Is Global Warming Causing Increased Clear Air Turbulence?

Filed Under: Media

Lately it sure seems like we’ve heard a lot of media reports of flights encountering clear air turbulence, to the point that diversions are necessary due to passengers and crew being injured (always keep those seatbelts fastened when you can, folks!). I wasn’t sure whether these kinds of incidents were actually increasing in frequency, or if we’re simply hearing about them more often, given the increased popularity of social media.

Nowadays we often have videos of these incidents, so there’s more of a story when news channels cover them.

While hardly scientific, I was actually thinking a few weeks ago about how smooth most of my flights have been the past couple of years. In January I had a bumpy flight on Air New Zealand from Auckland to Queenstown (the second bumpiest flight of my life), though other than that I’ve had almost nothing but smooth flights the past couple of years, even on typically bumpy transpacific routes.

I’m not suggesting there’s a decrease in turbulence, but rather just that I found it funny that I was randomly thinking about this a few days ago.

A new study suggests that there’s a big increase in clear air turbulence over the past couple of decades, and it’s being caused my global warming. This is all per a research fellow at Reading University. Per the Guardian, here’s the explanation for this increase:

“It is predicted there will be more and more incidents of severe clear-air turbulence, which typically comes out of the blue with no warning, occurring in the near future as climate change takes its effect in the stratosphere,” Dr Paul Williams, a Royal Society research fellow at Reading University, said last week.

Williams said that at heights of around 10 to 12km (6-7 miles), a typical cruising altitude for a modern passenger jet plane, temperature changes caused by increased amounts of carbon dioxide in the atmosphere have the effect of making different layers of airflow move at increased speeds relative to each other. When this unstable airflow produces clear-air turbulence – and there are no visual clues to give a pilot warning of what lies ahead – then the aircraft is thrown about with considerable force.

For example, in 2006, the US Federal Aviation Administration reported that the number of incidents in which turbulence caused serious accidents in US flights more than doubled between 1982 and 2003. Crucially, that figure includes adjustments made for the rise in numbers of flights produced by the growth of the aviation industry. “Several other studies have produced the same, consistent pattern of a considerable rise in incidents of turbulence – even after adjusting for the aviation industry’s growth,” added Williams.

This is (obviously) outside my area of expertise, though I sure found this interesting.

(Tip of the hat to Apurva)

  1. I think it is very possible and had developed this hypothesis myself already. 20 years ago flights were almost always smooth.

  2. There are indications that unusual climate events have been steadily increasing over the last 2 decades, and are most probably related to the accumulation of GHGs in the environment, which result in an increase in the thermal energy within our atmosphere. The hypothesis that clear air turbulence may be increasing due to changes in the global climate. This is theoretically sound since air currents are driven by temperature (buoyancy) leading to pressure differentials (potential for flow) between locations.

    However, it is difficult to judge whether the frequency of smoother or more turbulent flights are directly related to this. Most often, airline pilots can communicate with other aircraft and avoid pockets of CAT. In addition, airlines are moving towards more sophisticated detection of CAT and dampening of turbulence on the aircraft with the use of more sophisticated control for the control surfaces on the aircraft. The new generation composite wings have inherent flex to them which helps in dampening and then their are aircraft such as the 787-9 and the upcoming 787-10 which have algorithms to manipulate control surfaces in the fractional time it takes between detection of CAT by the probes at the nose and the travel of the wings through the CAT.

    Professor Paul Williams is certainly one of the scientists whose work was published in Nature Climate Change on the effects of climate change on CAT:

    He has some additional excellent articles with modeling and simulation with forecasts.

    There is excellent progress in the development of technologies, such as LIDAR, which would enable pilots to see instances of CAT (technically movement of water droplets) in the future – as soon as this technology can be miniaturized to fit within a normal commercial aircraft.

    Some fascinating stuff out there.

  3. I doubt it has anything to do with global warming and everything to do with the fact that there’s more than double the amount of flights than there was 20 years ago

  4. @ Ryan – Your statement has been disproven by the researchers; the article clearly states that the study takes into account the huge growth in air travel.

  5. A new study indicates the rate of studies blaming everything on global warming is up 10000%. Experts say this this due to grant money being easy to get if the predetermined outcome of the study is that global warming/climate change/global climate disruption/next catchy enviro phrase is to blame.

    These ridiculous studies come out every day, and the media jumps on them. What they don’t jump on is the numerous paper retractions and debunkings that happen a few months later when those who haven’t drank the koolaid look at the data. 97% consenus paper? Debunked and withdrawn. Hockey stick? Thoroughly discredited piece of garbage. Earth has experienced no statistically significant warming in nearly 20 years, yet for most of that time we have heard shrill warnings of calamities, math deaths, starvations, etc. Where are all the dead bodies? We only had 5 years to act…15 years ago. Time to move on the the next cause du juor.

  6. Congress should pass a law, hell make it an amendment, that there is no global warming and if Florida and Louisiana gets inundated in the future the people there better swim themselves to safety or drown. The government won’t be coming to help. The scumbags in Louisiana voted against federal aid after hurricane Sandy for new York but wanted federal aid for Louisiana recently. These republicunts are not just people with different ideology but are evil, racist people as bad as isis.

    Let the troll wars begin 😉

  7. Since global warming is an invention of the Chinese (source: D. Trump), then clear air turbulence is therefore also China’s fault.

  8. For me, CAT seemed much worse back in the ’80’s but that could be because I now fly mostly in the spring and fall on wide body planes. Not sure any of that is relevant but I recall the worst CAT flights for me were on MD80 planes.

    The thing I’m always surprised about is passengers who refuse to wear their seat belts in flight because they’re “uncomfortable.”

  9. @Credit
    Just like a good liberal, always love good scare stories where only the all powerful government and massive tax dollars can save the ignorant masses. You think people voting to not raise taxes is evil? I personally find it evil that you want to steal money from one group to hand it over to undeserving people and cronies who add zero value to society. Libs ignore real problems like border security, ISIS, divisive racial politics, entitlements, and only care of imaginary problems like the global warming boogie man that has resulted in nothing but grant money for scare stories and wealthy green energy cronie capitalists.

  10. All of my own research indicates leads me to believe in the scientific data supporting climate change. Sure, it is not an isolated incident and has occurred in the Earth’s history in the past. However, the rate of change since the age of industrialization is exponentially greater than any observed in the previous periods in the Earth’s history. Some interesting facts at

    Like stated by others above, I am not sure that clear air turbulence in flight can be directly correlated to climate change since there are just so many other factors in play, but changes in seasonal patterns are becoming consistent and becoming difficult to ignore.

  11. It all depends on when you start to measure. If you begin at the lowest point of the Little Ice Age, clearly it’s warmer now. If you start in the middle of the Medieval Warm Period, when Vikings had productive farms in areas of Greenland that are now under glaciers, and Northern England exported wine to France, it’s much colder now.

    Rather than trade slurs and insults, let’s just look at the predicted results of Global Warming (sic).

    20 years ago it was predicted that GW would mean the end of cold winters in the US; so much so that children born after 2005 would never see snow in their lives. Yet last winter the East Coast of the US had some the heaviest snowfall in recorded history. Hurricane Katrina in 2005 was the most deadly in US history. GW alarmists told us this was just the beginning of a catastrophic barrage of bigger, more frequent and more deadly hurricanes that GW as sure to produce. Yet Hermine, this year’s only hurricane to hit the US, was a mere Category One, and in fact the first hurricane to hit the US mainland in over a decade.

    GW alarmism is a multi-Billion dollar industry, and as the doctored “research” and “statistics” collapse, those who make their living from it are reduced to calling for those revealing the scam to be thrown in jail.

    As WR said above:

    “A new study indicates the rate of studies blaming everything on global warming is up 10000%. Experts say this this due to grant money being easy to get if the predetermined outcome of the study is that global warming/climate change/global climate disruption/next catchy enviro phrase is to blame.” 😉

  12. I am not sure about the effective increase in clear air turbulence due to climate change since the aviation sophistication to deal with such phenomenon have also evolved. However, there is a strong correlation between increases in greenhouse gas accumulation and changes to the climate based on atmospheric data that my students and I have collected over the last three decades and our scientific expeditions to the polar regions as well as the equatorial regions to study and track abnormal weather patterns, which are now occurring with higher frequencies. The science is fairly simple in that GHGs store a large fraction of the incident solar energy, which would otherwise be reflected out of the atmosphere and this will logically have an impact on the world’s climate from even a first law applied to a closed system.

  13. Well I may not have flown as much as some road worriers but typically in this part of the world (South China Seas) during monsoon and typhoon seasons – it does get more bumpy but again last evening when I was flying back from BKK to SIN on Scoot’s 787-900 (their latest – 11th) it was very little of turbulence despite warnings from Cap Carlos. Then again he was the same pilot that flew us up to BKK two days earlier. It was picture perfect landing. Yesterday he flew into the dark clouds and kept the seat belts fastened sign on for the longest time and when we were in the clouds it was a little turbulent but he handled it very well. So yes I do agree global warming has got to do with more CAT however I also think pilots that are extra cautious and take more diversions make a difference! And yes I agree folks that don’t buckle up are silly and stupid and if they get very hurt they have to blame no one except themselves.

  14. Well, the theory sounds plausible. But I have some doubts whether there is in fact more turbulence. Flying 170 flights a year (yes, not representative of all flights – but quite a lot) I have no evidence whatsoever of more turbulence. There is some turbulence now and then. Same 20 or 30 years back (when I flew much less). In fact, I think the early charter flights in aged Caravelles actually suffered of mich turbulence, also because of the huge wings of that bird. Also some routes are more prone to turbulence, e.g. across the Andaman Sea late at night is almost certainly experiencing turbulance – which has more to do with the geographic location than with climate change,

  15. Hi,

    Really enjoy the Blog and in particular the long haul flight reviews.

    Just wondering if posters are taking part in carbon offsets to reduce the footprint caused by the flights? As while not the leader in C02 emissions, flights are a large contributer.

    And if perhaps a post on travelers reducing their carbon footprint from flights?

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