Islands and sea-level rise

Global warming causes thermal expansion and ice melt, increasing seawater volume and provoking more frequent and more severe storms. As a result, small, low-lying islands are threatened with ecological degradation and submergence.

Background

Global warming threatens the survival of low-lying islands, deltas, and beaches. In 2010, the National Research Council, as reported by the US Environmental Protection Agency (EPA), estimated that by the year 2100, sea levels will have risen by 16–56 inches (40.64–142.24 centimeters) since 1990. Rising sea levels threaten human, animal, and plant life, as arable land and potable water are compromised. Refugee migrations and species extinctions result.

Conditions

For millennia before the nineteenth century, Earth’s sea levels remained relatively stable. However, as the pace of industrialization and urbanization accelerated around the globe, sea levels began to rise by millimeters per year. Tide gauges and satellite monitoring indicate that this rise has increased in recent decades. Two factors contribute to increases in sea volume. One is thermal expansion, which causes warming waters to increase in volume. The other is the melting of ice sheets and glaciers at the North and South Poles and in the mountains of the Andes, Alps, and Himalayas.

Retreating ice has been noted in all these regions. Ice melt in Greenland begins earlier each summer, leaving ever-smaller areas to refreeze by winter. The runoff water from the melt penetrates glaciers, loosening their attachment to rock surfaces. Large chunks then break away, in a process known as “calving,” launching masses of ice several square kilometers in area that float away, eventually melting in warmer waters. The snow and ice of ski fields in Switzerland have disappeared, as the snow line rises in altitude. Less snow and ice on the surface of the Earth reduces the deflection of sunlight, or albedo, thereby causing more warming in a positive feedback loop. Furthermore, thawing allows the escape of methane gases that have been locked in the frozen Earth, further strengthening the greenhouse effect.

Consequences

Islands are bodies of land surrounded by water, ranging in size from continents to tiny atolls. They can be found on all continents, oceans, and seas. One type of island rises from an underwater oceanic volcano, as the tip emerges above the water surface to form the island. The other type is an elevation of land on a continental shelf that rises above surrounding waters. Hawaii is an example of the former; the British Isles are instances of the latter. The smaller and lower in height an island is, the more vulnerable it is to rising seas. In addition to threats from rising sea levels, small islands are endangered by tropical storms, including hurricanes and cyclones. If the frequency and ferocity of these storms increase, the risk to islands does as well.

The consequences of this vulnerability are devastating in several respects. In addition to being submerged, small land bodies are being eaten away at their edges by erosion. Moreover, as salt water penetrates an island, salinity enters the water table below the island’s surface. The more salinity that freshwater absorbs, the less potable it is for drinking. Moreover, brackish water stunts or kills crops, reducing the food supply. The sustenance of not only humans but also wildlife is threatened.

Some islands are being abandoned by their inhabitants as the sea consumes the land. In 2009, facing predictions that their home would be completely submerged by 2015, the two thousand inhabitants of the Carteret Islands of Papua New Guinea began a community-wide evacuation effort that placed them among the world's first official climate-change refugees. Lohachara Island in the Bay of Bengal disappeared underwater in 2006; its residents fled to the mainland. Tuvalu, with a population under ten thousand, is a country of nine narrow coral atolls in the South Pacific. In 2024, NASA issued a dire warning for the Pacific Island nations of Tuvalu, Kiribati, and the Fiji islands that they would receive at least 6 inches (15 centimaters) of sea level rise in the next thirty years even if greenhouse gas emissions are reducted. These islands, along with the Maldaves and the Marshall Islands, are coral atolls with only a few feet of elevation, which puts people at risk because they cannot flee to a higher elevation. In 2014, for the first time, a Tuvaluan family was granted New Zealand residency based on their status as environmental refugees. Many more environmental refugees followed suit. According to the United Nations High Commission for Refugees (UNHCR), by 2022, about 84 percent of refugees and asylum seekers throughout the world were from climate-vulnerable countries.

By the early 2020s, scientists reported that global climate change had begun rapidly reshaping many islands around the world. Reports showed that many island nations would experience a drastic increase in flooding over the coming decades, with severe consequences for the islands' residents. Most importantly, scientists theorized that these environmental changes could no longer be prevented.

Prevention

Small island countries produce negligible amounts of greenhouse gases (GHGs), but they suffer most directly and critically the consequences of global warming caused by the major emitters. Small island countries act cooperatively through a number of organizations. The Global Islands Network (GIN) is an information clearinghouse and resources cooperative for islands all over the world. Complementing it is the Small Islands Development Network (SIDSnet), specializing in communications and information technology to support island maintenance and development. Members of the Alliance of Small Island States (AOSIS) coordinate their efforts through their respective UN diplomatic missions. The International Small Islands Studies Association (ISISA) is a professional organization that supports research about small islands. The International Scientific Council for Island Development (INSULA) supports the economic, technical, ecological, social, and cultural programs of the world’s islands and publishes INSULA: International Journal of Island Affairs, which specializes in nissology. Another periodical is the Island Studies Journal.

Context

Small, low-lying islands are idyllic yet fragile fragments of the Earth’s surface. Somewhat like a canary in a coal mine, their extinction is an early warning sign of ecological danger. Before they submerge, erosion and saltwater intrusion render them uninhabitable. Larger low-lying surfaces, such as delta regions and beaches, are also threatened. As more islands lose the means to sustain their populations, the number of environmental refugees in the world increases, putting further pressure on the planet’s remaining resources.

The inhabitants of small islands have contributed the least to global warming, yet they suffer the worst of its initial consequences. They therefore unavoidably raise issues of social and environmental justice. Global warming admits of several feedback loops. The more the conditions for warming accumulate, the more such conditions are strengthened. For any inhabitant of a low-lying island or mainland surface, the question of the survival of one’s physical environment is a daily concern.

Key Concepts

• atoll: an island or islet consisting of a lagoon enclosed wholly or partly by a coral reef
• brackish water: mixture of freshwater and seawater
• calving: separation of a large portion of ice from a glacier or ice shelf, creating an iceberg
• methane: a gas whose is considerably stronger than that of carbon dioxide
• nissology: the study of islands
• thermal expansion: a heat-induced increase in the volume of a liquid or gas

Bibliography

Adamson, Joni, Mei Mei Evans, and Rachel Stein, eds. The Environmental Justice Reader: Politics, Poetics, and Pedagogy. Tucson: U of Arizona P, 2002. Print.

"Climate Change and Disaster Displacement." United Nations High Commission for Refugees (UNHCR),www.unhcr.org/us/what-we-do/build-better-futures/environment-disasters-and-climate-change/climate-change-and. Accessed 10 Dec. 2024.

Diamond, Jared M. Collapse: How Societies Choose to Fail or Succeed. Rev. ed. New York: Penguin, 2011. Print.

"Future Climate Change." US Environmental Protection Agency. USA.gov, 4 Mar. 2014. Web. 26 Aug. 2014.

Gerdes, Louise I., ed. Endangered Oceans: Opposing Viewpoints. San Diego: Greenhaven, 2004. Print.

Lisagor, Kimberly, and Heather Hansen. Disappearing Destinations: 37 Places in Peril and What Can Be Done to Help Save Them. New York: Vintage, 2008. Print.

Maas, Amy. "Tuvalu Climate Change Family Win NZ Residency Appeal." New Zealand Herald. APN New Zealand, 3 Aug. 2014. Web. 26 Aug. 2014.

"NASA Analysis Shows Irreversible Sea Level Rise for Pacific Islands." NASA, 25 Sept. 2024, www.jpl.nasa.gov/news/nasa-analysis-shows-irreversible-sea-level-rise-for-pacific-islands/. Accessed 10 Dec. 2024.

Sundaresan, J., et al., eds. Climate Change and Island and Coastal Vulnerability. Dordrecht: Springer, 2013. Print.

Tompkins, Emma L., et al. Surviving Climate Change in Small Islands: A Guidebook. Norwich: Tyndall Center for Climate Change Research, 2005. PDF file.