Sep 24, 2018 - Science

Study: Sea level rise boosted Hurricane Florence's coastal flooding

Data: First Street Foundation; Chart: Chris Canipe/Axios

A sea level research and communications group's rapid analysis of the storm surge from Hurricane Florence has found that 1-in-5 of the homes impacted along the Carolina coast wouldn't have fared so badly had sea levels not risen significantly since 1970.

Why it matters: Sea level rise is one of the most significant effects of climate change that is already impacting society, and its footprint is only projected to grow. For example, the report also projects far more flooding from a similar, Florence-type storm in 2050.

The details: The First Street Foundation, a sea level research and communications group, sought to determine how many homes were affected by Hurricane Florence's storm surge compared to past storms.

  • To do this, they used data from recent federal government overflights of hard-hit coastal areas and obtained storm surge heights for 75 stations in the Carolinas and Virginia. They also relied on historical sea level elevation data.

Here's what they found:

  • Sea level rise since 1970 caused Hurricane Florence to "significantly affect" more than 11,000 additional homes.
  • Tidal data shows that the relative sea level off the Carolina coast has risen about a half-foot since 1970.
  • Hurricane Florence’s storm surge affected more than 51,000 homes by pushing water over 25% or more of each property.
  • The regional sea level, projected by the Army Corps of Engineers for just 30 years from now, is more than 1 foot above current levels. At that level, the same storm surge from Florence would have nearly double the impact — instead of 51,000 flood-affected homes, North Carolina would see 102,000 affected homes.

Take note: First Street Foundation is comprised of an unusual mix of scientists and marketers working together to communicate the risks of sea level rise. Some refer to it as an advocacy organization, but executive director Matthew Eby rejected that label in an interview with Axios, noting that it makes its methodology publicly available for review.

Go deeper: Sea level rise already causing billions in home value to disappear.

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