Debunked Claim: Early Season Hurricanes Increasing Because of Climate Change
Guest Post by Bob Vislocky, Ph.D.
Figures it wouldn’t take very long into the 2019 hurricane season for journalists to start screaming climate change. In this recent New Republic article by Eric Holthaus, the claim is made in the subtitle that “early season hurricanes is a sign of things to come for our warming world”.
Further into the article the author, who is a meteorologist, makes the claim that “as the Gulf of Mexico waters warm because of climate change, early-season hurricanes like proto-Barry could become more common.” Let’s investigate that assertion further using actual historical data.
The chart below displays the number of early season (June/July) landfalling hurricanes to strike the U.S. by decade ending in the year shown. Results show that despite 150+ years of global warming the frequency of early season hurricanes has actually declined by a small (but probably insignificant) amount, as evidenced by the dashed blue least-squares trend line. Certainly there is no clear evidence to support the author’s claim that they’re becoming more common.
However, what’s more infuriating is the blatant cherry picking and misrepresentation that also appears in his column. Specifically, Holthaus states that “in the 168 years of hurricane records, a July hurricane in Louisiana has only happened three times, and all of those occurrences have been within the past 40 years.” On the surface this statement is factually correct, but the implication is that climate change is causing the early-season July hurricanes since they all happened in just the last 40 years. However, let’s dig a little deeper, but instead of focusing solely on July hurricanes that hit Louisiana, let’s count ALL early-season hurricanes to strike Louisiana. Here’s the list:
(1) June 1886 (Unnamed, Cat 2)
(2) June 1934 (Unnamed, Cat 2)
(3) June 1957 (Audrey, Cat 3)
(4) July 1979 (Bob, Cat 1)
(5) July 1997 (Danny, Cat 1)
(6) July 2005 (Cindy, Cat 1)
Now the painting shows a completely different picture with half of all early-season hurricanes to strike Louisiana occurring before 1960, which is expected given no overall trend in June/July hurricanes. However, by purposefully omitting the June early-season hurricanes from his analysis the author is guilty of cherry-picking data in the least and more likely guilty of fraudulent reporting to promote an agenda. As a meteorologist, Holthaus should be embarrassed by his research. Guess he figured nobody would fact-check his work.