U.S. Tackles Sea-Level Rise Domestically, Globally

On September 25, 2024, Secretary of State Antony J. Blinken participated in the United Nations General Assembly's High-Level Plenary Meeting on "Addressing the Existential Threats Posed by Sea-Level Rise," where he highlighted the broad suite of actions the United States Government is taking to tackle the challenge of sea-level rise at home and around the world.

The most important step the global community must take to combat the worst impacts of sea-level rise is to accelerate global reductions of greenhouse gas emissions in this critical decade. At the same time, worsening impacts globally have made clear that we must simultaneously scale up efforts to build adaptation and resilience. Through the President's Emergency Plan for Adaptation and Resilience (PREPARE), the United States is supporting vulnerable developing countries around the world to build resilience to the impacts of the climate crisis, including those from sea-level rise. To address the impacts of sea-level rise both domestically and with our international partners, the United States is:

1. Investing in science to improve sea-level rise monitoring and predictions to better understand the impacts to low-lying islands and coastal areas at high-resolution;
2. Supporting efforts to translate and integrate scientific data for improved disaster preparedness and long-term adaptation planning;
3. Collaborating with partners to support regional and global efforts, particularly in the Caribbean and the Pacific.

Sea-level rise monitoring and predictions

To understand and manage the impacts of sea-level rise, it is critical that communities have access to current, scientifically accurate, and usable data. The United States is a global leader on ocean observation and modeling, and we are putting these tools into the hands of communities that need them at home and abroad, including by:

• Getting science into the hands of citizens and decisionmakers: The Interagency Task Force on Sea Level Change, an interagency group within the U.S. Global Change Research Program, just launched globalchange.gov, a federally co-produced web resource delivering authoritative sea-level science and information for the United States in a dynamic and interactive new site. Putting this information in the hands of State and local governments and stakeholders will facilitate timely and inclusive decision-making to safeguard populations, ecosystems, and livelihoods from the impacts of sea-level rise.
• Supporting the world's ocean observing capabilities: The National Oceanic and Atmospheric Administration (NOAA) operates over 50% of the Global Ocean Observing System, including over 20% of the tide gauges around the world, with more than 3,000 instruments collecting more than 1 million ocean observations every day. These observations allow us to monitor sea level, global ocean temperatures, and ocean currents that form the basis for sea-level rise predictions and projections which are openly shared to support global resilience efforts. Through the Bipartisan Infrastructure Law (BIL), NOAA has made $2.7 million in new investments to improve ocean observations, allowing us to improve and refine sea-level rise predictions for decision makers in the United States and around the world.
• Expanding high-resolution sea-level rise mapping for all Pacific Island countries to support their long-term adaptation planning: Enabled by over $285 million of investments in global sea level-related satellite missions and over $100 million in associated science during the Biden-Harris Administration, the National Aeronautics and Space Administration (NASA')s Sea Level Change Team built high-resolution technical assessments of future sea-level rise and associated impacts for every Pacific Island country. When combined with national adaptation planning, these assessments provide a scientific foundation for supporting climate-resilient, science-based decision-making to adapt to and manage the impacts of sea-level rise on lives, livelihoods, and ecosystems. The new tool will be here: https://sealevel.nasa.gov/flooding-analysis-tool-pacific-islands/ .
• Advancing global capabilities for predicting coastal impacts at high-resolution: Due to interactions between the ocean, ice sheets, and solid earth, sea levels do not change uniformly across the globe - resulting in further uncertainty for disaster managers and long-term adaptation planning. The Department of Energy's Los Alamos National Laboratory is working to extend the Energy Exascale Earth System Model (E3SM) to provide the first consistent regional sea-level projections from an Earth system model that account for these interactions. This capability will enable a more detailed understanding of sea-level change that is important for decision-making at the facility-level, with results that will be available globally. Los Alamos National Laboratory also has a well-established effort to simulate the compound risk from tides, waves, and sea-level rise through 2050 at facility-level resolution, a capability that currently can be applied anywhere in the world.
• Quantifying present and future coastal flood hazards in Guam and the Commonwealth of the Northern Mariana Islands to prevent loss of life and preserve livelihoods: The Federal Emergency Management Agency (FEMA), in partnership with DoD and USACE's Coastal and Hydraulics Laboratory, is quantifying present and future coastal flood hazards for Guam and the Commonwealth of the Northern Mariana Islands (CNMI). With probabilistic coastal flood hazard data describing extreme waves and water levels for current and future sea-level conditions, communities in Guam and CNMI will – for the first time – have a more precise understanding of flood risks to enable actions to protect their homes, businesses, and families. FEMA will use the data for incorporation into its flood maps. The joint study also represents the first within the Pacific basin that advances FEMA's goal of shifting to more comprehensive, graduated flood hazard and risk analysis.
• Understanding Sea-Level Rise in the Florida Everglades: Covering more than 6000 square kilometers, the Florida Everglades is a low-lying subtropical wetland ecosystem bordered by ocean on three sides. The Everglades provides numerous ecosystem services (e.g., supporting diverse fish and wildlife, storing carbon, providing clean water, and protecting coastlines) that are threatened by sea-level rise and storm intensification. U.S. Geological Survey (USGS) scientists have advanced understanding of the impact of sea-level rise in the Everglades through collaborations on: predictive modeling on and formulation of a decision support tool for ecological responses to sea-level rise and other hydrologic change; long-term marsh elevation measurements in threatened mangrove forests; prediction of the effects of sea-level rise on the habitat of an endemic endangered bird species; development of an Everglades vulnerability analysis that examines landscape-scale vegetation response to increasing salinity accompanying sea-level rise; and integration of sea-level rise into Everglades restoration plans.

Supporting adaptation & resilience for vulnerable communities

The Biden-Harris Administration has deployed an all-of-government effort to support U.S. communities and other countries as they adapt to and manage the impacts of climate change, including sea-level rise.

• Strengthening and expanding early warning systems: The National Oceanic and Atmospheric Administration (NOAA) has, over the past few years, helped implement an array of early warning systems that provide real-time, specific, and accurate information for natural hazards including tropical cyclones, flooding, and tsunamis, the impacts of which are worsened as sea levels rise. Early warning systems are an effective disaster risk reduction tool for Earth's changing climate and the challenges posed by rising seas. The critical information provided by these early warning systems has been essential to safeguarding lives and livelihoods in over 40 countries - particularly in the Pacific, the Caribbean, and Africa.
• Supporting sustainable development and ecosystem management: During the Biden-Harris Administration, the U.S. Agency for International Development (USAID) has programmed $86 million to date to help vulnerable coastal communities in more than 10 countries build resilience to climate shocks such as flooding and sea-level rise. Conserving marine and coastal ecosystems is an effective nature-based solution to adapt to the impacts of sea-level rise. In Madagascar, USAID is supporting the sustainable management of marine natural resources and protected areas, and improved governance of marine and coastal ecosystems, such as coral reefs, mangroves, and seagrass, as effective nature-based solutions for adapting to the impacts of sea-level rise. In Honduras, USAID is supporting the Conserving Coastal Ecosystems activity, which aims to improve coastal ecosystem management and generate economic opportunity for at least 10,000 Indigenous Peoples, especially Garifuna and Pech communities, across 150,000 hectares along Honduras' Pacific and Caribbean coasts and Bay Islands.
• Protecting access to resources in lawfully established maritime zones: Sea-level rise has the potential to shift coastal baselines and thus shift established maritime zones, such as exclusive economic zones. In 2022, the United States announced a policy stating that it will not challenge maritime zones and baselines that have been established consistent with international law and that are not subsequently updated despite sea-level rise caused by climate change. For the many countries that rely on the resources found within their exclusive economic zones, this policy helps preserve access to critical sources of food, livelihoods, and revenue.
• Committing to work with other States on issues relating to sea-level rise and statehood: For some States, particularly low-lying island States in the Pacific Ocean, increasing sea levels pose an existential threat. In 2023, President Biden announced that the United States considers that sea-level rise driven by human-induced climate change should not cause any country to lose its statehood or its membership in the United Nations, its specialized agencies, or other international organizations. The State Department is working with those States and others on issues relating to human-induced sea-level rise and statehood to advance these objectives.
• Protecting coastal infrastructure and promoting coastal resilience in the United States: During the Biden-Harris Administration, the U.S. Army Corps of Engineers has programmed approximately $2.55 billion in boosting domestic efforts to address sea-level rise by providing planning, engineering, and construction of infrastructure projects in the coastal United States and territories. For example, in Louisiana, USACE's Southwest Coastal Louisiana Hurricane Protection project is working to restore coastal ecosystems and elevate over 3,000 residential structures to design heights that include projected sea-level rise through the year 2075, reducing flood risk now and in the future for this vulnerable area. $120 million of construction funding for this project was provided in the 2022 Infrastructure Investment and Jobs Act. NOAA is also investing $4.1 billion from BIL and the Inflation Reduction Act to promote Climate Ready Coasts and Communities, through projects including habitat restoration, workforce development, and accelerating coastal community resilience via regional partnerships, technical assistance, and data access.
• Assessing vulnerability to climate impacts in Toamasina, Madagascar: Rapid sea-level rise and coastal flooding threaten Toamasina, Madagascar's second-largest and principal port, and its critical road and rail connections to the rest of the country. Through U.S. Department of State support for the Ocean Risk and Resilience Action Alliance, the Stimson Center has just completed a Climate and Ocean Risk Vulnerability Initiative (CORVI) assessment for Toamasina, together with the Ministry of Fisheries and Blue Economy of Madagascar and the Western Indian Ocean Marine Science Association. The CORVI in Madagascar compares a diverse range of ecological, economic, social, and political risks with 94 climate indicators to produce a detailed, place-based coastal risk assessment for Toamasina and recommendations for action to build climate resilience. The CORVI found that sea-level rise presented the 2nd-highest level of risk in the assessment, given the projected impacts on the city's road network and the single rail connecting Toamasina to the rest of the country.
• Comprehensive efforts to address sea-level rise impacts on U.S. installations and surrounding communities: The Department of the Navy has taken a comprehensive approach to understanding and addressing the impacts of sea-level rise on critical infrastructure, including through improved scientific understanding, nature-based solutions, and community partnerships. On the engineering side, the Navy has invested in 43 projects around the country to invest in nature-based and hybrid solutions to address issues like salt-water intrusion and coastal flooding impacting facilities. These efforts include investments in shoreline stabilization, erosion control, dune restoration, and wetland restoration. The Navy is also supporting states and communities to partner with their local installations as "one community" to identify natural threats that are likely to impair the continued operational utility of local military installations and assess potential impacts to shared critical infrastructure.

Collaborating with partners

Sea-level rise is a global challenge, so it requires global solutions. The United States is working with partners across a wide range of sectors to combat sea-level rise and the complex ways it impacts communities:

• Increasing support for the Pacific Resilience Facility (PRF): The Department of State has been a strong champion of the PRF since its inception, through both pledges of financial support and ongoing close coordination with the Pacific Island Forum's team. The initial U.S. pledge of $4.5 million from the Bureau of Oceans and International Environmental and Scientific Affairs to the PRF has already been supplemented by an additional pledge of $20 million, pending Congressional notification and completion of domestic procedures, that was just announced at the 53rd Pacific Islands Forum Leaders Meeting in Nuku'alofa, Tonga. This funding and our engagement will help the PRF establish core operational procedures and meet high quality fiduciary and safeguard standards, as well as support project preparation for an initial set of grants to bolster adaptation and resilience in the region.
• Collaborating to develop risk assessments in the Caribbean: The U.S. Global Change Research Program supports international collaboration to inform decision-making and disaster resilience at local and regional levels. Through the Latin American Caribbean Initiative (LACI), the USGCRP is partnering with 21 countries to develop risk assessments for climate-related topics such as water security, freshwater access, and extreme events exacerbated by sea-level rise. One project is to co-design a Water Security Observatory in the La Plata Basin to develop a decision support tool for policy makers on freshwater access, sea-level rise, and other water-related natural disasters with regional stakeholders among Brazil, Argentina, Chile, Bolivia, Paraguay, and Uruguay.
• Mitigating impacts on national security by improving data accessibility for island communities: The Department of Defense made significant investments towards understanding and building resilience to sea-level rise at domestic and overseas installations. This includes investment in the Kwajalein Atoll Sustainability Laboratory, a field lab jointly established with the Office of Naval Research and Republic of Marshall Islands to deploy and test innovative climate adaptation technologies for low-lying Pacific Island nations. The Department of Defense has also developed Climate Resilience Dashboards for the Marshall Islands, Micronesia, Guam, Commonwealth of the Northern Mariana Islands, American Samoa, and Diego Garcia, providing data visualization for over 20 climate change hazard indicators, including coastal inundation resulting from sea-level rise, storm surge, waves, and tides. These Dashboards are being used by the DoD for planning adaptation and recovery and reconstruction measures.
• Building capacity and resilience across the Pacific Islands: The Department of the Interior's U.S. Geological Survey (USGS) plays a key role in building capacity across the Pacific Islands region to address sea-level rise and associated challenges. For example, the USGS partners with other organizations to co-develop tools for visualizing sea-level rise (for example, American Samoa ), has facilitated development of a Pacific-wide mangrove monitoring network, and is originating models to simulate mangrove-coral reef interactions and inform investment in nature-based solutions to mitigate the effects of sea-level rise. The USGS is also expanding early warning systems for coastal flooding to include the impact of sea-level rise on amplifying flooding hazards for the Pacific Islands and collaborates with Pacific Islanders, Native Hawaiians, and local communities to exchange knowledge and co-develop best practices to meet the challenge of sea-level rise.
• Lowering barriers to accessing climate and disaster finance: Increasing access to climate and disaster finance will strengthen the ability for governments to plan for and respond to climate shocks and stresses, including sea-level rise. As part of USAID's $86 million commitment to supporting sustainable development and coastal ecosystem management, the U.S. Agency for International Development (USAID)'s Caribbean Resilient Economies and Sectors Activity (RESET) supports national governments and private-sector entities to lower barriers to accessing climate and disaster finance and to increase on-the-ground approaches and technologies for climate and disaster resilience across priority sectors. Seventy percent of the population in the Eastern and Southern Caribbean nations lives in coastal zones vulnerable to rising sea levels and severe weather conditions.
• Building an enduring network of island-to-island technical experts: The United States is a founding member of the Local2030 Islands Network, where we are partnering with island economies to promote community-led, bottom-up approaches to sustainable development and building resilience to climate change. With continued support totaling $15.6 million from the Department of State, this Network and its partners are producing and scaling island-led solutions to the climate crisis, including the impacts of sea-level rise, through centering local knowledge and local priorities. For example, in Palau, the Local2030 Islands Network is supporting U.S. partner Pacific Research for Island Solutions on Adaptation (RISA) to better understand historic flooding impacts and develop flood threshold tolerances for critical community assets under various sea-level rise and flooding projections. These findings are then translated to policymakers locally and nationally in Palau and translated for use by the more than 125 other island economies engaged in the Network's global peer-to-peer Communities of Practice.