From The Honest Broker

By Roger Pielke Jr.

Back in 2012, Jessica Weinkle, Ryan Maue, and I published the first peer-reviewed paper presenting a time series of global tropical cyclone landfalls of hurricane strength.

In that paper we concluded:

From currently available historical TC records, we constructed a long-period global hurricane landfall dataset using a consistent methodology. We have identified considerable interannual variability in the frequency of global hurricane landfalls; but within the resolution of the available data, our evidence does not support the presence of significant long-period global or individual basin linear trends for minor, major, or total hurricanes within the period(s) covered by the available quality data. Therefore, our long-period analysis does not support claims that increasing TC landfall frequency or landfall intensity has contributed to concomitantly increasing economic losses. Because of documented multidecadal variations in TC frequency and intensity on global and basin scales, our findings strongly support the usage of long-period historical landfall datasets for trend analysis (cf. Liebmann et al. 2010).

While there is continued uncertainty surrounding future changes in climate (Knutson et al. 2010), current projections of TC frequency or intensity change may not yield an anthropogenic signal in economic loss data for many decades or even centuries (Crompton et al. 2011). Thus, our quantitative analysis of global hurricane landfalls is consistent with previous research focused on normalized losses associated with hurricanes that have found no trends once data are properly adjusted for societal factors (e.g., Pielke et al. 2008; Crompton and McAneney 2008; Neumayer and Barthel 2011; Barthel and Neumayer 2012; Bouwer 2011; Raghavan and Rajesh 2003).

Since 2012, Ryan and I have updated the dataset every January. With 13 years of additional data, the conclusions of our 2012 paper remain current.

The figure below shows the updated time series for the period of available data at the global scale, 1970 to 2025. Last year was a fairly typical year, with 19 total landfalls, of which 7 were major hurricanes. Overall tropical cyclone activity in the Northern Hemisphere was below average and above average in the Southern Hemisphere.

The total includes:

• 5 in the Southern Indian / Australian region;
• 1 in the Eastern Pacific;
• 1 in the North Atlantic;
• 12 in the Western North Pacific.

Since 1970, the number of major hurricane landfalls has increased, while the number of minor landfalls has remained constant, meaning that a greater proportion of landfalling storms are at the higher intensities. This trend is consistent with the assessments of the Intergovernmental Panel on Climate Change for overall tropical cyclone activity (landfalling or not). Perhaps this is a signal of human caused changes in climate?

Well . . .

It is well understood that the 1970s and early 1980s were a period of lower tropical cyclone activity overall. We can get a longer-term perspective by looking just at the Western Pacific and North Atlantic, which together account for ~70% of total global landfalls, and have reliable data going back to 1950.

The figure below shows landfalls in these two basins from 1950 to 2025. You can see that there are no upwards trends in either major or minor landfalls, but there is an increase in major landfalls from 1970 to 2025 (not shown).

This longer-term perspective leads me to conclude that the increasing proportion of major landfalling storms from 1970 to 2025 is encompassed by historical natural variability. You can find a much deeper dive on this issue at the post below:

My conclusion is consistent with the IPCC AR61:

Identifying past trends in TC metrics remains a challenge due to the heterogeneous character of the historical instrumental data, which are known as ‘best-track’ data (Schreck et al., 2014). There is low confidence in most reported long-term (multi-decadal to centennial) trends in TC frequency- or intensity-based metrics due to changes in the technology used to collect the best-track data. This should not be interpreted as implying that no physical (real) trends exist, but rather as indicating that either the quality or the temporal length of the data is not adequate to provide robust trend detection statements, particularly in the presence of multi-decadal variability.

Of course, the rather tame science of detection and attribution with respect to tropical cyclone behavior is no match for climate hype.