Michael Mann: The Rise and Fall of the Atlantic Multidecadal Oscillation.

Pretty interesting. This will certainly motivate continued study by the broader climate science community, so we'll see how the story progresses. For the moment, though, I think the arguments he has laid out are actually rather compelling. Indeed, this is the very process of science in action.

AMO started out as a hypothesis proposing that the observed oscillation in historical data as well as some climate models of the time might have a physical cause in internal climate variability -- specifically by some interaction between the oceans and atmosphere. As any good hypothesis should, this makes predictions that can be tested further. However, as more robust coupled ocean-atmosphere models have developed, AMO-like behavior has become the exception rather than the rule. This is the first clue: the physics of ocean-atmosphere interactions generally does not produce the hypothesized effect.

The other clue is how the historical simulations, when given the known climate forcings (particularly the negative forcing due to aerosols), produce the same oscillation as seen in the historical data even up to the phase (which is suprising because there's no reason for the phase of an internal variation in a simulation to be the same as in nature). Furthermore, the oscillation appears in historical simulations of the last millenium, but vanishes when the forcings are removed. That suggests the evidence of an oscillation is an artifact of the forcings, rather than a true internal climate variation.


It is interesting as well to contrast AMO's story with that of dark matter and dark energy in cosmology. They both began as hypotheses to explain a limited set of observations, and it was entirely conceivable that they could be flaws in our models or artifacts of the data. And there are many who would have preferred to see them disappear in such a way. But with more time, more data, and more testing of their predictions, the evidence that they are real effects has only grown stronger.

I'm sceptical.  Mann is prisoner of his own models and has way too much invested in the anthopogenic story.  He's put himself in a position in which is only option is to increase the bets.  As Curry puts it: "Relying on global climate models, which don’t adequately simulate the multi-decadal internal variability, to ‘prove’ that such multi-decadal internal variability doesn’t exist, is circular reasoning (at best)".

Is Curry not likewise invested in a particular position? Does it matter? In science we should care most about the quality of the arguments and the evidence supporting them, not the motivations of the people making them.

As Curry puts it: "Relying on global climate models, which don’t adequately simulate the multi-decadal internal variability, to ‘prove’ that such multi-decadal internal variability doesn’t exist, is circular reasoning (at best)".

I certainly think it's unreasonable to expect climate models to accurately simulate ocean-atmosphere dynamics over timescales of decades, but I don't think I agree that this is a circular reasoning. Mann is investigating the circumstances under which the models do and do not generate AMO-like behavior, and comparing to expectations. If AMO is a real effect that involves ocean-atmosphere interactions (by its very definition), and it sometimes appears in older models, then we should expect that it make a more robust appearance in newer and more sophisticated coupled climate models, or at least appear about as often and strongly as it used to. Instead, Mann finds it is less robust, is in sync with the forcings, and nearly vanishes when the same models are run without the forcings.

That doesn't seem like circular reasoning, it seems like hypothesis testing.

Is Curry not likewise invested in a particular position? Does it matter? In science we should care most about the quality of the arguments and the evidence supporting them, not the motivations of the people making them.

Curry is strongly "invested" in the position against groupthink and cancel culture in the scientific community, which naturally gives a bias against certain other individuals, and she's studied and published on these large circulations herself and found the AMO to be real natural variability, so she has certainly not a fresh position herself.  Of course, debunking must be based on the evidence, but unavoidably a person's previous scientific merits do lead to a bias when new science is presented from the same person, and that's fine for a critical review, but I did not draw a conclusion here.  Mann is controversial, much for the hockey stick and his activism, which in fairness he was drawn into probably more than he intentionally ventured into himself.  I was a bit wowed, though, because this new position (though it seems to have been coming for a while now) will give Mann some challenges if the trends in temperature and sea ice particularly in the Atlantic arctic do not continue in the next three decades or so and if aerosols can't be forced to explain it.

It's not unreasonable to expect climate models to simulate at timescales of decades, the issue is more that they have been unable to do so, and by nature they're hard to test within the professional career of a scientist.  Yes, you can hindcast, but you still risk to fitting your model until you get the expected answer, and the past data you're attempting to match might to some degree also be modelled and have dependencies to what you try to confirm.  I would certainly expect climate models to simulate at timescales of decades well provided that they are founded on hard and complete observational data.  But they're not.  If we had centuries of satellite measurements coupled with rich instrument data on the ground, then maybe.  In climate science there seems to be this compulsive thought that if observational data are missing, it simply must be possible to model them somehow, and then you can do your science as it the model were real data.  That can easily lead to circular reasoning.  Climate science is not alone in this, though.  Sometimes we must accept that the data don't exist and we'll never know for sure, and new hypotheses will remain speculative until future observations judge them, even though we in some cases wont have them in our lifetime.

Michael Mann: The Rise and Fall of the Atlantic Multidecadal Oscillation.

Pretty interesting. This will certainly motivate continued study by the broader climate science community, so we'll see how the story progresses. For the moment, though, I think the arguments he has laid out are actually rather compelling. Indeed, this is the very process of science in action.

AMO started out as a hypothesis proposing that the observed oscillation in historical data as well as some climate models of the time might have a physical cause in internal climate variability -- specifically by some interaction between the oceans and atmosphere. As any good hypothesis should, this makes predictions that can be tested further. However, as more robust coupled ocean-atmosphere models have developed, AMO-like behavior has become the exception rather than the rule. This is the first clue: the physics of ocean-atmosphere interactions generally does not produce the hypothesized effect.

The other clue is how the historical simulations, when given the known climate forcings (particularly the negative forcing due to aerosols), produce the same oscillation as seen in the historical data even up to the phase (which is suprising because there's no reason for the phase of an internal variation in a simulation to be the same as in nature). Furthermore, the oscillation appears in historical simulations of the last millenium, but vanishes when the forcings are removed. That suggests the evidence of an oscillation is an artifact of the forcings, rather than a true internal climate variation.


It is interesting as well to contrast AMO's story with that of dark matter and dark energy in cosmology. They both began as hypotheses to explain a limited set of observations, and it was entirely conceivable that they could be flaws in our models or artifacts of the data. And there are many who would have preferred to see them disappear in such a way. But with more time, more data, and more testing of their predictions, the evidence that they are real effects has only grown stronger.

But we haven't yet identified what dark matter or dark energy are yet, it could be that some modified theory of gravity is needed (or quantum gravity)...perhaps it will be a combination of things we already know to exist and some which are conjectured?

well this is interesting

https://www.livescience.com/gravity-por ... stery.html

'Gravity portals' could morph dark matter into ordinary matter, astrophysicists propose

Is Curry not likewise invested in a particular position? Does it matter? In science we should care most about the quality of the arguments and the evidence supporting them, not the motivations of the people making them.

Curry is strongly "invested" in the position against groupthink and cancel culture in the scientific community, which naturally gives a bias against certain other individuals, and she's studied and published on these large circulations herself and found the AMO to be real natural variability, so she has certainly not a fresh position herself.  Of course, debunking must be based on the evidence, but unavoidably a person's previous scientific merits do lead to a bias when new science is presented from the same person, and that's fine for a critical review, but I did not draw a conclusion here.  Mann is controversial, much for the hockey stick and his activism, which in fairness he was drawn into probably more than he intentionally ventured into himself.  I was a bit wowed, though, because this new position (though it seems to have been coming for a while now) will give Mann some challenges if the trends in temperature and sea ice particularly in the Atlantic arctic do not continue in the next three decades or so and if aerosols can't be forced to explain it.

It's not unreasonable to expect climate models to simulate at timescales of decades, the issue is more that they have been unable to do so, and by nature they're hard to test within the professional career of a scientist.  Yes, you can hindcast, but you still risk to fitting your model until you get the expected answer, and the past data you're attempting to match might to some degree also be modelled and have dependencies to what you try to confirm.  I would certainly expect climate models to simulate at timescales of decades well provided that they are founded on hard and complete observational data.  But they're not.  If we had centuries of satellite measurements coupled with rich instrument data on the ground, then maybe.  In climate science there seems to be this compulsive thought that if observational data are missing, it simply must be possible to model them somehow, and then you can do your science as it the model were real data.  That can easily lead to circular reasoning.  Climate science is not alone in this, though.  Sometimes we must accept that the data don't exist and we'll never know for sure, and new hypotheses will remain speculative until future observations judge them, even though we in some cases wont have them in our lifetime.

I think acitivism is very necessary especially when our dumb politicians are in full on denial mode (especially with the large amount of funds they receive from the dirty fuel cartels- here they are getting in excess of 200,000 dollars per politician, for the ones who support their positions), but thankfully we are starting to shut down the pipeline projects (even did it before Trudeau did, which is perplexing since he purports to be progressive and yet wanted to keep the dirtiest type of oil flowing from the Tar Sands.)  This is why scientists and scientific organizations must also lobby for the type of policy they want to see enacted.

On the positive side, even the big oil conglomerates have admitted they reached peak oil in 2019 and the pandemic did something very positive in sounding the death knell for the industry and they've started to abandon many of their long term projects.  IMO we need to move more strongly to a combo of renewable and nuclear and I'm hearing the same old stuff about nuclear being "dangerous" which needs to be replaced by rational thought about how dangerous our future would be without nuclear energy.

I think acitivism is very necessary especially when our dumb politicians are in full on denial mode

It's extremely difficult to combine.

The trouble is that there are far more people than politicians in denial mode, such as anti fossil activists.  There will be no significant substitute for fossil fuel until nuclear gets recognised as the main energy source of the future.  And meanwhile nature keeps being turned into industry sites for renewable energy.  Only full denial can explain why people think fixing one problem by creating a greater one is a good idea.

But we haven't yet identified what dark matter or dark energy are yet, it could be that some modified theory of gravity is needed (or quantum gravity)

Quantum gravity is almost certainly needed at some point, but probably not in order to explain the effects of dark matter or dark energy (for which classical gravitational theories like Newton and GR appear perfectly adequate). We've also seen places where dark matter and regular matter become separated from each other, so it can't just be a modification to our understanding of the gravitational field due to regular matter. I've talked more about that in the Q&A thread.

I think acitivism is very necessary especially when our dumb politicians are in full on denial mode

It's extremely difficult to combine.

The trouble is that there are far more people than politicians in denial mode, such as anti fossil activists.  There will be no significant substitute for fossil fuel until nuclear gets recognised as the main energy source of the future.  And meanwhile nature keeps being turned into industry sites for renewable energy.  Only full denial can explain why people think fixing one problem by creating a greater one is a good idea.

it's ridiculous because I've seen fossil fuel advocates from big oil country talk about nuclear energy as if it's a pandemic virus.....when you try to tell people how safe modern nuclear energy is they say "you're the same kind of people that told us this pandemic wouldn't be so bad"- it's such an anti-intellectual response, that it shows that they aren't even going to listen to reason.  I've seen many on the environmental side willing to look at nuclear as the way out, but there are some hard heads there also.
We have so much corrupt money in our political system from the fossil fuel industry it's maddening but one huge positive of the pandemic was big oil lost a TON of money that it probably wont ever recover from.  Even they admitted they are past their peak.
Have a read here- to see the kinds of awful things they do in conservative states (a place I will never visit).
https://www.theatlantic.com/national/ar ... ry/384316/
Michael Hendryx, a public health researcher at Indiana University who studies the health effects of coal mining in West Virginia, also wasn’t surprised when he heard about the spill. Hendryx co-authored a series of studies that linked a number of troubling health outcomes to the areas with heavy coal mining. His research found that residents of West Virginia’s mining counties were more likely to suffer from kidney disease, obstructive lung diseases, and high blood pressure than their counterparts in non-mining counties. Other studies found higher rates of mortality, cancer, birth defects, total poverty, and child poverty in the areas surrounding mountaintop-removal coal mining sites.

 
 
Critics have often dismissed these studies for failing to demonstrate that these negative health effects are caused directly by mining. Hendryx’s most recent study, published last October, established that direct link by showing that the coal dust emitted into the atmosphere at mountaintop mining sites is carcinogenic.

“I entered this area of research with no preconceptions about whether or not I’d find evidence for health problems, but as the evidence has mounted, I am completely convinced that [mountaintop removal mining] is harmful to the health of people who live nearby,” Hendryx says.  “It causes air, water and soil pollution in residential communities close to mining. It is not an environment conducive to good health.”

“Because I’m a local, many view me as a Benedict Arnold,” he says. “I should know better because coal put food on my table, they tell me.” He says he’s been shot at numerous times and the brake lines in his truck were cut in what he believes was an attempt on his life. Walk keeps a bulletproof vest in his pick-up truck and his gun is always nearby.

These types of incidents aren’t unprecedented in the area. One of Walk’s mentors, the late Larry Gibson, was profiled in Pulitzer Prize winning journalist and social critic Chris Hedges’ most recent book. After becoming a prominent anti-mountaintop removal activist and testifying at the United Nations, Gibson was the target of an intense intimidation campaign. According to Hedges, Gibson’s cabin was burned down, two of his dogs were shot, trucks routinely tried to run him off the road, and he “endured drive-by shootings.”

 

Activists aren’t the only critics of the industry who are targeted for speaking out. Hendryx, who taught at West Virginia University before taking his current job at Indiana, says the coal industry has gone after his work with negative editorials in friendly newspapers and by funding its own research to dispute his findings. While at WVU, which accepts millions in donations from the coal industry, Hendryx says he had to tread carefully.

But we haven't yet identified what dark matter or dark energy are yet, it could be that some modified theory of gravity is needed (or quantum gravity)

Quantum gravity is almost certainly needed at some point, but probably not in order to explain the effects of dark matter or dark energy (for which classical gravitational theories like Newton and GR appear perfectly adequate). We've also seen places where dark matter and regular matter become separated from each other, so it can't just be a modification to our understanding of the gravitational field due to regular matter. I've talked more about that in the Q&A thread.

Thanks, I wanted to see what you thought of the gravity portal idea that was talked about in Science News!

I don't believe there is a conspiracy orchestrated by "Big Oil" which has turned the public opinion (and politicians) against nuclear.  I think it's a mix of general scepticism against invisible dangers, greatly exaggerated by environment activists, and all this has been very convenient for politicians given the cost barriers for going nuclear.

In Norway the political stand on nuclear power can be summarised like this:  The parliament thought about it in the 70's and concluded that it was not interesting for a small country like Norway.  We had hydropower, and besides, there was this promising oil in the North Sea.

I don't believe there is a conspiracy orchestrated by "Big Oil" which has turned the public opinion (and politicians) against nuclear.  I think it's a mix of general scepticism against invisible dangers, greatly exaggerated by environment activists, and all this has been very convenient for politicians given the cost barriers for going nuclear.

In Norway the political stand on nuclear power can be summarised like this:  The parliament thought about it in the 70's and concluded that it was not interesting for a small country like Norway.  We had hydropower, and besides, there was this promising oil in the North Sea.

Oil reserves are not endless. Providing electricity to a small country like Norway is easier than one like the United States. In addition, somewhere there are powerful rivers on which it is possible to build hydroelectric power plants, and in the United States there are clearly few such rivers for the whole country. Therefore, there is a need to create other sources of electricity.

I don't believe there is a conspiracy orchestrated by "Big Oil" which has turned the public opinion (and politicians) against nuclear.  I think it's a mix of general scepticism against invisible dangers, greatly exaggerated by environment activists, and all this has been very convenient for politicians given the cost barriers for going nuclear.

In Norway the political stand on nuclear power can be summarised like this:  The parliament thought about it in the 70's and concluded that it was not interesting for a small country like Norway.  We had hydropower, and besides, there was this promising oil in the North Sea.

Well the big oil companies around here like to capitalize on fear of nuclear technology and put money into commercials where they talk about it being unsafe.  The amount of money they've poured into politics here is horrendous.  The interesting thing is major oil companies are now investing in renewable tech (solar and wind) because they see that public opinion is against them and more restrictions are being placed on them and young scientists and engineers coming out of college dont want to work for them like they used to.
About nuclear, watch this 20 min interview with Bill Gates.  Even though there are some things about him I dont like, he is the most powerful man in the world and has the ability to make widespread usage of nuclear energy happen.

The interesting thing is major oil companies are now investing in renewable tech (solar and wind) because they see that public opinion is against them

What they're really doing is dodging risk.  They can't invest into something that is too risky politically.  Unfortunately, the best long term solutions are not the least risky ones.

The interesting thing is major oil companies are now investing in renewable tech (solar and wind) because they see that public opinion is against them

What they're really doing is dodging risk.  They can't invest into something that is too risky politically.  Unfortunately, the best long term solutions are not the least risky ones.

Fortunately I see some environmental sites like earther gizmodo picking up on what you said the risk is with some renewable tech like wind.  They are talking about the dangers it poses to the environment and warning against its overuse.  They stated that just because it is "renewable" doesn't mean it doesn't pose environmental hazards.  Here in NY/NJ we keep it well offshore and are more reliant on hydro.