An Inconvenient Attribution

Remember all the stories about Climate Change and European heat waves. We’ve heard for two decades?

New paper in nature communications

Recent decadal weakening of the summer Eurasian westerly jet attributable to anthropogenic aerosol emissions

Abstract

The Eurasian subtropical westerly jet (ESWJ) is a major feature of the summertime atmospheric circulation in the Northern Hemisphere. Here, we demonstrate a robust weakening trend in the summer ESWJ over the last four decades, linked to significant impacts on extreme weather. Analysis of climate model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) suggests that anthropogenic aerosols were likely the primary driver of the weakening ESWJ. Warming over mid-high latitudes due to aerosol reductions in Europe, and cooling in the tropics and subtropics due to aerosol increases over South and East Asia acted to reduce the meridional temperature gradient at the surface and in the lower and middle troposphere, leading to reduced vertical shear of the zonal wind and a weaker ESWJ in the upper troposphere. If, as expected, Asian anthropogenic aerosol precursor emissions decline in future, our results imply a renewed strengthening of the summer ESWJ.

https://www.nature.com/articles/s41467-022-28816-5

And here’s the press release

NEWS RELEASE 3-MAR-2022

Changes in air pollution linked with dry spells in Asia and summer heatwaves in Europe

Peer-Reviewed Publication

UNIVERSITY OF READING

Air pollution increases in South East Asia, combined with pollution cuts in Europe, may have had an important influence on European and Asian weather patterns in recent decades, new research has found.

Analysis of weather records and climate models by scientists at the University of Reading revealed that changes in air pollution levels in the two regions was likely the primary driving force behind changing atmospheric conditions that favoured prolonged summer extremes in Europe, as well as causing dry spells in Central Asia.

New research published in Nature Communications shows that the air pollution changes during 1979-2019 reduced the temperature gradient between the two regions, significantly weakening the jet stream over Asia.

These high-altitude winds have a strong influence on atmospheric circulation in the Northern Hemisphere, and shape weather across Europe and other mid-latitude areas.

Dr Buwen Dong, an NCAS scientist at the University of Reading, said: “Our findings suggest changes to air pollution had a greater influence on Northern Hemisphere summer weather than we thought.

“The research counters previous suggestions that the weakening of the summer jet stream was the result of rapid warming in the Arctic due to greenhouse gas emissions. It highlights another significant role human activity plays in driving extreme weather over vast regions.”

Air pollution is known to have a direct impact on surface temperatures, since the pollution particles prevents heat from the sun penetrating to the ground.

Increases in pollution in China and other areas of South and East Asia during the past 40 years therefore resulted in lower surface temperatures, while cuts in Europe led to clearer skies and hotter temperatures.

Temperature changes in different latitudes reduced vertical wind shear and therefore weakened the summertime Eurasian subtropical westerly jet – the ribbon of wind which extends east over Central Asia and northern China from the North Atlantic Jet Stream – by 7% over the period.

The researchers looked at the effect of greenhouse gases and pollution particles separately, and found that the former actually causes a strengthening of the jet stream, but was overpowered by the impacts of air pollution.

Dr Dong said: “As South East Asian countries fulfil commitments to cut their air pollution levels over the coming decades, we would expect to see the jet stream strengthen over Eurasia once again, potentially reducing the likelihood of prolonged heatwaves but increasing the likelihood of strong cyclones in mid-latitudes.”

https://www.eurekalert.org/news-releases/945228


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Bob Tisdale(@bobtisdale)
Editor
March 5, 2022 6:37 am

The abstract begins, “The Eurasian subtropical westerly jet (ESWJ) is a major feature of the summertime atmospheric circulation in the Northern Hemisphere. Here, we demonstrate a robust weakening trend in the summer ESWJ over the last four decades, linked to significant impacts on extreme weather. Analysis of climate model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) suggests that…”

That’s as far as anyone needs to read to understand that the paper is nonsense.

Regards,
Bob

Scissor
Reply to  Bob Tisdale
March 5, 2022 7:37 am

Physics be damned.

Drake
Reply to  Scissor
March 5, 2022 8:44 am

C’mon, the electrons moving around in those computers follow the rules of physics. You can’t blame the computers.

bonbon
Reply to  Drake
March 5, 2022 9:01 am

And those little electrons have no concept of the program they execute.
Bit like MSM, what?

Reply to  Bob Tisdale
March 5, 2022 10:11 am

True.

Doonman
Reply to  Bob Tisdale
March 5, 2022 2:40 pm

Model studies show model results. Since the CIMP6 model averages are only averages, the studies can only be average studies as well.

When you want excellence in policy results, average is not acceptable as input. So the study is useless.

dk_
Reply to  Bob Tisdale
March 5, 2022 3:05 pm

They lost me at “robust weakening,” but “linked to significant impacts on extreme weather” was obviously faith-based propaganda.

Jay Willis
March 5, 2022 6:38 am

Yeah, yeah, whatevs. Since it’s all models it shouldn’t be accepted as a scientific statement. There should be special peer reviewed journals for untested hypotheses, and other general speculation.

TonyL
Reply to  Jay Willis
March 5, 2022 6:48 am

Ummm, let me think…..
OK, we can have peer review of untested hypotheses, and other general speculation.
Somebody want to dedicate time and effort to review some speculation????
Do we have peer review volunteers??

Does not work.
What to do, what to do???

BINGO…BINGO!!

We put out a press release on YouReekAlerts!
Perfect!

Last edited 2 months ago by TonyL
DMacKenzie
Reply to  Jay Willis
March 5, 2022 11:16 am

They actually have the nerve to call a computer run of their model an “experiment”….something I have never heard any chemical engineer call very complex simulations of their modelled refinery or chemical plant…..The hubris runs deep, very deep with the cliSci guys.

Last edited 2 months ago by DMacKenzie
Trying to Play Nice
Reply to  Jay Willis
March 8, 2022 4:06 am

I thought all the Climate Science-related journals meet your criteria.

John Shotsky
March 5, 2022 7:02 am

The speed of the earth’s rotation at the equator is 1000 mph. (24,000 miles covered in 24 hours). The speed of the earth’s rotation at its axes is 0 mph. The jet streams are a product of that differential speed, and the shape of the earth, such as oceans, mountain ranges, etc. Next we will hear that CO2 causes these changes. There is nothing it can’t do, it seems.

Scissor
Reply to  John Shotsky
March 5, 2022 7:40 am

Physics be damned.

TonyL
Reply to  Scissor
March 5, 2022 9:08 am

It is settled science that CO2 causes continental drift and all the mountains created thereby. Added anthropogenic CO2 will make mountains both bigger and smaller.
You just do not understand radiative physics.

kazinski
Reply to  John Shotsky
March 5, 2022 2:06 pm

Well once we knew CO2 was causing tsunamis, earthquakes and volcanoes then nothing is off the table.

When the asteroid comes (and we know it’s coming), they’ll all be saying “Greta told us so”.

Andy Pattullo
March 5, 2022 7:08 am

I saw the words “analysis of climate models” and knew exactly what to do with the time it would have taken to read the rest – anything else but continue reading.

H.R.
Reply to  Andy Pattullo
March 5, 2022 7:24 am

Agreed, Andy. Scooping the kitty litter would be more productive and more pleasant.

Walter Sobchak
March 5, 2022 7:50 am

CIMP6. In other words video games. Video game results are not science.

Dave Fair
Reply to  Walter Sobchak
March 5, 2022 9:04 am

Even the UN IPCC CliSciFi AR6 had to throw out a bunch of the CMIP6 models.

MarkW
March 5, 2022 7:51 am

At least they are looking at things other than CO2.

PCman999
Reply to  MarkW
March 5, 2022 8:12 am

Hope springs eternal!

At least with the pollution hypothesis, the aerosols affect the total energy coming into the system, not how well it holds on to waste heat like with CO2.

It’s been suggested for many decades that any warming up to now was due to pollution reductions that mostly started in the 70s – the same time the Earth stopped cooling and started warming up giving rise to the co2 panic.

Also explains why the Earth cooled in spite of the co2 orgy during and after World War 2 up until the late seventies.

Environmentalists caused global warming!

meiggs
Reply to  PCman999
March 5, 2022 6:28 pm

likely true if you consider bag houses and sox scrubbers

2hotel9
March 5, 2022 8:01 am

So, where is the actual, physical proof of what they are claiming? Oh, is none. Okely dokely.

Gary Pearse
March 5, 2022 8:11 am

(air pollution aerosols) “causing dry spells in Central Asia.”

Don’t they attribute rainfall to aerosol nucleation? Haven’t they been enjoying bumper crops, making India a net exporter of grain? This is another example of tailor made conditions, wet or dry, hot or cold as the researcher wants it to be.

Outside of that, it seems plausible that the large areas of India and China making lots of sulphurous smoke are impacting weather. I’ve breathed the horrible air across China on several occasions.

Also “greater influence on Northern Hemisphere summer weather than we thought.” Everyday the ‘settled science’s gets falsified by their own consensus. It’s still really a climato-cocktail.

TomBR
Reply to  Gary Pearse
March 5, 2022 11:06 am

“Researcher” = rent-seeking propagandist.

bonbon
March 5, 2022 9:15 am

Aerosols are a sign that the modellers know full well Svensmark et. al are right.
They likely still cannot incorporate that into models. And if they do, anthropogenics are out the window, into orbit.
They are stuck between a rock and a hard-place – could not happen to nicer guys!

Opus
March 5, 2022 10:13 am

Ok, pollution causes cooling. That’s good right? But then pollution reduction in S.E. Asia causes stronger cyclones. We’re just FUBARed no matter what. But there’s no mention of polar bears. Can’t have a climate alarmist paper without polar bears.

Peta of Newark
March 5, 2022 10:34 am

Who’s gonna break it to these kiddies that Computer Generated Bafflegab was never very funny, or original, and died a natural death some number of years ago.
Once you understand one Retroencabulator, you understand them all.

There again, that’s ‘fashion’ innit

DMacKenzie
March 5, 2022 11:09 am

For a real belly slapping outright lie have look at Wired’s article today “climate-change-is-taking-a-bite-out-of-our-food-supply”

Purdue Al
Reply to  DMacKenzie
March 6, 2022 6:42 am

Who knew that overfishing isn’t what’s depleting the ocean of fish – it’s really climate change! And if crops grow bigger, they’re really unhealthy because they have less nutrients and more carbs! So climate change makes us fat before it ultimately starved us. Food production is way up, but the loons want to tell everyone it is way down.

The best part is they don’t blame the war in Ukraine on climate change policy. I’m not sure where these loons think the energy is going to come from. It takes more energy to make the solar panels than the energy one gets out of them. Renewables are a net negative, not unlike ethanol. Nothing renewable about solar panels and windmills that must be replaced.

Academia needs to publish to put out PhDs. All the fake science PhDs need to come from somewhere. So they generate lots of crap research. The journals they publish in have no standards as long as co2=bad. Even great peer reviewed journals like IEEE contain 80-90% useless articles because people need to publish in the academic world. Academia has been broken for a very long time. It’s a money making machine, not some noble pursuit.

kazinski
March 5, 2022 2:01 pm

They lost me at “CMIP6”. And I doubt they have any real data measuring the Jetstream over that time range.

But if they’re going to claim the model is “robust” then I better not see anymore claims that heatwaves are being caused by CO2, because this is the science.

Smart Rock
March 5, 2022 2:29 pm

Since they are looking at the last 40 years with the aid of the CMIP6 products, the aerosols they are “seeing” are more than likely part of the parameterisations introduced by the programmers to keep hindcasted global temperatures close to the “observed” (i.e. homogenised and adjusted) historical record. How many steps away from the real world does that make their research?

They could have used angels standing on pinheads to equally good effect.

I could be wrong, of course.

March 6, 2022 3:40 pm

“Air pollution is known to have a direct impact on surface temperatures, since the pollution particles prevents heat from the sun penetrating to the ground.”

Well,well,well. How much European/UK/US warming has been caused by the Clean Air Acts over the past 40 years as opposed to CO2?

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