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Global Warming - Impact Zones

Impact Zone - U.S. New Orleans

U.S. New Orleans
The Select Committee on Energy Independence and Global Warming addressed our nation's energy, economic and national security challenges during the 110th and 111th Congresses.

This is an archived version of the committee's website, where the public, students and the media can continue to access and learn from our work.

Warmer Oceans, Stronger Storms

There is perhaps no better example of the potential for devastating global warming impacts than the Gulf Coast and Hurricane Katrina. While the contribution of human-caused warming to Hurricane Katrina is difficult to quantify, scientists have unearthed a trend towards larger, more intense storms as oceans around the world warm. After Katrina, the response from the American public was to help New Orleans in any way possible. In order to protect the Gulf Coast over the long term, America should adopt policies that cut global warming pollution to reduce warming of the oceans.

Stronger Hurricanes

Hurricane formation is complex, but warm water is a necessity and also influences the strength of the storm. In a chilling instance of scientific soothsaying, scientists from MIT published a groundbreaking study on the link between increasing sea surface temperatures and hurricane intensity just one month before Katrina hit. A few weeks later, a similar study was released by researchers from Georgia Tech and the National Center for Atmospheric Research. The researchers at these respected institutions found that hurricane intensity - a measure of the strength and duration of a storm - had increased since the 1970s. Ocean temperatures had risen by about one degree Fahrenheit over this time, showing how a small difference in temperatures can have profound impacts on our planet. More recent research based on theory and state-of-the-art models indicates that tropical cyclones will becomes stronger by about 2 to 11 percent by 2100, with the largest storms becoming more frequent.

Protecting New Orleans

Compounding the challenges of stronger storms is the loss of New Orleans' natural protection. Within this century, at least 70 percent of the coastal salt marshes that protect New Orleans from the brunt of storms may be buried by rising sea levels. Some parts of New Orleans are already 8 feet below sea level. While its levees are designed to protect against flooding from the Mississippi River and Lake Pontchartrain, they do not adequately protect the city from sea level rise and more intense storms.

Congress has mandated that the Army Corps of Engineers protect the New Orleans area from a 100-year hurricane by the beginning of the 2011 hurricane season. To reach the 100-year hurricane protection level, the Corps is expected to raise levees as high as 27 feet above sea level in some areas. In order to account for sea level rise, continued loss of wetlands and increased risk of storms from global warming that is expected to occur in the next 50 years, the Corps may need to add several feet to the design heights in the future.

To protect New Orleans, building larger levees will not be enough. Strategies to reduce coastal vulnerability - from more rigorous building codes to improved emergency response - should be implemented.  Restoring natural coastal protections and addressing the drivers of global warming can ensure long-term protection.

You Can Still Help the Gulf Coast Rebuild Today!

Habitat For Humanity

American Red Cross




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