Chapter 27 of the Fourth National Climate Assessment describes changes already being felt in Hawai‘i and Pacific Islands, as well as what lies ahead. The top findings include:
- Dependable and safe water supplies are threatened by rising temperatures, changing rainfall patterns, sea level rise, and increased risk of extreme drought and flooding. Islands are already experiencing saltwater contamination due to sea level rise, which is expected to catastrophically impact food and water security, especially on low-lying atolls.
- Sea level rise has accelerated and is now damaging critical infrastructure such as transportation and housing, as well as beaches, ecosystems and cultural sites. In Hawai‘i, the value of all structures and land expected to be flooded by 2100 amounts to more than $19 billion statewide. The Pacific Islands will experience sea level rise higher than the global average, projected to further accelerate strongly after mid-century. Adaptation strategies that are implemented sooner can better prepare communities and infrastructure.
- Increasing ocean temperatures and acidification threaten fisheries, coral reefs, and the livelihoods they support. Widespread coral reef bleaching and death are occurring more frequently, and by mid-century these events are projected to occur annually, especially if current trends in greenhouse gas emissions continue. Bleaching and acidification will result in loss of reefs, leading to lower fisheries yields and loss of coastal protection and habitat.
- These changes imperil Indigenous peoples’ health and well-being and their relationships with lands, territories, and cultural resources.
- Climate change reduces the ability of habitats to support protected plant and animal species. Changes promote the spread of invasive species, threatening biodiversity, important to island people and a source of economic revenue. Some species are expected to become extinct and others to decline to the point of requiring costly protection.
