Questions about climate and physics

[accdd]

1)The atmosphere is an extremely complex system, so much so that weather forecasts beyond a few days are not possible.
Why are seasonal or 10-20 year climatological forecasts reliable?
I heard from a climatologist in a video on YB (I know it is not a valid source) that weather forecasts are an IVP while climatological forecasts are BVP or something like that. Can you give me more information about this?

2)It is often argued on TV and in the media that climate change will cause an increase in extreme events (such as tornadoes, hurricanes, floods). Based on what is this said? How do they know what new weather phenomena will occur as temperatures rise?
I cannot find evidence of this in the data.
Instead I can find evidence of increased temperature, an increased frequency of heat waves, more extensive droughts, and destruction of ecosystems.

3)How do you attribute a specific phenomenon to climate change?
Thank you

 

[russ_watters]

1. Weather is the conditions now and climate is averages over seasons/years. Predicting it's going to be 0C tomorrow and the average over next winter will be 0C are very different problems.

2. This one I'm not sure of so I'll let someone else give it a shot...

3. Depends on what you mean by "phenomenon". If you mean a specific weather event (like a storm), you can't. But you can track the number and intensity of storms over time and track how it changes.

 

[Baluncore]

How do they know what new weather phenomena will occur as temperatures rise?

They are not new phenomena. They are an increase in the severity of the extremes. That increase in severity occurs because the energy circulating in the atmosphere increases with the temperature.

 

[Vanadium 50]

(1) This is no different from saying that if I have one or a few molecules of air in a room it is difficult to predict when they will hit the walls, but if I have many moles of gas the pressure on the walls is well defined.

(2) The talking heads don't know what they are talking about. While the trend of most models is the predict more extreme weather events with increasing CO2, this is not universal among all places, times and types of weather events. It also ignores possibilities like "more but weaker storms". Pay them no mind.

(3) You can't. How can you compare againsta counterfactual? Heck, we don;t even know how much climate change is caused by climate change. That is, how much of the measurements are a) "real" in the sense that they are what we want to know and not proxies for it. and b) how much is human-caused.

My opinion is that a) is "a lot better than the critics say, but a little worse than the proposents say" and b) is "a little less than the consensus value." But these are opinions, not facts.

 

[jim mcnamara]

Please read:
White boxes -- https://en.wikipedia.org/wiki/Stevenson_screen
Weather buoys -- https://en.wikipedia.org/wiki/Weather_buoy
Answer to

Why are seasonal or 10-20 year climatological forecasts reliable?

These are the white boxes you see at airfields and weather stations, they house at least a recording thermometer: (daily high-low). They are in lots of places, and usually have been there recording for decades, sometimes more than a century. There is one, for example, at the South Pole, since 1958, a relative newcomer.
Oceans are dotted with weather buoys.

So we have longterm temperature data that can be treated as a population - in other words use math to do modeling and analysis. We discovered El Nino (and La Nina) this way --- these two are long term oscillations in multi-year climate. And. They affect climate world-wide.

So if we can do some more math on gigantic datasets dating back as much 100 years, it seems reasonable to assume that if we see a long term climate shift underway, and we can validate the shift in temperature shifts by comparisons with biological responses over the same periods as the temperature:
Tree ring comparisons, lake varves (pollen in the yearly layers of mud), northward movement of fishes, warm water algae. And so on.

These are a few of literally thousands of so-called proxy events.

You may want to consider understanding the concept of FUD versus actual data:
https://en.wikipedia.org/wiki/Fear,_uncertainty,_and_doubt

 

[accdd]

They are not new phenomena. They are an increase in the severity of the extremes. That increase in severity occurs because the energy circulating in the atmosphere increases with the temperature.

The fact that rising temperature may cause in increase of extreme phenomena is likely, but is it true?
The increase in many of the phenomena (both in intensity and frequency) that climatologists talk about are simply not true. There is no increase in hurricanes, nor tornadoes, nor floods, nor rain, nor storms.
What are the arguments for making these claims? Based on plausibility or based on models? And how accurate are the models in this field?

Another thing I don't understand is:
I heard one climatologist say something like, "We have to wait for the event attribution analysis to say that this flood is caused by climate change, but it probably is".
What is "event attribution analysis?" is it scientific?

You may want to consider understanding the concept of FUD versus actual data:
https://en.wikipedia.org/wiki/Fear,_uncertainty,_and_doubt

Why?

 

[Vanadium 50]

The fact that rising temperature may cause in increase of extreme phenomena is likely, but is it true?

How can you possibly know this? Suppose you saw CO2 go up, mean temperatures go up, and the number and severity of storms go up, How do you know what the cause was. Maybe it was the CO2, and maybe it was angering the god Oggity-Boogitty. How can you tell?

 

[Vanadium 50]

This thread is quickly getting away from any physics. Oggity-Boogitty predicts either a rapid change in diirection or a rapid closure.

 

[phinds]

The increase in many of the phenomena (both in intensity and frequency) that climatologists talk about are simply not true. There is no increase in hurricanes, nor tornadoes, nor floods, nor rain, nor storms.

Based on the reading I have done of government data, that statement is true but widely disbelieved by some scientists and particularly by the media, which makes its money with alarming stories, not with the truth.

And how accurate are the models in this field?

Not very.

EDIT: I should add, by the way, that there is no question but what the climate is changing, and for the worse in the short term. What is at issue is the extent to which humans are the cause vs natural long-term cycles.

 

[Bandersnatch]

What do the IPCC reports say?

 

[Motore]

The fact that rising temperature may cause in increase of extreme phenomena is likely, but is it true?

Well is it 100% true? We can never know. Is it more likely? According to this, absolutely.

 

[accdd]

Well is it 100% true? We can never know. Is it more likely? According to this, absolutely.

Thank you, that was what I was looking for.
So there are events attributable to climate change under some circumstances and others not. Much depends on models, observations, physical understanding of weather phenomena, etc.
Your link answers questions 2 and 3.

Does anyone have any links that elaborate on how climate models work and answer question 1?
I also accept Level I or A answers. I know basic statistical mechanics and basic fluid dynamics.

 

[pinball1970]

Thank you, that was what I was looking for.
So there are events attributable to climate change under some circumstances and others not. Much depends on models, observations, physical understanding of weather phenomena, etc.
Your link answers questions 2 and 3.

Does anyone have any links that elaborate on how climate models work and answer question 1?
I also accept Level I or A answers. I know basic statistical mechanics and basic fluid dynamics.

You may find this article interesting. There is a link to paper at the end.
https://phys.org/news/2023-05-atmospheric-evidence-human-caused-climate-co2.html

 

[hutchphd]

Thank you, that was what I was looking for.
So there are events attributable to climate change under some circumstances and others not. Much depends on models, observations, physical understanding of weather phenomena, etc.
Your link answers questions 2 and 3.

Of course the issue here is not what is truth. Science (physics in particular) is the best method availible to adjudicate our hard-won prejudices. If one could declare truths adjudication would not be necessary. Further complicating the process is the cost-benefit analyses required to institute action.
The model for action here is closer to medical practice than physical science. To demand proof "beyond all reasonable doubt" in the context of climate change is a recipe for inaction and what may follow. Rational decisions need be made on the basis of always incomplete data using best methods. We will always be in the realm of "preponderance of the evidence" and need to recognize this and get on with it.

 

[phinds]

Further complicating the process is the cost-benefit analyses required to institute action.

Yes, and that is something you rarely (essentially never) see done, particularly to any depth, in media reports about climate change. You'll see a lot about what could be done but little to nothing about how much it would actually cost.

 

[bhobba]

Of course the issue here is not what is truth. Science (physics in particular) is the best method availible to adjudicate our hard-won prejudices. If one could declare truths adjudication would not be necessary. Further complicating the process is the cost-benefit analyses required to institute action.

The science of this, in the area of climate prediction, is explained by physicist and founding member of the Centre for Medium Term Climate Prediction and, of course, member of the IPCC; Professor Tim Palmer



He is pushing hard to develop supercomputers that will allow better prediction of probabilities. But that it is probabilistic is beyond doubt.

Always remember science does not tell us what to do. Science does not say do not pee on power lines. It says urine is a good conductor. We decide what to do with what science tells us. We, as human beings, make decisions on what science tells us. This site discusses science, not the actions people should take regarding its findings.

Thanks
Bill

 

[bhobba]

Yes, and that is something you rarely (essentially never) see done, particularly to any depth, in media reports about climate change. You'll see a lot about what could be done but little to nothing about how much it would actually cost.

Very true.

Thanks
Bill

 

[bhobba]

What do the IPCC reports say?

I keep abreast of what one of the IPCC scientists, Tim Palmer, says. If you do an internet search, you can find his latest scientific evaluation of the evidence. The media reports on the IPCC science contradict much of what he says. I conclude that science is being filtered by some with agendas other than 'just the facts, ma'am, just the facts'. We must always try to sift opinions from facts - which these days can be particularly hard. That is why on this issue, I listen to highly reputable scientists like Tim Palmer, not the media.

His book 'The Primacy of Doubt' is a must read IMHO:
https://www.amazon.com/dp/1541619714/?tag=pfamazon01-20

Thanks
Bill

 

[phinds]

I conclude that science is being filtered by some with agendas other than 'just the facts, ma'am, just the facts'.

My conclusion exactly, except that I would say "many" rather than "some"

 

[bhobba]

My conclusion exactly, except that I would say "many" rather than "some"

And what does Tim Palmer say '“It’s impossible to say how much of an emergency we are in because we don’t have the tools to answer the question.’’.

You won't read that in the IPCC reports from the media talking heads. That's why he wants better supercomputers. I haven't seen much of a push for that. As I said, we decide as a society what to do about the facts - but not having those reported accurately does not help.

He is 70 now, so he is getting on a bit, and I think he is not an IPCC scientist at present, but he certainly was a few years ago.

Thanks
Bill

 

[Vanadium 50]

the IPCC reports

The I stands for "intergovernmental" - this is not some sort of arbiter of truth, it is something set up by one particular set of stakeholders. That set has its own point of view. Doesn't mean the report is as bad as its detractors say, but it does mean it needs to be viewed in light of how it was put together,

better supercomputers.

That is likely to help, but not in the way he thinks. Remarkable work has been done in combustion over the last 5-10 years, leading to better engines. An engine that is more efficient burns less fuel, and emits less CO2.

As far as direct modeling goes, this is hard. I know of no model that incorporates everything, and suspect such a model would exceed what is possible today by factors of millions, not two or three. Things are coupled in very non-obvious ways: increasing desertification puts dust and sand in the ocean, increasing its iorn content, which in turn increases the algae growth, which removes CO2 from the air...and so on and so on.

The second problem is how much tuning should be done on the data. If you had a model good enough to predict 5 hurricanes ina time window and you saw 4 or 6 would this be evidence in favor or against? A supercomputer is not going to tell you the answer to that.

 

[Motore]

The I stands for "intergovernmental" - this is not some sort of arbiter of truth, it is something set up by one particular set of stakeholders.

It is an organization funded by the member states and the payments are voluntary, so I don't know which stakeholders you are refering to. As independet organizations go, this one is right on top.
Besides, you don't look at the IPCC or some IPCC scientists, but you look at the available research. There is a lot to it, but one thing is that the scientific consensus on human-caused global warming is 99+%. Perhaps it is off topic, but I got a feeling some posts insinuating otherwise.

As for the OP, here is a research about attributing extreme weather events to global warming and it's challenges:
https://iopscience.iop.org/article/10.1088/2752-5295/ac6e7d/pdf

 

[phinds]

There is a lot to it, but one thing is that the scientific consensus on human-caused global warming is 99+%.

The consensus might be nearly that high for humans being responsible for SOME of global warming, but all of it? No way.

 

[phinds]

You keep indicating that you are skeptical about my posts but you offer no evidence to show that I'm wrong.

 

[Motore]

The consensus might be nearly that high for humans being responsible for SOME of global warming, but all of it? No way.

Never said anything about all of it, but certainly most of it.

You keep indicating that you are skeptical about my posts but you offer no evidence to show that I'm wrong.

Oh don't worry about me, I never comment on a topic without spending some time looking at the research.

https://iopscience.iop.org/article/10.1088/1748-9326/ac2774
https://en.wikipedia.org/wiki/Scientific_consensus_on_climate_change

 

[Vanadium 50]

Before one can quantify how much climate change humans have caused, we need to quantify how much there is. I hope this is obvious.

Can we use average global temperature? No, because climate change may move some areas. Besides, the baseline (pre-industrial) data is sparse, particularly for the oceans, and what there is seems to be highly variable,What about the number of extreme weather events? How do you define "extreme"? All hurricanes? Only above a certain size? Are blizzards in or out? And again you have sparse data at many places and times.

I have not seen a number that is universally (or nearly so) sum up the many things meant by "climate change" - average temperature, deviations in weather from the historical averages, frequency of extreme weather events, etc.. I haven't even seen the fights: "How dare you weight hurricanes over typhoons! You are being culturally biased!" "But that's what comes out when I sum over impacts."

The fact that feelings run so high about a number that is unknown and probably unknowable probably says more anbut the people interested in climate than the climate itself.

 

[phinds]

The fact that feelings run so high about a number that is unknown and probably unknowable probably says more about the people interested in climate than the climate itself.

Exactly.

 

[Motore]

Can we use average global temperature? No, because climate change may move some areas. Besides, the baseline (pre-industrial) data is sparse, particularly for the oceans, and what there is seems to be highly variable,

Sparse and variable but taking everything into account it still shows smaller global temperatures before preindustrial evolution with a high statistical significance.
https://nap.nationalacademies.org/read/11676/chapter/6
https://en.wikipedia.org/wiki/Proxy_(climate)

What about the number of extreme weather events? How do you define "extreme"? All hurricanes? Only above a certain size? Are blizzards in or out? And again you have sparse data at many places and times.

This is an active area of research as the OP and subsequent post were trying to determine. It has nothing to do with the fact of anthropogenic global warming.

The fact that feelings run so high about a number that is unknown and probably unknowable probably says more anbut the people interested in climate than the climate itself.

Do they? In this thread I was just trying to establish a known fact, presented in multiple research articles published by climate scientists (not particle physics scientist, biologists or whoever is not doing climate science) that the anthropogenic global warming is to the best current evidence a real thing, nothing else. It is mainstream science.
I sense more feelings running high on the opposite end, which is not backed by the best science. For me it almost verges on personal speculation which is not allowed on the forum.

 

[malawi_glenn]

Yes antropologic effects on the climate is mainstream science. Perhaps tomorrow we have a thread about why the Earth is flat.

 

[Vanadium 50]

global temperatures before preindustrial evolution with a high statistical significance.

Sue, but we have to agree that a) global temperatures are the right metric and b) what the baseline is before we can quantify whether the human impact is x^ or y%.

Is the baseline the Little Ice Age? 1000 AD? 1000 BC? Do we count pre-industrial human-caused climate change? One can be a lot more confident of the statement "it's far from zero" than "it's about two-thirds" because that prompts the question "two thirds of what?"

 

[DrClaude]

Thread closed pending moderation.

 

[bhobba]

The second problem is how much tuning should be done on the data. If you had a model good enough to predict 5 hurricanes ina time window and you saw 4 or 6 would this be evidence in favor or against? A supercomputer is not going to tell you the answer to that.

His point is it is inherently probabilistic, as the climate is chaotic. A better supercomputer will give us better probabilities. He knows this from his work on long-term climate change and medium-term climate prediction. When a hurricane is forming, it is impossible to predict what it will do - all you can do is give probabilities of what will happen. Better computers will give better predictions. It is of great practical value to those tasked with preparing for emergencies who are very interested in the probability of if, for example, it will hit Brisbane rather than miss Australia completely.

Just a note about how he does it. The models all require parameters. What he does is change the parameters slightly and run it again. The model must be run many times to get good probabilities - the more times, the better. Faster computers mean better models that can be run more times and get better probabilities. I think further discussion should be in a thread on the computational modelling of chaotic systems.

I don't think there is anything more to discuss, so I have permanently shut the thread.

Thanks
Bill