Sea Level Rise Added Billions of Dollars to Hurricane Sandy’s Storm Surge Damage

When it comes to sea level rise, buyers, sellers, owners, and real estate agents need to be aware of both the increased occurrence of nuisance flooding — tidal floodwaters that inundate neighborhoods on sunny days — and storm surges that can strike quickly and inflict billions of dollars in damages in a very short time.

A study recently released by researchers at Climate Central, an independent organization of scientists and journalists dedicated to informing the public about climate change, demonstrated the threat sea-level-rise-fueled storm surges pose to coastal communities. The researchers gathered information about Hurricane Sandy and concluded that a few additional inches of sea level rise contributed over $8 billion dollars worth of damage to the $62.7 billion the super storm inflicted on New York, New Jersey and Connecticut.

To arrive at that astonishing figure, the researchers analyzed water levels during Hurricane Sandy and compared it with an estimate of how high the water would have risen without human-caused sea level rise. Based on a conservative estimate of just over four inches of sea level rise added between 1900 and 2012, the year Hurricane Sandy struck, they estimated that sea level rise added $8.1 billion to the total tab the states had to spend repairing storm damage, including power grids and transportation networks.

The researchers noted in their analysis that economic damages may have been much higher than stated in their report. “Our estimates do not account for potential long-term economic effects, such as losses and gains in broad economic activity associated with employment and production changes across industries in the aftermath of a damaging cyclone event,” they wrote.

Climate Central’s chief scientist and CEO Benjamin Strauss, Ph.D., put the report in perspective: “Just a hands-width of sea level rise from climate change caused more than 10 percent of the damage from Sandy’s towering floodwaters. The implications are enormous. For any lesser ocean flood, the percentage must be higher.”

Clearly buyers, sellers, owners, and real estate agents can’t afford to ignore the influence ever-rising seas have on damaging storm surges when they’re evaluating coastal properties.

Twitter Helps Researchers Identify Localized Sea Level Rise Flooding

When it comes to identifying localized sea level rise flooding, tidal gauges aren’t necessarily giving the full picture.

Climate researchers published a study this week in the journal Nature Communications that concluded Twitter may provide a more accurate read on what’s actually going on on the ground. Why? For one thing, there are only 132 tidal gauge stations covering over 3,700 miles of the U.S. Gulf of Mexico and Atlantic coastlines. That leaves enormous gaps between the measuring locations.

As a result, the same high tide that causes little or no flooding in a location with a gauge could cause damaging flooding in another location with a different elevation or concentration of people and structures. The study says, “The same degree of inundation could have substantially different social impacts, depending on the distribution of people, infrastructure and economic activity along the coast.”

To get a clearer picture of how the flooding is impacting coastal locations, the researchers studied nearly half a million tweets sent by 5 million Twitter users in about 235 counties. What they found was that nuisance flooding was occurring in many locations that was not detected by tide gauges.

Most of the undetected nuisance flooding occurred in 22 counties, including those that encompass Miami, New York and Boston, with over 13 million people.

Having a clear picture of what’s happening everywhere is critical to drawing up plans to address the sea level rise flooding as the ocean level rises. “Understanding where coastal floods happen, identifying which meteorological and tide conditions produce floods, and grasping the consequences for flood-affected communities and infrastructure is critical for coastal flood preparation and response,” the study said.

Study co-authors, Frances C. Moore, of the Department of Environmental Science and Policy at the University of California, Davis, and Nick Obradovich, of the Max Plank Institute of Human Development in Berlin, Germany, caution that one major limit of their study is that once people get used to the nuisance flooding they become less likely to report it on social media.

The fact that even tidal gauges can’t always be relied on to give the complete picture of sea level rise flooding in a given area is all the more reason that buyers, sellers, owners and real estate agents need to rely on more than one source when considering the flood risk for a given piece of property.

New York City Debates Whether a $119 Billion Barrier is Enough to Hold Back Sea Level Rise

New York City and the Army Corps of Engineers are considering five options to protect the city from sea level rise. Among them is a six mile long set of retractable gates that would stretch from Queens, NY, to New Jersey.

Supporters see many benefits from the gates. They say the barriers would be far enough off shore to be out of sight for most land dwellers, they’d hold back storm surges, similar to the one from Hurricane Sandy that swamped lower Manhattan, and they’d be better at protecting everyone, not just the wealthy areas that are being shielded from flooding by land-bound solutions currently being built.

Opponents, however, worry that by the time the gate project is completed in 25 years it will be obsolete because of sea level rise. They’re also concerned that it will create even more problems for the city by preventing stormwater runoff from escaping back into the sea.

Residents, government officials, the Corps of Engineers and environmental groups will make the final decision. In the meantime, real estate owners along the city’s 520-mile coastline and adjacent areas need to keep informed about the debate and get involved if their property will be impacted.

You can read more about the great New York sea level rise debate in this New York Times article.