BROOKYLN, N.Y. — A model from the First Street Foundation, a nonprofit research and technology group dedicated to making climate risk accessible, found that more than 13.4 million properties will be exposed to hurricanes in 30 years that are not currently at such risk, as well as increased vulnerability of Mid-Atlantic states.
According to the agency, the increasing exposure is due the greater proportion of hurricanes that are expected to reach category 3 to 5 on the Saffir-Simpson Scale and the greater likelihood that storms will track farther northward along the East Coast.
In partnership with the global consulting and engineering firm Arup, the foundation also calculated the dollar value of expected damage and the associated downtime for each specific building structure, accounting for things such as the number of stories, residential or commercial category, spatial orientation of the building, roof type, building material and more.
The property level damage estimates show that on average, the nation can expect to see an annual loss of $18.5 billion this year resulting from hurricane winds, increasing to just under $20 billion in 30 years.
Of that $1.5 billion in increased damages, the vast majority, roughly $1 billion, comes from increased exposure in Florida alone.
“Quantifying hurricane wind exposure and the resulting financial implications for every property in the country ushers in a new era in the understanding of the physical impacts of climate change,” said Matthew Eby, founder and chief executive officer of First Street Foundation. “Compared to the historic location and severity of tropical cyclones, this next generation of hurricane strength will bring unavoidable financial impacts and devastation that have not yet been priced into the market.”
The forecasting method used by the foundation is one that is informed by historic observations of tropical cyclone formation, strength and landfall rates and adjusted to the realities of today’s environment accounting for current sea surface temperatures, atmospheric temperatures, and sea level using the latest climate models from the International Panel on Climate Change (IPCC), according to the group.
That allows for the creation of thousands of synthetic storm tracks to better understand the likelihood and severity of storm formations today and under future climate scenarios.
The First Street Foundation Wind Model was built on decades of peer-reviewed research and heavily informed and guided by the research from world-renowned scientist and MIT professor emeritus of meteorology Kerry Emanuel.
The model reveals extensive risk along the gulf and Southeast Atlantic coasts, with significant growing risk in the Mid-Atlantic and Northeast regions of the country. Overall, in the next 30 years, the expected Average Annual Loss (AAL) resulting from this risk increases from $18.5 billion to $19.9 billion, and 13.4 million properties are likely to face tropical cyclone wind risk that do not currently face such risk.
Ocean City has an AAL in 2023 of $3.2 million, increasing to $5.4 million in 2053, an increase of 67 percent.
The intensity of the hurricanes that develop in the future is expected to increase in the North Atlantic, the proportion of major hurricanes (category 3-5) has increased by four times since the 1980s, from about 10 percent of all tropical cyclone events to more than 40 percent of all events today.
Driving this increase in intensity are rising air temperatures that increase the temperatures and heat content of the upper ocean waters, providing the energy that fuels these storms.
Other environmental changes, including increases in the amount of moisture in the atmosphere and alterations to large-scale wind patterns, also influence the intensity of hurricanes and where they are likely to move.
A shift of storms poleward has already been observed in the global historical data and has been confirmed by modeling studies, which means that the probability of storms making landfall further north along the east coast of the U.S. is expected to increase.
While tropical cyclone wind events are most common and severe along the Gulf Coast, they pose significant risk in many parts of the United States, particularly along the East Coast.
Hurricanes are tracking farther northward. In the Northeast, there is a concentration of properties that will be newly exposed to some probability of tropical storm level winds or stronger in 30 years.
The northward increase in hurricane activity may have a significant effect on buildings that have not been built to a code that considers the wind speeds they will likely face over the next 30 years, the group says.
Annual damages are expected to increase by about 87 percent over the next 30 years. Additionally, the count of properties with any AAL from wind will increase by about 55 percent, with about 2.2 million newly affected properties by 2053.
The largest increase in maximum wind speeds will impact states in the Mid-Atlantic, which will see the largest increase in maximum wind speeds in the U.S. over the next 30 years, with some areas increasing in maximum wind gust speeds by 37 mph.
Additionally, some areas within this region can anticipate relatively large increases in the probability of experiencing a Category 1 hurricane or higher over the next 30 years when compared to today, with many areas expected to see an additional 1 percent annual probability. With this increase in exposure, the annualized damages are expected to increase by 50.3 percent
Additionally, much of the Mid-Atlantic sees relatively large increases in the probability of exposure to hurricane wind speeds, increasing by an additional 1 percent annual likelihood.
In the current year, there are about 3.5 million properties within the contiguous United States with a chance of experiencing Category 5 hurricane winds, but in 30 years that number increases to more than 5.6 million properties.
Additionally, there are about 10.3 million properties with a chance of experiencing Category 4 hurricane wind conditions this year, increasing to about 14.9 million properties in 30 years.
That illustrates the effect of the previously mentioned results that hurricanes that form in the future in a changing climate are expected to increase proportionally in severity, the group says.
The cities that will experience the largest percentage increase in the annual average loss over 30 years (filtered by those with at least $1 million in AAL this year) are primarily located along the Mid-Atlantic and Northeast coasts.
The top five cities by percentage increase in AAL include New York, N.Y. (increasing by 302 percent); Newport News, Va. (157 percent); Suffolk, Va. (124 percent); Hampton, Va. (117 percent); and Bluffton, S.C. (109 percent). Rounding out the top ten are Portsmouth, Va.; Chesapeake, Va.; Savannah, Ga.; Norfolk, Va.; and Port Royal, S.C.
