From WUWT
richardscourtney May 20, 2015 at 11:37 am

Jquip
You say

It’s worth noting here that the observations are *never* wrong — they simply are. However, our understanding of just what the instrument is telling us may be. Now, I’ll grant you that the theory in question here is not wrong if you’ll grant that the only possibility is that the theory behind the vast bulk of instruments is wrong.

But if you grant that, then we’ve no manner to test Climate Theories at all. And so it’s a cute novelty in the same boat as all the other currently untestable theories. Entertaining, but meaningless.

Yes, and I think the following anecdote is pertinent.

In 2000 there were 15 scientists invited from around the world to give a briefing at the US Congress, Washington DC. The briefing consisted of three panels that each provided a briefing Session. In each Session each member of the panel gave a presentation and then questions were invited from the audience.

Fred Singer chaired Session 1 that was about climate data.
I chaired Session2 that was about climate models.
David Wojick chaired Session 3 that was about political responses.

When I opened Session 2 to questions the first questioner asked in aggressive manner,
“ The first session said we can’t trust the climate data and this session said we can’t trust the climate models: where do we go from here ”.
Gerd Rainer- Weber started to stand to provide a detailed answer but, as Chairman, I signalled him to sit and I said,
“ Sir, the climate data are right or they are not.
If the climate data are right then the climate models don’t adequately emulate past climate.
If the climate data are not right then we cannot assess the climate models.
In either case, we cannot use the models to predict future climate.
So, I agree your question, Sir. Where do we go from here? ”

The questioner studied his shoes and Gerd indicated he was satisfied the answer needed no addition, so I took the next question .

Richard

●●

I don't think Climate Science has dealt with the unreliability of computer models, but Climate Scientists remain addicted to their products. There is no real climate science data for them to depend on.

Might I share my ignorance of the basics of CO2 induced global warming and perhaps propagate yet another subthread to this already fascinating topic (I didn't realize how little I knew or understood till I started reading this thread).

1. CO2 may be able to raise global temperatures by up to 1 degree C (unless negative feedbacks - mainly weather - offset some of this rise.
2. This rise will be amplified - mostly by the warmer atmosphere absorbing more water vapour (a more potent GHG) which will cause 3-4 degrees C additional rise (unless offset....)
3.This has caused the greater part of the temperature rise since the 1970s

The problem that I have not seen addressed is that the hypothetical additional water vapour in the atmosphere has to come from somewhere. It implies additional evaporation somewhere, in particular the arid and semi-arid regions of the earth and the oceans. Unfortunately in the 1970s, 1980s and 1990s rates of pan evaporation were decreasing and people were talking about global dimming. So there would have been less evaporation but greater amounts of atmospheric water vapour are postulated.
Since the late 1990s rates of pan evaporation have stabilized or slightly increased. Global dimming was attributed to aerosols - man made or resulting from burning forests. The post 1998 resumption of increasing pan evaporation rates was believed to be due to the imposition of pollution controls and the reduction of the use of coal in the industrialized West.

This raises further problems
A) If increasing evaporation rates resumed in 1998, why wasn't there an increase in global warming after the El Nino, rather than a pause?
B) Why was there a change in evaporation rates, when China continued and even accelerated its use of coal, and deforestation continued apace combined with massive burnings of tropical forest in southeast Asia?

The different AGW stories just don't seem to fit together.

Can someone explain?

The different AGW stories just don't seem to fit together.
Can someone explain?

Oct 24, 2017 at 12:21 PM | Supertroll

No. That is why the different AGW stories don't fit together.

There is a bit of a ding dong going on here now:
https://wattsupwiththat.com/2017/10/23/propagation-of-error-and-the-reliability-of-global-air-temperature-projections/

and it involves expert dingers and dongers, with varying opinions about the merits of basing politics and economics on computer modelled dodgy theories.

GolfCharlie. The problems I mention go back further than models. Global dimming should mean less evaporation leading to less atmospheric water vapour and lower temperature increases. There seems also no adequate explanation for the dimming, nor for why it has ceased.
Are the cessation of global dimming and global temperature increases linked and if so how?

Supertroll, before Computer Models, Climate Science couldn't "explain" anything. With Computer Models programmed by Climate Scientists to predict Global Warming caused by manmade CO2, they still can't.

HA HA golfCharlie, but I do hope someone takes my concerns more seriously.

Supertroll

Golf Charlie is going to wet himself when I say this, but global dimming is an area where nobody is certain what is going on.

I'm not sure how to approach this so I'll think aloud for a bit

You've seen the energy budgets. The variables affect either energy input to the system or energy output from it.

Global dimming is an input effect. It would probably be due to some combination of changes in sunlight, clouds, volcanic albedo or industrial albedo.

The greenhouse effect is an output effect, as is surface IR radiation so probably not directly relevant to global dimming.
P
Pan evaporation will be affected mostly by the amount of sunlight, with a contribution from atmospheric temperature and humidity.

Over the whole hydrological cycle the amount the of evaporation, water vapour and precipitation will vary with temperature, which is the resultant of all these interacting factors.

That's enough to start me off. Any thoughts?

SC asked: "Does the output of a model ensemble have any real or physical meaning or is it meaningless?"

A 'global' temp' is useless because it is made up of regional temps.

If Canada went up by 2C and Australia went up by 2C, would the fact that the global temp remained constant be helpful, meaningful or otherwise useful in any way shape or form?

The residents of those two countries would not be happy being told there was a pause........

That's enough to start me off. Any thoughts?

Oct 24, 2017 at 8:46 PM | Entropic man

Yes! You are more credible when expressing some honest uncertainty. I think Rumsfeld expressed it well.

"Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones."

Oct 24, 2017 at 10:22 PM | Unregistered CommenterSteve Richards

I can't speak for all Canadians but would hazard a guess they would generally be pretty pleased if temperatures went up 2 degrees.

2C up and 2C down, either way global temp remains static but each country notices a large change. Hardly a helpful metric?

Hardly a helpful metric?

Oct 25, 2017 at 12:11 PM | Steve richards

I think it is a useful metric, as a yardstick to compare computer enhanced "Global Warming" against.

If we had a better understanding of the causes of natural variation, that could for example, explain the MWP and LIA, no one would need to be panicking now.

Models are commonly used in other branches of science, particularly in engineering where multi-parameter calculations are conveniently automated. One example would be the specification for an aircraft wing.

Clearly, the rules need to be strict. Models need to be validated. If a model cannot successfully predict observation then it has failed. Partially successful models are deemed to have failed because such a model is not reliable.

What is an ensemble? The idea that a model either works or it doesn’t does not accommodate the concept of a model ensemble. A correct model cannot co-exist with another correct model. This would tell us that the validation regime is inadequate. There is just a slim possibility that there are independent solutions to a problem.

I suspect that model ensembles in climate science have nothing to do with any of that. Climate science, after all, does not follow the traditions of normal science.

A model is effectively a programme with variables, initialisation values, conditional statements and loops and a number of built in assumptions. A given model will produce a given result. I assume that if the model contains probabilities, then the model will produce a probability distribution of results if run a number of times.

Several nests of probabilities will widen the range of results. Some control of the result spread may be incorporated. This does not imply a more sensible model it simply cuts off the more ridiculous outputs.

The concept that a different set of conditions run in a different model can be included in order to enhance a modelled outcome is completely alien to logic.

The nice thing about an engineering model is that you can precisely define almost everything in advance.

You can define the shape and properties of the wing. You know the precise properties of the air flowing over it.

You can be confident that a computer model run will be repeatable. Set up the same conditions and you get the same result repeatably. In a simple deterministic physical system you can get away with that.

The problem comes when reality does things not covered by your model.

Remember the 2010 eruptions of Eyjafjallajökull. Fine ash was being blown across Europe and sucked into jet engines. When asked about the effects the engineers could only speculate because nobody had done either simulations or experiments.

Oct 26, 2017 at 9:42 PM | Schrodinger's Cat

Computers and models are not my "field", but I am familiar with failures that were blamed on models. Models can't be held liable for negligence.

Climate models have never been "verified" by genuine observed data, because the programming was flawed from the outset. It was designed to forecast how much Global Warming would occur and how quickly, because of Manmade CO2, not COULD Manmade CO2 cause Global Warming.

You are already familiar with this thread!
https://wattsupwiththat.com/2017/10/23/propagation-of-error-and-the-reliability-of-global-air-temperature-projections/

A lot of science and many reputations depend on proving the validity of Climate Models, and nothing seems to validate them.

Opportunistic man is back.

Em, " The problem comes when reality does things not covered by your model" is a model useful if it does not handle reality? Simple answer no.

Steve unfair criticism? Models are not reality. You are allowed to expand, modify, upgrade or reset models in the light of new circumstances, understandings or information. It would seem that climate models are being unfairly criticized here, when in fact they are the only realistic method of understanding even the basic elements of a fiendishly complicated system like Earth's climate. What needs criticism is the purpose to which climate models are put - long range predictions and proving the overwhelming importance of CO2 (rather than seeking other controls).

Oct 27, 2017 at 12:19 AM | Entropic man

I had not seen your post when I posted at 12:48 am.

Computer models are powerful tools, but are open to deliberate abuse, and inadvertent abuse due to the false confidence they generate. This story from 1997 was the result of the keel falling off a high tech racing yacht:

https://www.theguardian.com/fromthearchive/story/0,,1985507,00.html

It was not the first, and instances have occurred since. How was data obtained, so that it could be fed into models, such that they could "design" or validate a design?

Innovation is necessary for any technology to advance, and computer models have worked wonders, but the computer generated climate models have yet to prove anything to do with climate trends. How can they be depended on to diagnose and redesign the climate, if they can't explain natural variations such as the MWP and LIA?

If the MWP and LIA were due to changes in heat/cold caused by geothermal, solar variation etc etc, how do we know that the current rise and pause won't be followed by a fall? The models cannot be relied on, to do anything apart from predict warming, which they have done consistently, as required by Climate Science. Mother Earth has proved the failure of the models.

Supertroll, "Models" have increased the accuracy of 5-Day Weather Forecasts. It would be excellent if this accuracy could be extended to 10 days, and Taxpayers would consider it useful.

GolfCharlie.
"Models" have increased the accuracy of 5-Day Weather Forecasts".
I'm not sure this is exactly true. I believe the better predictions are due to satellite coverage and pattern recognition software.. Whenever the Met Office issues low probability predictions it's not because of a model, it's because records don't particularly match current conditions.

Oct 27, 2017 at 11:22 AM | Supertroll

Oh dear. I thought models had some benefit.

A 10 day weather forecast is still pie-in-the-sky, whilst Climate Scientists are confident about their predictions for 10-100 years.

Climate Scientist denied their models were wrong.
Then they denied it was their fault, blaming volcanoes, nino/nina etc
Now they deny admitting they admitted their models were wrong.
If Trump denies them further funding, they will claim that a new improved greener-than-white version is in development, to remove embarrassing stains from the Climate Science records. But if they remove all the stubborn underlying stains, there will be nothing left.

St, I do not think the critiscm of em and model use is too strong or unfair. How is it scientific in any sense of the word to publish results from models when the model makers know that a) the model is incomplete b) the results are used to change the world.
If the models were produced by under grads , grads or post docs as a means of research, fine, but don't publish in a public forum where uneducated like reporters and politicians can read it and act upon it. Models are useful, incomplete models are on there way to being complete. Just keep them quite till they are ready.
Would we use a part built road bridge model to verify the design? I think not.
Would we use a flight simulator with unknown functionality missing to certify pilots as being safe on type? Of course not.
Why are incomplete climate models allowed to see the light of day?
No excuse.

Oct 27, 2017 at 12:12 PM | Steve richards

I don't think Supertroll is trying to defend Climate Scientists or their models!

Climate models have been subjected to 20+years of the most expensive testing programme ever imagined, and paid for by the world.

The Climate Models failed.

Some people (not me) predicted this, and warned of the errors built into the science and the models. Climate Science is not capable of finding and correcting its own mistakes, as it still denies making any.

Climate Scientists are welcome to carry on at their own expense, until they have science that works, with models based on it. Meanwhile, those that questioned Climate Science, and its mutually dependent models should be listened to, not ignored by policy makers.