Americans at Risk of Flooding as Sea Levels Rise

Nearly four million Americans, occupying a combined area larger than the state of Maryland, find themselves at risk of severe flooding as sea levels rise in the coming century, new research suggests.

A new study, published, in IOP Publishing's journal Environmental Research Letters, asserts that around 32,000 km2 of US land lies within one vertical meter of the high tide line, encompassing 2.1 million housing units where 3.9 million people live.
 
For this study, the researchers created a new model to identify the areas of U.S. mainland that are at risk of flooding and, with a predicted sea level rise of 1 meter or more by the end of the century, suggest that the U.S. Government's currently designated flood zones should not be considered stable.
 
A second study, also published in Environmental Research Letters, corroborates evidence of the risk, showing that a majority of U.S. locations, from the 55 studied, will see a substantially higher frequency of storm-driven high water levels by the middle of the century; water levels that have previously been encountered only once-a-century.
 
Many locations would be expected to experience such high flooding every decade or more often.
 
Two ways in which global warming is causing sea levels to rise are thermal expansion – the expanding of water as it warms – and the melting of glaciers.
 
The first study, undertaken by researchers at Climate Central and the University of Arizona, shows that at a state level, areas surrounding the Gulf appear to be the most vulnerable, whilst in terms of population, Florida is the most vulnerable, closely followed by Louisiana, California, New York and New Jersey, illustrating significant exposure on every coast.
 
The researchers pick out greater Los Angeles as a largely-populated city of great concern, as previous research suggests that flooding may reach rare heights more swiftly in southern California than in any other mainland US area.
 
The second study examined the effect of heavy storms on past water levels at 55 stations across the US and combined these with estimates of future global sea level rises to predict the frequency and extent of future flooding.
 
The researchers, from Climate Central, the National Center for Atmospheric Research and the National Oceanic and Atmospheric Administration, liken the type of annual flooding that we may come to expect to the infamous high water levels brought about in New York in 1992, which managed to flood the subway system, as a result of a violent nor'easter (a storm coming in off the Atlantic).
 
"The sea level rise taking place right now is quickly making extreme coastal floods more common, increasing risk for millions of people where they live and work," according to co-author of both papers, Ben Strauss, researcher at Climate Central. "Sea level rise makes every single coastal storm flood higher. With so many communities concentrated on US coasts, the odds for major damage get bigger every year."

Download Center

  • Your Guide to Environmental Metrics that Drive Performance

    Translating sustainability into action starts with implementing the right metrics to assess your environmental risk and performance. Learn how to design metrics that improve your decision-making process and drive enterprise performance.

  • Unpacking ESG: 6 Questions You Were Too Afraid to Ask

    Environmental and Sustainability experts from Arcadis and Cority answer 6 of the most pressing questions EHS professionals have about getting started with Environmental, Social, and Governance (ESG) reporting.

  • 5 Keys to Best-in-Class Chemical Management

    Running a safe chemical program is challenging and complex: from knowing what's on-site to proper handling and disposal - all while navigating regulatory changes. Learn the best ways to mitigate chemical risk, get the most value out of your data, and gain buy-in for a chemical management solution.

  • Streamline Your Air Emissions Management

    See how consolidating all your emissions management functions into one centralized system can help you streamline your operations, more easily maintain compliance, and achieve greater time and cost savings.

  • A Crash Course in Creating the Right Environmental Scoring System

    Learn how to develop the right environmental scoring system so you can easily benchmark performance across all your facilities and gain a holistic view of your environmental programs.

  • Industry Safe