Dr. Roger Pielke Junior writes:
Our major update to the CONUS normalized hurricane loss dataset has now been published, after several years of effort and an intensive review process by Nature Sustainability.
Weinkle et al. 2018.Normalized hurricane damage in the continental United States 1900–2017, Nature Sustainability. https://www.nature.com/articles/s41893-018-0165-2
Direct economic losses result when a hurricane encounters an exposed, vulnerable society. A normalization estimates direct economic losses from a historical extreme event if that same event was to occur under contemporary societal conditions. Under the global indicator framework of United Nations Sustainable Development Goals, the reduction of direct economic losses as a proportion of total economic activity is identified as a key indicator of progress in the mitigation of disaster impacts. Understanding loss trends in the context of development can therefore aid in assessing sustainable development. This analysis provides a major update to the leading dataset on normalized US hurricane losses in the continental United States from 1900 to 2017. Over this period, 197 hurricanes resulted in 206 landfalls with about US$2 trillion in normalized (2018) damage, or just under US$17 billion annually. 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. A more detailed comparison of trends in hurricanes and normalized losses over various periods in the twentieth century to 2017 demonstrates a very high degree of consistency.
Some key excerpts from the paper:
Consistency check with climate trend data.
Long-term trends in hurricane landfall frequency and intensity provide a useful means of evaluating the results of a normalization methodology. A normalization should not be used to explore climate trends; climate data better serve that purpose. However, climate data can be used to perform a consistency check with a normalization. Trends in an unbiased normalization dataset should match corresponding trends in the incidence of extreme events for countries such as the United States that have heavily populated coastlines. After all, the goal of a normalization is to remove the signal of societal changes from a loss dataset as much as possible. Thus, if relevant extreme events have become more (less) common or more (less) intense, then over the same period we would expect a normalized loss dataset to show a corresponding increasing (decreasing) trend.
Landfalling hurricanes contribute significantly to disaster losses both in the CONUS and globally. Large loss years such as 2017 remind us of the magnitude of losses that are possible when several major hurricanes make landfall in a single year. However, our normalization analyses suggest that the losses in 2017 are far from a worst-case scenario. Losses from a single storm striking the CONUS, analogous to the Great Miami hurricane of 1926, could result in twice the total direct economic loss amounts of 2017, totalling well over US$200 billion. Loss potentials are certainly higher
than this for conceivable storms for which there is no historical analogue since 1900.
As growth continues, the United States should thus expect much greater hurricane damage in its future. Understanding the role of societal changes in loss potential, how such changes evolve over time and the role of disaster mitigation policies that might address loss potentials is essential to the design and implementation of effective actions under the targets of the Sustainable Development Goals.
Recently, the CONUS has experienced a long period of good fortune with respect to landfalling hurricanes, notably the 11-year stretch of no major CONUS hurricane landfalls that ended in 201720. Consequently, if coming years see storms make landfall at rates and intensities closer to observed historical averages, then we should expect larger losses than those observed from 2006 to 2016.
In addition, over climate timescales, any increases in major hurricane frequency or intensity above historical rates would lead to even greater losses. Whatever the future brings, addressing exposure and vulnerability to hurricanes will remain a permanent priority for communities along the US Gulf and Atlantic coasts seeking to implement sustainable and robust disaster mitigation policies in the face of an uncertain climate future.