Sandy Shows Future of Rhode Island’s Coastline
November 3, 2012
Contrarians argue that Hurricane Sandy isn’t proof of climate change. But local scientists say the recent storm offers more damning evidence that Rhode Island’s weather and landscape are undergoing a long-term transformation — one with a steep cost in dollars and human health.
Temperature. Perhaps the most significant and indisputable fact is that the Atlantic Ocean is warmer, so much so that a late-October storm didn’t lose steam over what should have been a colder sea. Instead, Sandy gained speed and strength as it headed north and became an enormous force of destruction.
Sea surface temperature is one of the most important variables, said John Merrill, professional of oceanography at the University of Rhode Island’s School of Oceanography.
Overall, water temperatures across the eastern seaboard exceeded the threshold that incites chaotic weather and powerful hurricanes. In some locations, the warmer water might be cyclical, in others regions the warming appears permanent. The temperature of Narragansett Bay, for instance, has increased an average of 3.6 degrees since the 1960s, according to studies.
The water temperature off New Jersey was 5 to 10 degrees above normal this year. Determining an average increase for the entire Atlantic Ocean is trickier, but the tropical regions where hurricanes form are also in a warming trend.
In addition to intensifying weather, warmer water expands, causing sea levels to rise. The Northeast is considered a hotspot, with sea levels climbing four times faster than the global average. During the past 100 years, sea level has risen a foot in Narragansett Bay, according to studies. URI researchers expect it to jump 3 to 5 feet by the end of the century.
Storm surge. Warmer air and warmer water produce more powerful storms, which deliver stronger winds and waves to coastal areas.
Sandy’s tidal surge was about 5 feet in Rhode Island, compared to 13 feet in New York and New Jersey. The height may sound harmless, but 5 feet in a low-lying coastal area with just a few feet of elevation means tidal surges can push deep inland.
In addition to flooding, a powerful storm surge is a wrecking ball to natural and manmade barriers along Rhode Island’s 400 miles of coastline. Sandy eroded beaches and displaced concrete walls and stone embankments, known as rip rap, across the state’s southern shore. Roads were damaged or destroyed in nearly every coastal community and on Block Island. A 200-foot section of sea wall and 2,800 feet of sidewalk in Narragansett were badly damaged. The state Department of Transportation (DOT) reported that sand and tons of large stones from coastal barriers were pushed inland and along coastal roads.
Before Hurricane Sandy arrived, the state’s southern coastline was losing 1 to 4 feet annually from wave action, according to the Coastal Resources Management Council (CRMC).
The damage shows that building protective barriers may not be the best solution to prepare for other storms, said John King, an oceanographer at URI’s oceanography school. “Storm surge and the general devastation is something we’re going to see more of in the future.”
Costs. The cost of climate change hits businesses, taxpayers and consumers. According the Rhode Island American Security Project, the new climate reality “poses a serious economic threat.” Droughts, flooding and seasonal temperature changes adversely impact agriculture, tourism and manufactures that rely on ports. Climate change also results in fewer plants and trees, and more pests, such as disease-carrying ticks and mosquitoes. Higher temperatures have already led to more air pollution and subsequent illnesses.
There will be significant changes to Rhode Island’s iconic shoreline, according to the CRMC’s management plan. “Future increases in relative sea level will displace coastal populations, threaten infrastructure, intensify coastal flooding and ultimately lead to the loss of recreation areas, public space and coastal wetlands.”
Most scientists are moving beyond the climate change debate to address reality. “We don’t attribute individual events to an evolving climate in a direct way,” Merrill said, “But it’s now documented that extreme events are more common.”
An important next step, he said, is to answer the questions facing Rhode Island and coastal areas around the world. “How do we deal with a rapidly changing environment? How do we know where the flood zones are? How do we know where to build and where we can’t?”