JANUARY 30, 2021
By Paul Homewood
Last May this story was being widely covered:
Stronger, deadlier and more frequent — that’s the trend scientists at the National Oceanic and Atmospheric Administration (NOAA) have seen in the past few decades, and they expect that trend to continue in the years to come, according to a new study.
Researchers at the University of Wisconsin and NOAA analyzed satellite data of tropical cyclones over the last 40 years and found category 3, 4 and 5 hurricanes were becoming increasingly common, CNN reported. Decade after decade, the likelihood of major global storms has increased, according to CNN.
“The change is about 8% per decade. In other words, during its lifetime, a hurricane is 8% more likely to be a major hurricane in this decade compared to the last decade,” James Kossin, author of the study, told CNN.
The statistician William Briggs published a rebuttal on his website this week, which was written by Greg Kent and attacked the statistical basis of the Kossin study. You can read it here.
The study looks at the period 1979 to 2017, and compares 1979-1997 with 1998-2017
Kent makes one crucial observation, without realising its true significance:
The pervasive erroneous calculations in the original paper and the invalid claim of statistical significance are not the only issues with Kossin et al. There is also reason to question whether the 10% increase in the proportion of major hurricane force winds was a global or largely regional phenomenon. Kossin et al presented results for each of the hurricane basins around the world. The data shows that the global results are driven largely by a single basin, the North Atlantic. The proportion of major wind speeds increased by 72% in the North Atlantic, far more than in any other hurricane basin. Western Pacific, which accounts for over 40% of the major hurricane force winds over the last 4 decades, showed a smaller proportion of intense storms in the later period (indicating a negative change). The other basins either showed no change at all between periods or the change was so small as to fail tests of statistical significance at traditional levels of confidence.
There is actually a very good reason why there have been more intense hurricanes since 1998 than before – the Atlantic Multidecadal Oscillation or AMO. Here’s what NASA have to say about the AMO:
The AMO was in cold phase between 1979 and 1995, and has been warm ever since. So the increase in hurricane intensity has nothing whatsoever to do with “climate change”, and instead is a consequence of natural ocean cycles.
In any other field of science, peer review would have spotted this fatal flaw in Kossin’s paper, which would never have been published.