Cities, like those recently affected by wildfires in California, are at the center of climate challenges. Several factors compound this vulnerability. Cities have large populations and concentrated economic activity, making them especially vulnerable to disruptions. Many large cities are situated in areas prone to environmental hazards—such as near oceans, rivers, and floodplains—which heightens their exposure to climate-related natural disasters. Urbanization trends further exacerbate these vulnerabilities as people often migrate to cities during crises in search of safety, resources, and opportunities.

As climate change intensifies, cities face a dual threat. They not only face risks of disasters that may force their own residents to relocate but also are often destination hubs for incoming populations fleeing rural areas affected by environmental changes. In the absence of adequate support systems, new urban migrants are often forced to settle in hazardous climate zones and are affected by subsequent disasters. This dual vulnerability places additional strain on urban infrastructure, public services, and social and economic dynamics, requiring anticipatory action and integrated strategies to strengthen urban resilience.

While cities are on the front lines of these challenges, they operate within international and domestic systems that have largely failed to meaningfully incorporate the perspective and realities of city-level governance mechanisms. The year 2026 brings a rare convergence of global forums and U.S. hosting responsibilities, including the Urban 20 (U20), a process created to highlight cities’ perspectives alongside the Group of Twenty (G20). As the United States serves as the host nation for the G20 this year, Los Angeles and New York City will host the U20 analogous process. This presents a genuine opportunity now for cities to shape national and international discussions—and, as the California experience shows, there is growing public support for doing so.

Although cross-border migration often dominates the headlines, research shows that most climate mobility occurs domestically, primarily through rural-urban flows. Preparing for and enabling orderly, safe, and dignified climate mobility must then become a priority for cities worldwide. Given this current reality, cities must take proactive steps to effectively address climate mobility, transforming disruptive shocks into opportunities that increase resilience, mitigate risks, and reduce the costs of inaction. These actions include supporting communities to allow for adaptation in situ to prevent displacement, as well as relocating those in harm’s way, protecting the dignity of those who move, and integrating newcomers into urban labor markets to boost economic growth and facilitate the energy transition.

Around the world, cities investing in climate mobility action are already reaping the benefits for their local economies, sustainability, and social cohesion. Studies show that integrating climate migrants into labor markets, for example, can be a highly cost-effective policy that, when managed effectively, can help host societies by supporting economic growth, meeting labor demand, addressing shrinking workforces in some countries, and advancing the green energy transition.

In the United States, many cities have also been integrating climate mobility into their planning. Since the mid-2010s, cities like Anchorage, Ann Arbor, Buffalo, Bozeman, Chico, Cincinnati, Charleston, Denver, Evanston, Orlando, and many others have been assessing the impact of climate mobility on their housing stock and affordability, transportation systems, and workforce through climate vulnerability assessments and action plans. In Ann Arbor, for example, the city’s research has examined how climate migration projections can inform the city’s planning for potential shifts in population, especially as they relate to hazard mitigation planning and the city’s imminent upgrades to its water treatment plant. In Charleston, the city has been making a concerted effort to plan for sea level rise by embedding resilience into city operations and long-term investment decisions, and cities like Buffalo and Cincinnati are positioning themselves as climate havens and preparing to receive those seeking safer places to live.

What Is Holding Cities Back?

Despite the growing urgency of climate mobility, cities face significant structural barriers—at both the international and domestic levels—that limit their ability to act.

First, cities are systematically excluded from international policy dialogues, processes, and institutions. Multilateral agencies and high-level diplomatic processes are designed to operate at the national level, limiting both devolved decisionmaking and meaningful consultative engagement with cities. As a result, national climate negotiations rarely coordinate with, or even account for, the governance mechanisms and priorities of urban actors. Cities generate much of the practical knowledge about what climate adaptation requires on the ground, yet they remain largely outside the rooms where international frameworks are designed.

Second, international finance, especially climate finance, is failing to reach cities. Less than 10 percent of global climate finance and only 1.2 percent of the humanitarian funding are allocated to local actors in urban areas. Several structural barriers compound this problem. City-level projects are often too small in scale to attract specialized climate funds oriented toward large national initiatives. And the financing landscape itself is deeply fragmented across the migration, development, humanitarian, and climate sectors, overwhelming the capacity of local governments to navigate multiple funding streams simultaneously.

Third, in the United States, domestic support structures for climate resilience are weakening when they are needed most. Against a backdrop of accelerating climate risk, the federal government is scaling back programs and funding for disaster preparedness, response, and recovery, as evidenced by the severity of the delays and obstacles in the operation of FEMA’s Building Resilient Infrastructure and Communities (BRIC) program. With a widening gap between the scale of climate impacts and the institutional capacity available to increase resilience and reduce the impact of disasters, greater responsibility has been shifted onto state and local governments to fill growing financing delays and funding gaps without commensurate resources.

This shift is already visible in public attitudes. For example, the 2025 Carnegie California Global Affairs Survey found that Californians—having lived through a year of wildfire losses, displacement, and federal policy reversals—are expressing declining confidence in the federal government and increased support for subnational government involvement in climate action. Moreover, the survey found that public support for greater state- and local-level decisionmaking regarding migration issues has also increased since 2023. Subnational jurisdictions’ practical experience with the intersection of climate and human mobility positions them well to ensure that the people most affected by climate mobility—those deciding whether to stay, rebuild, or move—are represented in international networks where global decisions are made. 

The Power of Now: Unlocking 2026’s Potential

Global forums like the Urban 7 Summit (U7) and U20 were created for cities to advocate for the inclusion of their needs, highlight their perspectives, and express their concerns about issues that matter to them in national and international forums. Established in Buenos Aires in 2017, U20 aims to incorporate city-focused expertise and policies into the G20 discussion and agenda. It includes many of the world’s largest urban economies and most populous cities. As New York City and Los Angeles will take on hosting responsibilities for U20 activities, this presents a unique opportunity for U.S. cities to actively participate in shaping the main priorities discussed at the U20, and consequently the G20.

Climate action has been a consistent focus for U20 members since the forum’s inception, and the intersection of climate risks and human mobility has become an increasingly prominent area of focus. The 2025 Johannesburg-Tshwane U20 Communique called on G20 governments to develop “an inclusive and human rights-based approach to human mobility and displacement, recognising that it is a phenomenon driven by various factors, including economic, political and climatic drivers—especially towards, within, and from cities.” This year, under the leadership of Los Angeles and New York, the U20 has an opportunity to build upon that foundation, moving beyond a broad recognition of climate change as a driver of mobility toward an articulation of what cities actually need to respond effectively. That means advocating for anticipatory action, flexible financing, and the tools to protect residents before, during, and after climate-related displacement.

Los Angeles’s responsibilities as host of the U20 arrive at a pivotal moment. After a year of major climate impacts and sweeping immigration policy changes, the city brings firsthand experience to a pressing global challenge. Networks like the U20 offer a forum for lesson sharing and learning and provide pathways to global and national dialogue and decisionmaking. Support for local and state officials engaging in international affairs and with international counterparts is also growing in California. As such, city diplomacy is becoming increasingly recognized as a path for addressing transnational challenges.

Climate mobility need not be a governance challenge that defines the coming decades. To address climate mobility effectively, four areas of investment are essential. Leaders of the U20 and the G20 should make commitments toward progress in the following areas.

First, cities need the data and analytical capacity to understand and anticipate how climate change will affect human mobility, both into and out of their jurisdictions. Better data collection, climate risk assessments, scenario planning, and modeling and forecasting of human mobility flows will empower local governments to anticipate challenges, develop coherent policies, and allocate resources effectively.

Second, cities need tools to enable urban residents to remain safely in place. Forced displacement can often be prevented by investing in climate adaptation and disaster risk-reduction measures, such as developing a sea level rise strategy or incorporating disaster preparedness strategies into city planning. These investments should enhance cities’ capacities to develop and implement disaster preparedness strategies, invest in resilience measures for slow-onset impacts such as sea-level rise and extreme heat, strengthen zoning codes to avoid building in high-risk areas, and implement community-based approaches such as nature-based solutions and climate-resilient infrastructure. Mechanisms that enable vulnerable and marginalized communities to meaningfully participate in planning and decisionmaking are equally essential.

Third, when remaining in place is not viable, cities need support to facilitate safe evacuations and managed relocations while protecting residents’ fundamental rights. This includes deploying early warning systems in disaster-prone areas; regularly updating evacuation plans based on current climate risk assessments; addressing the long-term social, cultural, and economic recovery needs of affected communities; and ensuring that any planned relocations are conducted with the free, prior, and informed consent of affected residents.

Finally, cities need resources to integrate those arriving in the context of climate change in a manner that receives them with dignity and without discrimination. This requires national and international mechanisms to invest in measures such as housing, infrastructure, and essential services. It also requires city-led initiatives to extend public services equitably to refugees, stateless individuals, and displaced persons. These investments will enable cities to receive and support those relocating due to climate risks and disasters.

Local leaders are uniquely positioned to understand immediate community needs and translate them into practical, grounded strategies. Ensuring that their perspectives shape international discussions is not just equitable; it is likely to produce better outcomes. The 2026 G20 and U20 offer a rare convergence of global attention and strategic opportunity. Los Angeles and New York should seize this moment to advance climate mobility from an underrepresented concern into a concrete international priority.