Need proof of Global Warming

[jshore]

[QUOTE=intention]
jshore, good to hear from you as always. You have made a claim which illustrates clearly a recurring problem with climate science.

This involves the citation of previous claims as “facts”. For example, you say we know “quite accurately” that the effect of doubling CO2 is approximately 3.8 watts/square metre change in forcing.
[/quote]

Nice to hear from you, intention. Actually, the “problem” you express is not unique to climate science. It is found in all sciences…Old settled knowledge is not always easy to come up with original references for.

My questions are:

1. If we know the CO2 forcing “quite accurately”, why do you say that the “~3.8” w/m2 figure is only approximate?

2. Where did this “~3.8 w/m2” figure come from? (Not who cited it, everyone cites it, but who showed scientifically that this is the correct figure, and how did they calculate it?). The IPCC TAR gives three different formulas for CO2 forcing (one of which uses 3.7 instead of 3.8 as you do), but all they say is that they are “similar in form to” or “based on” or “with a form similar to” earlier studies. They don’t say why they are different from the earlier studies. They don’t say why they were changed. They don’t say who changed them. They don’t say why they were based on those studies rather than other studies. The main “earlier study” referred to is James Hansen’s study of forcings using a very early GISS model … color me unimpressed. Results from an early climate model don’t give … what was your term … “quite accurate” scientific results. Yes, they give results, but those results cannot be simply assumed to be “quite accurate” as you are assuming.

I think this illustrates exactly my point of exaggerating uncertainties. As near as I can tell, this whole riff is based on the issue that one source says 3.8 W/m2 and another says 3.7 W/m2. Are you seriously concerned about the fact that the number is not known down to that accuracy?!? When I said that it is known quite accurately, I meant to something on the order of several percent. That is plenty accurate enough. It is kind of amusing to watch you make a mountain out of the molehole of a difference between 3.7 and 3.8!

Also, I am not sure why you are talking about climate models since I think you know that these calculations are based on radiative transfer models. While they might be built into climate models, that doesn’t really make them the results of climate models in the same sense that a prediction of the temperature change to a change in CO2 can be the result of a climate model.

Now, you might claim that this CH4 forcing calculation is scientifically based. To me, it is just a heuristic calculation with no known antecedents.

When you come back with answers to those questions, when you can identify the source of the CH4 calculations and all the rest, we can see how scientifically solid your claims are.

Well, all because you don’t know where it comes from doesn’t mean that nobody knows. Frankly, I have better things to do than to participate in your “auditing” of an entire field of science, down to some of the oldest and most settled pieces, because you don’t like the results and particularly the policy implications of those results.

In general, whether one is in the logarithmic regime, the linear regime, or somewhere in between depends on how saturated the bands are that the particular molecule absorbs at.

PS - Many of these wonderful, “quite accurate” things come out of the IPCC. There’s a good discussion of the so-called “review process” of the IPCC here, so you can see just exactly how well reviewed this stuff actually is. The IPCC reports are supposed to be among the most carefully reviewed documents in existence … but in truth, the review is pathetic, salient points are glossed over, and opposing views are simply ignored.

As I noted, the conclusions of the IPCC have been endorsed by the respected organizations in the scientific community, such as the U.S. National Academy of Sciences. It is understandable that when an issue is as politically contentious as climate science is, there will be some people who will dissent. One sees the same thing happening with evolution…You can check out the movie documenting all the supposed ways in which the intelligent design proponents have been persecuted here. (Strangely enough, Roy Spencer, one of the most respectable of the so-called “climate skeptics” from the point of view of his publication record and general standing in the scientific community is a proponent of intelligent design also.)

[brazil84]

[QUOTE=jshore]
You can go on to read about the plant and animal extinctions, which would likely also have widespread impacts on us.
[/quote]

This is getting a bit old. Does the article say that sea level rise will be a threat to billions of lives or not?

I doubt it.

Looks to me like Sentient Meat’s claim was not based on “peer-reviewed evidence,” but was simply speculation. A worst case scenario, if you will.

Which is why it was reasonable of me to speculate about the worst case in the opposite direction.

That is true when you harness them well. However, when you blindly

I have no idea what your point is.

[intention]

jshore, you say:

[QUOTE=jshore]
I think this illustrates exactly my point of exaggerating uncertainties. As near as I can tell, this whole riff is based on the issue that one source says 3.8 W/m2 and another says 3.7 W/m2. Are you seriously concerned about the fact that the number is not known down to that accuracy?!? When I said that it is known quite accurately, I meant to something on the order of several percent. That is plenty accurate enough. It is kind of amusing to watch you make a mountain out of the molehole of a difference between 3.7 and 3.8!
[/QUOTE]
Actually, it is amusing to watch you misunderstand me. What makes you think the difference is merely 3.7 vs 3.8? The IPCC alone gives three formulas, which differ by 6% up to the present. By the time of doubling, the difference will be 8%. This is well outside your “couple of percent”.

But that wasn’t my point. My point is that, although the IPCC gives figures that differ by 6%, we have no scientific study that says that any of them are right. All we have is Hansen’s 1988 claim, based on a climate model, and “updated” in unknown ways by unknown authors.

Next, you say that these are based on “radiative models”, and you wonder why I am talking of climate models … well, it is because (as you would know if you had read the reference I cited) the IPCC says that they are based on Hansen’s study involving the GISS climate model. That study is entitled “Global climate changes as forecast by Goddard Institute for Space Studies 3-dimensional model”, which is not a radiation model, it is a climate model. Don’t like it? Sue the IPCC.

Finally, you say:

[QUOTE=jshore]

[QUOTE=intention]
Now, you might claim that this CH4 forcing calculation is scientifically based. To me, it is just a heuristic calculation with no known antecedents.

When you come back with answers to those questions, when you can identify the source of the CH4 calculations and all the rest, we can see how scientifically solid your claims are.
[/QUOTE]
Well, all because you don’t know where it comes from doesn’t mean that nobody knows. Frankly, I have better things to do than to participate in your “auditing” of an entire field of science, down to some of the oldest and most settled pieces, because you don’t like the results and particularly the policy implications of those results.

In general, whether one is in the logarithmic regime, the linear regime, or somewhere in between depends on how saturated the bands are that the particular molecule absorbs at.
[/QUOTE]
jshore, I love how when you get to a claim you can’t back up, suddenly it’s not important, you have better things to do … either you back up your claim that these numbers are scientifically known to be accurate, or you don’t. You made the claim, but gosh, very sorry, now you have much better things to do than back it up.

Frankly, I didn’t mind it the first couple of times you did this, but it is getting kind of old … I respect your scientific knowledge, but I despise your habit of suddenly getting too busy to answer when the going gets tough. Not only that, you want to claim that I’m asking you to audit the entire field of climate science, when all I’m doing is asking you to back up your claim.

You made the claim, my friend, that the radiative forcings are scientifically and accurately known to within “several percent” … since you can’t (or won’t) back your claim up with the results of even one study, can we assume that you are retracting it?

w.

[intention]

[QUOTE=jshore]

[QUOTE=intention]
Third, I know of no peer-reviewed science that shows that CO2 poses a “significant threat” to anything. I do see lots of scientists claiming that in the media.
[/QUOTE]
Plenty of scientists claim this not only in the media but in their peer-reviewed papers.
[/QUOTE]
Cite? I find lots of scientists saying that CO2 “may” do this or “might” do that or “could” do the other in peer reviewed papers, which of course means nothing. I find peer-reviewed computer models that “predict” that a significant fraction of the world’s species will go extinct if the temperatures rise by 0.8°C (which is a joke, we’ve warmed that much in 150 years without losing a significant fraction of our species).

But I haven’t found a scientist saying that it actually does pose a “significant threat”. Doesn’t mean that it doesn’t exist, there’s a lot of garbage out there that is “peer-reviewed”, just that I haven’t found it.

w.

[intention]

SentientMeat, I appreciate your taking the time to respond. You say:

[QUOTE=SentientMeat]

[QUOTE=intention]
First, we have no evidence at all that the rate of sea level rise has changed in the slightest. None. Zero.
[/QUOTE]
But you accept the premise that higher temperatures cause water to expand, yes?
[/quote]
Certainly it does. Unfortunately, we don’t know how much higher the temperatures will get.

More importantly, we don’t know how long that increased temperature would take to warm the oceans … but most everyone says it will be centuries, not years.

Finally, the fear is not supported by evidence, which is what I said in the first sentence. The OP is looking for “proof” (which I assume means real observational evidence) of anthropogenic global warming. There is no evidence that the historical rate of sea level rise is changing, so there can be no anthropogenic evidence there.

[QUOTE=SentientMeat]

[QUOTE=intention]
Second, the sea level rise of say eight inches to a foot per century (which we had last century) did not (IIRC) kill scads of people.
[/QUOTE]
But you accept the premise that rising sea levels threatens sea level homes, yes?
[/quote]
Sure. And earthquakes threaten Californians. Sea level has been rising and falling for a long time, without human intervention. The OP is asking for proof that humans did it. To date, there is none.

More to the point, you said rising sea levels would kill people. Unless you can cite me someone killed by sea level rise of an eighth of an inch per year, I’ll have to put that in the “no proof” category as well.

[QUOTE=SentientMeat]

[QUOTE=intention]
Third, I know of no peer-reviewed science that shows that CO2 poses a “significant threat” to anything.
[/QUOTE]
But without a mitigating mechanism, a rising CO2 concentration will eventually pose a threat, yes? I don’t think I’ve ever heard you suggest that concentrations of 1000ppm plus would not be dangerously high, only that there is some mitigating mechanism which will stop it getting so high.
[/QUOTE]
The problem is, while we can be pretty sure that human activities are having some effect on climate, we don’t know either how much, or how, we are affecting the climate.

In part this is because our data is so poor. The global temperature measuring network was put into place to measure temperature for weather (degrees), not climate (tenths or hundredths of a degree). We don’t have accurate records for historical levels of many of the known forcing agents (black carbon (BC), organic carbon (OC), biogenic aerosols, land cover changes, a host of anthropogenic aerosols, a host of anthropogenic GHGs, land use changes, anthropogenic dust, and many more). In addition, the fact that there are new forcing agents discovered every year (bacteria as cloud nuclei, plankton generated cloud nuclei, etc.) means it is very likely there are other forcing agents we are not yetaware of.

But even if our data were good, we don’t understand the climate. Yes, we know that there is cloud feedback … but exactly how and where is it happening? What is driving it? We don’t even know if the earth has an equilibrium temperature or not, and if so, how it is determined.

My own research has led me to the conclusion that more heat in the tropics –> more evaporation –> more clouds and thunderstorms. More clouds and thunderstorms cool the earth in a variety of ways, including cutting down the solar energy entering the system.

This, of course, implies that the temperature response of the tropics (and thus the earth) is not fully determined by the change in forcing. In part, it is determined by the rate of cloud increase with temperature. An equilibrium is reached when increasing temperature (from more forcing) meets decreasing sunlight and increasing cooling (from more clouds from increasing temperature from more forcing). Unfortunately, however, we don’t even know the rate of cloud increase with temperature in sufficient detail to even broadly constrain the numbers …

And at the end of the day, it means we don’t know what would happen even with 2X CO2. Despite the fatuous claims of the modelers, we understand far too little of the control mechanisms of the global scale heat engine that we call the climate to make such calculations.

All the best,

w.

[intention]

Key Lime Guy, you raise an interesting point when you say:

[QUOTE=Key Lime Guy]

Anyway, my basic point stands, which is that warmer temps doesn’t necessarily mean less ice.

Do you have access to some alternative theory of thermodynamics we should all be aware of?
[/QUOTE]
The question is interesting because it points out how climate is often counterintuitive. For climate, you can be misled by simple physics and thermodynamics. For example, in recent years the thickness of the Antarctic Ice Cap has been increasing in many parts.

Why? Well, it hinges on the fact that a warmer world is a wetter world. Increased temperatures cause more evaporation. Since what goes up must come down, this means more rain and more snow. Or at least that’s the current scientific explanation for the increasing Antarctic ice depth.

It is a perfect example of why people who cite “simple physics” are often wrong when it comes to climate. Regarding climate, as near as I can tell, nothing is simple.

My regards to you,

w.

[jshore]

[QUOTE=brazil84]

This is getting a bit old. Does the article say that sea level rise will be a threat to billions of lives or not?

I doubt it.

Looks to me like Sentient Meat’s claim was not based on “peer-reviewed evidence,” but was simply speculation. A worst case scenario, if you will.

Which is why it was reasonable of me to speculate about the worst case in the opposite direction.
[/quote]

That article talks about sea level rises of several meters per century and eventual rises of “tens of meters”. While I don’t have any handy-dandy chart of how many people’s current homes would be underwater for a given rise in sea level, I am willing to bet that a rise of that sort of magnitude would in fact impact the lives of hundreds of millions of people, if not over a billion. (Here are some images of what given sea level rises will do to various coastlines around the world.) Would you be happier if Sentient Meat said “hundreds of millions” instead of “billions”?

I have no idea what your point is.

My point is simply that you are talking about the wonders of economic growth and technology to help people but, in fact, by protecting the entrenched outdated technology of fossil fuels so they continue to compete in a market where the externalities caused by these fuels are not internalized into their costs, you and the others defending the dinosaurs of the fossil fuel industry are hampering the development of the new technologies.

[jshore]

[QUOTE=jshore]
(Here are some images of what given sea level rises will do to various coastlines around the world.)
[/QUOTE]

Just to give you a rough idea, look at the maps for Bangladesh and note that the 2003 population of that nation is ~147 million and the projected population of that country in 2015 is ~181 million people.

[brazil84]

[QUOTE=jshore]
That article talks about sea level rises of several meters per century and eventual rises of “tens of meters”. While I don’t have any handy-dandy chart of how many people’s current homes would be underwater for a given rise in sea level, I am willing to bet that a rise of that sort of magnitude would in fact impact the lives of hundreds of millions of people, if not over a billion.
[/quote]

I didn’t ask about impact, I asked about actual significant threat to peoples’ lives.

And I’m not going to ask again.

You were asked numerous times to produce a cite to a peer-reviewed article stating that CO2 emissions posed a significant threat to the lives of billions of people, due to rising sea levels.

Please just acknowledge that you have been unable to do so.

My point is simply that you are talking about the wonders of economic growth and technology to help people but, in fact, by protecting the entrenched outdated technology of fossil fuels so they continue to compete in a market where the externalities caused by these fuels are not internalized into their costs, you and the others defending the dinosaurs of the fossil fuel industry are hampering the development of the new technologies.

Let’s see if I have this straight: Are you saying that, in general, technological and economic growth will be greater if restrictions are imposed on CO2 emissions?

[intention]

[QUOTE=jshore]

[QUOTE=brazil84]
This is the last time I will ask you: Please cite a peer-reviewed article that says that CO2 emissions pose a significant threat to the lives of billions of human beings due to rising sea levels.
[/QUOTE]
Here is an article by Jim Hansen and co. in the Proceedings of the National Academy of Sciences that talks about the possibilities of extremely large sea level rises:
[/QUOTE]
Before y’all get too deep into the details of Hansen’s paper, let me note that PNAS has two very different tracks for “peer review”.

If you are not a member, it looks like this:

[QUOTE=PNAS]
The standard mode of transmitting manuscripts is for authors to submit them directly to PNAS. Authors must recommend three appropriate Editorial Board members, three NAS members who are expert in the paper’s scientific area, and five qualified referees. The Board may choose someone who is or is not on that list or may reject the paper without further review. A directory of PNAS member editors and their research interests is available at PNAS Member Editor Directory Search. The editor may obtain reviews of the paper from at least two qualified referees, each from a different institution and not from the authors’ institutions
[/QUOTE]
On the other hand, if you (or any one of the host of co-authors) are a member of PNAS, it looks like this:

[QUOTE=PNAS]
An Academy member may submit up to four of his or her own manuscripts for publication per year. Members must secure the comments of at least two qualified referees.
[/QUOTE]
Yeah, that sounds real rigorous, all right, pick your own two referees, they sign off, you’re in …

jshore, perhaps you think that getting two of your friends to sign off on your paper constitutes “peer review”. I don’t. That paper is not “peer-reviewed” in the conventional sense of the word, which is likely why it is published in PNAS, rather than in Nature or Science or Journal of Climate.

w.

[aptronym]

The problem with these threads is that all the major posters in this thread seem to be unable to separate out the different questions that constitute the debate on global warming.

(1) Is the Earth heating up? This is a very fundamental question, because all the subsequent questions are irrelevant if you cannot understand the answer to this one.

While I’m trying hard to exclude cross-thread hostility, I want to make it known that many posters who disagree with the IPCC on later topics also disagree with the IPCC on this topic. That is, if you don’t agree that the Earth is heating up, why the hell debate what is heating it up, and what heating up will do?

(2) If the Earth is heating up, what is causing it? Again, this is the next most fundamental question, because all the subsequent questions are predicated on this one. Furthermore, agreement on all the previous answers pretty much need to be agreed on before this can be settled.

And let me point out again that people who disagree with the IPCC on later topics primarily disagree with the IPCC on this topic. If you don’t believe that humans have caused a warming in the past, it’s not surprising you don’t believe that humans will cause warming in the future. It’s not a problem with the models that predict future warming; it’s a problem with not understanding the potential and limitations of everything leading up to those models.

(3) How hot will the Earth get if we do X? This is the next most fundamental question - the first two must be answered correctly, or the answer to this will be necessarily incorrect.

It’s also important to note that essentially, here is where the IPCC report and most other reports are skating into uncharted territory. This is not unlike predicting where the stock market will be in 25 years as you plan your IRA - everyone is technically guessing, but some guesses are better than others.

(4) How much will it cost to fix the problem? This is the question that everyone wants to jump to, because it’s the most relevant. However, it’s unsurprising that if you don’t get the first three questions right, you end up with a horrendous diversity of opinion on this question.

Obviously, if you don’t believe the Earth is warming, then humans can’t be responsible, and thus, the cost of anything we might do will outweigh the benefits.

I strongly believe in answering the questions in the right order.

For the OP, the answers to the first two questions (1) and (2) can be found in the IPCC report. It contains the most complete information that we had as of early 2007, although the IPCC is admittedly not the best organization to be doing this. If you have questions about the IPCC report, you can always refer to the NAS report, which supports the IPCC. The IPCC report is the most complete; the NAS is the most reliable.

And if you’ll forgive the self-promotion, I took the time to write out a summary of what I consider to be the strongest and most reliable evidence for anthropogenic global warming - points (1) and (2) above. And by request, no answer relies on reconstructions of past temperature.

Summary of global warming’s basic principles

Now for question (3), I actually mildly disagree with jshore - the IPCC projections are reasonable, but they are not peer-reviewed in any meaningful sense. Projections of the future can’t really be peer-reviewed, because it’s unquestioned that if you do what they did, you’ll get the same answer they did. The real question is whether what they did is right, and that’s a very tough question to answer without just waiting to see.

That isn’t to say I agree with intention and brazil84, either. Both of these posters are arguing that the IPCC has (3) wrong because the IPCC has (2) wrong. Both intention and brazil84 are wrong about point (2), so it’s not really their fault they’re also wrong about point (3). If they were right about (2), they’d also be right about (3).

One poster (who I can’t find right now) stated that if you read the IPCC report (specifically, WG2), you’ll note that there are no major impacts on human well-being until about a +2.5[sup]o[/sup]C warming. This is important to note not just because it’s what climatologists generally agree on, but because that’s smack in the middle of all the projections. If we do nothing differently (IPCC SRES A1F), we can expect that our temperature will rise by +2.4 to +6.4 [sup]o[/sup]C). If we stop burning fossil fuels right now and return to the Stone Age, we can expect our temperature will rise by +0.3 to +0.9 [sup]o[/sup]C. That gives us the two ends of the spectrum.

[Sam_Stone]

[QUOTE=jshore]
That article talks about sea level rises of several meters per century and eventual rises of “tens of meters”. While I don’t have any handy-dandy chart of how many people’s current homes would be underwater for a given rise in sea level, I am willing to bet that a rise of that sort of magnitude would in fact impact the lives of hundreds of millions of people, if not over a billion. (Here are some images of what given sea level rises will do to various coastlines around the world.) Would you be happier if Sentient Meat said “hundreds of millions” instead of “billions”?

My point is simply that you are talking about the wonders of economic growth and technology to help people but, in fact, by protecting the entrenched outdated technology of fossil fuels so they continue to compete in a market where the externalities caused by these fuels are not internalized into their costs, you and the others defending the dinosaurs of the fossil fuel industry are hampering the development of the new technologies.
[/QUOTE]

I find it a little disingenuous that you would use the IPCC as an authority when it suits, but then trot out a number that is completely at odds with the IPCC’s 4th assessment report when it bolsters your argument.

According to the 4th assessment report, the worst-case scenario (SRES A1F1) has global temperatures rising to between 2.4 and 6.4 degrees C by 2100, with a corresponding sea level rise between 26 and 59 cm. This is a far cry from ‘tens of meters’.

[aptronym]

And for the OP (if he’s even still reading this thread), I strongly object to watching An Inconvinient Truth to get any sort of facts on global warming.

Allow me to point out an example of Gore’s less-than-honest portrayals of global warming: he claims or insinuates that global warming could cause the glaciers to melt, and if the glaciers all melted, sea levels would rise by 20 feet. Which is perfectly true - except no scientist in their right mind expects all the glaciers to melt under even the worst-case scenarios. The IPCC projects 7 inches to 23 inches of sea level rising. So while Gore may be technically correct, the impression he gives in the movie is absolutely incorrect.

Science should not be learned from movies, speeches, or any other medium in which errors can be introduced with misspeaking or dismissed as misspeaking.

If you want to learn about global warming, I suggest you read, not watch. The IPCC report is online, and each section has a Summary for Policymakers which is meant for a non-scientific audience. The National Academy of Sciences’ Climate Change Report is also online, and has a non-technical summary for policymakers. Each summary is between 5 and 20 pages, and full of charts so there’s not actually much text.

[brazil84]

[QUOTE=Sam Stone]
I find it a little disingenuous that you would use the IPCC as an authority when it suits, but then trot out a number that is completely at odds with the IPCC’s 4th assessment report when it bolsters your argument.
[/quote]

Well, you gotta give him credit for trying to come up with some kind of response to the challenge. Even if at the end of the day, he fell short.

In any event, the point is this: If you want to argue that the worst case scenario for global warming is that billions of lives are significantly threatened, you have to concede that aggressive mitigation efforts could also prove disasterous.

So it’s not a simple decision situation where one choice dominates the other.

[jshore]

Thanks for your response, intention.

[QUOTE=intention]

Actually, it is amusing to watch you misunderstand me. What makes you think the difference is merely 3.7 vs 3.8? The IPCC alone gives three formulas, which differ by 6% up to the present. By the time of doubling, the difference will be 8%. This is well outside your “couple of percent”.
[/quote]

Please don’t invent quotes by me. I didn’t say “couple of percent”; I said “something on the order of several percent”. In fact, in the IPCC report, they have the current CO2 forcing as ±10% (for 90%-confidence error bars).

jshore, I love how when you get to a claim you can’t back up, suddenly it’s not important, you have better things to do … either you back up your claim that these numbers are scientifically known to be accurate, or you don’t. You made the claim, but gosh, very sorry, now you have much better things to do than back it up.

Frankly, I didn’t mind it the first couple of times you did this, but it is getting kind of old … I respect your scientific knowledge, but I despise your habit of suddenly getting too busy to answer when the going gets tough. Not only that, you want to claim that I’m asking you to audit the entire field of climate science, when all I’m doing is asking you to back up your claim.

You made the claim, my friend, that the radiative forcings are scientifically and accurately known to within “several percent” … since you can’t (or won’t) back your claim up with the results of even one study, can we assume that you are retracting it?

My source is the IPCC report, which lists the uncertainty in the current CO2 forcing as being ±10%. If you don’t like that source, you are welcome to produce evidence that it is not correct. However, just claiming that it can’t be trusted based on not liking what you can find out about how the value was determined isn’t good enough.

You should also remember that this is not a full-time career for me (as I vaguely understand it is now for you…Correct me if I am wrong…Whether it is a paid career, or just what you have chosen to do for fun in retirement, I honestly don’t know). So, I am not able to do infinite amounts of research on things like the evolution of the value for the forcing due to CO2 that is quoted in the IPCC report. I am more interested in using my time to keep up with issues that really have more legitimate contention like the climate sensitivity.

[intention]

aptronym, thank you for your clear exposition of the issues, which you see as:

1. Is the earth warming?

2. Why is it warming?

3. How hot is it likely to get?

4. How much will it cost to fix?

Let me lay out my answers to these questions, along with another important question you have not included.

1. Yes, the earth is warming, and has been for hundreds of years.

2. To date, we don’t know why. Your main argument (in your linked post) seems to be that, since modelers claim they can simulate the warming using (tuned) climate models with anthropogenic forcings included and can’t if they do not include anthropogenic forcings, this shows that the anthropogenic forcings must be the cause of the warming.

If you don’t see the logical problem with that argument, let me know and I’ll explain it to you.

This logical flaw in your argument is shown dramatically by the lack of warming this century. This was not predicted, even by the model runs which include anthropogenic forcing … which means of course that either the natural forcing of those models, or the anthropogenic forcing of those models, or the other assumptions and parameters of the models, or all of them, must be wrong. Which, of course, invalidates your argument.

3. How warm will it get? See #2. However, even if you believe in AGW, you still have the problem of the wide, wide range of estimates of climate sensitivity. If they are at the low end, it won’t warm much at all. If they are at the high end, it will warm much more.

3a) The question you overlooked … Will this possible warming be a net benefit, or a net loss to the earth? AGW theory states that the warming will be mostly in the winter, at night, in the temperate zones. Call me crazy, but warmer winter nights in Canada doesn’t sound like a major disaster. Cold is much harder on animals, plants, and humans than heat.

4. How much will it cost to fix it? As you point out, until we know the answer to #2 and #3, this question can’t be answered.

On the other hand, I was less impressed with your hagiography of the IPCC. Did you bother to read the discussion I cited above, showing clearly that the IPCC is not doing its job, or are you determined to pursue ignorance regardless of the cost?

Or, if you don’t like that one, consider the Hockeystick. This was passed by peer review, and was included in the IPCC report (in part because the author was an IPCC Lead Editor) as one of the central arguments (and an enduring icon) for AGW. The only problem was … it was garbage. It contained a whole host of scientific errors, from the trivial to the gigantic.

So my question number 5) is, since the IPCC was totally suckered and taken in by a piece of pseudo-scientific junk like the Hockeystick, why should we believe it regarding other scientific questions?

All the best,

w.

PS - I’ve laid this out before, and I will do it again. The climate is a driven, chaotic, resonant, constructal, optimally turbulent, tera-watt scale planetary heat engine. It has a host of forcings and feedbacks, both known and unknown. It contains five major subsystems (ocean, atmosphere, cryosphere, lithosphere and biosphere), none of which is well understood. Each of these subsystems interact, force, and feedback both with the other subsystems as well as internally. Climate cycles, resonances, forcings, and feedbacks vary on spatial scales from molecular to planetwide, and on temporal scales from nanoseconds to millions of years.

The idea that we can take such a huge and unimaginably complex system, with both known and unknown resonances, cycles, forcings and feedbacks operating on all spatial and temporal scales, and say* “my whiz-bang climate model shows that if forcing A changes by 1.31 W/m2, then temperature B will change by 0.36°C”* is hubris of the highest order. Our understanding of climate is nowhere near that point yet.

It’s like looking at a big engine and saying “if we increase the temperature inside the cylinders, the engine will speed up”. Well, maybe it will … unless the engine has a governor, or a cruise control, or a thermostat, or cycle-locking, or is running out of gas, or is already running at its maximum speed, or will simply overheat and slow down, or is being controlled by some other subsystem, or the operator takes his foot off the gas …

And we don’t know yet if the climate has any of those things going on, our knowledge of the climate is in its infancy. Heck, we just found out last month that the major kind of cloud nuclei over the continents is not dust, or aerosols of some kind, or minute biogenic particles, or any of the things we believed until last month. The major kind of cloud nuclei over the continents is … bacteria!

People have studied clouds for hundreds of years, and just now we find out they’re mostly built around bacteria … and you seriously think we understand the climate system well enough to make century-long forecasts?

It is to laugh.

[jshore]

[QUOTE=Sam Stone]
I find it a little disingenuous that you would use the IPCC as an authority when it suits, but then trot out a number that is completely at odds with the IPCC’s 4th assessment report when it bolsters your argument.

According to the 4th assessment report, the worst-case scenario (SRES A1F1) has global temperatures rising to between 2.4 and 6.4 degrees C by 2100, with a corresponding sea level rise between 26 and 59 cm. This is a far cry from ‘tens of meters’.
[/QUOTE]

Two points:

First of all, I was responding to brazil84’s question about whether any peer-reviewed research exists supporting these ideas, not whether they are the most likely scenario.

Second of all, you have misinterpreted the IPCC said. For one thing, as you note their numbers are by 2100 and Hansen’s “tens of meters” are not. The IPCC agrees that sea level rise will continue far beyond 2100, even if greenhouse gases are stabilized by then. For another, the IPCC was very clear that their estimate of sea level rise was ignoring possible effect related to the dynamic breakup of ice sheets that they didn’t know how to estimate. Here is what they say in the Summary for Policymakers:

Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking. The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993
to 2003, but these flow rates could increase or decrease in the future. For example, if this contribution were to grow linearly with global average temperature change the upper ranges of sea level rise for SRES scenarios shown in Table SPM.3 would increase by 0.1 to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.

It is also worth noting that the IPCC says:

Global average sea level in the last interglacial period (about 125,000 years ago) was likely 4 to 6 m higher than during the 20th century, mainly due to the retreat of polar ice. Ice core data indicate that average polar temperatures at that time were 3°C to 5°C higher than present, because of differences in the Earth’s orbit.

(Note that that 3°C to 5°C are polar temperatures…not average global temperatures. Because of polar amplification, these are higher and the rough conversion that people often seem to use is that the polar temperature change is about a factor of 2 larger than the global temperature change.)

And, as I said in my first post on Hansen’s work: “Is Hansen right? Who knows…He is certainly more pessimistic than many scientists. But so far he has had a pretty good track record.”

[jshore]

[QUOTE=intention]

This logical flaw in your argument is shown dramatically by the lack of warming this century. This was not predicted, even by the model runs which include anthropogenic forcing … which means of course that either the natural forcing of those models, or the anthropogenic forcing of those models, or the other assumptions and parameters of the models, or all of them, must be wrong. Which, of course, invalidates your argument.
[/QUOTE]

Come on, intention, you know as well as I that natural variability makes it impossible to extract meaningful trends over that small an interval of time.

[intention]

[QUOTE=jshore]
Thanks for your response, intention.

…

Please don’t invent quotes by me. I didn’t say “couple of percent”; I said “something on the order of several percent”. In fact, in the IPCC report, they have the current CO2 forcing as ±10% (for 90%-confidence error bars).
[/quote]

Now you have me confused. The IPCC says that the 90% confidence interval for current CO2 + forcing is ±10% … but that says nothing about either the source or the accuracy of the 3.7 Watts/meter2 calculation.

(As an aside, since when is a 90% CI used in science* anywhere but the IPCC?* Have you tried using it in your field of science? In the TAR they used 95%, but not AR4 … why?)

Next, in true IPCC fashion, they don’t give any source for the 10% estimate.

Next, you have to watch the pea very carefully to see which thimble it is under. The IPCC does not claim that the ±10% is actually based on any source at all. Instead, they say:

[QUOTE=IPCC AR4]
Collins et al. (2006) performed a comparison of five detailed line-by-line models and 20 GCM radiation schemes. The spread of line-by-line model results were consistent with the ±10% uncertainty estimate for the LLGHG RFs [long-lived greenhouse gas radiative forcings] adopted in Ramaswamy et al. (2001) and a similar ±10% for the 90% confidence interval is adopted here.
[/QUOTE]
However, Ramaswamy 2001 is not a scientific paper, it is the IPCC TAR WGI … so all that the 10% CI is based on is, not a scientific study, but an earlier IPCC report. Weren’t you the guy arguing for peer reviewed studies?

Finally, are you claiming that 10% “on the order of several percent”?

[QUOTE=jshore]
My source is the IPCC report, which lists the uncertainty in the current CO2 forcing as being ±10%. If you don’t like that source, you are welcome to produce evidence that it is not correct. However, just claiming that it can’t be trusted based on not liking what you can find out about how the value was determined isn’t good enough.
[/quote]

See, jshore, you can’t have it both ways. The IPCC is not a peer reviewed source. In fact, it does no peer review at all, and states that fact quite clearly. And it makes absolutely no scientific claim about the 10% number you quoted, they just say that they “adopted” that figure because it was in the earlier IPCC report.

So no, I don’t like the source, nor should you. You claimed that certain things were scientifically known to within several percent. If you don’t have a peer reviewed citation for that, please just say so. Your citing the IPCC is … well … embarrassing for someone who has hyped peer review as the gold standard so often in the past. In addition to claiming the 3.7 ±10% is scientifically correct, the IPCC made the same claim of scientific validity about the Hockeystick … and we know how that turned out.

Plus, citing the IPCC is like citing Google – which part of it are you talking about? If you truly want to cite the IPCC, please provide references.

[QUOTE=jshore]
You should also remember that this is not a full-time career for me (as I vaguely understand it is now for you…Correct me if I am wrong…Whether it is a paid career, or just what you have chosen to do for fun in retirement, I honestly don’t know). So, I am not able to do infinite amounts of research on things like the evolution of the value for the forcing due to CO2 that is quoted in the IPCC report. I am more interested in using my time to keep up with issues that really have more legitimate contention like the climate sensitivity.
[/QUOTE]

It’s not my full time career either, nor am I retired. Not sure what your point is here.

So, I’ll say it again. If you don’t have any scientific peer reviewed studies that back up your claim, please just say so. Flailing about and citing the IPCC won’t do, as it is neither scientific nor peer reviewed.

w.

[jshore]

[QUOTE=intention]

See, jshore, you can’t have it both ways. The IPCC is not a peer reviewed source. In fact, it does no peer review at all, and states that fact quite clearly.
[/quote]

You are mixing things up here. What the IPCC says is that they review the peer-reviewed literature … but do not specifically try to act as peer-reviewers on each and every paper that they review, assessing it as a referee would. That is a different issue.

The report itself is a review paper of the peer-reviewed literature and it undergoes an extensive review process itself. (Yes, and I know that you aren’t happy with that process either…but, that is no surprise.)

In fact, the IPCC report is generally cited in a large fraction (probably the majority) of peer-reviewed papers in the field.

So no, I don’t like the source, nor should you. You claimed that certain things were scientifically known to within several percent. If you don’t have a peer reviewed citation for that, please just say so. Your citing the IPCC is … well … embarrassing for someone who has hyped peer review as the gold standard so often in the past.

Again, it is you who are confusing things. If it is wrong to cite the IPCC as a source then it is a mistake being made by the entire climate science community. Of course, you are probably willing to believe this, but there are those of us who do not believe that the most logical explanation to why you disagree with everyone else is that you are right and they are wrong. It remains me of the old joke about the mother who says as the marching band goes by, “Look, everybody is out-of-step but my Johnny!”

Plus, citing the IPCC is like citing Google – which part of it are you talking about? If you truly want to cite the IPCC, please provide references.

The ±10% is contained in the table of forcings in the SPM of the Working Group I report.