Climate Change Threatens Pacific’s Economic Backbone – How Rising Ocean Temperatures Could Disrupt Global Tuna Supply | Langit Eastern

The vast Pacific Ocean and the islands scattered within it produce more than half of the world’s tuna supply. Yet the nations most dependent on this resource face an existential threat from climate change. This is an in-depth analysis of how rising sea temperatures are endangering the economic backbone of Pacific island nations.

Kiribati may have a landmass the size of New York City, but its Exclusive Economic Zone (EEZ) spans over 3.4 million square kilometres — larger than India. This EEZ is spread across three island groups and grants access to an ocean abundant with skipjack, yellowfin, and bigeye tuna. In 2024, Kiribati generated $137 million from selling fishing licences to foreign fleets including Japan, China, the US, and the European Union. This figure represents more than 70% of government revenue — the highest proportion of any nation in the world. According to the IMF, this equates to roughly two-fifths of Kiribati’s entire GDP.

Tuna reacts to small changes in water temperature to within a tenth of a degree Celsius. As Pacific Ocean surface temperatures rise, tuna will migrate eastwards to cooler waters, away from many island nations including Kiribati. According to the Pacific Community, Kiribati is predicted to be among the worst affected by tuna stock migration. Preliminary modelling shows the country “could lose more than $10 million per year” in fishing access fees by 2050 if greenhouse gas emissions remain high. Local fishermen will also see catch decreases under both high and low emission scenarios, with the Line Islands estimated to lose up to two-thirds of catches even under the best-case scenario.

The UN’s Green Climate Fund (GCF) launched a $156.8 million adaptation project covering 14 countries and territories across the Pacific region. The project aims to build early warning systems so nations like Kiribati can better predict tuna stock redistribution. The Kiribati government is also expanding domestic tuna processing and canning facilities, and developing marine aquaculture for species like milkfish, snapper, and sea cucumbers. Yet as the permanent secretary of Kiribati’s Ministry of Fisheries puts it: “The highest point above sea level in Kiribati — unless you climb a coconut tree — is two metres. No water, no land, no resources other than fish.”