Sea Level Rise

CIRCA Sea Level Rise Projects & Products

CIRCA’s current research projects in the area of sea level rise are listed on the Sea Level Rise Projects & Products site. There you can find a description of ongoing projects and any products from the project, including tools, reports, data, presentations, etc.

Additional tools include:

Connecticut Sea Level Rise and Storm Surge Viewer
Sea Level Rise Connecticut Final Report Summary
Sea Level Rise Connecticut Final Report
Presentation (with audio)
Slides only

CIRCA works to enhance coastal resilience to sea level rise in Connecticut. Sea level change is caused by a number of factors summarized in the figure on the right (click to enlarge), but in recent decades ocean warming and ice sheet loss due to global warming have contributed significantly to global sea level rise. Along the east coast, including Connecticut, sea level rise rates are more rapid than the global average rate because of subsidence or sinking of the coastline.

CIRCA Local Sea Level Rise Scenarios for the State of Connecticut

In 2012 NOAA released global sea level rise scenarios that were referenced in Connecticut state statute requiring that sea level rise be considered in state and local plans of conservation and development and natural hazard mitigation plans. That same statute charged UConn CIRCA with updating the scenarios to be local for the state of Connecticut. On October 19, 2017 CIRCA presented the local sea level rise scenarios in a public meeting. View materials from the public meeting and presentations.  On March 27, 2018 CIRCA released a draft of the report and in October of 2018, a final report, Sea Level Rise in Connecticut was released.

Based on the scenarios CIRCA recommends that Connecticut plan for the upper end of the range of values projected of sea level rise or up to 20 inches (50cm) of sea level rise higher than the national tidal datum in Long Island Sound by 2050 and that it is likely that sea level will continue to rise after that date. The Institute also recommended that the scenarios be updated at least every 10 years, or more frequently, to incorporate the best available science and new observations.

Sea level rise projections for Connecticut based on local tide gage observations (blue), the IPCC (2013) RPC 4.5 model simulations near Long Island Sound (yellow line), the semi-empirical models (orange line) and ice budgets (magenta line) as in CPO-1.

Sea Level Rise and Coastal Flooding and Inundation in Connecticut

Sea level rise has multiple impacts on the Connecticut shoreline, including increased erosion rates, increased frequency of flooding, and coastal inundation. As sea levels rise the shoreline responds and beaches get eroded away and the coastline moves back. Other coastal features, like salt marshes, also migrate landward. With a relative higher sea level, a storm surge or high tide, that would not have been a problem in the past, now results in flooding. Inundation is the permanent drowning of our coastline. In the short-term the increase of 8 inches in sea level that we have already experienced since the mid-1800s is not as noticeable against the daily tides, however if sea level continues to rise at a rapid rate, the shoreline can expect to see somewhere between 1.9 and 6.6 feet of sea level rise by the end of the century based on the CIRCA local sea level rise projections.

Connecticut Legislation

CIRCA's final report provides the basis for sea level rise projections in Governor's Bill S.B. 7, which was introduced into the 2018 legislative session and was enacted into law as Public Act 18-82.

Senate Bill No. 7, Public Act No. 18-82

PA 18-82

Substitute Senate Bill No. 9, Public Act No. 18-50

PA 18-50

White Papers

Additional guidance for policy and planning are available in four white papers, released by CIRCA and UConn's Center for Energy and Environmental Law (CEEL)

Floodplain Building Elevation Standards

Height Restrictions on Elevated Buildings

Oceanfront State Coastal Management Programs

Statutory Adoption of Updated SLR Scenarios

(Credit: CT DEEP)

sea level rise illustration
(Click image to enlarge) The factors that contribute to sea level change, both on land and in the sea. Source: IPCC (2001)