Climate impact of clouds made from airplane contrails may triple by 2050
From the EUROPEAN GEOSCIENCES UNION
In the right conditions, airplane contrails can linger in the sky as contrail cirrus – ice clouds that can trap heat inside the Earth’s atmosphere. Their climate impact has been largely neglected in global schemes to offset aviation emissions, even though contrail cirrus have contributed more to warming the atmosphere than all CO2 emitted by aircraft since the start of aviation. A new study published in the European Geosciences Union (EGU) journal Atmospheric Chemistry and Physics has found that, due to air traffic activity, the climate impact of contrail cirrus will be even more significant in the future, tripling by 2050.
Contrail cirrus change global cloudiness, which creates an imbalance in the Earth’s radiation budget – called ‘radiative forcing’ – that results in warming of the planet. The larger this radiative forcing, the more significant the climate impact. In 2005, air traffic made up about 5% of all anthropogenic radiative forcing, with contrail cirrus being the largest contributor to aviation’s climate impact.
“It is important to recognise the significant impact of non-CO2 emissions, such as contrail cirrus, on climate and to take those effects into consideration when setting up emission trading systems or schemes like the Corsia agreement,”
…says Lisa Bock, a researcher at DLR, the German Aerospace Center, and lead-author of the new study. Corsia, the UN’s scheme to offset air traffic carbon emissions from 2020, ignores the non-CO2 climate impacts of aviation.
But the new Atmospheric Chemistry and Physics study shows these non-CO2 climate impacts cannot be neglected. Bock and her colleague Ulrike Burkhardt estimate that contrail cirrus radiative forcing will be 3 times larger in 2050 than in 2006. This increase is predicted to be faster than the rise in CO2 radiative forcing since expected fuel efficiency measures will reduce CO2 emissions.
CREDIT Bock and Burkhardt, Atmos. Chem. Phys., 2019
The increase in contrail cirrus radiative forcing is due to air traffic growth, expected to be 4 times larger in 2050 compared to 2006 levels, and a slight shift of flight routes to higher altitudes, which favours the formation of contrails in the tropics. The impact on climate due to contrail cirrus will be stronger over Northern America and Europe, the busiest air traffic areas on the globe, but will also significantly increase in Asia.
“Contrail cirrus’ main impact is that of warming the higher atmosphere at air traffic levels and changing natural cloudiness. How large their impact is on surface temperature and possibly on precipitation due to the cloud modifications is unclear,” says Burkhardt. Bock adds: “There are still some uncertainties regarding the overall climate impact of contrail cirrus and in particular their impact on surface temperatures because contrail cirrus themselves and their effects on the surface are ongoing topics of research. But it’s clear they warm the atmosphere.”
Cleaner aircraft emissions would solve part of the problem highlighted in the study. Reducing the number of soot particles emitted by aircraft engines decreases the number of ice crystals in contrails, which in turn reduces the climate impact of contrail cirrus. However, “larger reductions than the projected 50% decrease in soot number emissions are needed,” says Burkhardt. She adds that even 90% reductions would likely not be enough to limit the climate impact of contrail cirrus to 2006 levels.
Another often discussed mitigation method is rerouting flights to avoid regions particularly sensitive to the effects of contrail formation. But Bock and Burkhardt caution about applying measures to reduce the climate impact of short-lived contrail cirrus that could result in increases in long-lived CO2 emissions, in particular given the uncertainties in estimating the climate impact of contrail cirrus. They say that measures to reduce soot emissions would be preferable to minimise the overall radiative forcing of future air traffic since they do not involve an increase of CO2 emissions.
“This would enable international aviation to effectively support measures to achieve the Paris climate goals,” Burkhardt concludes.
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The publication is in Atmospheric Chemistry and Physics – link to the paper
Some thoughts:
- This is a model output, so take it with a grain of salt.
- They seem to only consider the Long Wave IR to space reflectivity for contrails as being the big forcing component, yet there’s a big reflectivity factor for incoming solar radiation too. And, that’s got to be considered. If contrails were only reflective one way (from the surface looking up) we’d not be able to take photographs like this one from space:
NOTE: Any discussion of “chemtrails” in this comment thread will be immediately deleted. -Anthony
It appears that these purported scientists ( Burkhardt et al) suffer the same belief that I suspect many do:
Namely that CO2 is a dirty great DUVET up in the sky and will eventually cook us as it’s Tog rating increases.
Being oblivious of the basic thermodynamics and the behaviour of water they struggle to comprehend so regurgitate the rubbish they have picked up from others with similar problems.
The cirrus clouds nudging the Tropopause contain ice crystals at very low temperature (around -50C) and these grow dendritically so are radiating more energy than they receive.
This radiated energy goes to space and results in a weight increase in the crystals due to the loss of the Latent Heat of fusion.
At a certain point gravity causes the crystals to fall and decend through the atmosphere sucking up energy as they morph towards the liquid form winding up as rain, snow or hail depending on circumstances.
The whole process is a wonderful way to cool the planet. Need I say more? you may draw your own conclusions from this; but there is much more to say albeit more complicated if you want to understand why the Satanic CO2 Meme is such a scam.
I have a trite saying for what it is worth: “The Earth sweats to keep cool, just like you and I”
Anthony, thank you for posting this article. I have been troubled and annoyed with the contrails and was hoping you’d post something about their effects. I yearn of my childhood days when the skies were fantastically blue and cloudless which are rare today.
How old are you ? 300 y ?
We all have such fond memories of childhood summer days but that is the result of heaving reporting bias, publication bias and nostalgia.
You will probably find that air was more opaque back then due to lower down industrial pollution. Records of cloud “amount” are about as vague as that term sounds. It’s actually quite hard to even define what you should be measuring.
Where I grew up and where I live now are the same – in a rural area where I could see for miles without a cloud in the sky and no pollution to even mention. The contrails then were sparse – 2 per day from Airforce jets which were very distinct but not so today as the sky is often hazy and cloudy from the many dissipating contrails. Please refrain from attempting to gaslight me into disbelieving my own dependable observations.
There is also the point that 60 years ago most commercial flights were 18-25Kft, Today they are 35-40Kft or even slightly higher, especially trans-Atlantic or trans-Pacific flights. 18Kft is just barely into the Cirrus cloud levels. 35-40Kft are deep into that area, and in the winter the only cirrus clouds that high are contrails. (Summer or the tropics is a different story-I have seen a CB anvil measured by radar at 85Kft)
Based on a quick scan of the comments, I’m glad I didn’t waste any time finishing the article.
OMG! Infant deaths TRIPLED in my community over the last decade!
Horrible news, right? Until you put it in PERSPECTIVE.
Ten years ago, ONE infant died from disease. Last year, two died in an auto accident. AND my community has a million people in it.
So, (I’m not going to bother finding the exact quotes) if contrails TRIPLE THEIR anthropomorphic effect and become a larger part of that effect, how do we know it will have ANY effect on the overall climate?
What is the percentage of CLIMATE (NOT climate CHANGE) that is “anthropomorphic”? Would be a relevant FACT (not really since that would be a fart it out of my ass guess) to include in the article.
I could go on, but it looks like the other commenters are taking this waste of time apart already.
Energy is a thermal property.
Heat is a thermal process, i.e. energy in motion from hot to cold.
Temperature is the comparative measurement of the kinetic energy in a molecular system.
No molecules = no temperature just like no molecules = no sound.
The notion that energy/heat gets “trapped” is thermal nonsense.
A volume with no molecules can still contain radiation, hence the temperature of the vacuum of space is about 3.5 Kelvin.
The current farce named “Climate Science” is proceeding via the attribution of horror after imagined horror to “Climate Change” in the broad sense. The ultimate, terrifying accumulation of all of these disasters is so large that even a child can detect existential threats to the whole human race. And children do, and some make headlines. It just gets better as more imaginations are allowed publicity and the terrors increase in intensity and scope. What a way to go.
Those of us who are heartily sick of this negativism look for some relief from the pessimism. We read papers involving atmospheric hots and colds attributed to clouds. They can cause big w/m2 changes with very little effort, but we optimists feel that there should be a fair chance that Nature has a balance, that some cloud changes will be hot, some will be cold in overall effect. Indeed, people like me look for papers where climate change is a benefit, not yet another fictional horror story.
The past indicates an absence of irreversible tipping points; this might indicate that there are both positive and negative feedbacks that tend to balance around a livable range for humans.
So why the heck does our pathetic crop of climate scientists rabbit on with negativism, while some of us older. more wise to the world scientists say that conditions for human life and comfort and enjoyment have never been better?
Geoff
Humans could possibly, theoretically, hypothetically, potentially, maybe, perhaps, conceivably destroy the planet.
So you’re saying there’s a chance?
🙂
rip
I think he just might be implying there could be.
zero chance. But, have to keep everybody nervous.
Aircraft contrails are not clouds.
In addition to failing to consider the reflective effects of clouds both from the ground up and from the contrail up, these researchers totally ignore the “edge effect”.
Very low clouds do tend to “trap” or reflect radiative heat emanating from the ground or water surface, but only when they cover a relatively large contiguous area. Contrails are extremely narrow and diffuse, and the edge effect of such narrow ice crystal formations likely overwhelms any other effects wrought by the reflectivity of the ice crystals.
This is half baked science – come back to us when you have a fully baked solution.
“… even though contrail cirrus have contributed more to warming the atmosphere than all CO2 emitted by aircraft since the start of aviation.”
It would appear that I’m mis-understanding something here: cirrus are crystals of water vapor, so it sounds as though water (in all its various forms) is a stronger control on climate than the demon gas.
Vlad
What an unlikely scenario!
By 2050 the EU’s irrational economic model of crony capitalism would have ensured that any wealth they had has been wasted away.
So why would anyone want to visit a bunch of 3rd rate nations where millions of unrepaired windmills sit idle, where decomposing solar cell detritus pollutes the land and water — to gawk at all their fancy minarets, travel on their poorly maintained and unreliable trains and roads to yet another dirty city or abandoned rotting industrial parks?
When they doubled back, I always thought that they must have forgotten something.
So what makes them think they sufficiently understand human-created clouds when they don’t understand the natural ones?
It’t the underlying theme in climate science: they can’t model the natural climate adequately but insist they can adequately model the same climate with added human complications. Unbelievable.
This scenario makes no sense to me. It only works if cirrus clouds are transparent to incoming solar radiation but reflective to outgoing. But don’t all clouds, whether made of ice particles or water droplets, increase albedo, hence deflect larger amounts of incoming radiation? Am I missing something here?
Simple solution for the green-loons — just add sulfur to the jet fuel. Burns to SO2 — viola.
I am betting that the image at the bottom of the post is an hours-long exposure, exaggerating the effect.
Just ban Airbus production out of an abundance of caution.
Good one.
The Key Statement: “Contrail cirrus’ main impact is that of warming the higher atmosphere at air traffic levels and changing natural cloudiness. How large their impact is on surface temperature and possibly on precipitation due to the cloud modifications is unclear,”
Clouds — even contrails-caused clouds, have also a cooling effect as they “shade” the Earth by blocking and reflecting outward some of the sun’s incoming energy.
Greenhouse gases added to the atmosphere above the tropopause (nominally 36,000 feet) actually cool the Earth since temperature there increases with altitude. Fly higher!
Science : Aircraft wreak havoc on ozone layer
15 February 1997
By Fred Pearce
“Three years ago Fahey sent a research plane to chase Concorde as it flew high
over the ocean near New Zealand, sampling exhaust gases in Concorde’s slipstream
10 minutes after the supersonic airliner had passed. He discovered much more
sulphuric acid, in the form of a very fine aerosol, than expected. And, using a
model of atmospheric chemistry developed by fellow researcher Bernd Kärcher
of the University of Munich, Fahey has shown how Concorde’s exhaust produces so
many particles.”
https://www.newscientist.com/article/mg15320692-500-science-aircraft-wreak-havoc-on-ozone-layer/
According to NASA data the Earth’s libido has been increasing, contrails or no contrails.
Do you mean ‘albedo’? Or do you know something about Earth the rest of us don’t?
2050 – just outside of the ‘day after tomorrow’ range.
How many times have they run this shell-game?
How will this be an issue in 2050 when everyone is “carbon neutered” by then?
Funny how “man made clouds” aka contrails are warming the planet, while natural clouds are cooling it???
Closer to the truth: yes, contrails are warming and likely by a much higher margin than indicated, but natural clouds are doing so even more. And that is the point that kills the GHE due to GHGs.
https://de.scribd.com/document/414175992/CO21
Hmm, so will this be used as an excuse to severely restrict air travel by the masses? Will the determination be made that only the so-called Climaterati and their patrons will be allowed to use air travel?
I expect to hear just such a proposal in 3…2…1….
It probably matters a tiny little bit what season the contrail happens in…in the winter, it is probably a cause of some slight warming, especially in the far northern latitudes as the water vapor delays some outgoing IR warmth, and in the summer is probably a net cooling, with some minor reflection of incoming solar. Maybe it’s a wash at the end of the year, I don’t really know. But I would assume there is some effect from the contrail in the atmosphere, but how much should probably be better formulated.
So their basic claim is that it is hotter when we create more clouds, than it would be with less clouds??
Which translates to it is hotter in the shade than in the direct sunlight??
Which means that we should be able to compare places of equal latitude which will have equal energy from the sun shining on them. Those with more cloud cover, will be hotter than those with less cloud cover.
So Atlanta, GA is hotter than Phoenix AZ ??
I don’t doubt that Cirrus clouds could have a net warming effect. I do doubt that it is statistically significant enough to extrapolate a small effect far into the future, with all other known and unknown variables remaining static. This is the scientific equivalent of astrology. Pick a few isolated bits of data you like, and ignore the ones you don’t. Make a prediction that will not occur until the astrologer is long gone, with your money.
Any pretence to accurate or careful science is not relevant to these people. Only anything that suppports the ‘Cause’ is to be permitted. The aim is to create an Elite entitled to Air Travel, affordable electricity, car transport, cheap food and political status, etc.. As for the rest of the population, they can eat the grass as far as these people are concerned just as their masters in the Soviet Union believed.