An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been part of a continent. Oceanic islands can be formed from volcanic activity, grow into atolls from coral reefs, and form from sediment along shorelines, creating barrier islands. River islands can also form from sediment and debris in rivers. Artificial islands are those made by humans, including small rocky outcroppings built out of lagoons and large-scale land reclamation projects used for development.
The Marshall Islands consist of two archipelagic island chains of 30 atolls and 1,152 islands, which form two parallel groups—the "Ratak" (sunrise) chain and the "Ralik" (sunset) chain. The Marshalls are located in the North Pacific Ocean and share maritime boundaries with Micronesia and Kiribati. Two-thirds of the nation's population lives in the capital of Majuro and the settlement of Ebeye. The outer islands are sparsely populated due to lack of employment opportunities and economic development.
Tuvalu is an island country in the Polynesian subregion of Oceania in the Pacific Ocean, about midway between Hawaii and Australia. It lies east-northeast of the Santa Cruz Islands, northeast of Vanuatu, southeast of Nauru, south of Kiribati, west of Tokelau, northwest of Samoa and Wallis and Futuna, and north of Fiji.
The Western Pacific nation of Tuvalu, formerly known as the Ellice Islands, is situated 4,000 kilometers (2,500 mi) northeast of Australia and is approximately halfway between Hawaii and Australia. It lies east-northeast of the Santa Cruz Islands, southeast of Nauru, south of Kiribati, west of Tokelau, northwest of Samoa and Wallis and Futuna and north of Fiji. It is a very small island country of 26.26 km2 (10.14 sq mi). Due to the spread out islands it has the 38th largest Exclusive Economic Zone of 749,790 km2 (289,500 sq mi). In terms of size, it is the second-smallest country in Oceania.
Maldives is an island country in the Indian Ocean, South Asia, south-southwest of India. It has a total land size of 298 km2 (115 sq mi) which makes it the smallest country in Asia. It consists of approximately 1,190 coral islands grouped in a double chain of 26 atolls, spread over roughly 90,000 square kilometers, making this one of the most geographically dispersed countries in the world. It has the 31st largest exclusive economic zone of 923,322 km2 (356,497 sq mi). Composed of live coral reefs and sand bars, the atolls are situated atop a submarine ridge, 960 km (600 mi) long that rises abruptly from the depths of the Indian Ocean and runs from north to south. Only near the southern end of this natural coral barricade do two open passages permit safe ship navigation from one side of the Indian Ocean to the other through the territorial waters of Maldives. For administrative purposes the Maldives government organized these atolls into twenty-one administrative divisions.
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Vanua Levu, formerly known as Sandalwood Island, is the second largest island of Fiji. Located 64 kilometres to the north of the larger Viti Levu, the island has an area of 5,587.1 square kilometres (2,157.2 sq mi) and a population of 135,961 as of 2007.
The Carteret Islands are Papua New Guinea islands located 86 km (53 mi) north-east of Bougainville in the South Pacific. The atoll has a scattering of low-lying islands called Han, Jangain, Yesila, Yolasa and Piul, in a horseshoe shape stretching 30 km (19 mi) in north-south direction, with a total land area of 0.6 square kilometres (0.2 sq mi) and a maximum elevation of 1.5 metres above sea level.
The Coral Triangle (CT) is a roughly triangular area in the tropical waters around Indonesia, Malaysia, Papua New Guinea, the Philippines, Solomon Islands, and Timor-Leste. This area contains at least 500 species of reef-building corals in each ecoregion. The Coral Triangle is located between the Pacific and Indian oceans and encompasses portions of two biogeographic regions: the Indonesian-Philippines Region, and the Far Southwestern Pacific Region. As one of eight major coral reef zones in the world, the Coral Triangle is recognized as a global centre of marine biodiversity and a global priority for conservation. Its biological resources make it a global hotspot of marine biodiversity. Known as the "Amazon of the seas", it covers 5.7 million square kilometres (2,200,000 sq mi) of ocean waters. It contains more than 76% of the world's shallow-water reef-building coral species, 37% of its reef fish species, 50% of its razor clam species, six out of seven of the world's sea turtle species, and the world's largest mangrove forest. The epicenter of that coral diversity is found in the Bird’s Head Seascape of Indonesian Papua, which hosts 574 species. Within the Bird’s Head Seascape, the Raja Ampat archipelago is the world’s coral diversity bull’s eye with 553 species. In 2014, the Asian Development Bank (ADB) reported that the gross domestic product of the marine ecosystem in the Coral Triangle is roughly $1.2 trillion per year and provides food to over 120 million people. According to the Coral Triangle Knowledge Network, the region annually brings in about $3 billion in foreign exchange income from fisheries exports, and another $3 billion from coastal tourism revenues.
Between 1901 and 2018, the average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise, with another 42% resulting from thermal expansion of water.
Climate change is particularly threatening for the long-term habitability of the island country of Tuvalu, which has a land area of only 26 square kilometres (10 sq mi) and an average elevation of less than 2 metres (6.6 ft) above sea level, with the highest point of Niulakita being about 4.6 metres (15 ft) above sea level. Potential threats to the country due to climate change include rising sea levels, increasingly severe tropical cyclones, high temperatures, and drought. King tides can combine with storm surges and the rising sea level to inundate the low lying atolls.
The North Shore, in the context of geography of the Island of Oʻahu, refers to the north-facing coastal area of Oʻahu between Kaʻena Point and Kahuku. The largest settlement is Haleʻiwa.
The effects of climate change on small island countries are affecting people in coastal areas through sea level rise, increasing heavy rain events, tropical cyclones and storm surges. These effects of climate change threaten the existence of many island countries, their peoples and cultures. They also alter ecosystems and natural environments in those countries. Small island developing states (SIDS) are a heterogenous group of countries but many of them are particularly at risk to climate change. Those countries have been quite vocal in calling attention to the challenges they face from climate change. For example, the Maldives and nations of the Caribbean and Pacific Islands are already experiencing considerable impacts of climate change. It is critical for them to implement climate change adaptation measures fast.
Climate change in Guam encompasses the effects of climate change, attributed to man-made increases in atmospheric carbon dioxide, in the U.S. territory of Guam.
Climate change is having serious impacts in the Philippines such as increased frequency and severity of natural disasters, sea level rise, extreme rainfall, resource shortages, and environmental degradation. All of these impacts together have greatly affected the Philippines' agriculture, water, infrastructure, human health, and coastal ecosystems and they are projected to continue having devastating damages to the economy and society of the Philippines.
Climate change is a major issue for the Maldives. As an archipelago of low-lying islands and atolls in the Indian Ocean, the existence of the Maldives is severely threatened by sea level rise. By 2050, 80% of the country could become uninhabitable due to global warming. According to the World Bank, with "future sea levels projected to increase in the range of 10 to 100 centimeters by the year 2100, the entire country could be submerged". The Maldives is striving to adapt to climate change, and Maldivian authorities have been prominent in international political advocacy to implement climate change mitigation.
Climate change in the Marshall Islands is a major issue for the country. As with many countries made up of low-lying islands, the Marshall Islands is highly vulnerable to sea level rise and other impacts of climate change. The atoll and capital city of Majuro are particularly vulnerable, and the issue poses significant implications for the country's population. These threats have prompted Marshallese political leaders to make climate change a key diplomatic issue, who have responded with initiatives such as the Majuro Declaration.
The coral reefs of Tuvalu consist of three reef islands and six atolls, containing approximately 710 km2 (270 sq mi) of reef platforms. The islands of the Tuvalu archipelago are spread out between the latitude of 5° to 10° south and longitude of 176° to 180°, west of the International Date Line. The islands of Tuvalu are volcanic in origin. On the atolls, an annular reef rim surrounds the lagoon, and may include natural reef channels. The reef islands have a different structure to the atolls, and are described as reef platforms as they are smaller tabular reef platforms that do not have a salt-water lagoon, although they may have a completely closed rim of dry land, with the remnants of a lagoon that has no direct connection to the open sea or that may be drying up.
Climate change in Fiji is an exceptionally pressing issue for the country - as an island nation, Fiji is particularly vulnerable to rising sea levels, coastal erosion and extreme weather. These changes, along with temperature rise, will displace Fijian communities and will prove disruptive to the national economy - tourism, agriculture and fisheries, the largest contributors to the nation's GDP, will be severely impacted by climate change causing increases in poverty and food insecurity. As a party to both the Kyoto Protocol and the Paris Climate Agreement, Fiji hopes to achieve net-zero emissions by 2050 which, along with national policies, will help to mitigate the impacts of climate change.
