The IPCC's hot model problem

[KLATTU]

Climate simulations: recognize the ‘hot model’ problem

The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.

www.nature.com

Too many climate researchers are making unrealistically dire projections about the future consequences of man-made climate change based on computer models that run way too hot, argues a new commentary in Nature.

The commentary's authors point out that the too-hot models reported in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) failed to reproduce historical climate trends, thus casting considerable doubt on their more catastrophic temperature increase projections. Consequently, the researchers note that the former practice of "simply taking an average" of all of the models together leads to higher projections of warming than is warranted.

Stop Using 'Too Hot' Climate Models, Says Nature Commentary

And avoid implausible, worst-case scenarios for greenhouse gas emissions too.

reason.com

When Gavin Schmidt is warning you about chicken little predictions, it's a problem.

 

[EdwinWillers]

Someone please grab a hockey stick and pop that bag of worthless hot air as a model.

You're right - there are too many people relying on man-made models that are... well... WRONG

 

[Loulit01]

Climate simulations: recognize the ‘hot model’ problem

The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.

www.nature.com

Too many climate researchers are making unrealistically dire projections about the future consequences of man-made climate change based on computer models that run way too hot, argues a new commentary in Nature.

The commentary's authors point out that the too-hot models reported in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) failed to reproduce historical climate trends, thus casting considerable doubt on their more catastrophic temperature increase projections. Consequently, the researchers note that the former practice of "simply taking an average" of all of the models together leads to higher projections of warming than is warranted.

Stop Using 'Too Hot' Climate Models, Says Nature Commentary

And avoid implausible, worst-case scenarios for greenhouse gas emissions too.

reason.com

When Gavin Schmidt is warning you about chicken little predictions, it's a problem.

Good God.

It is important to emphasize that, whereas unduly hot outcomes might be unlikely, this does not mean that global warming is not a serious threat. Multiple lines of evidence establish that the planet is more than 1 °C warmer than it was before the Industrial Revolution, and that further warming poses severe risks to society and the natural world. There are many aspects of climate change we do not yet understand, hence the continued necessity of climate science. But there is no serious disagreement that continued emissions will lead to dangerous levels of warming.

 

[Redress]

Climate simulations: recognize the ‘hot model’ problem

The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.

www.nature.com

Too many climate researchers are making unrealistically dire projections about the future consequences of man-made climate change based on computer models that run way too hot, argues a new commentary in Nature.

The commentary's authors point out that the too-hot models reported in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) failed to reproduce historical climate trends, thus casting considerable doubt on their more catastrophic temperature increase projections. Consequently, the researchers note that the former practice of "simply taking an average" of all of the models together leads to higher projections of warming than is warranted.

Stop Using 'Too Hot' Climate Models, Says Nature Commentary

And avoid implausible, worst-case scenarios for greenhouse gas emissions too.

reason.com

When Gavin Schmidt is warning you about chicken little predictions, it's a problem.

You should actually read your source article. Let me quote from paragraph 2:

Users beware: a subset of the newest generation of models are ‘too hot’2 and project climate warming in response to carbon dioxide emissions that might be larger than that supported by other evidence

So, what we actually have is a few people saying that a few of the newest models might, maybe, be too hot. Funny how that is not at all how you spun the source article...

 

[EdwinWillers]

You should actually read your source article. Let me quote from paragraph 2:

So, what we actually have is a few people saying that a few of the newest models might, maybe, be too hot. Funny how that is not at all how you spun the source article...

Um, we're adults here; we're able to read the article for ourselves and evaluate it ourselves.

We don't need to be treated like third graders and told what it said or what it means.

 

[Schism]

Um, we're adults here; we're able to read the article for ourselves and evaluate it ourselves.

We don't need to be treated like third graders and told what it said or what it means.

That's how the left view themselves. They're narcissistic know-it-alls who feel the need to nanny-state everyone else.

 

[Redress]

Um, we're adults here; we're able to read the article for ourselves and evaluate it ourselves.

We don't need to be treated like third graders and told what it said or what it means.

The point was the OP did not read the source past maybe the headline and misrepresented what the article said. Do try and fail less.

 

[EdwinWillers]

The point was the OP did not read the source past maybe the headline and misrepresented what the article said. Do try and fail less.

And my point is you are in no position to tell us what something says or what something means - which is PRECISELY what you're doing.

And you're definitely in no position to look down your nose at members here and snottily tell them "Do try and fail less."

Moreover, you don't know what the OP read or didn't read - you're just making an assumption and using that to accuse him of spinning the article and misrepresenting it, having said virtually nothing of value yourself about the article - one way or the other.

Did YOU read the article? Or did you stop at the second paragraph, having found your "smoking gun" for the accusations of spin and misrepresentation and proceed to post from there?

It's a fair question - because frankly, I read the article and didn't find the OP misrepresenting it at all. Maybe his verbiage wasn't as precise as you prefer; I don't know and I don't care - nor should anyone, really. I read the article and found zero warrant for accusing the OP of misrepresenting it.

Moreover, I liked their summary:

• Global warming levels force a simple question: when will the world reach a given level of warming? The answer, of course, is that it’s up to us. Reporting that severe risks and catastrophic outcomes are projected to occur at a particular time can give a false sense of inevitability and obscure the role of human choice in determining the future.

The bolded sentence is an excellent point they make by way of summary - and a wise one. And one which, I daresay had you read it, might have tempered your response a tad.

 

[Lord of Planar]

Climate simulations: recognize the ‘hot model’ problem

The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.

www.nature.com

Too many climate researchers are making unrealistically dire projections about the future consequences of man-made climate change based on computer models that run way too hot, argues a new commentary in Nature.

The commentary's authors point out that the too-hot models reported in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) failed to reproduce historical climate trends, thus casting considerable doubt on their more catastrophic temperature increase projections. Consequently, the researchers note that the former practice of "simply taking an average" of all of the models together leads to higher projections of warming than is warranted.

Stop Using 'Too Hot' Climate Models, Says Nature Commentary

And avoid implausible, worst-case scenarios for greenhouse gas emissions too.

reason.com

When Gavin Schmidt is warning you about chicken little predictions, it's a problem.

This has been obvious to anyone following the science with an unbiased mind.

 

[Lutherf]

I see “Hot model” in the title and get this?

 

[Lord of Planar]

Good God.

It is important to emphasize that, whereas unduly hot outcomes might be unlikely, this does not mean that global warming is not a serious threat. Multiple lines of evidence establish that the planet is more than 1 °C warmer than it was before the Industrial Revolution, and that further warming poses severe risks to society and the natural world. There are many aspects of climate change we do not yet understand, hence the continued necessity of climate science. But there is no serious disagreement that continued emissions will lead to dangerous levels of warming.

So?

A degree is understandable since we didn't start coming out of the Maunder Minima in 1713.

Of course there is no serious arguments. Any scientists that tries to argue against the agenda, is dealt with harshly.

 

[Loulit01]

So?

A degree is understandable since we didn't start coming out of the Maunder Minima in 1713.

Of course there is no serious arguments. Any scientists that tries to argue against the agenda, is dealt with harshly.

The Kool Aid runs deep in this one.

 

[ataraxia]

I see “Hot model” in the title and get this?

I know. I came here expecting to see a discussion of maybe how Dakota Johnson is now working at the IPCC and distracting all the scientists there or something. Oh well.

 

[Lord of Planar]

I see “Hot model” in the title and get this?

LOL...

My monitor backdrop is Jerry Hall:

 

[Loulit01]

LOL...

My monitor backdrop is Jerry Hall:

View attachment 67389221

https://wallpapersafari.com/redhead-wallpaper/

 

[Lord of Planar]

https://wallpapersafari.com/redhead-wallpaper/

I prefer the monochrome blue.

 

[Steve Case]

From the Nature article:

Earth is a complicated system of interconnected oceans, land, ice and atmosphere,
and no computer model could ever simulate every aspect of it exactly.

From the IPCC:

IPCC TAR Chapter 14 Page 774 Paragraph 14.2.2.2
In sum, a strategy must recognise what is possible. In climate research and modelling,
we should recognise that we are dealing with a coupled non-linear chaotic system, and
therefore that the long-term prediction of future climate states is not possible.

More from Nature article:

But there is no serious disagreement that continued emissions
will lead to dangerous levels of warming.

A fact free assertion if ever there was one. and then this:

AR6 authors decided to apply weights to each model before
averaging them,

That's just another form of fudging and pencil whipping.
These people have no shame.

Global warming levels force a simple question: when will the world
reach a given level of warming? The answer, of course, is that it’s up to us.

King Canute and the tide

 

[longview]

The point was the OP did not read the source past maybe the headline and misrepresented what the article said. Do try and fail less.

Perhaps it would be better to address the actual article vs some authors opinion about what the article says.
Climate simulations: recognize the ‘hot model’ problem

In previous generations of climate models in CMIP5, no model had an ECS of higher than 4.7 °C. In CMIP6, more than one-quarter of models have sensitivities that are greater than this, and around one-fifth show warming of at least 5 °C in response to a doubling of atmospheric CO2 concentrations, according to our analysis. Numerous studies have found that these high-sensitivity models do a poor job of reproducing historical temperatures over time4–7 and in simulating the climates of the distant past8. Specifically, they often show no warming over the twentieth century and then a sharp warming spike in the past few decades3, and some simulate the last ice age as being much colder than palaeoclimate evidence indicates7.

Wow, 25% show ECS warming of over 4.7C and 20% are over 5C.
When they say the models do a poor job of reproducing historical temperatures, let's consider
that first, there is only a 10 year lag between CO2 emission and maximum warming, CO2 emission to maximum warming.
Second that by 2011 when CO2 levels were at 392 ppm, that we were at 48% of the effects of doubling the CO2 level,
(1.80 W m-2 out of 3.71 W m-2). This would mean that 48% of the 2XCO2 warming should already be in the record.
If the 2XCO2 warming were actually 4.7C, then 2.28C of warming just from CO2 would need to be present by today.
IPCC AR6 reports that total warming above the preindustrial level is 1.07C, and not all of that is from Human causes.

 

[PoS]

All this nonsense just shows that the climate cult's so-called "science" really isnt science at all. Just made up numbers and hot air, which is typical of computer modeling.

 

[longview]

All this nonsense just shows that the climate cult's so-called "science" really isnt science at all. Just made up numbers and hot air, which is typical of computer modeling.

I would not say made up, but poor assumptions.
ECS is a measure of how the climate responds to an abrupt doubling of the CO2 level,
something that can never actually happen.
In addition the abrupt doubling throws off how the simulation responds.
The time lag between a carbon dioxide emission and maximum warming increases with the size of the emission
Notice how the time to maximum warming changes greatly based on the size of the pulse.
A doubling of the CO2 level would be roughly a 800 GtC pulse, or 31 years in this study.
The current Human emission is about 9.6 GtC.

In addition there is a problem with the business as usual scenario, they are still using RPC/SSP 8.5,
which calls for a CO2 level of some 1370 ppm by year 2100,
A level which I do not think we could reach if we wanted to.
Flawed assumptions, lead to flawed results.

 

[EdwinWillers]

All this nonsense just shows that the climate cult's so-called "science" really isnt science at all. Just made up numbers and hot air, which is typical of computer modeling.

Well, to be fair - modeling is a valid endeavor and has produced a lot of benefit to many.

That said, models rely on a varying number of inputs and variables to manage those inputs - variables which can be manipulated by the programmer, typically to bring the model's output more in line with the observed, but sometimes to bring the model's output more in line with what they want others to observe.

The latter is the situation here.

It's the illicit use of science to propagate a narrative, rather than it's valid use, which is to identify the narrative. Ironically, it was the latter use of science that exposed the former. And we need more of these brave individuals in our labs.

 

[KLATTU]

When you already have the answer you want before you create a model, it's not hard to get the model to confirm your answer.

 

[PoS]

Well, to be fair - modeling is a valid endeavor and has produced a lot of benefit to many.

That said, models rely on a varying number of inputs and variables to manage those inputs - variables which can be manipulated by the programmer, typically to bring the model's output more in line with the observed, but sometimes to bring the model's output more in line with what they want others to observe.

The latter is the situation here.

It's the illicit use of science to propagate a narrative, rather than it's valid use, which is to identify the narrative. Ironically, it was the latter use of science that exposed the former. And we need more of these brave individuals in our labs.

Modeling is just fluid dynamics. Unless all of your inputs are exact and factual, they wont be accurate, and as a prediction tool they would be next to useless if all youre relying on is estimates instead of actual data.

 

[EdwinWillers]

When you already have the answer you want before you create a model, it's not hard to get the model to confirm your answer.

Which we call "sculpting" in other venues.

I don't know that all weather modelers are complicit in sculpting, but we certainly know some of the climate change cultists are.

 

[EdwinWillers]

Modeling is just fluid dynamics. Unless all of your inputs are exact and factual, they wont be accurate, and as a prediction tool they would be next to useless if all youre relying on is estimates instead of actual data.

And you know what they say about "estimates."

Estimates are, by definition, wrong.

(otherwise they'd be "accurates")