The Emergence of Climate Security Risks in the Pacific 

Pacific Island Countries (PICs) have long faced structural vulnerabilities shaped by colonial legacies, geographic remoteness, limited land area, and narrow economic bases. Climate change has significantly amplified these challenges, increasingly posing existential risks for some Pacific Island societies (Pasisi, 2019). 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, despite the region's minimal contribution to global greenhouse gas emissions (McMurray et al., 2023).These trends are already reshaping livelihoods, ecosystems, and critical sectors such as fisheries, agriculture, and water systems, with cascading implications for mobility, governance, and social cohesion across the region (Pasisi, 2019).

From the 1990s onward, Pacific states emerged as early global advocates linking climate change to survival, sovereignty, and human security, embedding these concerns within regional frameworks emphasising human-centred and non-traditional security. This evolution was formalised in the Boe Declaration on Regional Security (2018) and its subsequent Action Plan (2019), which identified climate change as the region’s most severe security threat, with implications for governance, livelihoods, identity, and stability. This recognition reflects decades of evolving understanding that climate impacts extend beyond environmental degradation, constituting multidimensional risks shaping the social, economic, and political fabric of Pacific societies (Shibata et al., 2024).

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 for fiscal stability and service provision (McMurray et al., 2023; Palacios-Abrantes et al., 2021). At the same time, coral loss and coastal degradation are weakening nearshore fisheries, undermining food security and household income, particularly in subsistence and outer-island communities (McMurray et al., 2023). Because a significant share of Pacific livelihoods is concentrated in climate-sensitive sectors such as agriculture, tourism, and fisheries, both households and national economies remain highly exposed to climate shocks (Pasisi, 2019). As coping capacity erodes, these pressures contribute to rising unemployment, increased reliance on imported food and, in some cases, maladaptive coping strategies further undermining community resilience and increasing downstream risks of displacement and social instability (Steinkraus et al., 2024; Rüttinger & Khèdr, 2025).

Climate Stress Weakens Food, Water and Health Security 

Climate change is increasingly undermining access to safe water, adequate food and basic health services across Pacific Island Countries. Rising temperatures, altered rainfall patterns, droughts, flooding and saltwater intrusion are degrading freshwater resources, reducing agricultural productivity and disrupting coastal and nearshore fisheries that underpin local food security (McMurray et al., 2023; SPC, 2015). In low-lying atoll states, contamination of freshwater lenses is forcing greater reliance on rainwater harvesting, desalination and external assistance, heightening risks of water scarcity and placing additional strain on already limited health and service delivery systems, particularly following extreme events (Shibata et al., 2024). At the same time, climate impacts are reducing access to traditional, nutritious foods while increasing dependence on imported, low-nutrient alternatives, compounding public health challenges such as high rates of non-communicable diseases. As extreme heat, flooding and ecological change expand the spread of vector- and water-borne diseases (Pasisi, 2019). Over time, declining health, food and water security erode human capital and social resilience, acting as a threat multiplier that amplifies risks linked to livelihood loss, displacement and state fragility.

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). 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 generate significant economic shocks: climate-related disasters already cause an estimated USD 1.075 billion in annual losses, around 5% of Pacific SIDS’ GDP, placing sustained pressure on public finances and recovery systems (McMurray et al., 2023). Repeated disasters strain governments’ ability to deliver essential services, erode public trust, and widen inequalities when recovery is uneven. In some contexts, post-disaster periods are associated with increased opportunistic crime, social disorder, and pressure on policing and emergency services, particularly where response capacity is limited (Pasisi, 2019). Poorly designed or inequitable recovery efforts can further weaken social cohesion and reinforce existing vulnerabilities and grievances, increasing longer-term risks of fragility (Barry et al., 2025; Shibata et al., 2024).

Climate Change Shapes Mobility Trends and Heightens Displacement Risks

Environmental degradation, disasters and declining livelihood opportunities are accelerating mobility primarily within Pacific Island Countries, and to a more limited extent between islands and states (Pasisi, 2019;). In many cases, climate impacts undermine land habitability long before physical inundation occurs, as saltwater intrusion, erosion, and water scarcity reduce the viability of settlements and livelihoods. These pressures drive growing movement from outer islands to urban centres, as well as seasonal and distress migration, placing strain on housing, services, and labour markets and increasing risks of social tension (Pasisi, 2019; Barry et al., 2025;). Mobility also carries cultural and psychological consequences, as the loss of ancestral land and associated ecosystems threatens identity and community cohesion, particularly for atoll populations facing the prospect of long-term relocation (Shibata, et al., 2024). At the same time, mobility is uneven: financial, educational, health, and social constraints limit the ability of some individuals and communities to move. Where relocation occurs, outcomes are strongly shaped by customary land tenure systems, which regulate access to land through traditional authority structures. Without sustained dialogue and inclusive planning, relocation processes, particularly where land is scarce, may generate disputes and heighten the risk of social tension, with disproportionate impacts on vulnerable groups (Pasisi, 2019).

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, creating legal uncertainty around Exclusive Economic Zones that are central to governance, law enforcement, and natural resource management (McMurray et al., 2023). At the extreme, climate change raises existential concerns for low-lying atoll nations, as large-scale land loss challenges territorial integrity and long-term state continuity. As maritime features are altered or inundated, the long-term security of marine resource rights and the exercise of state authority over ocean spaces may be weakened (ILA, 2018; SPC, 2019). At the same time, climate-related pressures, such as weakened domestic capacity, economic vulnerability and expanding adaptation needs, interact with intensifying strategic competition among external powers. As maritime resources, ocean governance, and climate finance become increasingly politicised, Pacific Island Countries face heightened risks of geostrategic contestation and external influence (Paskal, 2010; Barry et al, 2025). Together, these dynamics may reduce effective control over marine resources and complicate long-term efforts to safeguard sovereignty, maritime rights, and regional stability.

Climate resilience strategies address climate-fragility risks by strengthening the capacity of societies to manage climate impacts and associated stresses. The Weathering Risk Report Climate, Peace and Environmental Resilience in the Asia-Pacific Region (2025) 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.