One Picture Says it All

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.

Perhaps I need to explain basic math. The rate of change is the slope of the graph at a given point. Look at the graphs of either carbon dioxide over time or temperature over time and observe how steep the curve is at any given point. That steepness is the rate. To my eye looking over the data graphs, including those at NOAA and NASA, there is no period where the steepness of the curves are anywhere close to the modern global warming event. The nice thing about scientific data is that anyone with basic knowledge can interpret it. Give it a try.

But you certainly don't have to take my word for it or do it yourself. Here is a piece on the unprecedented (in the past 650,000 years) levels and accelerating rate of carbon dioxide. And here is an extensive discussion of the issue (warning: PDF).

The most rapid warming events in the past followed ice ages. These changes took place over approx. 5000 years. The rates I see (roughly) are:

current warming: .74 degrees C in 100 years (mostly in the last 25 years and occurring at an accelerating pace, but let's keep the .74/100 as our rate). That means over the last 100 years the earth has seen a .0074 degree C increase per year on average. Keep in mind this very much underestimates the current rate because 75 of those years was much slower and the last 25 years much faster. But let's accept an underestimate of the current rate just to be conservative.

average warming after glaciations range from 4-7 degrees over 5000 years. Let's again be conservative by overestimating this (and simplify the calculation) by calling it 10 degrees over 5000 years. That is a rate of .002 degrees C per year on average.

This means that the current rate of change is MORE THAN three times the absolute FASTEST ever seen before. Keep in mind I deliberately underestimated the current rate and overestimated the post glacial rate. In itself, this three fold higher rate than ever seen before in the geological record would be worrisome, but not hugely worrisome. But keep in mind that the .002 degrees per year is the FASTEST ever seen before while the .0074 degrees per year is still accelerating.

But again, don't take my calculations at face value. Read the links I gave above and go to the NOAA and NASA websites and look at the raw data. That's what I do frequently. You can also see this breakdown of how no natural influence on climate can account for the current change (thanks John Mashey!).

[Editor's Note: Denial Drivel Deleted. Statements made without citation or actual data will be deleted. Statements made with citations that do not show actual data will be deleted. This is science, folks, not religion. For those curious about the denial arguements presented, most of them are listed here with refutations.

Oh...and to the author of the comment, continue to cite unsupported and disproven denial lobby crap and you will be banned. As to the numbers I used, if you actually HAD read the links you would have seen they are not eyeballed from a graph but are the standard numbers used.]

[Editor's Note: Further Denial Drivel Deleted. Statements made without citation or actual data will be deleted. Statements made with citations that do not show actual data will be deleted. This is science, folks, not religion. For those curious about the denial arguements presented, most of them are listed here with refutations.

Oh...and to the author of the comment, continue to cite unsupported and disproven denial lobby crap and you will be banned.]

... don't rely on the need to ban contradictory opinions. Either the theory can withstand criticism or not. If it withstands the criticism, there's no reason to ban other opinions. Acts of censure are made by tyrants and scoundrels.

Look, I presented data, citations and calculations BASED on data. You repeatedly give, as you yourself just admitted, opinion without any data, citations or calculations. All you do is give opinion, much of which has been completely debunked, some of it YEARS ago. I counter with more data, citations, etc. You repeat the same debunked opinion and talking points.

So, yes, you are right that science doesn't work this way. Science works by a comparison of data and citations. Let's do this: Cite one peer-reviewed paper that contradicts anthropogenic global warming. Can you do it? Have you ever even read a peer-reviewed article? Seriously. We really ARE talking science here, not your opinion. If you refuse to actually discuss data (a great deal of which I presented to you or referred you to) then your opinion is worthless. In science, opinion without data is not relavent. So play by the rules you set down: discuss science or get out. At the very least read what I refer you to because if you had you wouldn't have made a fool of yourself regarding the calculations I made, which were done using actual known data in the references I gave you and which I intentionally calculated to favor your opinion as much as I could...and STILL debunked your claim.

So once again: argue based on actual data and scientific information, NOT your ill-informed opinion.

Mole, what the heck is Thomas Friedman talking about in his piece today:

http://www.nytimes.com/2008/08/03/opinion/03Friedman.html?_r=1&hp&oref=s...

He wrote:

Their last drilling project here, which was completed in 2004, focused on the layers 14,500 to 11,000 years ago. That project is already causing a stir in the climate community. In an article just published in the journal Science Express, Dahl-Jensen’s team wrote about how it had discovered from the ice cores that the atmospheric circulation in the Northern Hemisphere over Greenland “changed abruptly” just as the last ice age ended around 11,700 years ago.

It seems to have been driven by a sudden change in monsoons in the tropics. The change was so abrupt that it warmed the Northern Hemisphere over Greenland by 10 degrees Celsius in just 50 years — a dramatic increase.

That can't be right, can it? I asked you for the second fastest rate of current warming after this one and your graph had no mention of this? You talked about warming over periods of 5000 years.

Or is the Northern hemisphere not global enough, and your graph ignores local aberrations, like 10 degrees warming over half the planet?

First off I haven't read the paper in Science Express yet (I suspect you haven't either) and I don't have access here at home. If I have a chance I will access it at work. But I have two comments.

First, you left out the rest. From the same article:

Some climate-change deniers would say that this proves that mankind is not important in changing the climate. Climate change experts, like Dahl-Jensen, say it’s not so simple: The climate is always changing, sometimes very abruptly, so the last thing that mankind should be doing is adding its own forcing actions — like pumping unprecedented amounts of greenhouse gases into the atmosphere. Because you never know — you never know — what will tip the balance and send us hurdling into another abrupt change ... and into another era.

So whatever else this new data suggests, it doesn't negate what has been shown about AGW.

Now, compare an El Nino year with a La Nina year. The differences are quite extreme. These are localized (both in time and geography) changes that can be quite rapid. One controversial theory that applies to the same region (Greenland) is that mini ice ages and warming trends have occurred locally due to the breakdown and reappearance of the North Atlantic Current. This was the premise (hugely exaggerated) behind that carppy movie about climate change. So you are not talking about global changes but regional. That said, the 10 degrees in 50 years sounds dramatic and sounds faster than the end of the Medieval Warming and beginning of the mini-ice age, though I'd have to take a closer look at the data. And I suggest you do as well.

For what it's worth, I don't take the NYT as all that great on science. I have found major errors in their coverage of molecular biology (right down to once claiming RNA was the building block from which DNA was made, or some such nonsense). So I personally would need to judge from closer to the primary material. Which I will try to get to, work permitting.

Mole, Friedman's last paragraph is interesting for a whole host of reasons. Let me put it up again (emphahsis added):

The climate is always changing, sometimes very abruptly, so the last thing that mankind should be doing is adding its own forcing actions — like pumping unprecedented amounts of greenhouse gases into the atmosphere. Because you never know — you never know — what will tip the balance and send us hurdling into another abrupt change ... and into another era.

Does anyone really know what the last thing we should or should not be doing when it comes to the climate? I don't think anyone is remotely capable of answering that question. Friedman's scientist suggests no "forcing actions."

What I've been trying to argue this whole thread is that no one knows the ratio between CO2 and warming. The theory that CO2 causes warming is sound, but how much warming for every part per million? What's the ratio? No one can answer that.

Friedman wants no forcing actions - how much CO2 is a "forcing action"? He doesn't know.

For all we know the CO2 we've put in the atmosphere has been a net positive. But, again, no one knows.

Wait a moment. Keep in mind that Freidman isn't a scientist. That is why I went to the National Geo article where they dwell more on what the scientists involved actually say, and also why I am going to be fairly restrained in any conclusions I make until I can either look at the actual article or discuss it with climate scientists. I do suggest you do the same.

As to "no one knows," that really isn't true. There are three planets that can be compared and there are hundreds of thousands of years of data where gas concentrations can be correlated with temperature. Let me remind you that what is happening was broadly predicted in the 1950's. The system is complex, which means there are uncertainties. But we do know that if you pump carbon dioxide into the atmosphre you WILL get warming. That is physics, as I said before. We pumped carbon dioxide into the atmophere and, to no one's surprise except the deniers, we got warming. No other source of the warming has been detectable. Volcanic effects have a totally different signature, yet Rush Limbaugh continued to claim that was the cause for years after it was debunked...and he used numbers he KNEW were wrong. Solar output also has a different signature and has not been able to explain what has been going on. Several hypotheses have been put forward about water vapor's effect (my wife's field, I should mention), and those have been ruled out. The only influence that fits the bill is carbon dioxide. Every single graph I have looked at other than very regional ones show the same thing. The biggest glitch in the AGW theory, the one that I considered an genuine reason for doubt, was the satellite data not matching the surface data. But that was resolved two years ago when the satellite data was resolved into the exact kind of stratospheric cooling and tropospheric warming that is considered characteristic of carbon dioxide driven (as opposed to any other cause) global warming. That stratospheric cooling and tropospheric warming was very distinctive and the satellite data wound up showing that. Surface data (land and ocean), stratospheric data and tropospheric data together point to carbon dioxide as the culprit.

So, no one knows the details definitively. I never claimed they did. In fact you have led me to data that shows I probably was wrong about the tipping point. But no climate scientist doubts that carbon dioxide generated by human activity is responsible for a significant part of modern global warming.

Mole you ended your last post with:

But no climate scientist doubts that carbon dioxide generated by human activity is responsible for a significant part of modern global warming.

Can you define "significant"? Everyone is vague on this point. The NY Times editorial page is vague. The IPCC says there's a 90% certainty that human activity is responsible for most of the observed warming. BTW, what exactly is 90% of most?

No scientist is willing to say that an additional amount of CO2 of X parts per million in the atmosphere will cause a global temperature increase of Y. They don't say it, because they don't know the answer. Too many variables and misunderstood phenomena muddle everything. There are too many bad predictions from the 1990s.

I think the theory of AGW is strong enough that it deserves money so it can be further studied and better understood.

I don't think there has been enough of a reason offered by anyone to justify spending a single dime trying to limit CO2 emissions.

You labeled me a "denier" earlier in this thread. I am not. I'm a realist.

Finally, Friedman's article said a sudden change in monsoons might have caused the 10 degree warming in the Northern Hemisphere over a 50 year period. Do not use this as supporting evidence for the "tipping point" theory in AGW.

Evidence of a potential tipping point for a completely different phenomena should not be used to justify tipping points in other/unrelated phenomena. If I'm sitting in a room that's getting warmer - it might be because the thermostat is on, and the room will incrementally get warmer unless I turn off the thermostat. There's no tipping point involved. But, if the room I'm in is on fire, it could still get warmer only incrementally for a while, but there are definite tipping points where the temperature can jump 100 degrees in seconds.

Just because fires and thermostats cause warming, doesn't mean they both have tipping points.

Just because monsoons and AGW might cause warming, doesn't mean they both have tipping points.

They are different phenomena.

Complex systems aren't like a simple chemical reaction, as you well know. So the exactness you imply you require is impossible in a complex system. In fact, the entire field of chaos theory (which I know little about personally) was developed to deal with systems inherently too complex to be amenable to exact predictions. In other words, although Newtonian physics believed that if you knew perfectly the initial conditions of a system you could predict the development and ultimate state of that system, in real complex systems you cannot have that exactness even IF you know the initial conditions perfectly. This applies even to things like the heartbeat, which also is subject to chaos theory. And yet cardiology works.

In fact all modern physics has even more fundamental uncertainty than even chaos theory. And yet we still understand how physical systems work.

I called you a denier because that is how you argued, using denial lobby arguements that were debunked years ago. But that doesn't mean that I am against debate. The original question from mrme (who IS a denier) was treated seriously, and in fact led me into considerable research (dealt with in another diary). Your question on the new Greenland data was taken seriously and does lead to a new appreciation on my part for the theory of tipping points. And I am hoping to do more to follow it up. Thanks to your question, this blog is one of the first discussing this new data from what I can find.

Which leads to that part of your question: tipping points. To what degree does evidence for one kind of tipping point support another kind of tipping point. That is unclear to me, at least. But keep in mind that the system being looked at is the same. The atmosphere and ocean are the main elements of the system which are acted on by the sun. So whatever the perterbation, the system is the same. The climate is a system that responds to perterbations the same way whatever their source. If you read the National Geo article you would see that the tipping point they seem to be identifying involves the change in an atmospheric current. The way these things are analyzed is to explore how the whole complex system evolves given specific perterbations. They all contain potential tipping points. The idea of a tipping point is not unique to any particular climate change system. But as far as I am aware no tipping point has been visible in the climate record to date...or at least nothing that was clearly a tipping point. So this could be the first demonstration that a tipping point can happen. The system is the same. It isn't a different climate. It is the same system. So it sheds light on what can happen to the system if perturbed too much. We are perturbing it excessively.

Which brings us to the evidence of how much we are contributing vs. natural effects. The main graph for that is this:

Blue regions are predicted range based on all natural causes. Black lines are actual temperature observations. Black lines deviate from blue ranges considerably. Pink regions are the predicted ranges if human generated carbon dioxide is added to the prediction. Only then does prediction match observation, and fit it well.

Not one piece of evidence has ever been published in a peer-reviewed journal has contradicted this. A great deal has been published that supports it. Again, the satellite data once seemed at odds with the predictions...but was resolved 2 years ago. As a scientist, that's where I put my money, particularly since the results will affect my son. When there is as strong a consensus in science as there is on global warming, it is really a damned good idea to listen to them.

I have also long argued that the things the US needs to do to adapt and deal with global warming can often be positive in themselves. Energy efficiency almost always is beneficial and saves money in the long run...and combats climate change. Altering our energy policy to get away from fossil fuels allows us to create local jobs and a more efficient energy network because fuel and power don't need to be transported as long distances...and combat climate change. America has dealt with crises from our earliest foundation through WW II. Shying away from those crises either through denial or surrender has never really been our way until recently. Now all of a sudden we are too weak to deal with a crisis? I don't buy it. We always came out stronger when we faced up to the crisis and dealt with it face on. And I believe America can do it now if we stop the denial and procrastination and face up to it.

Mole, what is the source for those temperature charts? Lambert had them in his piece debunking Evans that you linked to earlier in this thread and I pointed out in my post that you took down that it's the most compelling graph - but it's not sourced.

As for your ode to problem-solving America, I'm still not sure AGW is a problem.

Look, if CO2 was causing cooling, I'd be a lot more concerned. Global cooling would jeopardize agricultural output. AGW does not. I'm not sure a couple degrees of warming is bad.

If I accept cooling would be bad, and warming would be bad, than that means the Earth's ideal temperature was in 1950. Why should I believe that? How can anyone know what the ideal tamperature for the Earth is?

The methodology is in supplementary materials, appendix 9c.

As to the effects, keep in mind this will be about the hottest human civilization (probably not humans as a species) has had to deal with. If (and let's leave it at if for the moment because I have other things to do than argue this infinitely) sea level rises and summer temperatures over 120 degrees F become the norm, I'm willing to bet you won't be so happy (assuming you live near the coast like I do...and remember you have to take into account a higher storm surge as well). And we aren't talking ideal temperature for the "Earth." We are talking ideal temperature range for our civilization. Have you read Jared Diamond's book Collapse? Good book, deals with broader issues that include this kind of thing. Worth reading and written by a very smart guy. My favorite book by him is unrelated: Guns, Germs and Steel. But Collapse is more appropos to this discussion.

Found a National Geographic blurb on it.

First thing to note is that it is simlpy a single geographic point. So it shows a regional change...but it is not clear what it imlpies for global. I'd need more info than this to know. The data shows some interesting shifts over the Atlantic but don't show how that fits into a global pattern. Again, consider how dramatic shifts from El Nino to La Nina are over the entirety of the Pacific.

That said, it might lend support to one of the aspects of AGW that I have been skeptical of: tipping points. The idea of a tipping point is that there are certain changes that can dramatically and rapidly change climate to a whole new stable state. Some scientists have hypothesized various potential tipping points, but it remains a very controversial theory. It is a variation on AGW that I have been skeptical of.

This new data, from what I gather in the National Geographic article, suggests that tipping points DO occur. In essence it may be catching one in action and suggests some possible mechanisms (regional changes in atmospheric circulation).

What does this imply for AGW? As I said above, that isn't clear yet. But if it shows a GLOBAL rather than REGIONAL shift (as yet not clear), then it suggests that current AGW may be in line with past dramatic tipping points. It doesn't change the fact that no natural changes can be detected to account for the scale of is currently happening. It also suggests the scientists that hypothesize that we are heading for new tipping points may be correct (somewhat to my surprise) and we may see a rapid acceleration of global warming. That is not good since tipping points will make adaptation even harder.

The rate and extent of current climate change are, I have argued, unprecedented. Do I have to change that? In a way maybe, since I have been discounting the role of tipping points. In a way no because if the rate is unusually rapid (though not unprecedented if the hypothesis of tipping points is real) AND the temperature itself is highly unusual (considerably above the peak of the Medieval Warm period and still going up). So the key questions are: a.) how close to the peak are we? and b.) are the scientists who believe we are approaching tipping points right? Will we hit a tipping point in addition to the current trend?

Let me re-emphasize that the scientists you are referring to are not deniers. To quote the National Geographic blurb I cite above on the article:

"We are changing the climate," with greenhouse gas emissions, said study co-author Dorthe Dahl-Jensen, an ice and climate scientist at the University of Copenhagen, Denmark. "We are moving out of that stable state now."

So you are right that this new data may change my personal statements because of my previous skepticism about tipping points. I may have to start accepting the tipping point hypothesis based on this new evidence. But the new data doesn't seem to be altering scientists' acceptance of AGW, even the ones who have generated the new data.