There’s been “no trend” in the number and intensity of hurricanes hitting the continental U.S. and the normalized damages caused by such storms over the past 117 years, according to a new study.
“Consistent with observed trends in the frequency and intensity of hurricane landfalls along the continental United States since 1900, the updated normalized loss estimates also show no trend,” reads the study, published in Monday in the journal Nature.
“Over the entire dataset there is no significant trend in normalized losses, CONUS hurricane landfalls or CONUS intense hurricane landfalls,” reads the study. CONUS stands for “continental United States.”
While the nominal costs of hurricanes have increased in recent decades, that’s not because of global warming. Population growth and increased amounts of homes and infrastructure in hurricane-prone areas are driving costs up, the study found.
But the upward trend in nominal disaster costs disappears when economic growth is taken into account, the study found. In fact, had the 1926 Miami hurricane hit in 2018, it would have been the most damaging on record.
When controlled for economic growth, the study found “no trend” in normalized losses from hurricanes hitting the lower 48 states. The study analyzed data from 206 hurricane landfalls going back 117 years to 1900.
It’s the third in a series of papers looking at normalized hurricane damages. The new study includes economic losses from 2017’s devastating Atlantic hurricane season and adds in damage estimates from “missing” storms before 1940.
Pielke and Klotzbach also published a study in July that found no significant trend in the frequency or intensity of U.S. hurricane landfalls and that increased storm damages were driven by the “[g]rowth in coastal population and regional wealth.”
If anything, the July study showed a declining trend in U.S. hurricane landfalls — though not a statistically insignificant one. Klotzbach and Pielke’s newest paper, once again, shows that population and economic growth are behind increases in nominal hurricane costs.
Work by Klotzbach and Pielke on hurricane landfalls was largely ignored by authors of the U.S. government’s latest National Climate Assessment (NCA) report, which was released Friday. In fact, the NCA seems to suggest the opposite of what observational data shows.
In review comments, Canadian economist Ross McKitrick criticized NCA authors for leaving out data showing hurricane landfalls weren’t becoming more frequent.
McKitrick said national hurricane data going back more than a century “clearly indicate a drop in the decadal rate of U.S. landfalling hurricanes since the 1960s. The current decade is on the low end of hurricane frequency even with last summer’s busy season.”
“Yet you don’t mention this, instead you spin the topic to make it sound like the trends are all towards more cyclone activity. This paragraph is one-sided and misleading,” McKitrick wrote in his comments.
NCA authors disagreed with McKitrick’s criticism, arguing its choice to ignore hurricane landfall data was justified because they used “the entire dataset, which includes all basin-wide storms.”
Pielke also criticized NCA authors for omitting inconvenient hurricane data.
The NCA was produced with input from hundreds of scientists, including experts from 13 federal agencies. However, the report has come under fire for misusing climate projections to generate alarming media headlines.