Climate Change

[ewmayer]

Despite the latest controversy about allegedly-fudged temperature proxy measurements, the *real* Achilles heel of the AGW crowd (and its political arm, the IPCC), is the overreliance on numerical modeling, specifically the General Circulation Models (GCMs) on which so many of the AGW predictions are based. Having done a bit of time-dependent fluid dynamics simulation myself during my graduate-school days, it is obvious to me that to assert any kind of "confidence" in the results of GCMs is patently ludicrous, given the huge uncertainties of the numerous model inputs and parameters, the extremely poor spatiotemporal resolution of the models (even of the very best ones running on most powerful computers on earth), and the fundamentally nonlinear and chaotic nature of the dynamical systems the GCMs are attempting to model. Here is an article which describes the dire state of the GCMs in detail:

A Climate of Belief: The claim that anthropogenic CO2 is responsible for the current warming of Earth climate is scientifically insupportable because climate models are unreliable

In 2001, a paper published in the journal Climate Research13 candidly discussed uncertainties in the physics that informs the GCMs. This paper was very controversial and incited a debate.[14] But for all that was controverted, the basic physical uncertainties were not disputed. It turns out that uncertainties in the energetic responses of Earth climate systems are more than 10 times larger than the entire energetic effect of increased CO2.[15] If the uncertainty is larger than the effect, the effect itself becomes moot. If the effect itself is debatable, then what is the IPCC talking about? And from where comes the certainty of a large CO2 impact on climate?
...
Figure 2a shows the temperature trends produced by 10 GCMs investigated in the “Coupled Model Intercomparison Project” (CMIP) at the Lawrence Livermore National Laboratory,17 showing what would happen if atmospheric CO2 were to increase at a steady 1% per year (about twice the current rate) for 80 years. The climate models excluded other “external forcings,” such as volcanic explosions, human-produced aerosols, and changes in solar intensity, but included internal feedbacks such as heat transfer between the oceans and the atmosphere, changes in snowfall, melting of ice caps, and so on. These GCMs are either identical with, or generally equivalent to, the GCMs used by the IPCC to predict the future temperatures of Earth climate in Figure 1 (SPM-5).

Along with the GCM projections, Figure 2a shows the trend from a very simple model, in which all that happens is passive greenhouse gas warming with no climate feedbacks at all. Nevertheless, for all its inherent simplicity, the passive warming line goes right through the middle of the GCM trend lines.

This result tells us that somehow the complex quintillion-watt feedbacks from the oceans, the atmosphere, the albedo, and the clouds all average out to approximately zero in the General Circulation Models. Apart from low intensity wiggles, the GCMs all predict little more than passive global warming.
...
Since the satellite era especially, specific aspects of climate such as cloudiness or surface temperature have been monitored across the entire globe. GCM climate models can be tested by retrodiction — by making them reproduce the known past climate of Earth instead of the future climate. Physical error in GCMs can be quantified by comparing the retrodicted past with the real past.

retrodicted over the similar 1979–1988 period23 by 10 revised GCMs.[24] The GCMs had been used in one attempt to reproduce the observed cloudiness, and were then revised and re-tested. This study was published in 1999, but the fidelity between GCM retrodictions and observed cloudiness has hardly improved in the past nine years.[25

Looking at Figure 3, the GCMs do a pretty good job getting the general W-shape of Earth cloudiness, but there are significant misses by all the models at all latitudes including the tropics where clouds can have a large impact on climate.[26] So, how wrong are the GCMs?

One approach to determining error is to integrate the total cloudiness retrodicted by each model and compare that to the total cloudiness actually observed (SI Section 3). Calculating error this way is a little simplistic because positive error in one latitude can be cancelled by negative error in another. This exercise produced a standard average cloudiness error of ±10.1%, which is about half the officially assessed GCM cloud error.[24] So let’s call ±10.1% the minimal GCM cloud error.

The average energy impact of clouds on Earth climate is worth about -27.6 W/m2. [27] That means ±10.1% error produces a ±2.8 W/m2 uncertainty in GCM climate projections. This uncertainty equals about ±100 % of the current excess forcing produced by all the human-generated greenhouse gasses presently in the atmosphere.[10] Taking it into account will reflect a true, but incomplete, estimate of the physical reliability of a GCM temperature trend.

So, what happens when this ±2.8 W/m2 is propagated through the SRES temperature trends offered by the IPCC in Figure SPM-5 (Figure 1)? When calculating a year-by-year temperature projection, each new temperature plus its physical uncertainty gets fed into the calculation of the next year’s temperature plus its physical uncertainty. This sort of uncertainty accumulates each year because every predicted temperature includes its entire ± (physical uncertainty) range (SI Section 4).

Figure 4 shows the A2 SRES projection as it might have looked had the IPCC opted to show the minimal ±10.1 % cloud error as a measure of the physical accuracy of their GCM-scenarioed 21st century temperature trend. The result is a little embarrassing. The physical uncertainty accumulates rapidly and is so large at 100 years that accommodating it has almost flattened the steep SRES A2 projection of Figure 1. The ±4.4°C uncertainty at year 4 already exceeds the entire 3.7°C temperature increase at 100 years. By 50 years, the uncertainty in projected temperature is ±55°. At 100 years, the accumulated physical cloud uncertainty in temperature is ±111 degrees. Recall that this huge uncertainty stems from a minimal estimate of GCM physical cloud error.

In terms of the actual behavior of Earth climate, this uncertainty does not mean the GCMs are predicting that the climate may possibly be 100 degrees warmer or cooler by 2100. It means that the limits of resolution of the GCMs — their pixel size — is huge compared to what they are trying to project. In each new projection year of a century-scale calculation, the growing uncertainty in the climate impact of clouds alone makes the view of a GCM become progressively fuzzier.

My Comment: So the various model parameters are all tweaked to keep the results from diverging improbably far from zero-change over the course of simulated time, but crudely enforced "stability" does not make the implied error bars any smaller - but of course the IPCC is very careful not to advertise those. The chaotic nature of the climate-dynamic model systems (by way of extreme sensitivity to model inputs and simulation parameters) becomes clear in the following discussion of some GCM internal benchmarks:

The difficulty is serious even over short times. The inset to Figure 4 shows that after only 20 years, the uncertainty from cloud error is ±22° and for forcing, it’s ±3°. The effect of the ~1% forcing uncertainty alone tells us that a 99% accurate GCM couldn’t discern a new Little Ice Age from a major tropical advance from even 20 years out. Not only are these physical uncertainties vastly larger than the IPCC allows in Figure SPM-5 (Figure 1), but the uncertainties the IPCC allows in Figure SPM-5 aren’t even physical.[16]

When both the cloud and the forcing uncertainties are allowed to accumulate together, after 5 years the A2 scenario includes a 0.34°C warmer Earth but a ±8.8°C uncertainty. At 10 years this becomes 0.44±15° C, and 0.6±27.7°C in 20 years. By 2100, the projection is 3.7±130°C. From clouds alone, all the IPCC projections have uncertainties that are very much larger than the projected greenhouse temperature increase. What is credible about a prediction that sports an uncertainty 20–40 times greater than itself? After only a few years, a GCM global temperature prediction is no more reliable than a random guess. That means the effect of greenhouse gasses on Earth climate is unpredictable, and therefore undetectable. And therefore moot.

The rapid growth of uncertainty means that GCMs cannot discern an ice age from a hothouse from 5 years away, much less 100 years away. So far as GCMs are concerned, Earth may be a winter wonderland by 2100 or a tropical paradise. No one knows.

Direct tests of climate models tell the same tale. In 2002, Matthew Collins of the UK Hadley Centre used the HadCM3 GCM to generate an artificial climate, and then tested how the HadCM3 fared predicting the very same climate it had generated.[28] It fared poorly, even though it was the perfect model. The problem was that tiny uncertainties in the inputs — the starting conditions — rapidly expanded and quickly drove the GCM into incoherence. Even with a perfect model, Collins reported that, “It appears that annual mean global mean temperatures are potentially predictable 1 year in advance and that longer time averages are also marginally predictable 5 and 10 years in advance.” So with a perfect climate model and near-perfect inputs one might someday “potentially [predict]” and “marginally [predict],” but can not yet actually predict 1 year ahead. But with imperfect models, the IPCC predicts 100 years ahead.

[ewmayer]

The above article continues:

In light of all this, why is the IPCC so certain that human-produced CO2 is responsible for recent warming? How can the US National Academy of Sciences say, in a recent brochure, that, … Earth’s warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere”?[30] This brochure offers a very telling Figure 4 (SI Section 5), showing the inputs to 20th century global temperature from a GCM projection. Only when the effects of human greenhouse gasses are included with normal temperature variation, we are told, does the GCM projected temperature trend match the observed temperature trend.

But their Figure 4 has another trait that is almost ubiquitous in GCM temperature projections. It shows no physical uncertainty limits. We are given a projected temperature trend that is implicitly represented as perfectly accurate. NAS Figure 4 would be more truthful if the National Academy presented it complete with ±100 degree uncertainty limits. Then it would be obvious that the correspondence between the observations and the projection was no more than accidental. Or else that the GCM was artificially adjusted to make it fit. It would also be obvious that it is meaningless to claim an explanatory fit is impossible without added CO2, when in fact an explanatory fit is impossible, period.

It is well-known among climatologists that large swaths of the physics in GCMs are not well understood.[31] Where the uncertainty is significant GCMs have “parameters,” which are best judgments for how certain climate processes work. General Circulation Models have dozens of parameters and possibly a million variables,[32] and all of them have some sort of error or uncertainty.

A proper assessment of their physical reliability would include propagating all the parameter uncertainties through the GCMs, and then reporting the total uncertainty.[33] I have looked in vain for such a study. No one seems to ever have directly assessed the total physical reliability of a GCM by propagating the parameter uncertainties through it. In the usual physical sciences, an analysis like this is required practice. But not in GCM science, apparently, and so the same people who express alarm about future warming disregard their own profound ignorance.

So the bottom line is this: When it comes to future climate, no one knows what they’re talking about. No one. Not the IPCC nor its scientists, not the US National Academy of Sciences, not the NRDC or National Geographic, not the US Congressional House leadership, not me, not you, and certainly not Mr. Albert Gore. Earth’s climate is warming and no one knows exactly why. But there is no falsifiable scientific basis whatever to assert this warming is caused by human-produced greenhouse gasses because current physical theory is too grossly inadequate to establish any cause at all.
...
So, then, what about melting ice-sheets, rising sea levels, the extinction of polar bears, and more extreme weather events? What if unusually intense hurricane seasons really do cause widespread disaster? It is critical to keep a firm grip on reason and rationality, most especially when social invitations to frenzy are so pervasive. General Circulation Models are so terribly unreliable that there is no objectively falsifiable reason to suppose any of the current warming trend is due to human-produced CO2, or that this CO2 will detectably warm the climate at all. Therefore, even if extreme events do develop because of a warming climate, there is no scientifically valid reason to attribute the cause to human-produced CO2. In the chaos of Earth’s climate, there may be no discernible cause for warming.[39] Many excellent scientists have explained all this in powerful works written to defuse the CO2 panic,[40] but the choir sings seductively and few righteous believers seem willing to entertain disproofs.

[__HRB__]

Hooray - Finally the thread-title got its soap-boxy presupposition back!

Originally Posted by ewmayer

[...]

Originally Posted by ewmayer

[...]

I don't see how those posts can in any way be interpreted as scientific evidence in support of global warming - they seem to illustrate lack of evidence - so here's some non-scientific evidence from as early as 1991:

http://www.youtube.com/watch?v=pw5vW4avWAc

The next thing we'll know is that the forest is moving, the trees are alive...

http://www.youtube.com/watch?v=iSr8KxbNVqQ

[mdettweiler]

Originally Posted by ewmayer

Despite the latest controversy about allegedly-fudged temperature proxy measurements, the *real* Achilles heel of the AGW crowd (and its political arm, the IPCC), is the overreliance on numerical modeling, specifically the General Circulation Models (GCMs) on which so many of the AGW predictions are based. Having done a bit of time-dependent fluid dynamics simulation myself during my graduate-school days, it is obvious to me that to assert any kind of "confidence" in the results of GCMs is patently ludicrous, given the huge uncertainties of the numerous model inputs and parameters, the extremely poor spatiotemporal resolution of the models (even of the very best ones running on most powerful computers on earth), and the fundamentally nonlinear and chaotic nature of the dynamical systems the GCMs are attempting to model. Here is an article which describes the dire state of the GCMs in detail:

A Climate of Belief: The claim that anthropogenic CO2 is responsible for the current warming of Earth climate is scientifically insupportable because climate models are unreliable

My Comment: So the various model parameters are all tweaked to keep the results from diverging improbably far from zero-change over the course of simulated time, but crudely enforced "stability" does not make the implied error bars any smaller - but of course the IPCC is very careful not to advertise those. The chaotic nature of the climate-dynamic model systems (by way of extreme sensitivity to model inputs and simulation parameters) becomes clear in the following discussion of some GCM internal benchmarks:

Cheesehead, this article that Ernst posted quite nicely puts much of what I've been trying to say over the course of our debate into much clearer and more scientific words than I could have hoped to. As the article stated near the end, "there is no scientifically valid reason to attribute the cause to human-produced CO2." The uncertainty in our knowledge of Earth's climate is just too great to even come close to predicting any trends whatsoever. To therefore come out and say that anyone who disagrees with the "scientific" conclusion that AGW is occurring must be crazy--as you've, in more or less words, attempted to peg me throughout our debate--is indeed quite anti-scientific.

Therefore, as I said up in post #583, because science truly does not provide any evidence whatsoever for AGW, the debate is no longer in the realm of science but instead in that of politics. Namely, it is on the question of whether our country's policy should be dictated by science, or by emotional alarmism based on a fabricated hypothesis.

Originally Posted by __HRB__

Hooray - Finally the thread-title got its soap-boxy presupposition back!

Indeed, the old title was much more fitting. (The original version of it, that is: Global Warming: Hoax or real threat to mankind?) As quite eloquently demonstrated by the news article Ernst posted, there is no scientific evidence whatsoever for anthropogenic global warming (which, for those of you wanting to quibble with semantics, is the obvious reference intended by the words "global warming" in the thread title). Rather, the real question it's all just a hoax, or a real threat to mankind.

Actually, I must say I believe it's both: it's one of the biggest and best hoaxes ever created in all of known history, and as such it has the potential to dupe people to such a degree that it's indeed a real threat to mankind's liberty and quality of life.

[__HRB__]

@ewmayer & the Clouds (GNFARB)

http://www.trutv.com/shows/conspiracy_theory/index.html

Global Warming – NEW!
Premiere On: Wed, December 16 at 10P
Whether global warming is real or not, it's believed some people are using the issue to make billions of dollars, start a one-world government and control our lives, from the cars we drive to the foods we eat. Jesse Ventura starts with Al Gore and goes far beyond as he uncovers the evidence that leads to one man thought to be behind the global warming conspiracy.

According to episode one even the stooopid military can move them with HARRP! I betcha that's something they didn't teachya in grad-school!!

[cheesehead]

Originally Posted by mdettweiler

However, given the recent findings about extensive "fudging" of major climate models,

Are you sure you read those exaggerated sensationalist reports correctly?

AFAIK, no one has alleged that any of the recently-hacked memos says anything about climate models being fudged. If you actually read that, will you please give me a link?

Even if you assume that the scientists involved aren't intentionally skewing the data, as Ernst said in post #575, the scientists themselves admit there's "large uncertainty in the models".

Quantify "large", please.

As I posted, the range is range from 1.1°C and 6.4°C and the most likely range is 1.8°C to 4.0°C. Did you happen to notice that all of those figures are above 1.0°C?

Therefore, it would seem that we're not going to resolve this debate by means of climate models or "scientific data"; there's too much uncertainty as to the reliability of the presentation of the data.

No, there isn't.

What there is, is too little scientific understanding on the part of you anti-AGWers. Where's that data that supports your arguments, Max?

If it was a less controversial (and easier to model) field, say zoology, then perhaps we wouldn't have to worry so much about the veracity of the data, but here, it's key.

Yes, but your apparent disregard for the exact meaning of "large" is just another example that shows that you're using anything you can to justify your preconceptions, _not_ using science to disprove AGW!

Why, exactly, do you use only rhetoric to support your position, not data?

It seems, then, that this debate must leave the realm of science and enter the realm of politics.

You'd like that, wouldn't you? Abandoning/ignoring the science, that is.

Did the scientists involved in producing the data lie, and if they did, to what extent?

(1) This is a matter that needs investigating. Debate in forums will not reach the truth; good investigation will.

(2) Even though only one small sector of one type of data is in question, you and the other anti-AGWers keep talking as though a much larger amount was in doubt. It's not. (If you disagree, please present _evidence_ to support your claim!) Your apparent exaggeration of the amount of data that has been called into doubt is typical of your use of rhetoric rather than science to debate.

BTW, a couple things I'd like to say in regard to the "alternative hypotheses" I presented earlier, so you don't start ranting more about me "dodging": I presented those as possible "pretty good guesses" (post #486), not as evidentially backed up scientific hypotheses.

That's right; you didn't. Yet somehow in your mind an unsupported hypothesis is stronger than a hypothesis that's supported by many lines of independent evidence.

If those potential responses to that data are so easy to formulate, then how come we haven't seen the pro-AGW crowd even attempt to shut them down scientifically?

They have been ... for years ... in scientific fora. The _scientific_ debate is over. The public debate going on now in mass media involves those who don't understand the science., and uses rhetoric, not science.

Again, this is not sufficient to disprove AGW, but it does present another area that pro-AGW scientists need to address in order for their argument to be as airtight as they claim it to be.

They _have_ addressed it ... in the scientific fora. Al the anti-AGWers are doing is resurrecting, in nonscientific fora, old faulty arguments that have already been scientifically refuted.

[cheesehead]

Originally Posted by mdettweiler

Cheesehead, this article that Ernst posted quite nicely puts much of what I've been trying to say over the course of our debate into much clearer and more scientific words than I could have hoped to.

... which just demonstrates your poor understanding of what science is.

As the article stated near the end, "there is no scientifically valid reason to attribute the cause to human-produced CO2."

Actually, I recently posted links to, and quotes from, sources that _do_ provide evidence "to attribute the cause to human-produced CO2" and other GHGs.

Apparently, the article Ernst posted is from someone who is _not aware_ of the clinching scientific evidence in the Evans paper!

The Evans paper showed that the increased downward heat flux has a spectrum that matches the spectra of the human-produced GHGs. That is conclusive evidence, but you just don't understand why it is so conclusive!

Go ahead: show me that you understand the importance of the spectral data.

I dare you.

Just because you don't understand something doesn't mean that something is of no consequence.

Go ahead. Refute the long-wave spectral evidence, if you can. _It conclusively proves that the warming is due to human-generated GHGs!_

Show me that you understand that data in the Evans paper.

- - -

Ernst,

I continue to await your refutation of the Evans paper.

Well ??????? Why your silence about that conclusive spectral evidence? Is it because you can't see a way to use rhetoric to get around its proof that the recent warning has been due to anthropogenic GHGs?

How do you "hoax" infrared spectra that can be seen by anyone with the proper equipment? How did the "hoaxers" manage to get Earth's atmosphere to exhibit false spectra? (Yeah, I know -- you'll claim that data is falsified, too.)

If it's really, truly a "hoax", why don't the anti-AGWers simply show us all that the spectrum of the recent change in downward IR flux does _not_ match the spectra of human-generated GHGs? THAT would expose the "hoax" in a very public manner! So why don't they do it ?????????????? (But don't give me any guff about anti-AGWers' not understanding long-wave IR spectra.)

You can't fool Mother Nature, and Mother Nature is showing us that the recent global warming IS due to human-generated GHGs.

But understanding that does require a certain amount of scientific knowledge. So sorry to be elitist, AGW-deniers, but that's the way it is.

The only debate still going on involves folks who do not have enough scientific understanding to appreciate the evidence. But scientific understanding is not required for conspiracy theories, so conspiracy theories are the last refuge for AGW-deniers.

[cheesehead]

Ernst,

The article you most recently cite, "A Climate of Belief", has something in common with the Spiegel article that Max cited: it has a fatal flaw because its central theme is missing a key ingredient.

The Spiegel article discussed why global warming had paused -- which, fatally for its theme, ignores that global warming has _not_ paused when one takes total _global_ warming, including subsurface ocean warming, into proper account.

Similarly, the Skeptic article's thesis subtitle, "The claim that anthropogenic CO2 is responsible for the current warming of Earth climate is scientifically insupportable because climate models are unreliable" has the fatal oversight that the claim that anthropogenic CO2 is responsible for the current warming of Earth climate is not based on climate models. Instead, that claim is based on multiple independent lines of evidence such as actual measurements -- for example, as in the Evans paper.

AGW uses climate models to predict future global climate change, but it does not use them as evidence for the claim that anthropogenic CO2 is responsible for the current warming of Earth climate. AGW is not contradicted by the climate models, but that lack of contradiction is not the same as being, supposedly, based on climate models.

Note: the Evans paper uses the results of some models, but not the GCMs criticized in the Skeptic article. Instead, they are more specialized and limited models, such as of "radiative forcing at the tropopause", "increases in the greenhouse radiation", and "the background emission of the atmosphere ... using the radiative transfer code, FASCOD3 (Clough et al., 1988)". Then the Evans results are compared to (not depend upon) global climate models.

Thus, all the GCMs mentioned in the Skeptic model do not matter to the Evans results. Evans doesn't use any of them. Evans compares its non-global-climate-model results to a subset of results predicted by climate models, and finds reasonable agreement. Independent lines of evidence, as is true throughout the evidence for AGW, in contrast to the Skeptic article's false assertion that the AGW hypothesis is based on climate models.

You really need to be more careful in what you choose to hold up as support for your anti-AGW opinions, Ernst, just as Max needs to be more careful in what he claims to be "convincing" and "science".

- - -

Originally Posted by mdettweiler

this article that Ernst posted quite nicely puts much of what I've been trying to say over the course of our debate into much clearer and more scientific words than I could have hoped to.

Max,

Actually, what your endorsement of the article Ernst posted quite nicely illustrates is, once again, your weakness in scientific understanding, just as all the other pieces of supposed anti-AGW evidence you've presented have served only to highlight your own skimpy science background, not bolster your anti-AGW position.

You need to be more cautious about following Ernst's lead. You've demonstrated in multiple ways that your grasp on what constitutes true science is weak. Here, you demonstrated that you failed to see the fatal flaw in the Skeptic article that Ernst cited (whereas I noticed it in a few seconds). You let yourself be led astray by your bias, and your science understanding is too weak to have alerted you as to what you were overlooking in the article.

Ernst, on the other hand, should have noticed the problem. I think his science understanding is good enough to have caught the flaw in the Skeptic article ... except that he forgot to be skeptical about that article.

- - -

Please, both of you, stop posting articles with such easily-found flaws. They waste everyone's time (or worse: lead other readers astray), and just wind up providing me with further examples of the errors in your own reasoning about AGW. It's hard for me not to let my irritation seep into my responses.

I don't have time to properly explain all of the mistakes in your anti-AGW positions, because (just as with creationism) it takes only a few seconds for one of you to spout some faulty idea, but takes me an hour to properly lay out and explain the error for you and other readers.

I can't possibly keep pace with all your anti-AGW flaws, so please at least give me the consideration of posting fewer so-easily-spotted ones that you (Ernst, anyway) should be able to spot by yourself with a short period of skeptical examination.

[cheesehead]

Originally Posted by mdettweiler

As quite eloquently demonstrated by the news article Ernst posted, there is no scientific evidence whatsoever for anthropogenic global warming (which, for those of you wanting to quibble with semantics, is the obvious reference intended by the words "global warming" in the thread title).

Wrong again, Max.

Rather, the real question it's all just a hoax, or a real threat to mankind.

It's a real threat, Max, but not the way you think it is.

Actually, I must say I believe

... but you've shown us -- repeatedly -- that your personal belief is no guide to distinguishing science from not-science. (No wonder you abandoned that PM interchange.)

it's both

I do hope that some day you will study real science enough to know the difference between it and not-science.

it's one of the biggest and best hoaxes ever created in all of known history,

Wrong ...

and as such it has the potential to dupe people to such a degree that it's indeed a real threat to mankind's liberty and quality of life.

Max,

It's you who are being duped by the AGW-deniers. I hope you wake up soon to realize how big the ring in your nose is that you're being led around by.

- -

P.S. Please try to post some actual evidence, not just hot air, to support your position. I'm still waiting.

[cheesehead]

Ernst,

Is there any conceivable evidence that would convince you that AGW is real? If so, what?

In the meantime, are you having any trouble with crafting that Evans refutation I want to see?

[Batalov]

Ernst needs to drop everything he is doing. Immediately!
Duty calls! Someone is wrong on the internet.