Climate change is a global issue, but sea-level rise is not experienced equally. Across the Pacific, low-lying island countries face threats to homes, drinking water, food production, infrastructure and, ultimately, the continued habitability of their land.

For many Australians and New Zealanders, sea-level rise is discussed as a future coastal-planning problem.

For some Pacific communities, it is already part of daily life.

Higher seas increase the reach of storm surges, accelerate coastal erosion and allow salt water to enter soils and underground freshwater supplies. Roads, homes, schools, power systems and health facilities may be damaged long before an island is permanently submerged.

The United Nations has warned that sea-level rise will accelerate and make some low-lying coastal and island areas increasingly difficult to inhabit.

Tuvalu

Tuvalu is among the countries most frequently associated with sea-level rise.

Its islands are extremely low, leaving communities exposed to flooding, erosion and saltwater intrusion.

The threat is not limited to losing land. It includes damage to crops, contamination of drinking water, pressure on housing and the cost of repeatedly repairing essential infrastructure.

Tuvalu has also been prominent in efforts to ensure that its sovereignty and maritime rights continue even if climate change alters its physical territory.

Kiribati

Kiribati consists of widely dispersed islands and atolls across a vast area of ocean.

Many communities live only a small distance above sea level. Rising seas can contaminate freshwater lenses beneath the islands and reduce the land available for settlement and agriculture.

Relocation within Kiribati is difficult because much of the country faces similar physical constraints.

Marshall Islands

The Marshall Islands faces comparable exposure.

Its narrow atolls support homes, roads and critical infrastructure within metres of the shoreline. Even comparatively small changes in sea level can magnify the effects of storms and unusually high tides.

The legacy of nuclear testing also gives Marshallese concerns an added dimension, as erosion and flooding may affect contaminated sites and waste-storage structures.

Other vulnerable countries

Low-lying areas of the Federated States of Micronesia, Papua New Guinea, Solomon Islands, Fiji, Tonga and Vanuatu are also exposed.

Not every Pacific country will experience the same effects. Some islands are mountainous and offer opportunities for communities to move inland or to higher ground.

Even there, however, relocation may mean leaving customary land, burial places, fishing grounds and culturally important sites.

Climate displacement is not simply a question of moving houses. Land in the Pacific is closely connected to ancestry, community authority and identity.

Australia and New Zealand are affected too

Australia faces rising risks to coastal communities, ports, roads and low-lying infrastructure. Its external territories, including the Cocos Islands, are particularly vulnerable.

An Australian submission to the United Nations warned that sea-level rise could contribute to water and food insecurity, loss of settlements and infrastructure, poorer health and damaged livelihoods across the Blue Pacific.

New Zealand faces erosion, flooding and difficult decisions about whether some communities can be defended indefinitely or must eventually retreat from vulnerable shorelines.

Both countries will also face pressure to support Pacific adaptation, disaster response and migration arrangements.

Can the islands be protected?

There is no single solution.

Possible responses include:

• Sea walls and coastal barriers
• Restoring mangroves and reefs
• Raising buildings and roads
• Improving freshwater storage
• Relocating critical infrastructure
• Planned movement to safer land
• International finance for adaptation

Engineering can protect some places, but not every settlement can be surrounded by increasingly expensive barriers.

Adaptation must also be led by the affected communities. An outside government may see relocation as a practical response, while residents may see it as the loss of land, history and belonging.

More than an environmental issue

Sea-level rise raises difficult legal questions.

Can a state retain its maritime boundaries if its coastline changes? Does sovereignty continue if a population is forced to live elsewhere? Who pays for displacement caused largely by emissions produced outside the Pacific?

The United Nations has recognised that the issue affects statehood, human rights, resources and the protection of displaced people—not merely the physical environment.

For the Pacific, climate change is therefore economic, cultural, legal and strategic.

The countries contributing least to global emissions are among those facing the most profound consequences.