Approximately one million people live on atolls such as the Maldives, Tuvalu, Kiribati and the Marshall Islands. These islands are only a few tens of centimeters high, making them among the places most at risk from rising sea levels due to climate change. In the past century, five uninhabited Solomon Islands have already disappeared under the waves.

Popular with travelers, the islands have the highest percentage of threatened land as they are all atolls. So, which islands are most rapidly submerged and become uninhabitable due to climate change? As it turned out, answering this question is not so easy. Four Islands shows why.

Mainadu, Huvadhu Atoll, Maldives

First, scientists don’t have accurate elevation data for many of these remote islands, and even if they did, that information couldn’t predict when they would be submerged.

“Atoll islands are very dynamic places,” said Geronimo Hussmann, a researcher at the Global Climate Forum. “They change shape, increase in size. Sometimes they come together very quickly.”

A 2018 paper examining Mainadu Island in the Maldives found that such coral reef islands can grow on sand. But the islands get new sand from coral reefs, and global warming is killing the corals. At an additional 2 degrees Celsius, 99% of coral reefs would die. At 1.5 C some coral remains.

Roy Namur Island, Kwajalein Atoll, Republic of the Marshall Islands

Islands do not have to disappear to become uninhabitable. First, when waves hit islands at sea level, they contaminate fresh groundwater with salt. Sea level rise means frequent flooding, and groundwater cannot survive daily or even annual floods: food trees die and water has to be imported.

2018 article Science Developments Flooding on the island of Roi-Namur in the Marshall Islands was analyzed. Most atoll islands are projected to run out of drinking water by the 2060s (if global climate targets are not met) or by the 2030s if ice sheets collapse under a “worst-case scenario” of climate change. Thousands of Marshall Islanders have already emigrated.

Mundu, Laamu Atoll, Maldives

Many islanders are adapting despite devastating floods; Therefore, simply defining “livable” is a difficult task. “It stings the hive,” Hussmann said Live Science.

Just a few blocks wide at its widest end, Mundu Island in the Maldives has a school, beautiful beaches and many sports teams. Less than 200 people live in it – but even this number is surprising.

In 2004, a flood destroyed Munda and its neighbor Calheida. The government declared that the two islands would remain uninhabited in the future – “Mundu received basically no public sector investment,” Hussmann said – but many Mundu families returned. According to Hussmann, islands without central government funding may become uninhabited at first, but political will can bring surprises.

Fongafale, Funafuti Atoll, Tuvalu

Urban islands receive more investment than rural islands, but they also face challenges. Tuvalu, the capital of Fongafale Island, is home to approximately 4,000 people. By 2100, 95% of the island could be submerged during high tides. To combat this, Tuvalu recently added artificial hills to one side of the island. The long-term plan is to expand the island by about 50% and then upgrade both sides.

But a 2022 analysis that included multiple risk factors found that even these conservation efforts would fail to make the islands livable: The decline in the ecosystem would hurt tourism, fisheries, and the islanders’ ability to fund solutions. The scale and speed of global efforts to limit climate change will make a tangible difference. Which islands and island communities ultimately survive will depend largely on how the rest of the world responds. Source