Coastal zones occupy a unique and complex position within the global geography of displacement. These areas serve simultaneously as places of abundance and peril: enriched with marine resources, bustling trade routes, and fertile lands, yet acutely vulnerable to the multifaceted impacts of climate change such as rising seas, intensified storm surges, and land subsidence. For millions of individuals forced from their homes by environmental degradation, conflict, or economic hardship, coastlines often represent the closest available refuge. However, the very forces that make coastal zones attractive also generate new risks, potentially triggering secondary or repeated displacement. Understanding the intricate intersection of environmental and human geography in coastal zones is essential for crafting policies that safeguard displaced populations while preserving the ecosystems they depend upon.

The Dual Role of Coastal Zones: Refuge and Risk

Coastal regions have historically drawn human settlement due to their rich resources and strategic advantages. Today, nearly 40 percent of the world's population resides within 100 kilometers of a coastline, with many of the largest and fastest-growing cities located in these areas. This demographic concentration creates both opportunities and vulnerabilities for displaced populations. On one hand, coastal economies offer diverse employment opportunities in sectors such as fishing, tourism, port logistics, and informal trade, which can absorb labor from displaced groups. On the other hand, these regions are increasingly threatened by the direct environmental impacts of climate change, which undermine their long-term habitability and resilience.

Environmental Drivers of Displacement

Sea-level rise stands out as the most pervasive environmental driver of coastal displacement worldwide. The Intergovernmental Panel on Climate Change (IPCC) projects that, under high-emission scenarios, global mean sea levels may rise by up to one meter by 2100. This rise poses a profound threat to low-lying deltas, islands, and coastal urban centers. In addition to inundation, coastal erosion progressively shrinks habitable land, while saltwater intrusion contaminates freshwater aquifers critical for drinking water and agriculture.

Extreme weather events, such as tropical cyclones and storm surges, are becoming more frequent and intense, exacerbating the risk to coastal residents. For example, in Bangladesh’s Sundarbans delta—the world’s largest mangrove forest and a UNESCO World Heritage Site—rising salinity and repeated storm damage have already compelled thousands of farming families to abandon their ancestral lands. Many migrate toward urban centers such as Khulna and Dhaka, where they often settle in informal, overcrowded neighborhoods. These movements generate complex internal displacement patterns that challenge urban infrastructure and social cohesion.

Ecosystem degradation further amplifies displacement risks in coastal zones. Natural coastal ecosystems—including mangrove forests, coral reefs, and seagrass beds—serve as vital buffers against erosion and storm surges by dissipating wave energy and stabilizing sediments. When these ecosystems suffer degradation due to pollution, overfishing, unsustainable coastal development, or climate stresses such as ocean acidification, their protective functions diminish. A 2020 study published in Nature Communications revealed that areas in Southeast Asia experiencing mangrove loss saw a 20–30 percent increase in flood-related displacement, underscoring the critical role ecosystem health plays in human security.

Human Geography Factors Influencing Displacement

Human activities profoundly reshape coastal landscapes and influence displacement patterns. Rapid urbanization in many coastal cities is often unplanned and poorly regulated, leading to the proliferation of informal settlements on floodplains, riverbanks, and reclaimed land. These densely populated neighborhoods tend to be situated in hazard-prone zones due to their low cost and proximity to economic opportunities. For displaced populations, particularly internal migrants seeking work, these areas represent a double-edged sword: they offer livelihoods but expose residents to heightened environmental risks.

For instance, Manila, the capital of the Philippines, is home to nearly 4 million people living in informal communities along waterways and the shoreline. Many of these residents are internal migrants fleeing poverty or conflict in other parts of the country. These settlements lack adequate infrastructure and sanitation, making them vulnerable to typhoons and flooding events that can trigger repeated displacement.

Tourism development and industrialization also contribute to displacement through economic pressures. Coastal land is often converted from traditional fishing or agricultural use into resorts, ports, or special economic zones. In Kenya's coastal region, the expansion of large-scale tourism resorts along the Indian Ocean has marginalized small-scale fishers and farmers, pushing them onto less secure, erosion-prone land. This phenomenon, sometimes termed “climate gentrification,” displaces vulnerable populations not through direct environmental forces but through rising land prices and restricted access to safe, productive territories.

Case Studies: Coastal Displacement in Action

Examining specific geographic and social contexts provides insight into the complex interactions between environmental change and human mobility in coastal zones.

Bangladesh: Migration from the Sundarbans Delta

The Sundarbans delta, shared between India and Bangladesh, is one of the world’s most climate-vulnerable regions. Its extensive mangrove forests provide critical ecosystem services but face increasing threats from sea-level rise, saltwater intrusion, and intensified cyclones. These environmental stressors have led to repeated crop failures, loss of freshwater resources, and destruction of livelihoods, forcing many residents to migrate.

A 2021 survey conducted by the International Organization for Migration (IOM) found that approximately 70 percent of households in the Bangladeshi Sundarbans had at least one member who migrated in the past decade, either for work or shelter. While many of these migrants relocate to nearby urban centers, a significant portion undertakes longer-distance migration to Dhaka or even abroad, particularly to Middle Eastern countries as labor migrants. The out-migration of working-age adults leaves behind communities dominated by elderly individuals, women, and children, increasing dependency burdens and straining limited social services.

Manila and Jakarta: Urban Coastal Displacement and Sinking Cities

Manila and Jakarta exemplify how rapid urbanization and environmental change combine to heighten displacement risks in coastal megacities. Both cities are experiencing significant land subsidence caused primarily by excessive groundwater extraction, which compounds the effects of rising sea levels.

In Jakarta, some areas are sinking at rates up to 25 centimeters per year, rendering large sections increasingly uninhabitable and prone to flooding. The Indonesian government’s decision to relocate the national capital to Borneo partially responds to these challenges, aiming to reduce exposure to climate risks and overcrowding. Nonetheless, millions remain vulnerable in the current urban footprint.

Similarly, Manila’s informal settlements along rivers and coastlines are repeatedly devastated by typhoons and flood events. Due to a lack of affordable alternative housing, displaced families often rebuild in the same hazardous locations, perpetuating a cycle of displacement, poverty, and environmental degradation. This cyclical displacement creates long-term socio-economic vulnerabilities and undermines urban resilience.

Small Island Developing States (SIDS): Loss of Homeland and Cultural Identity

For Small Island Developing States (SIDS) such as Tuvalu, Kiribati, and the Maldives, displacement is not merely temporary but represents the potential loss of entire homelands. Saltwater intrusion, land erosion, and increasing storm surges make many atolls uninhabitable, threatening not only physical survival but also cultural continuity and sovereignty.

The concept of “planned relocation” has emerged as a policy response to imminent displacement in these contexts. However, planned relocation raises complex ethical, legal, and social challenges, as it involves uprooting communities from ancestral lands and disrupting cultural identities. In Fiji, the government has identified over 800 communities at risk of forced relocation by 2050, and some villages, such as Vunidogoloa, have already been moved inland. These relocations highlight that displacement from coastal zones encompasses profound questions about identity, tradition, and the right to self-determination.

Key Challenges to Sustainable Refuge in Coastal Zones

While coastal zones can serve as critical refuge areas for displaced populations, several structural challenges undermine their ability to sustainably host these communities.

Resource Scarcity and Potential for Conflict

Freshwater scarcity is a critical constraint in coastal areas, where aquifers are increasingly compromised by saltwater intrusion. The influx of displaced populations intensifies demand for limited water resources, often leading to competition and social tensions. In the Horn of Africa, for example, coastal towns such as Kismayo and Bossaso in Somalia have witnessed conflicts between host communities and internally displaced persons (IDPs) over access to freshwater and grazing lands.

Fisheries, a vital source of food and livelihoods, are also under strain due to overexploitation and shifting fish stocks driven by climate change. Displaced populations who rely on fishing may inadvertently exacerbate resource depletion unless inclusive, community-based management frameworks are established. Without cooperative governance, resource competition can escalate into conflicts that further destabilize fragile coastal communities.

Governance and Policy Gaps

Most national and international legal frameworks currently fail to adequately recognize or address the phenomenon of “climate refugees.” The 1951 Refugee Convention, for example, does not encompass environmental displacement, leaving millions in a legal and policy vacuum. Coastal zone management is often fragmented among multiple agencies responsible for environment, disaster risk reduction, urban planning, and social welfare, resulting in uncoordinated responses that overlook displaced populations’ needs.

In many developing countries, informal settlements along coasts suffer from insecure land tenure, which restricts residents’ access to formal services, credit, and adaptation funding. Without secure rights to land or housing, displaced populations have little incentive or ability to invest in resilient infrastructure or long-term adaptation measures, perpetuating their vulnerability to future displacement events.

Ecosystem Degradation and Feedback Loops

Displacement itself can contribute to further degradation of coastal ecosystems. The concentration of large populations in informal settlements often results in untreated sewage discharge, mangrove clearance for housing, and overfishing. This degradation diminishes natural coastal defenses, increasing vulnerability for all residents—both displaced and host communities.

Breaking this destructive feedback loop requires integrated displacement management that incorporates coastal conservation and ecosystem restoration. Without such coordination, environmental degradation will accelerate, exacerbating displacement risks and undermining resilience.

Opportunities for Integrated Solutions

Despite the significant challenges outlined, coastal zones offer unique opportunities to build resilience among displaced populations through integrated environmental and social strategies that address both human and ecological needs.

Ecosystem-Based Adaptation (EbA)

Ecosystem-Based Adaptation (EbA) involves the restoration and sustainable management of natural habitats to reduce vulnerability to climate impacts while providing social and economic benefits. Restoring mangroves, coral reefs, and coastal dunes can reduce erosion, buffer storm surges, and improve biodiversity, all of which contribute to enhanced community resilience.

In Vietnam, for example, mangrove replanting projects combined with sustainable aquaculture have not only mitigated typhoon impacts on coastal villages but also created new income opportunities for displaced households. Such projects explicitly involving displaced persons as active participants—rather than passive beneficiaries—can foster social integration and reduce pressures on urban social services.

The Philippines’ “Mangrove for Livelihoods” initiative in the Southern Leyte province trains internally displaced persons in mangrove nursery management and eco-tourism guiding. This approach simultaneously supports ecosystem health and provides displaced people with sustainable livelihoods.

Community-Led Planning and Participatory Governance

Top-down coastal management approaches often fail to account for the unique needs of vulnerable groups, including displaced populations. Participatory planning processes that engage displaced individuals, host communities, local governments, and civil society organizations can produce more equitable and contextually appropriate outcomes.

In Odisha, India, the government’s “Integrated Coastal Zone Management Project” actively involves fishing communities and migrant workers in the development of early warning systems and evacuation routes. This inclusive approach has significantly reduced cyclone mortality rates even as coastal settlements have grown due to migration, demonstrating the effectiveness of participatory governance in disaster risk reduction.

Climate-Resilient Infrastructure and Early Warning Systems

Investing in climate-resilient infrastructure is critical to reducing displacement risks in coastal zones. This includes constructing or retrofitting sea walls, elevated roads, flood-proof housing, and multipurpose cyclone shelters. However, infrastructure must be designed with meaningful input from displaced communities to ensure it meets their specific needs and cultural preferences.

Bangladesh’s “Climate Resilient Infrastructure” program exemplifies this approach by building cyclone shelters that double as schools and community centers, providing safe refuge for displaced families during emergencies while serving everyday social functions. Complementing infrastructure investments, early warning systems that disseminate alerts through mobile phones, community radio, and local networks have proven effective in enabling timely evacuations. Regular testing and maintenance of these systems are essential to maintain community trust and responsiveness.

Policy Frameworks and International Cooperation

Global governance of coastal displacement remains fragmented, but progress is being made at multiple levels to improve policy coherence and resource mobilization.

Roles of the UNFCCC, IOM, and Other Actors

The United Nations Framework Convention on Climate Change (UNFCCC) has established the Warsaw International Mechanism for Loss and Damage, which explicitly recognizes displacement as a critical issue linked to climate impacts. While dedicated funding streams for coastal and climate-induced relocation programs remain limited, the mechanism provides a foundation for future financial and technical support.

The International Organization for Migration (IOM) has developed guidelines on “Migration, Environment and Climate Change” to assist states in incorporating migration considerations into National Adaptation Plans (NAPs). Countries such as Fiji, Kenya, and Bangladesh have begun integrating displacement into their climate policies, signaling growing recognition of this challenge.

International cooperation is also essential to address cross-border displacement and to share best practices in coastal adaptation, ecosystem restoration, and community resilience building. Multilateral funding mechanisms, capacity-building initiatives, and knowledge exchange platforms can support vulnerable coastal states and communities in managing displacement risks more effectively.

In conclusion, coastal zones embody complex dualities as both sanctuaries and hotspots of vulnerability for displaced populations. The intertwined environmental and human geography factors demand integrated, multi-scalar approaches that balance ecological conservation with social equity. Through ecosystem-based adaptation, participatory governance, resilient infrastructure, and strengthened policy frameworks, it is possible to transform coastal zones into sustainable refuges that safeguard human dignity and ecological integrity in an era of accelerating climate change.