The Sea Level Rise Technical Report provides the most up-to-date sea level rise projections available for all U.S. states and territories; decision-makers will look to it for information.
This multi-agency effort, representing the first update since 2017, offers projections out to the year 2150 and information to help communities assess potential changes in average tide heights and height-specific threshold frequencies as they strive to adapt to sea level rise.
There were four main takeaways from the report:
- The Next 30 Years of Sea Level Rise. Sea level along the U.S. coastline is projected to rise, on average, 10 – 12 inches (0.25 – 0.30 meters) in the next 30 years (2020 – 2050), which will be as much as the rise measured over the last 100 years (1920 – 2020). Sea level rise will vary regionally along U.S. coasts because of changes in both land and ocean height.
- More Damaging Flooding Projected. Sea level rise will create a profound shift in coastal flooding over the next 30 years by causing tide and storm surge heights to increase and reach further inland. By 2050, “moderate” (typically damaging) flooding is expected to occur, on average, more than 10 times as often as it does today, and can be intensified by local factors.
- Emissions Matter. Current and future emissions matter. About 2 feet (0.6 meters) of sea level rise along the U.S. coastline is increasingly likely between 2020 and 2100 because of emissions to date. Failing to curb future emissions could cause an additional 1.5 – 5 feet (0.5 – 1.5 meters) of rise for a total of 3.5 – 7 feet (1.1 – 2.1 meters) by the end of this century.
- Continual Tracking. Continuously tracking how and why sea level is changing is an important part of informing plans for adaptation. Our ability to monitor and understand the individual factors that contribute to sea level rise allows us to track sea level changes in a way that has never before been possible (e.g., using satellites to track global ocean levels and ice sheet thickness). Ongoing and expanded monitoring will be critical as sea levels continue to rise.