The folly of linking tornado outbreaks to climate change

In times of tragedy, there are always hucksters trying to use that tragedy to sell a position, a product, or a belief. In ancient times, tragedy was the impetus used to appease the gods and to embrace religion. In light of yesterday’s op-ed on The Center for American Progress’s Think Progress blog that essentially blames Republicans for last week’s devastating tornadoes, it seems some opportunists just can’t break the pattern of huckster behavior in the face of disaster.

The Think Progress piece cites Kevin Trenberth, a senior scientist at The National Center for Atmospheric Research in Boulder, Colorado:

“Given that global warming is unequivocal,” climate scientist Kevin Trenberth cautioned the American Meteorological Society in January of this year, “the null hypothesis should be that all weather events are affected by global warming rather than the inane statements along the lines of ‘of course we cannot attribute any particular weather event to global warming.’”

It should be noted that during that AMS conference in January, Dr. Trenberth called people who disagreed with that view “deniers” in front of hundreds of scientists. Even after being called out on the issue, he left the hateful term intact in his speech. Clearly, he is a man with a bias. From my perspective, these articles citing Trenberth are opportunistic political hucksterism at its finest. Unfortunately, there are many people like Trenberth who don’t bother to cite some inconvenient facts.

First, let’s look at the claim that tornadoes are on the increase, in parallel with the climate change that is claimed. In a previous article, I cited this graph from the National Climatic Data Center:

Obviously, when NCDC tallies the number of F3-F5 tornadoes from this recent outbreak and gets around to updating that graph, there will be an uptick at the end in 2011 that is on par or even higher than the famous 1974 tornado outbreak. The point though is that despite the 1974 uptick, the trend was down.

As The New York Times notes:

The population of the South grew by 14.3 percent over the last decade, according to the Census Bureau, compared with 9.7 percent for the nation as a whole. Of those states hardest hit by tornadoes this year, some were among the fastest growing, notably Texas and North Carolina.

This graph illustrates the relationship between population and tornado-related deaths (source: NOAA’s U.S. Severe Weather Blog, SPC, Norman, Oklahoma):

Let’s look at other figures. Yesterday, Dr. Roger Pielke Junior got an updated graph from NOAA to bring it to 2010:

That graph is a testament to the improved lead times, accuracy, and dissemination of severe weather warnings by the National Weather Service, whose members did an outstanding job during this severe weather event. Mike Smith, in his book Warnings: The True Story of How Science Tamed the Weather, discusses the vast improvements we’ve witnessed since the early days of severe weather forecasting. He writes of the recent outbreak:

There is no question that the current storm warning program, a collaborative effort of the National Weather Service, private sector weather companies like AccuWeather, broadcast meteorologists, and local emergency managers have saved hundreds of lives during these recent storms through excellent forecasts and warnings. This image shows the tornado warning (red hatched area) for Birmingham that was issued more than 20 minutes before the tornado arrived.

Can the warning program be improved? Certainly. The National Weather Service’s new dual-polarization radar will improve flash flood warnings and will incrementally improve warnings of tornadoes that occur after dark.

But in the immediate aftermath of these tragic storms we seem to have learned two things: People need to respond to today’s highly accurate warnings. For some reason, the media (see examples here and here seems determined to downplay the quality of the warnings which may have the effect of driving down response rates.

Second, they must have a place to take shelter. Most mobile home parks and many homes in the South do not have underground shelters or safe rooms. Mobile home parks and housing developments should look to constructing these in the future.

Because of the 30 minutes of advance warning in this case, and many other advance warnings during this outbreak, plus the super-saturation of live television coverage, plus the fact that weeks in advance my colleague, Joe D’Aleo, co-founder of the Weather Channel and now at Weatherbell LLC, discussed the likelihood of a super-outbreak of severe weather occurring due to the juxtaposition of cold air from snowpack in the Northern plains with warm moist air in the South, people knew the storms were coming; they just had few options for shelters that would survive at F3-F5 category tornado intensity. The death toll issue seems to be shelter, not lack of forecasts, warnings, or awareness.

The attempts at linking the tornado outbreak to “global warming” have been roundly criticized in the meteorological community. Thursday there was a denouncement of the tornadoes-to-global-warming link in this story from Physorg.com.

“If you look at the past 60 years of data, the number of tornadoes is increasing significantly, but it’s agreed upon by the tornado community that it’s not a real increase,” said Grady Dixon, assistant professor of meteorology and climatology at Mississippi State University.

“It’s having to do with better (weather tracking) technology, more population, the fact that the population is better educated and more aware. So we’re seeing them more often,” Dixon said.

But he said it would be “a terrible mistake” to relate the up-tick to climate change.

Anticipating this sort of nonsense in the current political climate that seeks to blame humans for the weather, last month The National Weather Association, representing thousands of operational meteorologists, forecasters, and television-radio meteorologists in the United States, adopted their first-ever position statement on climate change and severe weather events. They state:

Any given weather event, or series of events, should not be construed as evidence of climate change.

The NWA emphasizes that no single weather event or series of events should be construed as evidence of a climate trend. Daily weather is subject to extreme events due to its natural variability. It is only the occurrence of these events over decades that determines a climate trend.

No clearer statement could be rendered. It mirrors what a NOAA scientist at the Storm Prediction Center said yesterday to Fox News:

Greg Carbin, the warning coordination meteorologist at NOAA’s Storm Prediction Center in Norman, Oklahoma, said warming trends do create more of the fuel that tornadoes require, such as moisture, but that they also deprive tornadoes of another essential ingredient: wind shear.

“We know we have a warming going on,” Carbin told Fox News in an interview Thursday, but added: “There really is no scientific consensus or connection [between global warming and tornadic activity]…Jumping from a large-scale event like global warming to relatively small-scale events like tornadoes is a huge leap across a variety of scales.”

Asked if climate change should be “acquitted” in a jury trial where it stood charged with responsibility for tornadoes, Carbin replied: “I would say that is the right verdict, yes.” Because there is no direct connection as yet established between the two? “That’s correct,” Carbin replied.

Historically, there have been many tornado outbreaks that occurred well before climate change was on anyone’s radar. Here’s a few:

1908 Southeast tornado outbreak 324 fatalities, ≥1,720 injuries

1920 Palm Sunday tornado outbreak ≥380 fatalities, ≥1,215 injuries

1925 Tri-State tornado ≥747 fatalities, ≥2,298 injuries

1932 Deep South tornado outbreak ≥330 fatalities, 2,145 injuries

1952 Arkansas-Tennessee tornado outbreak 208 fatalities

1965 Palm Sunday tornado outbreak 256 fatalities

April 3-4 1974 Super Outbreak 315 fatalities

All of these occurred before “climate change” was even on the political radar. What caused those if “global warming” is not to blame? The real cause is La Niña, and as NOAAwatch.gov indicates on their page with the helpful meter, we are in a La Niña cycle of ocean temperature in the Pacific.

Here’s what it looks like on satellite measurements. Notice the cool blue:

The U.S. Climate Prediction Center explains the reason for such outbreaks in relation to ocean temperature cycles:

Since a strong jet stream is an important ingredient for severe weather, the position of the jet stream helps to determine the regions more likely to experience tornadoes. Contrasting El Niño and La Niña winters, the jet stream over the United States is considerably different. During El Niño, the jet stream is oriented from west to east across the southern portion of the United States. Thus, this region becomes more susceptible to severe weather outbreaks. During La Niña, the jet stream and severe weather is likely to be farther north.

Note the collision zone in the U.S. Southeast during La Niña patterns.

Finally, let’s examine the claims of global warming being linked to the tornado outbreak. If this were true, we’d expect the globe to be warmer, right?

Thunderstorms (and all weather for that matter) form in the troposphere, that layer of the atmosphere that is closest to the surface, and extends up to the stratosphere.

Dr. Roy Spencer, climate scientist from the University of Alabama, Huntsville, tracks the temperature of the troposphere. The university system that he tracks the temperature daily with is inoperable, due to the storms. People who have been watching it prior to this event know the current global tropospheric temperature is lower in April than the norm, but we can’t show it today. The last global value he plotted showed this:

The global temperature anomaly of the troposphere today is about the same as it was in 1979. If there’s any global warming in the troposphere, it must be a figment of an overactive imagination on the part of people who seek to link it to the recent tornado tragedy.

Dr. Roy Spencer sums it up pretty well on his blog:

It is well known that strong to violent tornado activity in the U.S. has decreased markedly since statistics began in the 1950s, which has also been a period of average warming. So, if anything, global warming causes FEWER tornado outbreaks…not more. In other words, more violent tornadoes would, if anything, be a sign of “global cooling,” not “global warming.”

Anyone who claims more tornadoes are caused by global warming is either misinformed, pandering, or delusional.

The people who seek to link this tragedy to the political movement of climate change should be ashamed of themselves. The only “deniers” here are the ones who deny all the long-established counterevidence of their bogus claims for political gain.

Anthony Watts operates the most visited blog on climate science in the world, www.wattsupwiththat.com.

  • oldman12

    Mr. Watts claims no global climate change theories accompanied historic tornado breakout events…he is wrong… the 1974 breakout occurred when climate gurus were predicting the onset of a new ice age. I can imagine that particularly nasty event was seen as a prelude by global cooling theorists to even more horrible weather as we descended toward reglaciation and the end of civilization.

    Temperatures and sea levels have been rising for 20,000 years…and they would continue to rise whether homo sapiens had survived the Toba super volcano or not….the big problem for civilization occurs when temperatures begin going down. Check out the Eemian interglacial to see our future. We seem to be heading toward a “blow-off” temperature spike(much like internet stocks in 2000) to be followed by a 100,000 year spiral downward. Obama should have spent that trillion dollars on eminent domaining Panama and removing the istmus of Pananma whose formation 30 million years ago altered ocean currents which was a prime factor(along with the upshoot of the Himalayas) in creating the current ice age we find ourselves.

  • ChillytheAlaskan

    Hey Harry,
    We have a choice to believe the climate deniers or the climate liars. I’ll take the deniers. You sound like the typical progressive, wrongly thinking you are so much smarter than the conservatives, when it is actually just the opposite. That is why the progressives are so in to giving each other awards and titles that don’t mean s**t, like Nobel Peace Prizes.

    Real scientists don’t hide their data, use deception, distortion, and lies. They aren’t afraid to have skeptics use their data to look for mistakes and for others to be able to confirm and duplicate their results. Liars and cheats won’t let others look at their work, because they fear being exposed.

    CO2 compromises about 4% of the atmosphere, of which man contributes about 3%, and you think this minuscule contribution is the cause of global warming? You are nuts!

    By the way, our prisons are full of high IQ people, while many people who had meager educations, ended up self made millionaire’s. You on the other hand, insist on ignoring the results of other scientist, high IQ and highly educated, and insist your BELIEF is correct, or maybe you owe your income to government grants on global warming and don’t want the gravy train to end.

    Unfortunately, the alarmist have a LONG history of predicting these disasters, and have not been correct once, and again are on the wrong side of this issue. I have hundreds of articles on scientist disproving time after time the hypothesis of global warming, but the alarmist believers just won’t accept facts. http://www.heartland.org/environmentandclimate-news.org/article/29687

  • The_anniebanannie

    Excellent article, Mr. Watts.

    • truebearing

      I second that! Just filled with inconvenient FACTS.

  • Harry Braun


    Why is it considered good politics on the conservative side of the political spectrum in the United States to attack the dignity of highly regarded scientific organizations?


    Because not a single reputable scientific organization, or reputable scientist for that matter, thinks that man-made global warming is a myth, or that global warming and climate change aren’t very serious problems that require immediate attention.

    I care about the opinions of smart people.

    That said, without a doubt the most well-known high IQ society is Mensa, which is both the oldest and largest high IQ society in the world. However, a lesser known fact is that as far as exclusivity goes, Mensa isn’t even in the same ball park as some of the others. Of the close to 60 similar organizations that limit membership to people who are within a certain high percentile of the Intelligence quotient (IQ), Mensa is actually one of the easier groups to get into. Mensa’s only requirement for membership is that one score at or above the 98th percentile on certain standardized IQ or other approved tests. That percentile equates to the top 2% of all people or 1 person in 50.

    By the way, the minimum accepted score for Mensa on the Stanford-Binet 5 intelligence test is 132. It takes about 1½ hrs to complete.

    As far as exclusivity goes, this is how Mensa stacks up against some of the other high IQ societies:

    * • The International High IQ Society is open to 1 person in 20.
    * • Mensa is open to 1 person in 50.
    * • The Triple Nine Society is open to 1 person in 1000.
    * • The Prometheus Society is open to 1 person in 30,000.
    * • The Mega Society is open to 1 person in 1,000,000.
    * • The Olympiq Society is open to 1 person in 3,500,000.
    * • PARS Society is open to 1 person in 3,500,000.

    By comparison, Olympiq and PARS are actually 70,000 times more exclusive than Mensa. According to the numbers, of the 7 billion people who currently inhabit the earth, only the top 2000 would potentially make the cut for Olympiq or PARS, whereas, the top 140,000,000 would potentially make the cut for Mensa. Comparatively, it’s a huge difference.

    For the special few that are at or above the 1 person in 1,000,000 range, standard IQ tests just aren’t enough. For example, the Stanford-Binet 5 only ranges from 40 to 160. People above that range are required to take special, usually un-timed, and usually unsupervised tests that have been normalized using standard statistical methods.

    You can find out if you’re Mensa material here:


    Incidentally, one of the smartest women in the world is a 41-year-old Australian named Laura N. Kochen, an Olympiq Society member.

    She’s an active member of Greenpeace as well as Red Cross International.


    There are no highly intelligent global warming deniers, period.

    Every scientific organization on the planet is in agreement with the conclusions of the IPCC.

    • truebearing

      Harry Braun-but-no-brain,

      You assert that: “not a single reputable scientific organization, or reputable scientist for that matter, thinks that man-made global warming is a myth, or that global warming and climate change aren’t very serious problems that require immediate attention.”

      Where is your evidence? Are you so delusionally grandiose that you think your disjointed ramblings are some kind of irrefutable polemic, or scientific proof? If your goal is to display pomposity and arrogance, you have succeeded magnificently. If it was to argue the case for global warming, it was profoundly lacking. You’d be lucky to get into a Community College with drivel like that.

      And what of your irrelevant maunderings on intelligence societies, none of which would accept you without substantial financial compensation? What does that have to do with global warming, or your idiotic premise regarding the reputability of scientists? If I’m reading you correctly, this blather about these intelligence societies is meant to somehow buttress your imbecilic attempt at defending global warming. It didn’t, but it did out you for the intellectual buffoon and fraud that you are.

      Next time you vainly attempt to refute someone, try answering their position with evidence, their reasoning with better reasoning, and their science with superior science. You didn’t accomplish anything with your nonsense but add to the mountains of evidence that global warming fanatics have deluded themselves into thinking they are more intelligent than their superiors.

      Define “reputable”, dim wit.

  • Harry Braun

    The folly of hillbillies pretending to be scientists:

    As far as the Republican Party is concerned, the jury is still out on the age of the earth.

    According to a recent Gallup Poll, 50% of Republicans are strict young earth creationists:


    In other words, 50% of Republicans think that science is wrong about the age of the earth.

    By the way, the Republican Party in the United States is the only political party on the planet to be in denial of the conclusions of the IPCC, when in fact every scientific organization on the planet is in agreement with those conclusions.

    On of the most vocal global warming deniers in the party was recently cornered in the halls in Washington DC.

    Judge for yourself:


    Incidentally, as far as any science goes, comparing a global warming denier like James “Mountain Jim” Inhofe to a Nominated AGU Fellow is kind of like comparing a kid working part time at Jiffy Lube to Mario Andretti’s chief mechanic.

    Actually, it’s more like comparing a baboon to a human.

  • nomnom

    Notice the straw-man in this article occurs about 3 paragraphs in. Anthony Watt’s says “First, let’s look at the claim that tornadoes are on the increase”

    What claim? Who made it? Not the scientists he is talking about in the introduction of the article. What they said is quite reasonable – that climate change will affect the variables that cause weather, so all weather events will be affected by climate change.

    Anthony Watt’s attempt to smear actual scientists in this way is despicable given his brazen claim that global temperature anomaly is the same as 1979 when anyone looking at that graph can see he has cherrypicked two points and ignored the overall trend which is upward.

    • http://www.facebook.com/people/Bville-Doc/100000215663799 Bville Doc

      If that’s the only fault you can find in Mr. Watts’s piece, then I’d say he did pretty well for a “non-scientist”. What I find interesting is how in the minds of the global warming/climate change alarmists, the only “actual scientists” given any credibility are those in agreement with their position.

      I’m wondering how many of the “prophesies” made by the UN scientists have to be embarrassingly disproven before at least a a few of the zealots start to admit that maybe this isn’t such “settled science” after all.

      The “straw man” in this debate is the ridiculous non-scientific “undefeatable hypothesis” these “actual scientists” have created. This, in turn, is spewed by the true believers with rapturous breathless enthusiasm despite mounting evidence that anthropogenic climate change evidence is sorely lacking and the CO2 data taught to the masses is a simplistic explanation for a natural phenomenon. And both sides seem unable to differentiate between the concepts of climate and weather.

      This is increasingly looking like just another agenda-driven social engineering cudgel for the nanny state progressives to beat us over the head with. What can I say? I guess I’m a “denier.”

      • nomnom

        That one fault underlies the entire premise of the article

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  • mememine69

    In the United States at least, former climate change believers are now en masse contacting local district attorneys, politicians and law makers to have the leading scientists and especially leading news editors subjected to criminal charges for knowingly sustaining the criminal exaggerations of the CO2 mistake for the last 25 years. It is now appearing that issuing CO2 death threats to billions of children unnecessarily has not gone unnoticed and unlike Bush getting away with his false war in Iraq, the false war of climate change will sooner or later be dealt with in the courts.
    And keep in mind that it was the scientists themselves that made environmental protection necessary in the first place when they supposedly polluted the planet with their evil chemicals and cancer causing pesticides and so how ironic is it that we bowed like fools to our Gods of science for 25 years of “unstoppable warming”?
    Scientists are not gods and don’t forget that scientists also produced cruise missiles, cancer causing chemicals, land mine technology, nuclear weapons, germ warfare, cluster bombs, strip mining technology, Y2K, Y2Kyoto, deep sea drilling technology and now climate control. Proof of consensus not being real is the fact that scientists did not march in the streets when IPCC funding was pulled, the EPA was castrated and Obama’s not even mentioning the “crisis” in his state of the union speech. Consensus was a myth because if it were true, the consensus scientists declaring a climate emergency would act like it was an emergency and demand their CO2 mitigation be taken seriously. We believed a handful of lab coat consultants who said we could CONTROL the planet’s temperature and prevent it from boiling. Pure insanity as history will call this modern day witch burning. The new denier is anyone still believing voters will vote YES to taxing the air to make the weather colder. Not going to happen.
    REAL planet lovers don’t hold scientists as Gods and bow to politicians promising to make lower the seas and scare kids with such doomsday glee.

    Stay tuned. We missed getting Bush for his false war and a wave of former believer rage will get this one right. Call the courthouse.
    The Internet, an open sewer of untreated information, mostly used as a search engine for like minded opinions instead of knowledge.