Surging Seas Sea level rise analysis by Climate Central

Rising Seas a Real Threat to New Jersey

By Ben Strauss & Robert Kopp
July 10, 2012

Note: First published in The Newark Star-Ledger & NJVoice

The sea isn’t flat and, with a warming climate, it’s not expected to rise at the same rate everywhere. Using the science that tells us how much and how quickly it will rise is critical to making policy decisions that protect our coastal communities and our economy.

The northeastern United States is particularly vulnerable to sea-level rise caused by the slowing of the Atlantic Meridional Overturning Circulation — the “ocean conveyor belt” that carries heat from the Caribbean to Europe. The motion of this conveyor belt maintains an uneven sea surface along the East Coast of the United States. As the planet warms, the conveyor belt will slow and that uneven surface will flatten — adding to global sea-level changes an additional, regional sea-level rise in the Northeast.

According to a 2009 review by researchers at the Geophysical Fluid Dynamics Laboratory in Princeton, state-of-the-art climate models predict that changes in the conveyor belt would cause the sea level off New York City to rise about 8 inches more than the global average this century. And now a new U.S. Geological Survey study suggests that sea level in the northeastern United States is already rising faster than the global average.

Global and regional rates of sea-level rise are expected to accelerate further as ice sheets and glaciers melt and warmer oceans expand. The Intergovernmental Panel on Climate Change’s 2007 projections of between 8 and 24 inches of global sea-level rise this century are widely viewed by scientists as likely underestimates, with some researchers projecting more than a 4-foot rise. That’s without taking into account the extra sea-level rise expected in the northeastern “hot spot,” which includes New Jersey’s coast.

A recent analysis by the Princeton-based nonprofit Climate Central found that 140,000 people in New Jersey live within 3 feet of the high-tide line. When the 4-foot storm surge associated with a once-in-50-years storm is taken into account, a 3-foot sea-level rise would place the homes of 400,000 New Jerseyans at risk.

The risks posed by sea-level rise highlight the importance of employing real science to inform policy and preparedness. Yet the North Carolina Senate recently considered legislation requiring that only historical sea-level trends — not projections based on observed accelerations or current scientific models — be used for planning purposes. A compromise bill enacted July 3 bans the use of sea-level rise projections by the state’s Coastal Resources Commission for the next four years. Comedian Stephen Colbert dubbed this the “sea, no evil” approach to tackling climate change.

Luckily, we in New Jersey have so far been spared political debates about the facts of sea-level rise. But we’re not totally free of the “sea, no evil” strategy; here, it is exercised not by our leaders, but by ourselves.

Earlier this year, a property-rights lawsuit by two homeowners concerned about their ocean view effectively stopped beach replenishment in Harvey Cedars, where almost all homes are on land less than 7 feet above high tide. While replenishing beaches cannot hold off the effects of surging seas forever, the efforts to block even this simple, short-term measure highlights the critical challenges ahead.

Sea-level rise poses severe risks for New Jersey’s Shore communities — risks that are being better understood thanks in large part to publicly funded research into climate change and its effects. The fruits of this research need to be the subject of a frank public discourse, not of denial or litigation. Policy and preparedness decisions based on the best available (and continuously improving) science are crucial to protecting our communities and coastal environments.

Robert Kopp is an assistant professor of Earth & Planetary Sciences at Rutgers University, associate director of the Rutgers Energy Institute and a member of the American Geophysical Union. Benjamin Strauss is director of the Program on Sea Level Rise at Climate Central.

Photo by Cathy Cramer.