See, Al Gore Told You So.

Hurricanes have been in the news lately, thanks to the United States getting whacked by hurricanes Helene and Milton in quick succession. The two hurricanes followed intersecting tracks, with some areas of the U.S. state of Florida getting grazed or hit by both storms.

Milton near peak intensity just north of the Yucatán Peninsula on October 7
Milton near peak intensity just north of the Yucatán Peninsula on October 7, image from Wikimedia Commons

Both hurricanes were enhanced by record-high sea surface temperatures in the Gulf of Mexico. This led to the storms undergoing rapid intensification. You don’t have to be a rocket scientist - or even a climate scientist - to suspect this added punch might have something to do with human-caused global warming.

Gee, where are all these hurricanes coming from?
Gee, where are all these hurricanes coming from? Image from Wikimedia Commons.

However, if you are a climate scientist, you might be working in one of the hotter (no pun intended, although noted) areas of research in your field right now: Extreme event attribution. That’s where climate scientists borrow concepts and methods from epidemiology, such as attributable fraction among the exposed, and using techniques such as climate modeling, they determine the degree to which an extreme weather event was made more likely, and/or more severe, by human activity.

For a technical introduction to the field, see the short but dense book Attribution of Extreme Weather Events in the Context of Climate Change (2016) from the National Academies Press. Paper copies are available for purchase or you can download the free PDF. And if you can explain chapter 3 to me that would be great - it turns out that I’m not an expert on climate modeling, go figure.

But I follow the field enough to know that extreme event attribution has progressed rapidly. In the prehistoric days of maybe 10 or 15 years ago, climate scientists might have taken a year or more after a big storm, drought, heat wave, or wildfire to offer their calculations on the degree to which climate change made the event more likely and/or more intense. Today scientists can present those results while a weather event is so fresh that Trump hasn’t finished lying about it. See for example World Weather Attribution’s articles, such as their take on Milton: Yet another hurricane wetter, windier and more destructive because of climate change (11 October, 2024). They got that result out to journalists in time to include with live coverage of the storm and its immediate aftermath. Although not a game-changer, this new scientific capability is an important incremental advance in the long battle of explaining science to the public. Whether these results come out in days or years doesn’t make much difference to the science, but it can make a big difference to the short attention spans of laypeople in rapid news cycles. If you weren’t directly affected by a particular hurricane, you’ve probably moved on to other concerns after a year.

If you’ve lived in the USA for a while you might suspect that landfalling hurricane strikes have been getting more frequent and more intense. And you would not be wrong, although not all of the difference is directly due to human influence. In the Atlantic hurricane basin, tropical cyclones form every year during hurricane season, traditionally spanning the months from June through November (such storms can form at any time of year, but they’re rare in the months out of season). As you can see from the historical storm track map, many storms stay out to sea and do not directly strike the US mainland - although our Caribbean and Central American neighbors are often not so lucky. Wikipedia says, “On average, 14 named storms occur each season in the North Atlantic basin, with 7 becoming hurricanes and 3 becoming major hurricanes (Category 3 or greater).”

Tracks of North Atlantic tropical cyclones from 1851 to 2019
Tracks of North Atlantic tropical cyclones from 1851 to 2019, image from Wikimedia Commons

So, there are multiple Atlantic tropical storms every year, some usually reaching hurricane strength, and it’s just random luck whether or not they get steered by winds and fronts into hitting some particular nation.

After the exceptionally hard hurricane season of 2005, the U.S. enjoyed a remarkable run of favorable “luck” up to 2016 when Hurricane Matthew blasted numerous islands including Haiti and the Bahamas, then grazed the U.S. east coast (without making landfall, but still causing several billion dollars in damage and claiming 47 American lives). At the time, “the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, tweeted Oct. 5 it [had] been 4,000 days since the last major hurricane hit the United States (or approximately 10.9 years).”

As will come as no surprise to anyone, climate change deniers at the time siezed upon the lull in American landfalling major hurricanes as “proof” that Al Gore was “wrong”. Gore, as the reader may recall, was and remains instrumental in bringing climate change to broad public awareness including with his slide show, TED talk, book, and movie An Inconvenient Truth (2006). The movie poster features an arresting graphic of a smokestack belching a hurricane-shaped cloud, rather un-subtlely suggesting the causal link. The movie came out shortly after the then-record-setting 2005 Atlantic hurricane season. At the time climate scientists had been warning about the obvious connection between a warming climate resulting in warmer sea surface temperatures which would make conditions more favorable for tropical cyclones to form and gain intensity. However, other factors (such as wind shear) also influence cyclogenesis, so it’s not quite as simple as “hotter planet, more storms.” The 2005 Atlantic hurricane season was exceptional for its time (indeed, it’s still exceptional, although no longer sui generis, having been rivaled in some aspects by subsequent highly active seasons). In no way were climate scientists claiming 2005 represented a new normal for landfalling major hurricanes hitting the USA, but rather to point out that the odds were steadily creeping up in lockstep with the Keeling Curve. So whether it might take years or decades for the figurative chickens to come home to roost, persisting with our fossil-fueled business as usual meant they were coming. Or perhaps instead of chickens I should call them gray swans. (That’s a play on the term black swan which refers to a possible event which was previously unknown and unexpected; a gray swan is an event that scientists already know is possible but has not happened yet, or at least has not happened since humans began keeping good records. Climate change science abounds with gray swans.)

But despite all that nuance, climate change deniers siezed on the America-centric landfalling major hurricane lull post-2005 as evidence that climate change was bunk.

Even at the time that was already a technicality, since a “major” hurricane is one with wind speeds of Category 3 or higher on the Saffir–Simpson scale. However, wind speed is only one measure of a storm’s severity and destructive impact. In 2012, Hurricane Sandy struck Cuba as a Category 3 hurricane (a major hurricane) before moving north to menace other countries including the U.S. By the time Sandy made landfall in the U.S. state of New Jersey, it was “only” an extra-tropical cyclone with hurricane force winds of Category 1 strength, but the extremely large size of the storm (the largest tropical cyclone ever seen in the Atlantic) extended its impacts to 24 U.S. states and several Canadian provinces. It inflicted $68.7 billion (2012 USD) in damage, $65 billion in the U.S., making it the seventh-costliest hurricane in U.S. history. So, the hurricane “lull” wasn’t much of one.

Among the deniers making hay off of that trope was a very well-compensated one, the late Rush Limbaugh. Limbaugh “was the host of The Rush Limbaugh Show, which first aired in 1984 and was nationally syndicated on AM and FM radio stations from 1988 until his death in 2021.” Limbaugh was one of the most influential figures in the American conservative movement after the Ronald Reagan era. He pioneered the use of grievances and lies to energize and grift the same subset of Americans that Donald Trump later continued to energize and grift with the same playbook. Limbaugh made lying cool again, to such an extent that even some conservatives took pause. See for example: Rush Limbaugh Leaves Behind a Conservative Movement No Longer Interested in Truth. That Alarms Me as a Conservative (February 17, 2021) by Joe Walsh.

Limbaugh authored seven books with the first two making the New York Times best-seller list. His second book, See, I Told You So (1993), inspired the snarky title of this blog post: See, Al Gore Told You So. In 1993, climate change science was still in its middle school phase, and the world was much less far along with the increasing pace of climate change impacts we see today (and which are likely to grow geometrically worse in the coming decades, barring an unprecedented and unlikely collective human effort to stop burning fossil fuels). But even way back then, Limbaugh was denying climate science with arguments whose irrelevance was only rivaled by their nonfactuality. For example, Limbaugh claimed, falsely, that U.S. forest cover was then higher than it was when the White Man first landed on what is now the United States. The actual figure was 75%, or about a quarter of the originally forested land was then de-forested, and very little of the original old-growth forest remained, most having been logged at some point. But as anyone who has read much about climate science knows, this factoid has very little to do with the climate change forecast. First, while forests matter to climate change, both in terms of causes and effects, they aren’t the main cause: fossil fuels are. Second, the state of the world in 1993 wasn’t what climate change was mainly about - instead climate scientists were making predictions about the future. By analogy, in 1993 Rush Limbaugh hadn’t gotten lung cancer yet.

An increasing number of those climate change predictions are coming true right now, such as the obliteration of Limbaugh’s 2016 talking point. Only a clinically insane person could imagine that the USA is experiencing any kind of lull in landfalling major hurricanes now. Sadly, or perhaps not sadly in the minds of his many victims, Limbaugh isn’t around to experience his comeuppance, not that he would have mourned the loss of a single talking point. Limbaugh died at age 70 on February 17, 2021 of lung cancer. He was a longtime cigar smoker and a former cigarette smoker. Wikipedia says he had previously downplayed the link between smoking and cancer deaths, arguing that it “takes 50 years to kill people, if it does.” Depending on when Limbaugh started smoking, he might have been about right on that 50 year figure. Even so, he probably robbed the world of a good ten more years of his disinforming, at least.

As a slight consolation, conservative disinformation has led to the emergence of numerous fact-checking sites; here is a list. Given the amount of disinformation Limbaugh spread during his career, he commands a lot of space in the fact-checking ecosystem. See for example these PolitiFact links:

Allison Graves’ fact-checking piece is directly relevant to this post, as it shows how Limbaugh’s talking point wasn’t even right in the year 2016 when the American landfalling major hurricane lull was still a thing. Graves hits all the right notes, but the article could use an update since it doesn’t reflect recent progress in extreme event attribution, which I mentioned near the top of this post.

As a general rule I recommend always looking up the fact-checks whenever you read or hear any politician on the right spouting off. You can do the same thing for politicians on the left, but it turns out that left-leaning politicians lie considerably less often. And when they do lie or misstate and get fact-checked, they often issue retractions, while right-leaning politicans tend to double down on their lies. Politicians on the right tend to decry the fact-checkers as “radical left fake news” when those politicians themselves get fact-checked, and then they tweet and tout the same fact-checkers on those rare occasions when they catch a politician on the left in a Pinnochio. (“Pinnochio” is a rating system for falsehoods used by Glenn Kessler, a journalist and fact-checker for the Washington Post.)

3:39 AM 10/17/2024 - Correction to the original: Glenn Kessler uses but did not coin the “Pinnochio” rating system for the Washington Post fact-checking department. See my comment below for more explanation.

0 comments: