Talked to one global warming scientist (my wife) about it briefly. Will consult a bigger wig soon if I get the chance. But based on that brief discussion with my wife:

Nothing new here and nothing that is supported. First off, my own question just as a scientist myself and a semi-journalist: what is this guy's qualifications. He says he did "carbon accounting, building models for the Australian Greenhouse Office..." but that isn't necessarily the same as being a scientist. My wife, who does climate modeling, though it isn't the main part of her research, didn't think a model of what the guy claimed he modeled would be very reliable. What is his doctorate in? He sounds like a computer guy, which means his grasp of the physics may be weak. That is not an accusation, but a question. He is not someone who is well known in the field from what I have been able to acertain. But my brief exploration may not have been extensive enough. So my first question is why should this guy's word be taken over top scientists who focus not on carbon accounting (which may not involve much actual climatology) but on actual physics and atmospheric sciences?

Now to Evans' four points.

1. He makes an unsupported statement here that is the basis of this point and probably the second point. Claiming that there is one definitive "signature" to look at is a big leap and not widely accepted, yet it is the basis of his claim. He needs to support this assertion before it can be taken seriously. Specifically, anthropogenic global warming does NOT require the formation of "a hot spot about 10km up in the atmosphere over the tropics" according to my wife. She would be very interested in Evans' evidence for this, but you might notice he asserts it unsupported. That is unscientific. I do intend to try and see if anyone else out there thinks this is a supported hypothesis, but so far he seems to state it from nothing. My guess is that it is one of several possible hypotheses and he is picking it without letting on that it isn't definitive, but I'd need to look into it more.

2. This is a bit silly. The physics of how pretty much every atmospheric gas interacts with solar radiation and affects temperature is well worked out. He admits that the physics is known and he admits that global warming is happening. What he fails to say is that once you have the physics you can observe what is actually happening and see if it fits the physics. In this case it does. I have always said that global warming isn't really a hypothesis so much as proof of principle. We know from physics that atmospheric carbon dioxide will trap heat. We know that carbon dioxide is rising and that temperature is rising in pace with the carbon dioxide rise. This fits the prediction quite well. No one disputes the physics and no one disputes that what is observed fits the physical theory. This would be considered standard scientific evidence in support of the anthropogenic global warming hypothesis. A prediction is made based on physics and the observed changes match well with what is predicted. Evans suggests that something more is needed. In my field you can do controlled experiments. In earth's climate we have physics and real observation (and comparisons with Mars and Venus) but of course we can't have the control where we observe earth without the carbon emissions. Yet that seems to be what he wants. Basically the realities of the field are that you have the physics and you have observation of what is really happening and in this case the observation fist precisely what you would predict from physics and supports the anthropogenic global warming hypothesis.

3. My wife laughed at this. Simply put the "urban heat island" thing is a red herring. Climatologists have been well aware of this and have taken it into account for years now. Even I know this. The surface measurements are NOT corrupted by the heat islands. The heat islands are well understood and taken into account. As to satellite data, my wife wasn't sure what the most up to date stuff is, so she wasn't ready to comment on Evans' claims, but I am thinking back to some scientific papers that came out I think two years ago that reconciled the satellite data with the surface data. Basically the satellite data combined two layers of the atmosphere, one of which is cooler than the other naturally. This masked warming. Once a way was found to separate the data from the two layers the atmospheric data from satellites fit perfectly with surface temperature measurements. I think I cover this here (buried somewhere in the middle). I am not sure if this is the satellite data Evans is referring to, though, since he isn't really clear on what part of the atmosphere he is talking about. I would like to follow up more on this if I get the chance.

4. ice cores??? My wife really laughed at this claim. No one...NO ONE claims to be able to use ice core data to pinpoint cause and effect within an 800 year time frame. Current warming of course is not judged by ice core measurements, but the half a million year record that provides context does depend on ice cores, of course. Ice core data is not precise enough to make the claim Evans does about cause and effect. No one can say anything about which is cause and which is effect from ice cores, so his fourth point is completely invalid. He is probably just looking at a graph without taking into account the statistical error, so he is assuming a precision of the timing of events that is misleading him.

So that is a brief comment based mostly on my wife's reading of the article (and she does study this stuff) and my own more limited knowlege. I will try to look more in dept at some point if I can.

Also, until I can talk with someone else I want to consult, I can refer you to here for further refutaion of Evans in general.

Mole, you wrote:

"We know from physics that atmospheric carbon dioxide will trap heat. We know that carbon dioxide is rising and that temperature is rising in pace with the carbon dioxide rise. ... This would be considered standard scientific evidence in support of the anthropogenic global warming hypothesis. A prediction is made based on physics and the observed changes match well with what is predicted. Evans suggests that something more is needed."

By "prediction" do you mean a climate model? How accurate do climate models have to be to "match well" with observed changes? The last few decades suggest that, thus far, climate models have not "matched well" with what's actually been observed in the climate.

I think Evans' point is that the previous beliefs about CO2 and warming has been overstated. X amount of CO2 might still lead to a temperature increase of Y, but Y is not nearly as large a value as previously thought.

That's why no climate model has yet to "match well" with actual observation. Temperatures are not quite "rising in pace with the carbon dioxide rise," because the assumptions about the ratio of X to Y are incorrect.

I think this because no one will come out and say 'X amount of carbon dioxide leads to Y degrees of warming.' Such a prediction would be immediately contradicted by observational evidence. That's why I don't understand how you can write this: "Basically the realities of the field are that you have the physics and you have observation of what is really happening and in this case the observation fist (sic) precisely what you would predict from physics and supports the anthropogenic global warming hypothesis."

Could you point to a single example where a prediction about global temperatures and the subsequent observation of global temperatures were "precisely" the same?

Evans is ultimately arguing that the amount of warming we're experiencing compared to the additional CO2 in the atmosphere is so low that it's not worth spending any money on the problem.

But, that last point is a public policy question, not a scientific one.

On a gas by gas basis we have a pretty good idea of what level of warming one can expect. Similarly given a particular albedo we can predict what kind of warming to expect. But, on the real earth you have a complex interplay of many gasses and other factors including feedback. And let me be clear that I am not saying any model is perfect...sorry if I gave that impression. What I was saying is that the physics predicts increased CO2 WILL lead to increased warming and we are putting more CO2 into the atmosphere and we are seeing a warming trend that matches the curve of increased CO2 very nicely. There is no other source of CO2 or methane or anything that has changed over the same time period with the same dynamics. But CO2 and warming match very well and we know the CO2 we are putting into the air. Occam's razor (NOT a scientific principle, mind you, but a convenient tool) suggests we explore the CO2 warming idea first.

So far all alternatives (the various water vapor hyptheses, for example...or Rush Limbaugh's idiotic Mt. Pinatubo "hypothesis") to explain modern global warming have fallen flat and been pretty much ruled out, so far anyway. By contrast the predictions of the current anthropogenic models for global warming have made predictions that are coming true. The initial increased snowfall and thickening of the ice sheets even as ice shelves break up. The subsequent loss of ice sheet thickness. Deniers tried using claims that there was increased snowfall and thickness over the ice sheets as evidence against global warming, ignoring the fact that it was PREDICTED by the current global warming models and came true. I haven't noticed much comment on the newer data that the ice sheets are finally starting to thin (as predicted) from the denial lobby. Similarly, I have been hearing for some 15 or 20 years predictions from the current models that we would see, in addition to an overal increase in the average global temperature, we would see an increase in both extremes, more extreme heat as well as extreme cold, and increased storminess. Those were early predictions. And, though increased storminess still remains somewhat controversial, overall those predictions of increased extremes within an overall increase in average temps has come to pass. Yet the deniers used every record cold spell as "evidence" that global warming wasn't happening, ignoring that record cold AS WELL AS record heat was predicted by the models.

I have some updates on this and probably should give it its own diary, but I am finding that Evans'credentials are that he has a PhD in electrical engineering. This gives him no real claim to being a "rocket scientist" (his term) and not necessarily any expertise in climate. So you have an electrical engineer who did carbon accounting for Australia claiming he knows better about climate that climatologists. This alone should raise a red flag in your mind. As to his claims about the "signature"of anthropogenic global warming being "a hot spot about 10km up in the atmosphere over the tropics," turns out this has been debunked already.

The "hot spot about 10km up in the atmosphere over the tropics" is NOT a prediction for doubling CO2. In fact a stratospheric COOLING is a signature for doubling CO2. And we have had stratospheric cooling HAPPEN. In fact that stratospheric cooling for awhile masked another prediction of the current models. The current models predict that surface warming would be accompanied by tropospheric warming. Satellite data (as I mention above) originially did not detect such a tropospheric warming. This was used by deniers as evidence against global warming, and was, in my mind, reasonable evidence. However, a couple of years ago this issue was resolved. The satellite data combined measurements from the stratosphere and troposphere in a way that was not at first appreciated, if I understand correctly. The new info came when these were separated. What was found was tropospheric warming AND stratospheric cooling, which are predictions of the current global warming models based on anthropogenic CO2 release. This is the kind of thing I mean when I say the predictions are precisely correct. Something as complex as surface warming, stratospheric cooling and tropospheric warming, have come true. By conrast the models based on increased solar output do NOT predict stratospheric cooling, so are less acurate.

This article really refutes Evans very effectively and I can't do it justice in this comment. I will however say that you are right that the models have had some major errors. Their basic predictions have come to pass. But the rapidity and severity of the changes have been worse than the models predicted. The pace of change at the poles has been faster than predicted, though the pattern has been correct. Part of the difference is realizing that the dynamics of an ice sheet melting weren't as simple as once thought and that early melting actually sinks large fissures into the sheet, accelerating the melting. THat wasn't predicted, but the error went against the deniers claims even more. There also are predictions that are much more controversial than the basic anthropohenic model. For example the collapse of the North Atlantic current is something I consider unlikely. But keep in mind that prediction is not supported by all models and makes more assumptions than the basic model makes. Sadly that kind of prediction, which all scientists will admit is controversial and essentially a hypothesis that may or may not come to pass, gets the same attention as predictions, like stratospheric cooling and ice sheet thickening, that have already come to pass.

I hope this helps.

Mole,

The link that supposedly debunks Evans is to a guy who has no climate credentials. His background and agenda is stated here.

Now, I think intelligent people can educate themselves on a subject without obtaining a degree, but, you seemed to think it was important that Evans was not properly accredited. So, I'm pointing this out merely because you might be trying to have it both ways on that issue.

As for my response to your comments - you are still giving climate models too much credit. Secondly, you're allowing them to predict vague things like 'thinner ice' or 'more extreme weather.' These sort of predicitions give you a 50/50 shot of being right through sheer chance.

Scientists have been publishing climate models for decades, some of them are bound to be vaguely accurate, but none are specific or meaningful, particularly when you can dismiss the bad ones and cherry-pick the handful that came out 'sort of right' ten years later.

But, you lost me before you started citing example of accurate predictions. Relying on Occam's razor, you wrote the following: "So far all alternatives... to explain modern global warming have fallen flat and been pretty much ruled out, so far anyway."

Here's the problem I have with that line of logic. Let's assume you are correct that all explanations of the current warming have fallen flat. Well, there still HAS to be a theory that can explain massive Earth warming that does not involve human activity. Why? Because there have been NUMEROUS episodes in the Earth's past which involved MASSIVE amounts of warming. Many of these episodes occurred before humans existed.

The theory of AGW is thus fatally flawed to me. It's a fact that the Earth goes through cyclical warming and cooling periods. These processes are poorly understood as you point out. Yet, this minor warming period is widely believed by adherents of AGW to be mostly manmade. How can anyone possibly know that without understanding the natural processes that have caused previous warmings and effectively rule those causes out? You can't rule a factor out until you've identified it.

See my point?

No I don't get your point because it leaves out a critical point, but let me go through point by point.

I was careful to point out that Tim is a computer modeler. That means he has experience with the models, which is more qualified than either Evans or I am. What I do not know is whether Lambert has published peer reviewed articles on climate. If he has, then he blows Evans away completely. If not, then he at least uses actual data and cites sources, which is what scientists do, rather than merely make broad, definitive statements without backing like Evans does. But yes, I pointed out everyone's relative qualifications and said that whatever anyone's qualifications, keeping to the data is key.

Next, the predictions from the models were not vague. Stratospheric cooling within overall warming was a pretty specific prediction and one that is the real signature of carbon dioxide caused global warming. It was Evans who brought up distinctive "signatures." I was pointint out that he was dead wrong about that signature. Increased snowfall at the poles leading to thickening ice sheets followed by thinning is not vague. It is a complex prediction...and has come to pass. Many of these predictions are not just generated by some random computer out there. There are actually only a handful of these models (I know there is one running at Columbia because that is where my wife works) and the predictions I am talking about are pretty much consensus predictions. Look, making predictions then seeing if they come true is how science works. ANY science. It is what I do every day. By any scientific standard, AGW is very well supported by the evidence. Keep in mind there is not one single peer-reviewed article that presents evidence contrary to AGW, while there are hundreds presenting supporting evidence. When you are a scientist that TELLS you something.

Now as to your final point. No one has ever denied that there are climate fluctuations due to natural causes. If you had actually read the Lambert paper (sounds like you didn't) you would have seen that scientists have already compared natural warming vs. AGW and AGW is the only way to explain the current warming. It is the figure that shows each continent separately as well as ocean vs. land. Furthermore, I suspect you haven't even looked at the basic data showing warming (something even Evans admits is happening...at least sometimes). The amount of warming today is unprecedented as is the amount of carbon dioxide in the atmosphere. The RATE of warming is unprecedented, as is the rate of increase of CO2. These have been unprecedented over 5 million years that they can study. Let me say that again: in the entire history of earth that scientists can study (5 million years), there has never been anywhere near this much carbon dioxide in the atmosphere, nor has there been a warming event that has happened this fast. That is two unprecedented events that have never happened in the entire period scientists have been able to study. That indicates something different is happening. AGW explains these two unprecedented events well.

Some deniers talk about the Medieval warming as evidence that this has happened before. That warming was smaller and slower than the current warming. Rate is a big thing in the current warming. It is SO MUCH FASTER than anything that has happened in 5 million years.

No natural cause can explain that unprecedented rate of change. AGW does explain it and it has made predictions about what will happen that have largely come to pass as predicted or have come to pass FASTER than predicted. No amount of denial can change all this.

Mole, I guess you're acknowledging that the climate has changed in the past due to natural factors we don't fully understand.

Because now you're saying it's the RATE of warming that's unprecedented and unnatural.

Yet, I've read that it has stopped getting warmer, and Revkin in the New York Times recently wrote that models now suggest it won't start warming again for a decade.

So, when did this supernatural (or, if you prefer, anthropogenic) rate of warming occur? We know it wasn't between 1940 & 1970. So, are you talking about 1975-1998? If not, when? And how much warmer did it get? What was the rate? And what was the second fastest rate of warming scientists know of?

Just curious.

Mole, you wrote this: "Look, making predictions then seeing if they come true is how science works. ANY science. It is what I do every day. By any scientific standard, AGW is very well supported by the evidence."

Generating hypothesis and testing them through experimentation is at the heart of the scientific method. Climatology is not as rigorous as say, Chemistry, because it's hard to have controlled experiments. Chemists don't rely on models as much as climatologists because they can experiment. Similarly, new medicines are tested on actual subjects with rigorous controls, not through models.

I'm not saying that makes climatology not a science. But, we need to be careful about how much weight we put on models. If there was a truly reliable climate model out there, we'd know about it. It doesn't exist. There's too many variables and unknowns. Models have a hard time RECREATING PAST CLIMATE.

I'm not saying AGW doesn't have some logic to it. I just think it's vastly overstated. My biggest problem with it, is that the media and advocates have designed it to be unfalsifiable. There has not been a single major meteorological event in the last 20 years that hasn't been used by someone as evidence of AGW. At some point, a theory that is supported by everything stops becoming a theory and becomes more like a religion.

Look at the damned data I showed. If you don't do that, don't even pretend you understand science. And don't even pretend that anyone has ever said there isn't natural fluctuation.

Let me say it again. The amount of C02 in the atmosphere is unprecedented PERIOD. There has never been a point in the last 5 million years when it has been this high. Temperature is also high. The rate of change of BOTH is unprecedented and their rate of change match. Anyone with even the slightest common sense will realize that something unusual is happening. The question then is WHY is it unusual. The current warming started really being noticeable in the early 20th century, though even in the late 19th century a few meterologists who were compiling long term records noticed changes. The rate of change during this period was rapid, but not definitively unprecedented. The first clear articulation of anthropogenic global warming was from the 1950's where the similarity in the rate of increase of CO2 and temperature was clear. This was when the science of global warming really started...around the time DNA was first being studied in earnest. The science is not new.

There is a clear inflection point in both the CO2 and the temperature curves around the 1970's. After that inflection point we are in an unprecedented rate of change for both. Don't know why you pick 1988 because the curve continues to have that abnormal rate of change to this year. No other source of CO2 can account for this. And, as the graphs I show you which you clearly didn't look at indicate, no natural causes can fully account for the temperature increase. Only when anthropogenic factors are included can the change be accounted for.

As to using meterological events as evidence for global warming, NOT ONE SINGLE SCIENTIST has EVER used a single meterological event in that way. Deniers do that every time there is single day it is unusually chilly. Scientists know full well that individual meterological events are single data points and it is only the overall pattern that is significant. So please don't lie. You know scientists don't do this. Or you damned well should.

Let me be clear. If you continue to ignore the data presented here and in what I cite, don't bother commenting. I get sick and tired of the either ignorance or actual dishonestly that deniers display. The data are pretty damned clear and have become more and more solid each and every year. Not one single peer-reviewed paper has ever been published in any jounral that presents even one datum that contradicts AGW. By contrast hundreds of peer-reviewed papers have been published supporting AGW. Yet you, in all your "wisdom" (and apparent ignorance of the data) seem to know better. That sounds borderline delusional on your part.

mole, the squid has some interesting points, here. He asked you two direct questions to which you responded with taunts and threats. The were: what exactly is this unprecedented rate of climate change (as in degrees per year, say) and what is the second most rapid case on record. I looked through the tables you provide and didn't find the answers to these questions. So, do you know? Is rapidity of climate change rate even a figure that's been studied or recorded historically or is it a concept that was brought into play after climate change panic became a dominant theme? I don't know the answer, I'm just asking because you didn't answer him.