The Emergence of Climate Security Risks in the Pacific 

Pacific Island Countries (PICs) have long navigated vulnerabilities associated with remoteness, small market size, limited land area, and dependence on natural resources. Climate change has significantly amplified these challenges. Sea-level rise, warming temperatures, ocean acidification, and increasingly extreme weather events have accelerated since the mid-20th century, with many impacts occurring faster in the Pacific than global averages (McMurray et al., 2023). These climatic trends are already reshaping livelihoods, ecosystems, and critical sectors such as fisheries, agriculture, and water systems across the Pacific (Barry et al., 2025).

As early as the 1990s, Pacific regional frameworks began integrating human security perspectives. The Boe Declaration (2018) formally identified climate change as the region’s most severe security threat, emphasising that climate change affects governance, livelihoods, identity, and stability (Pacific Islands Forum, 2018). This recognition reflects decades of evolving understanding that climate impacts are not merely environmental issues, but multidimensional risks shaping the social, economic, and political fabric of Pacific societies (Shibata et al., 2024).

This case study draws directly on the risk-pathway structure developed in the CSEN Climate-Fragility Brief: Pacific Islands Region which outlines climate-fragility pathways specific to Pacific Small Island Developing States (Pasisi’s., 2019). 

Climate Impacts Create Multi-Layered Pressures 

Climate Change threatens livelihoods and the blue economy

Climate change is undermining Pacific livelihoods by damaging the ecological and economic systems that sustain fisheries, tourism and coastal economies. Rising ocean temperatures, marine heat stress and ocean acidification are accelerating coral bleaching and degrading reef ecosystems, while cyclones such as Pam (2015), Winston (2016) and Harold (2020) have caused extensive destruction to coastal assets (Barry et al., 2025). Changing ocean conditions are also disrupting fish stocks, with warming waters projected to push commercially important species out of Pacific Exclusive Economic Zones, reducing fisheries revenues that governments depend on (McMurray et al., 2023; Palacios-Abrantes et al., 2021). Nearshore fisheries are simultaneously affected by coral loss and coastal degradation, threatening food security and household income (McMurray et al., 2023). These ecological pressures compound significant economic shocks: climate-related disasters already cause an estimated USD 1.075 billion in annual losses, around 5% of Pacific SIDS’ GDP, and up to 75% of Pacific Islanders’ incomes are expected to be negatively affected, particularly in agriculture, tourism and fisheries. These impacts contribute to rising unemployment, increased reliance on imported food and, in some cases, maladaptive coping strategies such as environmentally damaging small-scale mining, further undermining community resilience (Steinkraus et al., 2024; Rüttinger & Khèdr, 2025).

Climate Change Threatens Land Availability and Usability

Rising sea levels, coastal erosion and saltwater intrusion are reducing the availability and usability of land across the Pacific, particularly in low-lying atoll nations. The region is experiencing up to four times the global average rate of sea-level rise, leading to severe land degradation, inundation and the disappearance of islands (McMurray et al., 2023). Coastal vulnerability is high: 68.8% of people in Kiribati, 74.3% in the Marshall Islands and 64.9% in Tuvalu live within 200 metres of the shoreline (Kumar et al., 2020). Saltwater intrusion is contaminating freshwater lenses in atoll states, threatening drinking water and agriculture, while intensifying rainfall and flooding further degrade living conditions and public health (Barry et al., 2025). These pressures exacerbate food and water insecurity, generate land-use disputes and strain customary tenure systems. As conditions deteriorate, internal relocation becomes more likely, heightening tensions between sending and receiving communities and raising concerns over contested land, resources and inter-island relations (Shibata et al., 2025). If global emissions remain high, sea-level rise may cause land loss on a scale that could render entire nations such as Tuvalu and Kiribati uninhabitable within this century (Schroeder, 2024).

Disasters Exacerbate Vulnerabilities and Strain State Capacity

More frequent and intense disasters, particularly cyclones, droughts, storm surges and flooding, are increasingly overwhelming state capacities across the Pacific. Tropical cyclone intensity has risen in recent decades and is expected to worsen as ocean temperatures continue to increase (Kuleshov et al., 2014; Deo et al., 2022). Events such as Cyclone Pam, which destroyed up to 90% of housing in parts of Vanuatu, show how rapidly extreme weather can erase development gains and strain government resources (McMurray et al., 2023). Storm surges, king tides and flooding damage infrastructure, contaminate freshwater lenses and undermine agricultural land, while droughts associated with stronger El Niño cycles further disrupt water supplies and undermine livelihoods. These impacts strain governments’ ability to deliver services, erode public trust and widen inequalities when recovery is uneven (McMurray et al., 2023). In some contexts, social cohesion weakens, contributing to rises in opportunistic crime or disorder following disasters, while poorly designed or inequitable recovery efforts can reinforce existing vulnerabilities and grievances (Barry et al., 2025; Shibata et al., 2024).

Climate Change Shapes Mobility Trends and Heightens Risks

Environmental degradation, disasters and declining livelihood opportunities are accelerating mobility within and between Pacific islands. Land loss, storm surges and water scarcity increasingly push people from outer islands toward urban centres, while seasonal and distress migration is rising as environmental conditions worsen (Barry et al., 2025). These inflows strain housing, services and labour markets in cities, increasing risks of tension between newcomers and long-term residents and, in some cases, contributing to weakened social cohesion (Steinkraus et al., 2024). Mobility also carries cultural and psychological consequences, as the loss of ancestral land threatens identity and community cohesion, particularly for atoll populations facing the prospect of long-term relocation (Shibata, et al., 2024). At the same time, some individuals and communities cannot move due to financial, educational, health or social barriers; in the Marshall Islands, for example, migration opportunities are limited by language, education and income constraints. Without inclusive planning and dialogue, disputes over relocation areas, especially where customary land rights are strong, are likely to emerge.

Climate Change Spurs Sovereignty, Maritime Boundary, and Geostrategic Concerns

Climate change intersects with sovereignty and geopolitics in ways that pose significant security risks for Pacific Island Countries. Sea-level rise threatens the physical baselines used to determine maritime zones, raising concerns about the long-term security of Exclusive Economic Zones and associated resource rights (McMurray et al., 2023). Changing ocean conditions are altering the distribution of transboundary fish stocks, challenging resource management and complicating economic planning for states that depend heavily on fisheries (Palacios-Abrantes et al., 2021). At the same time, climate-related pressures, such as weakened domestic capacity, economic vulnerability and expanding adaptation needs, can increase exposure to external influence, particularly amid growing strategic competition between major powers in the region (Barry et al, 2025). These dynamics create risks of boundary ambiguity, increased geostrategic contestation and reduced control over marine resources, all of which may affect the ability of Pacific Island Countries to safeguard sovereignty and maintain stability.

Conflict resolution refers to strategies that address climate-fragility risks and support peaceful, resilient societies. The Weathering Risk Report Climate, Peace and Environmental Resilience in the Asia-Pacific Region identifies key entry points for intervention, focusing on reducing pressures linked to mobility, strengthening regional and international cooperation, and expanding local capacities to cope with accelerating climate risks.

1. Strengthen resilience for migrants and staying communities. Support community-based disaster risk management, early warning systems and rural livelihood investments to reduce forced displacement. Recognise mobility as a legitimate adaptation strategy and design relocation and migration policies in close consultation with affected communities, including IDPs, youth, host communities and non-migrants
2. Improve governance of climate-related mobility. Develop transparent, inclusive processes for planned relocation and internal migration, addressing land tenure challenges and host-community relations. Draw on lessons from the Australia–Tuvalu Falepili Union and community-led initiatives such as the Carteret Islands programme.
3. Platform Pacific voices in regional and global institutions. Strengthen the role of the Pacific Islands Forum in UN bodies and other international fora. Ensure consistent technical and financial support for Pacific participation in climate–peace diplomacy and facilitate regular engagement with civil society to align global policy with community needs.
4. Build local and regional climate-security capacities. Expand context-specific research and regularly update climate-security assessments at district and community levels. Support workshops, training and community-led adaptation initiatives that centre local knowledge and inclusive participation across gender, class and ethnicity.