IPCC vs Reality

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TallDave
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Post by TallDave »

tomclarke wrote:My initial position, along with vankirkc, is that when nearly all the experts in the field tell me AGW is real and quantify it I believe this, or at least take it seriously.
This is known as argument by authority. It is a logical fallacy to rely on authority in an area with so much uncertainty. Expert predictions have poor track records under such circumstances (they actually do worse than non-experts).
(2) The variety and lack of rigour in the arguments against AGW is dissapointing.
It's even more disappointing that pro-AGW arguments are so varied, weak and flakey, and are presented with so much more certainty than they merit. They have the added disappointment of being the basis for spending trillions of dollars, unlike anti-AGW arguments.
if there are problems in the GCM consensus they don't come from obvious fallacies (which would be detected and incorporated into revised models) (
Except that they all commit the same obvious fallacy of assuming AGW is the forcing factor, which critics keep pointing out but GCM modellers never fix, because the whole point of GCMs is to attempt to estimate the AGW forcing factor. This is like being assured that hand grenade manufacturers are doing everything possible to make their product safe for the people you're throwing them at, except for the part where they explode.

Also, the interesting quality about unknown factors is that they aren't known. This is a problem for all modelling.

tomclarke
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Post by tomclarke »

Simon wrote:Because when about half of them are alarmists it biases the sample.
Your definition of alarmist is no doubt somone who projects alarming consequences from the status quo. If half the GCMs do this (as they do) it is not surprising that the scientists running them are alarmists. You argue:

they are alarmists => they are prejudiced => their science must be bad

Alternatively:
Their science is alarming => they publish alarming projections

is simpler.

But either way, your assessment of prejudice (based on judgement) is fallacious. You can detect prejudice by inconsistency, bad arguments, lack of logical support, etc. Not by disagreement with your own prejudice.

You & a few others on this thread attribute all these characteristics to AGW argumnets, I know. When I have investigated the deatils they have not added up. I see prejudice in the simplistic and often (though not always) internally inconsistent anti-AGW arguments.

The case that AGW is reading trends into data that has so much internal variability this is unwarranted is much more difficult to shoot down. I am not inclined to shoot it down. It must remain a hypothesis for any scientist working in the field.

Were I such it is likely that after having reviewed properly all the evidence, following the consensus, I would give that hypothesis a low probability. But how I rated it could not be determined by the simplistic arguments (pro or anti) that get trotted out by those who do not have the inclination or time to read the source material carefully and with an open mind.



The case against the consensus can only be made if you agree with TallDave:
This is known as argument by authority. It is a logical fallacy to rely on authority in an area with so much uncertainty. Expert predictions have poor track records under such circumstances (they actually do worse than non-experts).
This argument was I believe advanced by Armstrong & Green. Armstrong is well-known as an academic studying economic forecasting. His views are therefore understandable. Economic arguments tend to involve assumptions about the behaviour of human agents which are clearly (in the case of classical economics) wrong. And there is no accepted theory of how to include human complexity into economics that allows prediction.

If these statements are applied to any forecasting based on physical systems they will underestimate the skill of proper quantitative techniques. Of course, you can posit physical questions which cannot be answered because chaos predominates. Simon argues (on no evidence) that global temperature evolution is such a question. The "consensus" argues that climate is predictable:
At very short timescales - well (accurate local weather forecasts)
At short timescales - not so well (regional long-term forecasts)
At medium timescales - not at all
At long timescales - only when averaged over time and space.

The GCMs model a parameter - climate sensitivity - that has the max possible averaging, all the globe, and a timescale of 10s of years.

Given the known underlying physical basis for this it requires some creativity to imagine that when spatial and temporal variations are averaged out it would not be predictable.

Simon has this creativity. He supposes that some parameter of the climate behaves chaotically with strange attractors having a periodicty of more than 150 years. Random dynamic evolution from one strange attractor to another can then result in the observed 20th Century temperature trend.

While this is theoretically possible, it stretches credibility. What is the set of dynamic parameters that has such a long time constant? What is the chance of this random process just happening to duplicate 20th C CO2 forcing?

So I can't dismiss, this, it just seems less likely than that CO2 forcing causes this increase.

All this is said from a non-expert viewpoint - since TallDave believes non-experts do better than experts. Sounds to me rather like the school boards in Kansas who tried to prevent teaching of the "consensus" view that species evolved through natural selection. They no doubt had also read Scott Armstrong.

bcglorf
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Some things I just don't get

Post by bcglorf »

<I>
Given the known underlying physical basis for this it requires some creativity to imagine that when spatial and temporal variations are averaged out it would not be predictable.
</I>

That sounds like it could also be said of plasma physics, and be just as untrue. We know that climate involves not only ocean currents, but the composition of the whole atmosphere as well. I'd say the default expectation should be that it is not predictable in any meaningful manner.

As for whether alarming results are moving scientists to speak or alarmist scientists are reading things too strongly I feel pretty strongly on that too. To me it's the simple tenet that extraordinary claims require extraordinary evidence. No data source or record shows historically unprecedented temperature change. The indirect record through proxies going back thousands and tens of thousands of years as of yet registers nothing unusual it self about today's temperatures, or lacks the resolution to say anything about the last 100 years. The directly measured record going back a little over 100 years again shows a tame graph with nothing leaping out as an anomalous warming.

There is NO RECORD I have found, and I've looked, of unprecedented global warming, or a trend towards such. It is only when one takes the proxy data and tacks on the directly measured data at the end that an anomalous temperature jump occurs, and the line is EXACTLY where the source of data changes. I'm inclined to demand the change of data be thoroughly ruled out before claiming that climate itself has radically altered at the exact moment that coincides with the start of directly measured data being introduced to the recreation.

bcglorf
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another thing

Post by bcglorf »

What I do know is that a large body of people with credentials are telling me that it is real, and that we don't have a lot of time to do something about it. The question in my mind is this...is inaction today in the name of certainty worth the risk that ten or twenty years down the road we could be looking at a very long and very substantial humanitarian crisis?

Sorry, for me that sounds more like religion. Think about how the following question has been answered by the masses in the past.

Does everyone that isn't Roman Catholic really go to hell?

The masses answer was eerily similar:
I don't know. What I do know is that a large body of people who are well educated are telling me that it is real, and that we don't have a lot of time to do something about it. The question in my mind is this...is inaction today in the name of certainty worth the risk of a very long and very substantial suffering?

TallDave
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Post by TallDave »

This argument was I believe advanced by Armstrong & Green. Armstrong is well-known as an academic studying economic forecasting.
Actually, he studies climate forecasting as well. Though of course he also criticized the AGW economic forecasts.
And there is no accepted theory of how to include human complexity into economics that allows prediction
Actually there are quite a few such theories. For instance: you tax something, you get less of it. You subsidize something, you get more of it. And of course there's the supply/demand price curve. These all get applied every day by people trying to predict futures markets. The unpredictability in, say, soy futures has much more to do with the unpredictability of climate than of people. In fact, people are probably the most predictable part of economics, because they're rational actors.
If these statements are applied to any forecasting based on physical systems they will underestimate the skill of proper quantitative techniques.
It's a good thing no one did that. It's also a good thing forecasters have studied the predictive reliability of such quantitative models. Would you like to know what they found their reliability has been?
What is the chance of this random process just happening to duplicate 20th C CO2 forcing?
What measured forcing are you referring to? We have thirty years of reasonably clean data. There's no forcing evident there. If you measure proxies from the end of the Little Ice Age you find a spaghetti graph that shows a rebound but the modern data doesn't agree with the GISS data, which in turn is a total FUBAR based on stations of which 80% don't meet the official standards and administered by a man who calls coal trains the equivalent of Auschwitz. Looking at the historical data over long periods, we find CO2 trails temperature change, making a cause/effect relationship dubious.
Last edited by TallDave on Mon Jun 08, 2009 8:24 pm, edited 2 times in total.

KitemanSA
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Re: another thing

Post by KitemanSA »

bcglorf wrote: What I do know is that a large body of people with credentials are telling me that it is real, and that we don't have a lot of time to do something about it. The question in my mind is this...is inaction today in the name of certainty worth the risk that ten or twenty years down the road we could be looking at a very long and very substantial humanitarian crisis?

Sorry, for me that sounds more like religion. Think about how the following question has been answered by the masses in the past.

Does everyone that isn't Roman Catholic really go to hell?

The masses answer was eerily similar:
I don't know. What I do know is that a large body of people who are well educated are telling me that it is real, and that we don't have a lot of time to do something about it. The question in my mind is this...is inaction today in the name of certainty worth the risk of a very long and very substantial suffering?
Unfortunately, you stopped your analogy too soon. Continue on with "Of course it is not worth the risk! Therefore I shall tax you (tithe you) to obtain the money to subdue (aka convert or be killed) anyone who is not Roman Catholic".

TallDave
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Post by TallDave »

Sorry, for me that sounds more like religion. Think about how the following question has been answered by the masses in the past.
The consensus of those working in the theological field is that God exists and needs about 10% of your pay. And since God acts mysteriously, nothing can disprove his existence.

Hey, that all sounds a bit familiar...

MSimon
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Post by MSimon »

.is inaction today in the name of certainty worth the risk of a very long and very substantial suffering?
Is doing the wrong thing today in the name of certainty worth the risk of a very long and very substantial suffering?

FIFY

Cause if the climate is getting colder we could be in for a very rough ride in terms of food.
Engineering is the art of making what you want from what you can get at a profit.

tomclarke
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Post by tomclarke »

TallDave wrote:Actually there are quite a few such theories. For instance: you tax something, you get less of it. You subsidize something, you get more of it. And of course there's the supply/demand price curve. These all get applied every day by people trying to predict futures markets. The unpredictability in, say, soy futures has much more to do with the unpredictability of climate than of people. In fact, people are probably the most predictable part of economics, because they're rational actors.
TallDave - on this thread we will I think not agree. Your quote above restates the tenets of classical economic theory. They are not true. Certainly they do not reflect the complexity of human reactions. For a simple example, the current instability in oil price futures is not predicted by classical economic theory, nor is it the result of rational actors. For a larger example, the recent debt bubble was typical of markets but totally irrational, and not modelled or predicted by economic theory.

But don't take my word for it. Anyone involved in the stock market would say that inverstors (and markets) ar ruled by fear and greed, and prone to irrational swings.

TallDave
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Post by TallDave »

It's come to this:
As the investigation continues as to what brought down the French airliner over the Atlantic Ocean with 228 people on board, a Russian climatologist believes global warming played a significant part …
Oh dear God no.

TallDave
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Post by TallDave »

For a simple example, the current instability in oil price futures is not predicted by classical economic theory, nor is it the result of rational actors.
Sure it is. There's an open conspiracy to set oil prices as high as possible for the rational benefit of those controlling large quantiies of oil. It's called OPEC. There will always be a lot of price instability in a tightly-controlled commodity with relatively inflexible demand and a long build-out time for new production. This is simple supply and demand theory: the price line is very steep over small fluctuations in such situations.
For a larger example, the recent debt bubble was typical of markets but totally irrational, and not modelled or predicted by economic theory.
Balderdash. It was a natural result of rising real estate prices, low interest rates, and political pressure to lend to people who could not repay their loans. Lots of people predicted it and commented on it while it happened, sometimes during Senate hearings.
Anyone involved in the stock market would say that inverstors (and markets) ar ruled by fear and greed, and prone to irrational swings.
That's mostly a limited information problem. There may be occasional swings of irrationality in one sector or another, but if capitalism were essentially irrational we'd all be communists instead because that would work better. Overall, markets are very rational. Oh, and btw: fear and greed are rational too.

Markets do experience bubbles, but economics is hardly unpredictable on that basis alone. Generally, people will act rationally based on available information. Human behavior tends to smooth uncertainty in modelling economics, rather than making it worse (e.g., as a commodity's price rises, people buy less of it).
Last edited by TallDave on Mon Jun 08, 2009 9:51 pm, edited 2 times in total.

tomclarke
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Post by tomclarke »

bcglorf wrote:
Given the known underlying physical basis for this it requires some creativity to imagine that when spatial and temporal variations are averaged out it would not be predictable.


That sounds like it could also be said of plasma physics, and be just as untrue.
Good analogy. Here is what spatial & temporal averaging does to an (isolated and physically confined) plasma:

Changes in temperature (averaged over entire plasma and timescales longer than instability timescales) can be related to total energy fluxes in and out (counting fusion as another energy flux). Note this assumes that the plasma can be contained. [note this is not precise. Conservation of mass-energy is precise but for this to be reflected in temperature we need to assume average volume stays the same - and the nonlinear relationship between volume and temperature means constant average of one may not imply constant average of other. But it is nearly true.]

Over very short timescales details of flow can be predicted. Over longer timescales the inherent chaos makes local prediction impossible.

bcglorf
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But it's not confined

Post by bcglorf »

Here is what spatial & temporal averaging does to an (isolated and physically confined) plasma

Yes, and that's equivalent to predicting the overall energy in the climate system if we assume it too is isolated and confined. Of course it is rather easy and redundant to state it will remain constant. The problem of course is that it is NEITHER.

Climate models on a simplistic level can attempt to measure energy in and energy out and come up with predictions, which would is straightforward enough and people don't disagree there. The problem is that greenhouse effects are dominated by cloud formation, and as Simon has repeatedly pointed out, the models aren't even sure of the sign to attribute to water vapor. I'm going from memory, but CO2 is responsible for an estimated what, 5%? Let be generous though even since I can't remember and say CO2 is responsible for 10% of it and H2O is responsible for about 60%. If our models can't even get the sign for the 60% right, maybe we needn't panic about what the models currently tell us about the 10%?

TallDave
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Re: But it's not confined

Post by TallDave »

bcglorf wrote:our models can't even get the sign for the 60% right, maybe we needn't panic about what the models currently tell us about the 10%?
Especially since there's little evidence even unreliable GCM estimated temps have any negative overall impact.

I would much rather see the AGW money going toward monitoring things like asteroids and the Yellowstone caldera, which are true existential threats.

OTOH, there's this compelling AGW evidence.

vankirkc
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Post by vankirkc »

MSimon wrote:
.is inaction today in the name of certainty worth the risk of a very long and very substantial suffering?
Is doing the wrong thing today in the name of certainty worth the risk of a very long and very substantial suffering?

FIFY

Cause if the climate is getting colder we could be in for a very rough ride in terms of food.
Doesn't it depend on what the 'wrong thing' is, and what its effect will be?

Let's stipulate that CO2 has no impact on climate whatsoever, but that we won't learn this conclusively until 10 years from now.

What will the harm have been if CO2 emissions are limited until then?

I don't really see what the big deal is in regards to limiting CO2 emissions. In the pursuit of that goal a lot of other convenient side effects will fall out, namely improvements in energy efficiency, conservation of the limited petrochemical supply, fostering of alternative energy sources, improvement in industrial pollution control technology, etc.

So what's the big dark down side that you are so obviously afraid of? The only thing I can think of is higher prices or taxes. And if that's it, it seems like a very shallow reason to risk the future of humanity.

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