More Coastal Dwellers, Not More Hurricanes, Hike Dollar Damages

Economic damage from hurricanes hitting the United States has been doubling every 10 to 15 years, the study shows, and is currently at about $10 billion annually.

In their study of hurricane damage from 1900 to 2005, published in the current issue of the journal "Natural Hazards Review," the researchers warn that if more people settle along hurricane-prone shores, future economic hurricane losses may be far greater than they are today.

"We found that although some decades were quieter and less damaging in the U.S. and others had more land-falling hurricanes and more damage, the economic costs of land-falling hurricanes have steadily increased over time," said Chris Landsea, one of the researchers as well as the science and operations officer at the National Hurricane Center in Miami.

"There is nothing in the U.S. hurricane damage record that indicates global warming has caused a significant increase in destruction along our coasts," said Landsea.

Damage to property at Pensacola, Florida done by Hurricane Dennis. July 16, 2005. (Photo by Jocelyn Agostino courtesy FEMA)

The team used two different approaches, which gave similar results, to estimate the economic damages of historical hurricanes if they were to strike today. Both methods used changes in inflation and wealth at the national level.

The first method utilized population increases at the county coastal level, while the second used changes in housing units at the county coastal level. The results illustrate the effects of the tremendous pace of growth in vulnerable hurricane areas.

If the Great Miami Hurricane of 1926 were to hit today, the study estimates it would cause the largest losses at $140 billion to $157 billion, with Hurricane Katrina second on the list at $81 billion.

"Unless action is taken to address the growing concentration of people and property in coastal hurricane areas, the damage will increase by a great deal as more people and infrastructure inhabit these coastal locations," said Landsea.

The narrow coastal fringe that makes up 17 percent of the land area in the lower 48 states is home to more than half of the nation's population, according to a study released in 2005 by the National Oceanic and Atmospheric Administration, NOAA.

Entitled "Population Trends Along the Coastal United States: 1980-2008," the NOAA study shows that in 2003, about 153 million people - 53 percent of the nation’s population - lived in the 673 U.S. coastal counties.

In 1980, that 33 million fewer people lived in the coastal counties.

Los Angeles County and Riverside County in California, and Harris County, Texas experienced the greatest increases in population from 1980 to 2003.

The NOAA population report projected that by the year 2008 the coastal county population would increase by seven million nationwide.

Also by 2008, the combined population increase of San Diego, San Bernardino, Orange and Riverside counties in California will account for 12 percent of the total U.S. coastal population increase, the NOAA population study forecast.

In 2003, 23 of the 25 most densely populated U.S. counties were coastal and almost one quarter of the nation’s seasonal homes were found in the coastal areas of Florida.

The team of scientists on the Natural Hazards Review study include university, government and private sector scientists from the United States, the UK and Australia. They conclude that potential damage from storms is growing at a rate that may place "severe burdens on exposed communities."

Avoiding huge losses will require a change in the rate of population growth in coastal areas, major improvements in construction standards, and other mitigation actions.

The Natural Hazards Review paper, "Normalized Hurricane Damage in the United States: 1900-2005," was written by Roger A. Pielke Jr. of the University of Colorado; Joel Gratz of ICAT Managers, Inc.; Chris Landsea; Douglas Collins of Tillinghast-Towers Perrin; Mark Saunders of University College London; and Rade Musulin of Aon Re Australia.

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