U.S. Report: Climate change threats to Pacific Islands increase; adaptation strategies to build resilience guided by island wisdom

PI-CASC contributes insight, resources to Fifth National Climate Assessment

A clear beach is shown in the foreground, with green lands and buildings along the background.

Pacific Island ecosystems, cultural resources, infrastructure, human health, and livelihood are all at risk of degradation because of climate change, but these island communities can build resilience against such harms through adaptive actions driven by local and Indigenous Knowledge.

This was the sentiment put forth in the Fifth U.S. National Climate Assessment (NCA 5) — a comprehensive report on climate change risks, impacts, and responses authored and reviewed by scientists, scholars, and public servants across the nation. Representatives from the Pacific Islands Climate Adaptation Science Center (PI-CASC) were among the 16 authors and 41 technical contributors who produced the Hawai‘i and U.S.-Affiliated Pacific Islands chapter of the report.

“Disproportionately, our Pacific Island communities endure and suffer the impacts of a changing climate — from rising sea levels burying low-lying islands and destroying entire ecosystems, to intense typhoons battering vulnerable island communities and infrastructure and spreading invasive species. However, the Pacific peoples and the islands we call home have a long history of adapting to changing conditions. Adaptation is key to resilience, and this report helps provide a clear view of the challenges our region faces so that we can identify strategies to curb threats of climate change,” said PI-CASC Regional Administrator Dr. Mari-Vaughn Johnson, who is the federal coordinating lead for the Hawai‘i and U.S.-Affiliated Pacific Islands chapter.

Chapter takeaways

The chapter emphasizes the following points:

  • Climate change impairs access to healthy food and water. Increasing temperatures, altered rainfall, flooding, pollution, and fisheries decline will further affect food and water availability.
  • Climate change undermines human health. Climate shocks and stressors compromise healthcare and worsen long-standing social and economic inequities that contribute to illness, but community strengths and adaptation measures can boost resilience.
  • Rising sea levels harm infrastructure and islands’ economies. Sea level rise intensifies loss of territory and disrupts livelihoods, but governments and communities are innovating through renewable energy, green infrastructure, and sustainable economic growth.
  • Responses help to safeguard tropical ecosystems and biodiversity. Increased fire risk, severe droughts, and ocean changes have broad negative impacts on native plants and wildlife, and ocean ecosystems. Effective adaptation strategies include ecosystem protection and restoration, invasive species measures, and fire prevention.
  • Indigenous Peoples and their knowledge systems are central to the resilience of island communities amidst the changing climate.

The assessment demonstrates that efforts to reduce greenhouse gas emissions and limit climate change impacts are underway in every U.S. region, including the Pacific Islands. A key addition to the National Climate Assessment since its last edition in 2018 is the chapter’s key message on human health and its emphasis on food security, integration of Indigenous Knowledge, and recognition of data inequities for the Pacific Islands and U.S. Caribbean.

“It is becoming increasingly evident that overall human well-being is threatened by climate change. Additionally, climate change further agitates stressors that are beyond our control, such as natural disasters and pandemics. As island communities, we must always be prepared to face these unfortunate new realities, and it starts with staying informed. We hope the information we have curated for this report will be an effective resource in the decision-making process,” said Dr. Romina King, PI-CASC University of Guam lead and one of the authors for the regional chapter.

The full National Climate Assessment is published as an interactive website at and Chapter 30: Hawai‘i and US-Affiliated Pacific Islands at

About the Fifth National Climate Assessment

Mandated in the Global Change Research Act of 1990, the National Climate Assessment provides authoritative scientific information about climate change risks, impacts, and responses in the U.S. The assessment reflects the scientific consensus and is widely used for decision-making but does not include policy recommendations nor advocate for any specific policy.

The Fifth National Climate Assessment includes 32 chapters on physical science, national-level sectors (such as water, energy, agriculture, ecosystems, transportation, health, infrastructure, etc.), regional impacts in the U.S., and responses. The assessment was written by a diverse team of more than 500 Federal and non-Federal authors and more than 250 technical contributors from every state. The report has undergone multiple rounds of review, including three opportunities for public comment, extensive agency review, and an external review by the National Academies of Sciences, Engineering, and Medicine.

The Hawai‘i and U.S.-Affiliated Pacific Islands chapter is backed by nearly 500 citations from published literature.

Contact the authors of the Hawai‘i and U.S.-Affiliated Pacific Islands Chapter

  • Abby Frazier, (Chapter Lead Author, whole report)
  • Zena Grecni, (Chapter Author, human health, chapter key messages)
  • Victoria Keener, / (Chapter Author, human health, fresh water)
  • Romina King, (Chapter Author, sea level rise and the built environment, Guam)
  • Kirsten Oleson, (Chapter Author, oceans and fisheries, economics, human health, water and food)
  • Malia Nobrega-Olivera, (Chapter Author, cultural resources)
  • Christopher Shuler, (Chapter Author, water and food)
  • Ann Kloulechad-Singeo, (Chapter Author, water and food, and local cultural resilience to climate change, Palau)