The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls

Roi-Namur Island on Kwajalein Atoll serves as our test case

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The Problem

Many U.S. Pacific islands are atolls fringed with coral reefs and have maximum elevations of 3–5 meters, with mean elevations of 1–2 meters. Sea level in the western Pacific Ocean has been increasing at a rate 2–3 times the global average, resulting in almost 0.3 meters of net rise since 1990. The 2012 US National Climate Assessment provided global sea level rise scenarios that ranged from 0.2 to 2.0 meters by 2100. Regional scenarios are needed. A high surf event in December 2008 overwashed numerous atolls in Micronesia, ruining freshwater supplies and destroying agriculture on approximately 60% of the inhabited islands. Sea-level rise will exacerbate the hazards posed by climate change (storms, waves, temperatures, precipitation, etc.) to infrastructure, freshwater supplies, agriculture, and habitats for threatened and endangered species on U.S. and U.S.-affiliated atoll islands.

Project Objectives

1. Provide basic understanding and specific information on storm-wave-induced overwash and inundation of atoll islands that house Department of Defense (DoD) installations.
2. Assess the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
3. Use Roi-Namur Island (Reagan Test Site–U.S. Army Kwajalein Atoll) on Kwajalein Atoll in the Republic of the Marshall Islands (U.S. Associated Pacific Islands) as a test case based on historical information, sea-level rise predictions, and global climate model (GCM) output.