Gulf Stream map [image credit: RedAndr @ Wikipedia]
The lead and co-author have clearly different views on this:
Lead author: “While we can definitively say this weakening is happening, we are unable to say to what extent it is related to climate change or whether it is a natural variation.”
Co-author: “It saddens me to acknowledge, from our study and so many others, and from recent record-breaking headlines, that even the remotest parts of the ocean are now in the grip of our addiction to fossil fuels.”
What have headlines got to do with science research?
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The Gulf Stream transport of water through the Florida Strait has slowed by 4% over the past four decades, with a 99% certainty that this weakening is more than expected from random chance, according to a new study.
The Gulf Stream — which is a major ocean current off the U.S. East Coast and a part of the North Atlantic Ocean circulation — plays an important role in weather and climate, and a weakening could have significant implications, says Science Daily.
“We conclude with a high degree of confidence that Gulf Stream transport has indeed slowed by about 4% in the past 40 years, the first conclusive, unambiguous observational evidence that this ocean current has undergone significant change in the recent past,” states the journal article, “Robust weakening of the Gulf Stream during the past four decades observed in the Florida Straits,” published in Geophysical Research Letters.
The Florida Straits, located between the Florida Keys, Cuba, and The Bahamas, has been the site of many ocean observation campaigns dating to the 1980s and earlier. “This significant trend has emerged from the dataset only over the past ten years, the first unequivocal evidence for a recent multidecadal decline in this climate-relevant component of ocean circulation.”
The Gulf Stream affects regional weather, climate, and coastal conditions, including European surface air temperature and precipitation, coastal sea level along the Southeastern U.S., and North Atlantic hurricane activity. “Understanding past Gulf Stream changes is important for interpreting observed changes and predicting future trends in extreme events including droughts, floods, heatwaves, and storms,” according to the article.
“Determining trends in Gulf Stream transport is also relevant for clarifying whether elements of the large-scale North Atlantic circulation have changed, and determining how the ocean is feeding back on climate.”
“This is the strongest, most definitive evidence we have of the weakening of this climatically-relevant ocean current,” said Chris Piecuch, a physical oceanographer with the Woods Hole Oceanographic Institution, who is lead author of this study.
The paper does not conclude whether the Gulf Stream weakening is due to climate change or to natural factors, stating that future studies should try to identify the cause of the weakening.
“While we can definitively say this weakening is happening, we are unable to say to what extent it is related to climate change or whether it is a natural variation,” Piecuch said. “We can see similar weakening indicated in climate models, but for this paper we were not able to put together the observational evidence that would really allow us to pinpoint the cause of the observed decline.”
. . .
The study builds on many earlier studies to quantify long-term change in Gulf Stream transport. While the weakening found in the current study is consistent with hypotheses from many previous studies, Piecuch noted that the current study is “water-tight” and is “the first unequivocal evidence of a decline.”
Piecuch said that the finding of definitive evidence of the weakening of the Gulf Stream transport of water “is a testament to long-term ocean observing and the importance of sustaining long ocean records.”
The current study, which is part of a bigger six-year project funded by the National Science Foundation to make new measurements of the Gulf Stream at the Florida Straits, emphasizes the importance of having long-term observations, he said. “The more subtle that the change is that you are looking at, the longer is the observational record that you need to be able to tease that subtle change out of an observational time series.”
Full article here.
Tallbloke's Talkshop 
Linked to climate change? Cause or effect?
Researchers and the media need to stop crying ‘wolf’ about the Gulf Stream
There are many, many things we should worry about when it comes to global warming. But worrying that the Gulf Stream will stop is not one of them, says one Norwegian oceanographer.
30. May 2022
Lars H. Smedsrud is a professor at the Geophysical Institute at the University of Bergen.
Together with his colleagues he has summarized what researchers know about the development of the Gulf Stream over a period of more than a hundred years.
Smedsrud has a clear message: There is no need to worry.
https://sciencenorway.no/climate-global-warming-marine-research/researchers-and-the-media-need-to-stop-crying-wolf-about-the-gulf-stream/2020932
Important to note that the Gulf Stream is just one component of the AMOC and that other studies, using more data (RAPID) show no long term decline in AMOC.
Lead author: “While we can definitively say this weakening is happening, we are unable to say to what extent it is related to climate change or whether it is a natural variation.”
Of course it is a “Natural Variation” due to “Natural Climate Change”!
This was not looked at a thousand years ago, climate is still cycling inside the bounds of the last ten thousand years.
Warm tropical water will always flow into the Arctic and cold currents will always flow back to the the tropics, the flow may and must have natural alternating cycles just like alternating warm and cold periods.
I somehow doubt a few ppm extra CO2 in the atmosphere can cancel thermohaline circulation and Coriolis forces no matter what “climate scientists” and their Playstation models have to say about it.
The co-author has a declared bias — and states it in the paper. Junk Science.
https://www2.whoi.edu/site/piecuch/christopher-piecuch/
“Associate Scientist in the Physical Oceanography Department at WHOI, where he has been since 2018. He holds BA, MSc, and PhD degrees from the University of Rhode Island. He is currently an associate editor at the AGU journal Earth’s Future. Chris has served on committees for advancing diversity, equity, and inclusion at WHOI.”
Does this sound familiar?
Gulf Stream at its weakest in more than a millennium
BY GES · 26. FEBRUARY 2021
“If we continue to drive global warming, the Gulf Stream System will weaken further – by 34 to 45 percent by 2100 according to the latest generation of climate models,“ concludes Rahmstorf. “This could bring us dangerously close to the tipping point at which the flow becomes unstable.” [bold added]
https://www.successfulgreen.com/gulf-stream-at-its-weakest-in-more-than-a-millennium/
Yes, that Rahmstorf – well-known alarmist. What happened to the Arctic sea ice tipping point found in climate models? 🤔
more BS climate models telling me I have to get rid of my grill and lawn mower or we’re all gonna die, DIE I TELL YA!! or something.
Of course it’s all a fund raiser for useless PhD’s that would better serve the rest of us working at Home Depot or Chipotle’s.
I am extremely sceptical that they can measure this to an accuracy anywhere near 4%. The flow is not extremely constant is it?
Study:
Key Points
Gulf Stream volume transport through Florida Straits declined by 1.2 ± 1.0 Sv during the past 40 years (95% credible interval)
We find a weakening trend in the Gulf Stream by applying Bayesian methods to synthesize cable, in situ, and satellite data sets congruently
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‘1.2 ± 1.0’ doesn’t show much accuracy?
Isn’t that something one learnt studying STATISTICS ?
Deduction ( Mine) that it either DID or didn’t very much change the flow rate.
“‘1.2 ± 1.0’ doesn’t show much accuracy?”
Close enough for Government work, oldbrew!
Yes, I meant to spell it out but got sidetracked: So the change was (exactly) somewhere between ZERO (point 2) and TWO (point 2) Sv … no’ very much , was it?
I’m sure a lot of people can go to sleep tonight, happy in that knowledge.
‘future studies should try to identify the cause of the weakening’
Good luck with that if it’s really a 0.2% change.
Climate mythology:
The Gulf Stream, European climate and Abrupt Change
Richard Seager
Lamont-Doherty Earth Observatory of Columbia University
The Gulf Stream-European climate myth
The panic is based on a long held belief of the British, other Europeans, Americans and, indeed, much of the world’s population that the northward heat transport by the Gulf Stream is the reason why western Europe enjoys a mild climate, much milder than, say, that of eastern North America. This idea was actually originated by an American military man, Matthew Fontaine Maury, in the mid nineteenth century and has stuck since despite the absence of proof.
We now know this is a myth, the climatological equivalent of an urban legend. In a detailed study published in the Quarterly Journal of the Royal Meteorological Society in 2002, we demonstrated the limited role that ocean heat transport plays in determining regional climates around the Atlantic Ocean.
http://ocp.ldeo.columbia.edu/res/div/ocp/gs/
Study: Is the Gulf Stream responsible for Europe’s mild winters? (2002)
Click to access Seager_etal_QJ_2002.pdf
Richard Seager’s presentation to the New York Academy of Sciences:
The Gulf Stream, European Climate and Abrupt Climate Change
Click to access Seager_NYAS_GulfStream.pdf
– – –
Conclusions are still fairly alarmist but not quite for the usual reasons.
OCTOBER 9, 2023
New study finds that the Gulf Stream is warming and shifting closer to shore
by Woods Hole Oceanographic Institution
However, the basic drivers of the Gulf Stream—atmospheric wind patterns and the Earth’s rotation—will not disappear in a changing climate, so there is no concern that the Gulf Stream will shut down.
“That’s not to say that it won’t shift or change its strength, but those basic ingredients are all it takes to have a warm, fast Gulf Stream flowing along the U.S. East Coast,” said Todd. [bold added]
https://phys.org/news/2023-10-gulf-stream-shifting-closer-shore.html