining multiple frameworks—acknowledging historical duties and security risks while also making a forward-looking case for proactive investment.
The Investment Perspective: A New Framework
While duty-based and security-based arguments are familiar in refugee and climate discourse, viewing climate displacement through an investment lens represents a novel analytical framework. Investment, in this context, means allocating resources now with the expectation of positive returns over time—not just for migrants themselves, but for both sending and receiving societies. This marks a significant departure from traditional humanitarian approaches that view refugee support primarily as a cost or burden, and also from the national security framework. Governments that can overcome the short-termism of the political cycle to invest for the long term, whether by building up infrastructure, pension, or higher education systems, significantly outperform those that cannot.Footnote 12
I propose examining how potential host societies can invest strategically in climate migration finance today to secure significant medium-term benefits. The current pattern is inefficient: climate-vulnerable populations often lack resources to relocate, leading them to repeatedly rebuild in hazardous areas—a pattern that ultimately costs governments more through recurring disaster response. Financial efficiency demands avoiding repeated rebuilding in disaster-prone areas; instead, global financial institutions should identify and support communities willing to relocate proactively, as Charlotte Finegold and Erica Bower argue.Footnote 13
Just as climate adaptation investments aim to reduce future damages, proactive migration policies can create pathways that benefit both sending and receiving countries. This investment approach operates through three channels: supporting in-country climate adaptation (the most significant and well-understood pathway), enabling selective westward migration (economically promising but politically challenging), and developing regional mobility and reciprocal disaster response frameworks.
Hosting more migrants and refugees in western democracies is a politically difficult proposition at present. Nevertheless, these efforts represent a sound long-term investment, when the political winds shift. For the U.S., the National Academy of Sciences has documented that while first-generation immigrants initially impose net fiscal costs, particularly at state and local levels due to education expenses, second-generation immigrants become among the strongest economic contributors in the population.Footnote 14 They contribute more in taxes than either their parents or other native-born residents, reflecting higher educational achievement and wages. Immigration has also helped the U.S. avoid demographic stagnation while boosting innovation and entrepreneurship through the importation of skills — a finding particularly relevant given current strategic competition with China. Initial costs in education and integration are more than offset by innovations, entrepreneurship, and fiscal contributions of subsequent generations. Just as climate adaptation investments aim to reduce future damages, proactive migration policies can yield long-term social and economic benefits that exceed short-term costs.
Moreover, when thinking of investment, it is important to focus both on average, and on tail events. In financial markets extraordinary returns often come from rare “tail events”—outliers that drive disproportionate outcomes. “Almost everything in life that is huge, profitable, famous, or influential, is the result of a tail event,” argues Morgan Housel, in his overview of both high-risk venture capital, and also more conservative S&P 500 patterns.Footnote 15 The potential upside of migration is particularly striking if we consider these positive tails. Immigrants and their children have been responsible for a large proportion of extraordinary successes—for example, they have founded 44 percent of Fortune 500 companies.Footnote 16 Migration policy should focus on enabling these transformative contributions while managing aggregate costs, benefits and risks as well.
An attractive feature of the investment framework is that it justifies wealthy states’ coverage of these short-term costs through borrowing, rather than through higher taxes. Both the U.S. and EU responses to the Coronavirus pandemic, notably the Inflation Reduction Act and the NextGenerationEU program, involved extraordinary borrowing to finance hundreds of millions in clean energy investments.Footnote 17 And as Janka Deli explores elsewhere in this volume, the NextGenerationEU template can serve as a model for future efforts to finance climate mobility.Footnote 18 That said, Western financing, whether through multilateral institutions or through bilateral projects, is unlikely to suffice, given the scale of the climate challenge. For this reason, the next section turns to responsibility sharing, an effort to bring in more resources and more types of resources from a broader range of actors, in order to multiply the effects of these efforts.
From Responsibility Dumping to Responsibility Sharing
Elena Chachko and I have argued elsewhere that we must distinguish between regressive “responsibility dumping” arrangements and progressive “responsibility sharing.”Footnote 19 This distinction is particularly critical for climate mobility, where the three considerations outlined earlier—permanent displacement, gradual onset with worsening cycles, and overlapping vulnerabilities—demand a fundamentally different approach to responsibility allocation.
Traditional approaches have often amounted to responsibility dumping—wealthy nations simply deflecting migrants to poorer, less stable countries without adequate support. This pattern is especially problematic for climate displacement, as it fails to acknowledge the permanence of displacement, ignores the predictable nature of gradual-onset climate impacts, and compounds the vulnerabilities of already marginalized populations. In contrast, the key features of genuine responsibility sharing include: (1) hosting commitments by more affluent nations; (2) substantial financial investments in countries hosting migrants; (3) multilateral frameworks; and (4) legally binding commitments. In the context of climate displacement, there is significant progress on elements (2) and (3)—significant funding commitments made through multilateral fora. And the Global Compact for Refugees, which Sarah Deardorff Miller has called a “potential game changer because it initiates changes relating to financial, rhetorical and coordination mechanisms that further engage development actors in refugee situations,” broadly satisfies elements (1), (2), and (3), even as it is non-binding and strictly distinguishes between refugees and all other displaced persons.Footnote 20
I turn next to three regional examples of successful historical models of responsibility sharing: the U.S.-led response to displacement from Indochina in the 1970s and 1980s, the EU-led response to displacement from Ukraine since 2022, and the EU-Turkey deal in response to displacement from Syria in 2015–2016. There is no doubt that the EU-led response to Ukraine is literally an off-the-charts responsibility-sharing response. Elena Chachko made many charts to graph various responsibility sharing and responsibility dumping efforts, including UN-, EU-, and U.S.-led efforts over time, and had to add a postscript once Russia invaded Ukraine as our axes no longer worked. To make sure that the perfect does not become the enemy of the good however, besides outlining the Ukraine response, I also present two more mixed responses that are still worth considering as models.
Successful Models of Responsibility Sharing
Historical examples can help illustrate how combining hosting commitments with strategic investment can create sustainable solutions. The U.S. response to Indochinese displacement (1970s–1980s) offers a compelling model: beyond resettling 1.3 million refugees from Vietnam and Laos, America implemented regional development strategies that transformed Southeast Asian economies from refugee sources to growth centers. This approach addressed the permanence of displacement by providing both resettlement pathways and developmental investments that prevented future displacement—a framework particularly relevant for climate mobility where return is often impossible.
The EU’s response to Ukrainian displacement exemplifies exceptional responsibility sharing. It provides visa-free travel, work, and education opportunities across the EU for millions of Ukrainians,Footnote 21 coupled with tens of billions in direct economic support to Ukraine. This comprehensive approach—combining immediate protection with substantial investment in Ukraine’s recovery—created an unprecedented response framework. While such generosity has occasionally prompted governments to extend similar protections to other groups (as when the Biden administration expanded temporary protections to nationals of Cuba, Haiti, Nicaragua, and Venezuela already in the United States), the Ukrainian response’s extraordinary scale makes it a challenging template for broader application. Nevertheless, it helps anchor conversations about the limits of what is possible when duty, security, and investment concerns align perfectly.
While the Ukraine response represents an ideal model of responsibility sharing, the much-maligned EU-Turkey deal offers a pragmatic second-best alternative for climate mobility frameworks. The EU’s €6 billion aid package to Turkey for hosting nearly four million Syrians demonstrated effective regional burden-sharing at manageable cost. Turkey’s subsequent integration measures—work permits, public school access, higher education quotas, and citizenship pathways—show how proximity-based hosting can adapt to permanent displacement needs while maintaining cost efficiency. This approach balances financial realism with protection goals, combining reasonable support with integration opportunities. Rather than pursuing the extraordinary but difficult-to-replicate Ukraine model universally, climate displacement strategies might more feasibly adopt this mixed approach: limited Western hosting complemented by substantial financial investment in regional solutions that recognize displacement’s permanence while respecting displaced persons’ frequent preference to remain in culturally familiar environments. The fact that many hosting nations are themselves climate vulnerable only amplifies the need for responsibility sharing.
Conclusion
The transformation from viewing climate mobility solely through duty-based or security lenses to incorporating an investment framework represents a crucial evolution in addressing this global challenge, especially in an era of rising nationalism. While historical responsibilities and moral obligations remain important foundations, reframing climate mobility financing as a strategic investment offers an additional compelling path forward. The successful examples of responsibility sharing from the U.S. response to Indochinese refugees to the EU’s unprecedented support for Ukraine, demonstrate that combining hosting commitments with substantial financial investment can create sustainable solutions. As climate displacement intensifies, wealthy nations must move beyond responsibility dumping to embrace genuine responsibility sharing through both direct hosting and strategic financial support. This approach not only fulfills moral obligations but also serves the long-term interests of both sending and receiving societies, creating a more resilient global framework for managing climate mobility.
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