Monday, June 24, 2013

The Impact of Sea Level Change on Coastal America

An interesting interactive map by Climate Central provides us with a glimpse of the impact of global climate change on coastal states in America.  I happen to live in a coastal area and have already seen the impact of storm surges on our coastline; faster rates of coastal erosion and unprecedented damage to infrastructure are becoming more and more common.

Global sea level has risen about 8 inches since 1880.  This may not seem like much, but according to Climate Central, nearly 5 million people in 2.4 million homes live a mere 4 feet above high tide, a level that is lower than the one in one hundred year flood line for most areas.

The tool provided by Climate Central allows visitors to search out areas that will be prone to flooding and provides a timeline of the risks involved in flooding.  Here are a couple of examples:

Note that the areas in grey will be flooded if the level of the sea rises by four feet (i.e. a combination of sea level rise, storm surge plus tide), a scenario that has a one in six chance of occurring by 2020.  This will impact 181,000 people living in over 78,000 homes.

 Even a one foot rise in the aforementioned water level will have this impact on Manhattan:

Let's look at one other area as shown on this map which shows the impact of a four foot rise in water level on Miami/ Fort Lauderdale and surrounding area:

This scenario has a one in six chance of occurring by 2050 and will impact 59,000 people living in 35,000 homes.

The delicate balance between sea level and climate change is just that; delicate.  Unfortunately, the high concentration of Americans living slightly above sea level will find out the hard way just how painful the situation will be as the interaction between stormier weather and rising sea levels becomes more and more apparent.


  1. I live in New Orleans. The Climate Central map you reference states there is 1/6 chance of 1ft sea level, storm, and tide flooding by 2020 in Grand Isle. By that metric alone the data is bogus - I guarantee there is 100% change that will happen within the next year.

    Yes sea level rise is a concern but a millimeter or so every year has no correlation to any increase in climate activity that you could perceive over the course of your life.

  2. Thank you for your informative post. To anyone not seeing the rising sea level as a problem they should talk to the residents in Venice, Italy. I have written several post about the environment, one concerns the recent Presidential climate Initiative and another about the bizarre weather we are experiencing. This weather is often under-reported. Thanks again.