Study Highlights Sea-Level Rise On The US Atlantic Coast

Researchers from Rutgers University say the rate of increase in sea level in the 20th century along the US Atlantic coast was the fastest seen in 2000 years. Researchers say that southern New Jersey had the fastest rates of sea-level rise in the entire US. According to the team, global increases in sea level from melting ice and warming oceans between 1900 and 2000 resulted in a rate of increase that's more than twice the average for the years 0 to 1800.

For the study, Rutgers researchers looked at what contributed to sea-level change over 2000 years at six cities along the coast in Connecticut, New York City, New Jersey, and North Carolina using a sea-level budget. The use of the budget enhances understanding of processes driving sea-level change, according to the team. Processes impacting the rise in sea levels include global, regional (such as land subsidence), and local (such as groundwater withdrawal).

Lead study author Jennifer S. Walker says having an understanding of sea-level changes at sites over the long-term is critical for regional and local planning and responding to future increases in sea levels. The study says rising sea levels resulting from climate change threatened to flood low-lying islands, cities, and lands permanently. Increasing ocean levels also increase the vulnerability of these areas to flooding from coastal and other storms.

The new study estimates sea-level budgets for longer time frames over 2000 years, which is different from most sea-level budget studies limited to the 20th and 21st centuries. The team is currently investigating how their method could be applied to other sites worldwide to understand how processes driving increasing sea-level have changed and could shape future change.

The team used statistical models and developed a sea-level budget for six cities for their study. They divided sea-level records into global, regional, and local components discovering that regional land subsidence, or sinking of the land since the Laurentide ice sheet retreated thousands of years ago, dominated each site's budget for the last 2000 years. The total sea-level rise for each of the six cities during the 20th century ranged from about 1 to 1.4-inches per decade.