BTW, Demonstrable AGW = 0. Again.

[Diogenes]

I'm not saying that they are *necessarily* wrong, but when someone lies to me to try to prove their point and the lies are so easily uncovered I get mighty suspicious.

Therefore you are completely fed up with the apostles of "Global Warming" ?

I have yet to see a serious attempt to disprove current global warming.

Then you are not listening.

I have yet to see any attempt that doesn't fall to tiny sharp pieces when poked with a stick.

That is my opinion of the Anthropological global warming theory. It keeps falling to pieces. The proponents lie. They get caught lying. It's a pretty consistent aspect of the topic.

Just being inclined to shout that you are right for longer than me does not make you right.

Haven't been shouting. Pretty much ignore this issue. It's idiot bait as far as i'm concerned. If you can't understand what the spectrographic absorption characteristics of water means, I don't know how to help you.

It makes you not worth engaging with.

Good day, sir.

I have long since come to that conclusion for You, Skipjack, Palladin, AcesHigh, and perhaps a few other people. At this point it is no longer about engaging you, it's more about denying you the opportunity to spread idiot crap without rebuttal.

[tomclarke]

A (I hope) unpolemic detailed reply to your unpolemic post.

BTW, I tend to agree with you regarding Watts. If his only function was to post bunk, I would completely agree with you. However, I don't think you can ignore his other function of revealing bunk, which at times he has done quite respectably. Without blogs like his, nobody would be serving this function.

I would argue that the scientific process does this well. Unless you reckon there is a global conspiracy (difficult to see how this is coordinated) NEARLY ALL scientists value truth, and whatever the preconceptions this wins out in the end. Look on James Annan's blog for reaction to now known incorrect IPCC bayesian prior for climate sensitivity for example of changes made in lower climate sensitivity direction. Look at wide range of sensitivity projections from reputable models to see that the scientific community is not all using the same assumptions, or anything like.

That said, his tendency to fight fire with fire is not great. So, yes, like most media, it takes a bit of a discerning reader to get anything out of his site. FYI, I did take a tiny bit of offense at the implication that I don't read both sides of the debate, but that is neither here nor there.

apologies, it was under the asumption that you were not seeing the AW obvious daftness.

As to the rest of your post, I tend to disagree with the conclusion that natural variability is only seen over long time scales. I don't think that has adequately been established.

It is a bit subtler than that. The reasons for variability are more or less all known.
biosphere changes
solar irradiance changes
changes in solar wind/GCR
volcanic/meterorite hit changes
earth orbital changes
ocean current changes

You can go through these and you find the combination of large change + large rate of change in forcing is not met for any of these except mega-volcanos & mega-meterite events - we know these produce extinction events. I'm not saying we can be 100% certain but each of these causes has been looked at in tdetail and neither appears to be likley to fit the bill.

I suppose you might add GCR changes from very near supernovas but some work has been done and they don't look large enough.

I would also add that we may well have many extinction-level events on geological timescale, some of which are known. But what would your balance of costs be on low carbon energy vs cost of extinction-level climate change event?

Also, intuitively, a high climate sensitivity does not make sense to me, especially since the feedbacks in question are not feedbacks to CO2 concentrations but are feedbacks to increased temperature - regardless of whether higher temps are caused by CO2 or not. My intuitive sense of things is admittedly not scientific,

I don't think either of us can have a highly predictive intuition here.

but when I look to scientific attributions I find only computer models and weak attributions claiming no other physical explanation for the current warming (or prehistoric). While I agree that computer models are based on physical processes, I think our understanding of those physical processes is far from complete and am therefore very dubious of the idea that they represent any evidence for a high sensitivity.

The issue is what prior you should use for sensitivity in absence of strong evidence. There is a clear mechanism (increased temp resulkts in increased H2O in air). Human civilisation could only have developed in a phase where climate is relatively stable, which means positive feedbacks not too large compared with natural forcing changes. I have not looked carefully at the published work here, I agree one ought to be able to bound H2O feedback based on response to known natural forcing variability. (I think this might have ben done for solar irradiance changes?). But I'm certainly not going to assume science here is wrong without having investigated in detail.

Also, I am aware of the precautionary principle. Most of your post is a restatement of it. I do not believe that the precautionary principle can be applied without understanding the economics of action vs inaction. If suffering from action is greater than suffering from inaction, then we should obviously not act. There is an awful lot of suffering in the world as a result of too little energy. Assuming that the potential suffering from warming necessitates continuing or increasing that suffering is not an assumption we should take lightly.

I agree with the equation. This is a political issue more than science. At least teh science is les clear even than AGW attribution. My intuition, perhaps not informed, would say major global temperature changes would have very high cost, whereas now economy is less sensitive to energy costs than it once was, and renewables/fission look like a decent medium-term substitute.

There was a recent UK report arguing that inaction costs much more than action but this is economics not science, and was politically driven, so I don't have much confidence in it.

Finally, while I am sure that we will continue to disagree about the likelihood for a catastrophic outcome from our use of fossil fuels, I suspect that the fact that we are both on this blog is a good indication that we agree on a need to eventually move away from them. I believe that we need to advance our capability of building safer and more efficient nuclear power and that we need to develop new energy storage technologies to eventually move all electricity and everyday transport away from fossil fuels. I think this is doable. I am a big fan of LFTR. Hopefully, fusion one day.

Yes, people's avoidance of nuclear is just wrong, when compared with other risks we take, e.g.:

globalisation makes risk of kill 10% population or more flu epidemic almost crtin on 100 yr timescale.

Availability of cheap plentiful bad food and cars (hence less exercise) makes very high cost in premature death/disease. I take this as a cost to society as a whole, to be balanced with CO2 reduction energy costs. My point is that we accept very high costs in some areas. (Although individual cost due to these factors is chosen, so much less objectionable, the cost to society as a whole is borne by all of us).

[tomclarke]

Diogenes,

There can be many arguments over the science, vs skipjack & me above.

But you seem to be arguing that the basic physics and chemistry of the atmosphere radiation balance is different from that accepted generally. This is clear and definite science. I'm good enough myself to follow and explain every step in detail (with a bit of help) so if you like on another thread we could go through the science step by step and determine where we disagree. It would take a while, becaus eit is complex, but be quite possible.

The bottom line from this is:
CO2 is forcing
H2O is feedback, not forcing, since equilibrium time of H2O in air is short - about 20 days if I remember right.
Value of H2O feedback is uncertain, but take home higher temp => more H2O => more greenhouse effect seems likely on simplistic analysis though not certain because other effects like cloud cover canages could in principle trump direct H2O effect.

Therefore you are completely fed up with the apostles of "Global Warming" ?

I have yet to see a serious attempt to disprove current global warming.

Then you are not listening.

I have yet to see any attempt that doesn't fall to tiny sharp pieces when poked with a stick.

That is my opinion of the Anthropological global warming theory. It keeps falling to pieces. The proponents lie. They get caught lying. It's a pretty consistent aspect of the topic.

Just being inclined to shout that you are right for longer than me does not make you right.

Haven't been shouting. Pretty much ignore this issue. It's idiot bait as far as i'm concerned. If you can't understand what the spectrographic absorption characteristics of water means, I don't know how to help you.

It makes you not worth engaging with.

Good day, sir.

I have long since come to that conclusion for You, Skipjack, Palladin, AcesHigh, and perhaps a few other people. At this point it is no longer about engaging you, it's more about denying you the opportunity to spread idiot crap without rebuttal.

[tomclarke]

...(climate|global warming|etc.) denier...

And at that point I typically tune out the argument trying to support AGW.

I agree that polemics or ad homs on either side are unhelpful. But if you exclude these the anti-AGW case collapses, since it depends on significant character assasination of many working scientists.

I can therefore understand the frsutration that leads to this phraseology when arguing the mainstream case, even though strictly you are right it should not be used, and I would normally try not to use it.

[hanelyp]

I have yet to see a serious attempt to disprove current global warming.

It should be up to those calling for draconian action to prove that there is global warming, and that the measures they want will help.

So far all I see is a wreck of data that even manipulated barely peaks outside uncertainty, and models with major deficiencies that don't match what is observed.

[Diogenes]

Diogenes,

There can be many arguments over the science, vs skipjack & me above.

But you seem to be arguing that the basic physics and chemistry of the atmosphere radiation balance is different from that accepted generally. This is clear and definite science. I'm good enough myself to follow and explain every step in detail (with a bit of help) so if you like on another thread we could go through the science step by step and determine where we disagree. It would take a while, becaus eit is complex, but be quite possible.

The bottom line from this is:
CO2 is forcing
H2O is feedback, not forcing, since equilibrium time of H2O in air is short - about 20 days if I remember right.
Value of H2O feedback is uncertain, but take home higher temp => more H2O => more greenhouse effect seems likely on simplistic analysis though not certain because other effects like cloud cover canages could in principle trump direct H2O effect.

You seem as if you are right on the edge of grasping my point.

You grant that H20 diffusion increases with heat. You grant that H20 is a far better absorber of IR and other radiation, ala the "greenhouse effect." You grant that these two things together constitute a positive feedback effect which according to the theory ought to result in an ever increasing temperature.

Where I don't think you are following is in the area of what's stopping the positive feedback from creating a runaway greenhouse effect. Water vapor flips from a positive feedback effect, and it BECOMES a negative feedback effect. Rather than continuously increasing the temperature via absorption, it actually reduces temperature via reflection.

My argument is that the system is self regulating, and the dominate component of this regulation is the ability of water vapor to reflect radiation away from the planet. It's reserve ability to accomplish this is so great as to make all other factors trivial and irrelevant. No plausible amount of CO2 or Methane can possibly overcome water vapor's ability to compensate for it.

The negative feedback capabilities of water vapor are simply too large to be seriously impacted by any other gas. Water vapor has too much leverage over any other effect. They (other gases) are as to a mosquito trying to hold back an automobile.

[Diogenes]

I have yet to see a serious attempt to disprove current global warming.

It should be up to those calling for draconian action to prove that there is global warming, and that the measures they want will help.

This.

[tomclarke]

You seem as if you are right on the edge of grasping my point.

You grant that H20 diffusion increases with heat. You grant that H20 is a far better absorber of IR and other radiation, ala the "greenhouse effect." You grant that these two things together constitute a positive feedback effect which according to the theory ought to result in an ever increasing temperature.

OK - this is your misunderstanding. Positive feedbacks do not result in ever-increasing temperature unless they are so large as to make the system unstable. Basically there is a stabilising negative feedback from the black body radiation out, which increases as temperature increases. As long as total other feedback is less positive than this is negative the system will be stable, but with forcing inputs effectively amplified. I'll give you the math if you need it, it is simple.

Where I don't think you are following is in the area of what's stopping the positive feedback from creating a runaway greenhouse effect. Water vapor flips from a positive feedback effect, and it BECOMES a negative feedback effect. Rather than continuously increasing the temperature via absorption, it actually reduces temperature via reflection.

All these effects, feedbacks and forcings, are for small peturbations approximately linear. As above, a stable surface temperature results from forcings + feedbacks as long as the total feedbacks (including BB radiation - the big one) are negative. Adding a positive H2O feedback to the mix then amplifies the effect of forcings without leading to instability.

For larger changes the system will indeed have many nonlinear effects which come into play. But this is a second-order effect.

My argument is that the system is self regulating, and the dominate component of this regulation is the ability of water vapor to reflect radiation away from the planet. It's reserve ability to accomplish this is so great as to make all other factors trivial and irrelevant. No plausible amount of CO2 or Methane can possibly overcome water vapor's ability to compensate for it.

I can do the maths to show you. Quantitatively the overall greenhouse effect is roughly 50% - the surface radiation is approx 390W/m^2 - the BB radiation to space is approx 237W/m^2. Of this 153W/m^2 greenhouse effect H2O contributes roughly 95 and CO2 roughly 50.

These are total figures. We then consider how the figures change if for example CO2 doubles and therefore forcing is 1.5W/m^2, and methane increases by more than 2 for a forcing of 0,5W/m^2 (this is the current increase in GH effect over pre-industrial times- that 50 becomes 52). That will increase temperature and as a result the H2O GH contribution will also increase (say by roughly 2W/m^2 for example). The total forcing of 4W/m^2 is then balanced by BB radiation feedback of -5.5W/Km^2 to give total surface temp increase of roughly 0.8K instead of the 0.25K expected from CO2 forcing alone.

The negative feedback capabilities of water vapor are simply too large to be seriously impacted by any other gas. Water vapor has too much leverage over any other effect. They (other gases) are as to a mosquito trying to hold back an automobile.

You can see from the maths and figures that the mosquito does have a significant effect. If you diagree with the ballpark figures here we can go through the emmission characteristics at different frequencies and CO2/H2O absorption, and work out from first principles for a single atmospheric layer, then integrate over many layers. I'm prepared to do this at a very coarse level of approximation.

Best wishes, Tom

[Skipjack]

The proponents lie.

Yeah the global conspiracy of hundreds of scientists. Makes total sense that...
Same problem as all the big conspiracy theories like the moonlanding or the twin tower theories. Too many people would have to be involved.

[palladin9479]

The proponents lie.

Yeah the global conspiracy of hundreds of scientists. Makes total sense that...
Same problem as all the big conspiracy theories like the moonlanding or the twin tower theories. Too many people would have to be involved.

There is no global conspiracy, never has been. There are political agendas being followed and those agenda's control the grant money for the scientists involved. Funding a study to "disprove AGW" would be met with harsh criticism prior to the study even starting, anyone who was hired to conduct the study would find their careers torpedoed no matter what happened. No conspiracy just politics infecting science.

Also what needs to be understood is that climatology is not a "hard" science. It's just theoretical experimentation with statistical models of various data sets. Pick the right data and model combination and you can "predict" the Earth entering an ice age, use a different model and data set and the Earth explodes into Venus like atmospheres.

Added to the above issue is that body is generating their own data, it's all done via proxy. Their taking data from other scientific studies, modifying them (this is the biggest source of issues, undocumented modification) then creating a model that takes your data creates the results you want. Do this over and over again until you can put it on a big board with an arrow spiking up showing the world exploding into a fireball, unless people do what you say.

I have no doubt the earth's temperature is rising, it has risen and fallen for the better part of the last billion years. My issue is the role CO2 has with the atmosphere, CO2 levels have been several times higher then they are now, and the earth didn't explode into Venus. That fact alone disproves most of the AGW theory, if the Earth's had higher temperatures and higher concentrations of CO2 in the past and didn't explode into a fireball, then us having higher temperatures and higher CO2 now will not cause it to explode into a fireball. The most we're doing is shifting the weather patterns in the atmosphere by altering water vapor levels (the real controller of our climate). It has been experimentally proven that higher amounts of water vapor in the atmosphere reduce total solar energy input due to high atmospheric cloud formations reflecting back solar energy before it gets trapped under the water vapor.

The climate system on this planet has been self regulating for the past billion+ years, the rise of the animal species known as homo sapien in the last 50 thousand years will not alter that fact. Our industrial history is a little over 200 years, ~300 if your counting renaissance. That is incredibly, stupidly small on a global scale. That is what makes most of the AGW proponents claims absurd. Their saying the planets billion+ year old self regulating system is somehow vulnerable and fragile and that the smallest increase in CO2 is breaking it.

[tomclarke]

The climate system on this planet has been self regulating for the past billion+ years, the rise of the animal species known as homo sapien in the last 50 thousand years will not alter that fact. Our industrial history is a little over 200 years, ~300 if your counting renaissance. That is incredibly, stupidly small on a global scale. That is what makes most of the AGW proponents claims absurd. Their saying the planets billion+ year old self regulating system is somehow vulnerable and fragile and that the smallest increase in CO2 is breaking it.

With respect:

300 years is small compared with geologic times, agreed.

However the change we have made in ecosystem during this 300 years is not small. The fact that it has been made so quickly is actually problematic, because ecosystems can happily survive slower chnages in climate, with species adapting and moving, but not fast chnages.

The increase in CO2 is nearly 100% over 150 years. This puts CO2 at a level never seen in past 1,000,000 years. In terms of warming the effect is logarithmic, so for example in deep historic times when 20% less radiation from the sun was balanced by higher GH effect, and CO2 levels were maybe 16X current levels, that would be only 4X the warming effect that the change from pre-industrial to now has caused.

So you can see that a 100% increase in CO2 is not "the smallest increase". I agree it will not break (in geological terms) teh earth's climate. But it could move us to any one of a range of past climates which were much less suitable for homo sapiens than the current, very moderate, temperatures have been. And in terms of the world economy a change of only 1C makes a big diference to crops, pests etc. A change of 5C means that different areas become suitable for agriculture, and crops change everywhere. Also seaboard towns throughout the world become unviable, and temperate climes become tropical with necessary changes to housing, infrastructure, etc.

The economic cost is extraordinarily large, compared with the costs of CO2 reduction which many on this thread complain about.

Exact comparison is complex, but your statement that this is "incredibly, stupidly, small on global scale" is unsustainable.

[tomclarke]

Funding a study to "disprove AGW" would be met with harsh criticism prior to the study even starting, anyone who was hired to conduct the study would find their careers torpedoed no matter what happened. No conspiracy just politics infecting science.

This shows a misunderstanding. There is no single theory of AGW to disprove. There are a whole load of different bits of evidence, from completly different areas of science, which add up together to make AGW a near certain conclusion. There is still much uncertainty about the level of AGW, as well highlighted in the IPCC reports.

Of course, there are many well-funded groups working on models, data, etc which imply much lower levels of AGW than the median value. So the idea you need to be pushing AGW up to be funded is wrong.

[Skipjack]

This shows a misunderstanding. There is no single theory of AGW to disprove. There are a whole load of different bits of evidence, from completly different areas of science, which add up together to make AGW a near certain conclusion. There is still much uncertainty about the level of AGW, as well highlighted in the IPCC reports.

Yepp.
I used to be slightly sceptical of the whole thing, especially in the beginning. I have since changed my mind bit by bit.
My take on it is: Whether it is entirely manmade or not is not 100% certain, but it is getting warmer. We know that we are certainly contributing. Take our contribution out of the equation and we might at least be able to slow the whole thing down and make the end result less severe.
Personally I am more than happy to get rid of fossil fuels for economic, health and political issues, if we had a cheap enough alternative, which we currently dont have. This is why I am here on this board.

[hanelyp]

There is no single theory of AGW to disprove. There are a whole load of different bits of evidence, from completly different areas of science,

There are a multitude of models, but it looks to me like they all involve CO2 as a greenhouse gas and H2O as a multiplier. Even dismissing that, the mutability of the broader concept makes it scientifically untestable.

As far as temperature records, that is plagued by questionable and badly documented 'corrections', apparent cherry picking of data, and temperature monitoring stations that fail standards.

which add up together to make AGW a near certain conclusion.

This does not follow. The set of AGW models does not cover the set of plausible climate models. There is also a multitude of potential models without global warming, and even leading to a new ice age.

And, to repeat, there are problems with the data.

There is still much uncertainty about the level of AGW, as well highlighted in the IPCC reports.

Uncertainty exceeding the quality signal.

[tomclarke]

There is no single theory of AGW to disprove. There are a whole load of different bits of evidence, from completly different areas of science,

There are a multitude of models, but it looks to me like they all involve CO2 as a greenhouse gas and H2O as a multiplier. Even dismissing that, the mutability of the broader concept makes it scientifically untestable.

Those are two elements in the equation which are demonstrably and absolutely true. They rest on physics, not complex models. But there are many other strands of evidence of course.

As far as temperature records, that is plagued by questionable and badly documented 'corrections', apparent cherry picking of data, and temperature monitoring stations that fail standards.

It is certainly complex, but the BEST project, addressing exactly those questions from a skeptic starting point (with skeptic funding) found that the mainstream position was broadly correct.

which add up together to make AGW a near certain conclusion.

This does not follow. The set of AGW models does not cover the set of plausible climate models. There is also a multitude of potential models without global warming, and even leading to a new ice age.

Really? The models with some level of scientific competence vary greatly in what they predict, but the evidence for warming (from physics alone - you don't need temperature data to model the effect of CO2 and H2O in the atmosphere) is overwhelming. Please show me these ice age models?

And, to repeat, there are problems with the data.

My guess is that you have not read the many papers dealing with those problems. Nor the detailed BEST study looking at the raw data and validating it from scratch? Because if you had, you would not come to that conclusion. Sure there are problems. That does not mean the data cannot be used. Where is your "can do it" attitude?

There is still much uncertainty about the level of AGW, as well highlighted in the IPCC reports.

Uncertainty exceeding the quality signal.

Assertions like that convince me less than serious attempts to quantify the uncertainty. IPCC AR4 does a decent job, but current state of the art is even better. Look at James Annan's work for example.