Economic damage to the coastal United States from sea level rise and other climate change factors could range from the hundreds of billions to $1.1 trillion by the end of the century, according to a new study.
The study, “Joint effects of storm surge and sea-level rise on US Coasts,” was published this month in the scientific, peer-reviewed journal Climatic Change. Its findings represent the exhaustive work of researchers from several organizations, including Industrial Economics, WindRiskTech, the University of New Hampshire, the Woods Hole Group and the EPA’s Climate Change Division.
The study combined the assessments of three climate change models to produce the most detailed picture to date of the financial toll rising sea levels and storm surges will have on America’s coastal communities through 2100. In some cases, the additional damage from expected storm surges increased the national scale costs associated with sea level rise (SLR) adaptation by a factor of two.
“Total costs of adaptation to SLR through 2100 range from $1.3 billion in Washington State to $51 billion in Miami,” the authors write, “increasing to $1.6 billion in Washington State to $130 billion in Miami when also considering adaptation to storm surge.”
Whereas sea level rise will wreak direct, immediate damage to the U.S. coasts, storm surges will have less predictable impacts on cities, due to researchers’ “current inability to estimate indirect effects such as loss of critical infrastructure, business interruption, and debris removal costs.” These residual impacts could make up an even greater component of overall damage than their estimates show.
Across the 17 areas analyzed in the study, the authors note that the change in the total cost of adaptation when incorporating storm surge “ranged from zero percent in Oregon State to an increase of 420 percent in Tampa.”
Depending on the scenario used, the total undiscounted costs of adapting to sea level rise and increasing storm surges ranged from $840 billion at the low end to $1.1 trillion at the high end.
When greenhouse gas (GHG) mitigation strategies were added into the mix, the cost of adaptation dropped by up to $98 billion through 2100 (when considering SLR alone). The authors note that the benefits of greenhouse gas mitigation do not really kick in until mid-century, due to GHG emissions’ delayed impact on the climate.