French Polynesia

Current Forecast: French Polynesia and a Changing Climate

The future of human habitation and economic production in French Polynesia depends on its ability to adapt to and mitigate sea-level rise and coral bleaching and acifidication.

The islands, in brief: French Polynesia is composed of 118 islands and atolls, 67 of which are inhabited, within a Pacific Ocean expanse of some 2.5 million square kilometres. Its total land area is 4,167 square kilometres. The islands are an overseas collectivity of the French Republic consisting of five island groups: the Society Islands archipelago, the Tuamotu Archipelago, the Gambier Islands, the Marquesas Islands and the Austral Islands. Tahiti, which is located within the Society Islands is the best-known and most populous island, home to the capital, Pape’ete, and some 68% of the population of about 270,000. Tourism drives the country’s economy, consisting of around 25% per cent of GDP.

Rising seas threaten coastal populations: Most of the city of Pape’ete has an elevation of zero to 15 metres and is surrounded by a shallow lagoon, with coastal beaches along the outer edge. Tahiti is a volcanic island with mountainous peaks, with several over 2,000 metres high. The rough terrain and mountainous features have led to a small amount of inhabitable land left for French Polynesians. The Tuamoto archipelago, one of several land masses with an elevation of one to two metres above sea level, could disappear in the coming decades. A 2013 study of French-controlled islands found that French Polynesia and New Caledonia were most at risk of seeing their islands completely submerged under rising sea levels. With oceans expected to rise by about 50 centimetres at the current rate, the rising of the sea will have a large impact on the
country’s habitation and topography.

Coral bleaching threatens fisheries and natural barriers against heavy storms: French Polynesia has experienced seven episodes of coral bleaching over the last 20 years. The most damaging episode occurred in 1991, in which about 20 per cent of coral colonies perished. The damage to the country’s coral reefs has led to a decline in the number of lagoon fish and the overall ocean food chain. This impacts the country’s subsistence fishing but also fisheries exports. The degradation of coral as a result of bleaching and acidification may threaten the country’s natural physical barriers against heavier storms. The islands are surrounded by atolls, which are made of coral and enclose lagoons at their centres. With heavy storms expected to become more frequent and the coral damaged by bleaching, the islands’ natural protection could be lost and leave the land vulnerable to weather events.

The Response

The collective government of French Polynesia, and the larger government of the Republic of France, have gathered a limited amount of data on the potential impacts of climate change and the appropriate response effort. The government has stated that there is the possibility that persons in islands affected rising seas could migrate to other areas of French Polynesia, such as the Marquesas Islands, which have higher altitudes and state-owned land. French Polynesia was the first country to sign an agreement to construct floating islands off its coast for alternative habitation. The islands will feature solar-powered platforms connected to other modular platforms in a branch-like structure. The firm in charge of the floating-islands project is set to study the project’s economic and environmental impact before construction begins.