The effect of climate change on small island countries can be extreme because of low-lying coasts, relatively small land masses, and exposure to extreme weather. The effects of climate change, particularly sea level rise and increasingly intense tropical cyclones, threaten the existence of many island countries, island peoples and their cultures, and will alter their ecosystems and natural environments. Several Small Island Developing States (SIDS) are among the most vulnerable nations to climate change.
Some small and low population islands are without adequate resources to protect their islands, inhabitants, and natural resources. In addition to the risks to human health, livelihoods, and inhabitable space, the pressure to leave islands is often barred by the inability to access the resources needed to relocate. The nations of the Caribbean, Pacific Islands and Maldives are already experiencing considerable impacts of climate change, making efforts to implement climate change adaptation a critical issue for them.
Efforts to combat these environmental changes are ongoing and multinational. Due to their vulnerability and limited contribution to greenhouse gas emissions, some island countries have made advocacy for global cooperation on climate change mitigation a key aspect of their foreign policy. Governments face a complex task when combining gray infrastructure with green infrastructure and nature-based solutions to help with disaster risk management in areas such as flood control, early warning systems, nature-based solutions, and integrated water resource management. As of March 2022, the Asian Development Bank has committed $3.62 billion to help small island developing states with climate change, transport, energy, and health projects.
Greenhouse gas emissions
Small Island Developing States make minimal contribution to global greenhouse gas emissions, with a combined total of less than 1%. However, that does not indicate that greenhouse emissions are not produced at all, and it is recorded that the annual total greenhouse gas emissions from islands could range from 292.1 to 29,096.2 [metric] tonne -equivalent.
Impacts on the natural environment
Expected impacts on small islands include: extreme weather events changes in sea level increased sensitivity and exposure to the effects of climate change. deterioration in coastal conditions, such as beach erosion and coral bleaching, which will likely affect local resources such as fisheries, as well as the value of tourism destinations. increased inundation, storm surge, erosion, and other coastal hazards caused by sea-level rise, threatening vital infrastructure, settlements, and facilities that support the livelihood of island communities. reduction of already limited water resources to the point that they become insufficient to meet demand during low-rainfall periods by mid-century, especially on small islands (such as in the Caribbean and the Pacific Ocean) invasion by non-native species increasing with higher temperatures, particularly in mid- and high-latitude islands. There are many secondary effects of climate change and sea-level rise particular to island nations. According to the US Fish and Wildlife Service, climate change in the Pacific Islands will cause "continued increases in air and ocean surface temperatures in the Pacific, increased frequency of extreme weather events, and increased rainfall during the summer months and a decrease in rainfall during the winter months". This would entail distinct changes to the small, diverse, and isolated island ecosystems and biospheres present within many of these island nations.
Sea level rise
One of the dominant manifestations of climate change is sea level rise. NOAA estimates that "since 1992, new methods of satellite altimetry (the measurement of elevation or altitude) indicate a rate of rise of 0.12 inches per year". Similarly NASA calculates that the average sea level rise is 3.41 mm per year and that sea-level rise is directly caused by the expansion of water as it warms and the melting of polar ice caps. Both of these changes are dependent on global warming as a result of climate change. Sea level rise is especially threatening to low-lying island nations because seas are encroaching upon limited habitable land and threatening existing cultures. Stefan Rahmstorf, a professor of Ocean Physics at Potsdam University in Germany notes "even limiting warming to 2 degrees, in my view, will still commit some island nations and coastal cities to drown."