Climate Experts: Data And Figures The Media Won’t Tell You About Global Tropical Cyclones

This post is co-authored with Ryan Maue, whose Weather and Climate Substack I highly recommend. —RP

In 2012, Jessica Weinkle, Ryan Maue, and I published in the Journal of Climate the first climatology of global landfalling tropical cyclones of at least hurricane strength. Since then, Ryan and I have updated the time series every year. [emphasis, links added]

Landfalling hurricanes (also called typhoons or cyclones) are an important subset of tropical cyclones because these storms cause the most damage of any type of extreme event, with most of these losses occurring in the United States.

The figure below shows the total global landfalling hurricanes and major hurricanes from 1970 to 2023.

The graph starts in 1970 because that is when reliable information is available globally, however, several basins have records that go back further in time.

The figure below shows the same data with linear trends for minor (Saffir/Simpson Categories 1 and 2) and major (S/S 3+) hurricanes.

You can see that since 1970 there has been no trend in landfalls of minor hurricanes and an upward trend in major hurricanes. Might this be the consequence of human-caused climate change?

We can get a sense of the meaningfulness of a trend that started in 1970 by looking further back in time for the Western North Pacific and North Atlantic, which together saw 67% of all global hurricane landfalls from 1970 to 2023.

The combined landfalls of minor and major hurricanes for these two basins are shown below and there is no trend in either category.

Below is the same data, but starting from 1970 you can see that major hurricane landfalls increased over this shorter period, in contrast to beginning the analysis in 1950 when data for these two basins was first available.

In technical terms, the detection of change has not been achieved — which is fully consistent with the scientific consensus of NOAA and the IPCC.

Without detection, there can be no attribution under the IPCC framework for detection and attribution.

Given the large interannual and decadal variability in tropical cyclones, data are easily cherry-picked (intentionally or unintentionally) to identify spurious trends.

The figures below show the distribution of global landfalling storm counts for major and total hurricanes from 1970 to 2023, showing large variability.

Landfalling hurricanes are of course just a subset of tropical cyclones, as many storms stay out to sea. Ryan has just updated his excellent figures on global tropical cyclone activity.

The figure below shows running 12-month sums of all hurricanes and major hurricanes since 1980.

The figure below extends back to 1970 and includes tropical storms, which are tropical cyclones that are less than hurricane strength, but Ryan warns of pre-1980 data:

“Data prior to the mid-1980s is spotty in parts of the Southern Hemisphere and Eastern Pacific with the lack of satellite imagery. The 1970s intensity data has large uncertainty [+missing] outside of the Western Pacific and North Atlantic.”

While doing his update Ryan discovered a remarkable fact: During 2023, the running three-year sum of major hurricanes was at its lowest since 1980. Interesting!

Finally, from the excellent data maintained by Phil Klotzbach at Colorado State University, we can look at yet another set of metrics — Accumulated Cyclone Energy (ACE, which combines frequency and intensity) and ACE per hurricane.

These figures are shown below, and you can clearly see no trends in these metrics since 1980. Over this period and according to these metrics, hurricanes have not become more intense.

The Honest Broker is written by climate expert Roger Pielke Jr and is reader-supported. If you value what you have read here, please consider subscribing and supporting his work.

About RPJ: Roger Pielke Jr. has been a professor at the University of Colorado since 2001. Previously, he was a staff scientist in the Environmental and Societal Impacts Group of the National Center for Atmospheric Research. He has degrees in mathematics, public policy, and political science, and is the author of numerous books. (Amazon).

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