Climate change threatens tuna economy powering Kiribati’s ocean empire

The vast Pacific Ocean has long been the economic lifeblood of Kiribati, a low-lying island nation whose survival is intimately tied to the sea—but that dependence is now becoming its greatest vulnerability.

Warming waters driven by climate change are threatening to displace tuna stocks that generate the majority of Kiribati’s government revenue, raising serious questions about the country’s long-term economic survival, BBC writes.

Kiribati consists of 33 scattered islands spread across a territorial Exclusive Economic Zone (EEZ) of more than 3.4 million sq km—an area larger than India. Despite its tiny landmass, roughly the size of New York City when combined, the country sits at the heart of one of the world’s richest tuna fisheries, including skipjack, yellowfin, and bigeye tuna.

Yet this abundance is increasingly uncertain. More than 70% of government revenues come from selling fishing licenses to foreign fleets, the highest proportion of any country globally. In 2024 alone, Kiribati generated $137 million from these licenses, which officials describe as a “critical financial lifeline.”

As Riibeta Abeta, permanent secretary for the Ministry of Fisheries, explains, such agreements accounted for almost three-quarters of government income between 2018 and 2022, equivalent to around two-fifths of GDP.

However, climate change is disrupting the ocean systems that underpin this model. Scientists warn that rising sea temperatures are pushing tuna populations eastward toward cooler waters, potentially outside Kiribati’s EEZ.

“Tuna react to small changes in water temperature to within a tenth of a degree of celsius,” says fisheries specialist Simon Diffey, noting that even minor warming can trigger large-scale migration shifts.

The implications are severe. Abeta warns that the resulting loss of fishing access fees could introduce “significant volatility to the country’s revenue,” with government projections suggesting potential annual losses of more than $10 million by 2050 under high-emission scenarios. While optimistic models suggest stable tuna biomass under lower emissions, local fishers are expected to suffer declines under all scenarios.

“The Line Islands are set to be the worst affected, with a loss of two-thirds estimated under the low-emission scenario alone,” according to Pacific Community projections.

At the same time, Kiribati’s population—currently about 130,000—is growing, intensifying pressure on already limited land and food resources.

Food security is becoming an urgent parallel crisis. Fish consumption in Kiribati averages around 100kg per person annually, compared with 9kg in the United States and 22kg in Japan. But declining local stocks are forcing greater reliance on imported foods, raising costs and reducing nutritional quality, particularly in remote islands.

In response, international and domestic adaptation strategies are emerging. The Green Climate Fund has launched a $156.8m regional programme aimed at improving forecasting and resilience in 14 Pacific nations.

“This is helping Pacific Island countries get ahead of climate change by strengthening their food security based on better information,” says Hemant Mandal, GCF director for Asia and the Pacific.

The initiative aims to develop early warning systems for shifting tuna stocks while supporting food security through alternative fisheries. Meanwhile, Kiribati is expanding domestic tuna processing, developing aquaculture, and exploring diversification into tourism, renewable energy, and sovereign wealth investments.

“Kiribati retains grounds for optimism and strategic opportunity,” Abeta says.

Yet the underlying challenge remains stark. Kiribati’s vast ocean territory—once a source of stability and wealth—is increasingly becoming a moving target, reshaped by warming seas and the accelerating realities of climate change.

By Sabina Mammadli