katrina

As climate change accelerates, rising sea levels are putting coastal communities at greater risk of flooding and storm surge. Driven by melting glaciers and warming oceans, global sea levels are rising at an increasing rate. For low-lying cities like New Orleans, even small increases can have serious consequences. And that risk is compounded by another factor: the land itself is sinking.

Much of New Orleans already sits at or below sea level, and parts of the city and its surrounding wetlands are gradually sinking. While most of the city remains stable, a new study by researchers from Tulane University suggests that sections of the region’s $15 billion post-Katrina flood protection system may require ongoing upgrades to keep pace with long-term subsidence.

The study, recently published in the journal Science Advances, used satellite data to track changes in ground elevation across Greater New Orleans between 2002-2020. The researchers found that some areas – including neighborhoods, wetlands, and even concrete floodwalls – are sinking by more than an inch each year. In some spots, the land is dropping by nearly two inches annually.

Alarmingly, some of the concrete floodwalls and levees built to protect the city after Hurricane Katrina are themselves sinking. In a few cases, they are losing elevation faster than sea levels are rising, reducing their capacity to block storm surges.

The study highlights how satellite monitoring can play a critical role in guiding infrastructure maintenance and urban planning – not just in New Orleans – but in vulnerable coastal cities around the world.

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Vertical land motion in Greater New Orleans: Insights into underlying drivers and impact to flood protection infrastructure

Photo, posted September 22, 2010, courtesy of U.S. Army Corps of Engineers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Superstorm Sandy was the deadliest hurricane of 2012 and one of the most destructive hurricanes ever to hit the United States. According to the National Oceanic and Atmospheric Administration, Superstorm Sandy caused an estimated $74.1 billion dollars in damages. That figure made it the fourth-costliest storm in U.S. history, trailing only Hurricane Katrina in 2005 and hurricanes Harvey and Maria in 2017. Superstorm Sandy affected 24 states and all of the eastern seaboard.

New York was one of the states pummeled by Superstorm Sandy. The storm brought flood-levels to the region that had not been seen in generations. But according to a new study published in the journal Climatic Change, those flood levels could become much more common.

Researchers at Stevens Institute of Technology have found that 100-year and 500-year flood levels could become regular occurrences by the end of the century for the thousands of homes surrounding Jamaica Bay, NY. The researchers say climate change is the culprit.

Using anticipated greenhouse gas concentration levels, the research team created simulations to find the probability of different flood levels being reached by the end of the century. The researchers found that the historical 100-year flood level would become a one-year flood level by the year 2100. 500-year floods, like Superstorm Sandy, would become a four-year flood level by the end of the century.

While this particular study is specific to Jamaica Bay, it does serve as an example of just how severe and costly the consequences of climate change will be.

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Once in a lifetime floods to become regular occurrences by end of century

Photo, posted October 29, 2012, courtesy of Rachel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

New Orleans is sinking

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Once In A Lifetime Floods And Climate Change | Earth Wise

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