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What is the correct value of Climate Sensitivity?

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Why? Clouds are affected by the concentration of water vapour. It seems fairly logical that an increase in water vapour will lead to an increase in clouds which, in turn, provide a negative feedback effect. The logic is only complicated because a lot depends on the type of clouds that form (i.e. some increase warming and some decrease it). Also, sensitivity is likely non-linear (i.e. higher at the end of ice ages, slower as ice retreats and plants grow) and you could see different types of clouds form as temperatures change.

Sorry, I should have written 'basically zero' rather than 'less than zero' in my earlier comment.

With respect to cloud formation being an overall negative feedback, I agree (as I have stated earlier in this thread and despite the fact that many climate change studies suggest or assume that clouds are a positive feedback). The lapse rate feedback is also a significant negative feedback. However, there are also positive feedbacks such as an increased albedo feedback due to less glaciers, higher sea levels and changes in plant cover, CO2 and methane being released from the ocean as it warms (though the CO2 feedback should not be considered when trying to evaluate the effect of climate sensitivity), and a reduction in the latitudinal temperature gradient from global warming resulting in a lower amount of blackbody radiation being emitted by the earth to space than would occur if the latitudinal temperature gradient remained constant.

I have a hard time believing that the combined effect of all these other feedbacks is either basically zero or negative, which is needed to get these low climate sensitivity estimates.

In any case, if you look at the corrections I made to the 1.99 C equilibrium climate sensitivity paper in the original post and post #18, you will see that 2.95 C is a better estimate of equilibrium climate sensitivity when some of the assumptions made by Craig Loehle are relaxed.

You have said in the past that you trust empirical evidence more than computer models, have you not? Well here I have shown that the empirical evidence suggests a climate sensitivity of 2.95 C. Does this new evidence not change your perception of the Earth's true climate sensitivity (to one that is higher and closer to the mainstream scientific community)? 2.95 C is still slightly on the low-side and, as I have mentioned earlier, the assumption of constant decay rate may bias this estimate upward slightly.

Edited by -1=e^ipi

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Well here I have shown that the empirical evidence suggests a climate sensitivity of 2.95 C. Does this new evidence not change your perception of the Earth's true climate sensitivity (to one that is higher and closer to the mainstream scientific community)?

Sensitivity is just a number. What matters are the effects of warming and the plausible policy choices to deal with said warming. I don't believe that mitigation is a remotely plausible course of action given the technology currently available so even if sensitivity was >5C it would not change my opinion on the policy choices. What would change my mind is a politically and economically viable CO2 free energy source that can be deployed everywhere that needs power.

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Sensitivity is just a number. What matters are the effects of warming and the plausible policy choices to deal with said warming. I don't believe that mitigation is a remotely plausible course of action given the technology currently available so even if sensitivity was >5C it would not change my opinion on the policy choices.

Equilibrium climate sensitivity is a very important 'number' that is very relevant. If climate sensitivity were 100 C then 'the Earth will boil over' due to human emissions as Obama claims it will. Of course I would argue that equilibrium climate sensitivities over 4C are unrealistic unless we are talking about the middle of an ice age. But seriously though, the value of climate sensitivity is very relevant. If we both accept that there exists an 'optimal' global temperature, above which the marginal effect of increasing the global temperature on humanity + the environment is negative and below which the marginal effect of increasing the global temperature on humanity + the environment is positive, and if we both accept that the 'optimal' global temperature is slightly above 15 C (which I think we both do, correct me if I am wrong) then how much warming one gets from emitting CO2 is very relevant because eventually global temperatures might reach a point where the marginal effect is negative.

Plausibility of other options such as mitigation or geoengineering would require performing a cost-benefit analysis. But in any proper cost-benefit analysis you will need estimates of climate sensitivity.

What would change my mind is a politically and economically viable CO2 free energy source that can be deployed everywhere that needs power.

Why would that necessarily change your mind? If the marginal external effect of CO2 emissions were positive, and fossil fuels were still economically viable with alternatives, then what reason would there be for a 'change'? Your statement doesn't even take into account cost of different sources either, just if it can be deployed everywhere. Are you implicitly accepting the alarmist claims about the environmental impacts of CO2?

As an aside, I have been reading various blogs and scientific papers in my spare time recently. This one is relevant for this subject because it gives some more credability to the 2C estimates:

http://www.cato.org/blog/current-wisdom-even-more-low-climate-sensitivity-estimates

I also recommend this related one on CO2 social cost estimates:

http://www.cato.org/blog/closer-look-epas-determination-social-costs-carbon

Edited by -1=e^ipi

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Equilibrium climate sensitivity is a very important 'number' that is very relevant.

Whether sensitivity is 2 or 4 or somewhere between is irrelevant. The earth will warm and the consequences of that warming we care about, and, even if we know the consequences our policy options are constrained by technology so even if it would be ideal to eliminate CO2 emissions we can't do that. All we can really do is adapt.

Why would that necessarily change your mind. If the marginal external effect of CO2 emissions were positive, and fossil fuels were still economically viable with alternatives, then what reason would there be for a 'change'?

The most plausible scenario is warming will be both good and bad and the net effect could be positive but that does not eliminate the bad - just compensates for it at a macro level. At a micro level there will be some people and some places that end up getting hurt from climate change. Therefore, it is not unreasonable to say that if eliminating CO2 emissions cost nothing then we should eliminate CO2 emissions because politically people obsess over the bad and ignore the good.

But we live in the real world and, IMO, eliminating CO2 emission is not remotely plausible given economic and political constraints. We could reduce the rate of CO2 emission growth but that is not going to make much of a difference. The only real options are adaptation. My hypothetical was based on the assumption that a currently unknown energy source becomes available which has economics comparable to fossil fuels without the political opposition associated with nuclear. If this hypothetical source appeared I would change my opinion on whether mitigation was a viable policy option. This does not imply that would be necessarily better - that would require the cost-benefit analysis that you refer to - just that it is a viable option and worth considering. Mitigation is not worth considering as we stand today because no mitigation policy can succeed.

Edited by TimG

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Whether sensitivity is 2 or 4 or somewhere between is irrelevant. The earth will warm and the consequences of that warming we care about

And the amount of warming (the consequence) depends on climate sensitivity. Thus climate sensitivity is not irrelevant.

and, even if we know the consequences our policy options are constrained by technology so even if it would be ideal to eliminate CO2 emissions we can't do that. All we can really do is adapt.

Even if there were zero alternatives (no nuclear, no hydro, no solar, no wind, no geothermal, no tidal, no geoengineering), if the marginal effect of increasing atmospheric CO2 is negative then there is a negative externality associated with the burning of fossil fuels that is not being internalized by the market. In that case, it would still make sense to implement a pigouvian tax on CO2 emissions equal to the negative externality associated with those CO2 emissions (assuming that the effect of the tax exceeds implementation costs). The size of the externality depends very much on the amount of warming expected for a given increase on CO2, which depends on climate sensitivity. Assuming that other effects of increasing CO2 such as the CO2 fertilization effect and ocean acidification are dominated by the temperature effect, then doubling the climate sensitivity from 2C to 4C means that the externality roughly doubles, which means that the optimal Pigouvian tax roughly doubles as well.

The most plausible scenario is warming will be both good and bad and the net effect could be positive but that does not eliminate the bad - just compensates for it at a macro level. At a micro level there will be some people and some places that end up getting hurt from climate change. Therefore, it is not unreasonable to say that if eliminating CO2 emissions cost nothing then we should eliminate CO2 emissions.

That is unreasonable. Your position appears to me to be basically "As long as someone is worse off for policy X, we should not do policy X". This gives irrational preference to the status quo. For example, if we applied this to the recent free trade agreement with South Korea, because Ontarian manufacturing and South Korean beef farmers are worse off, then the free trade agreement would have not been allowed to go through despite the FTA being of net benefit to both countries. If a policy is of net benefit relative to alternatives, then it should be implemented. That is the whole point in doing a cost-benefit analysis.

But we live in the real world and, IMO, eliminating CO2 emission is not remotely plausible given economic and political constraints.

No, but it still make sense to restrict its emission via a CO2 emission tax.

We could reduce the rate of CO2 emission growth but that is not going to make much of a difference.

Of course it will. Every molecule of CO2 makes a difference. If you reduce CO2 emissions then you slow the rate at which the climate changes.

The only real options are adaptation.

Proof? And why can't adaptation also include a CO2 emission tax?

If this hypothetical source appeared I would change my opinion on whether mitigation was a viable policy option. This does not imply that would be necessarily better

Yet earlier you were going on about if someone is harmed from climate change and if CO2 emissions cost nothing then humans should eliminate CO2 emissions. Your going well beyond claims about mitigation being a viable policy option.

that would require the cost-benefit analysis that you refer to

Which requires equilibrium climate sensitivity, which you think is 'irrelevant'.

Mitigation is not worth considering as we stand today.

So because it doesn't make sense to completely eliminate CO2 emissions, no effort should be taken to reduce CO2 emissions. Did I get that argument correct?

Edited by -1=e^ipi

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And the amount of warming (the consequence) depends on climate sensitivity. Thus climate sensitivity is not irrelevant.

Except we have no reliable way to translate a magic number between 2 and 4 into consequences that are sufficiently differentiated to result in different policy choices depending on what the exact number is.

In that case, it would still make sense to implement a pigouvian tax on CO2 emissions equal to the negative externality associated with those CO2 emissions (assuming that the effect of the tax exceeds implementation costs).

Estimates of the social cost of carbon are wild guesses based on dubious economic models (i.e. how many of those models predicted the collapse of oil prices?). More importantly we already have a pigovian tax on gasoline in Canada at $344/tC which is 8 times the average estimates of the SCC. This has probably reduced emissions growth compared to a hypothetical scenario with no tax but it is not large enough for anyone to notice (Canada has one of the highest per capita emissions in the world despite the tax).

IOW - gasoline taxes around the world show why the idea that carbon taxes at politically viable levels cannot really change people's behaviors because the incremental cost of reducing emissions far exceeds the cost of these taxes.

That is unreasonable. Your position appears to me to be basically "As long as someone is worse off for policy X, we should not do policy X".

This is reality. People who are harmed complain endlessly and when there is a public good they often have to be compensated. In this case, any "benefit" from warming will not be attributed to CO2 - only the harms will be attributed because that is the way the media/scaremongers work. So in the scenario with no benefit that people will acknowledge, no cost to reduce emissions and obvious harm the then it would be impossible to argue against CO2 reductions. But that is an imaginary scenario.

That said, this argument does not apply to all things. With trade agreements people are willing to accept the premise that there are winners and losers but such thinking is absent from the climate debate because the scaremongers have dominated the field for so long.

Proof? And why can't adaptation also include a CO2 emission tax?

Explain why Canada has the highest per capita emissions despite a >$300/tC tax on gasoline and >50% of electrical power produced by hydro and nuclear? The short answer is carbon taxes don't reduce emissions unless there is a viable alternative. When there is no alternative carbon taxes can only work by slowing economic growth and that is not politically viable.

So because it doesn't make sense to completely eliminate CO2 emissions, no effort should be taken to reduce CO2 emissions. Did I get that argument correct?

I don't see a carbon tax as a mitigation policy because, as I noted above, their effect at politically acceptable levels is negligible. A mitigation policy is where targets are set for emission reductions and incentives/regulations designed to force people to reduce emissions are adopted. Such policies will invariably fail and will waste resources that would be better allocated to adaptation. Edited by TimG

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Except we have no reliable way to translate a magic number between 2 and 4 into consequences that are sufficiently differentiated to result in different policy choices depending on what the exact number is.

Estimates of the social cost of carbon are wild guesses based on dubious economic models (i.e. how many of those models predicted the collapse of oil prices?). More importantly we already have a pigovian tax on gasoline in Canada at $344/tC which is 8 times the average estimates of the SCC.

There are methods. A cost benefit analysis can calculate the social cost of carbon dioxide emissions (not carbon, please call it carbon dioxide emissions). The fact that many people are making dubious assumptions (that are often politically motivated) in their cost benefit analyses does not make the approach of cost benefit analysis incorrect. It just has to be done properly.

This has probably reduced emissions growth compared to a hypothetical scenario with no tax but it is not large enough for anyone to notice (Canada has one of the highest per capita emissions in the world despite the tax).

So are you saying just because the effect of a policy is small that it should not be implemented even if it is of net benefit?

And the fact that Canada has a high per capita emission level does not refute anything. It's called being a cold, empty, developed country.

IOW - gasoline taxes around the world show why the idea that carbon taxes at politically viable levels cannot really change people's behaviors because the incremental cost of reducing emissions far exceeds the cost of these taxes.

The fact that the demand for fossil fuels is highly inelastic is not an argument against implementing a tax. If there is a negative externality then in a competitive market one of the ways to solve this issue is to implement a Pigouvian tax equal to the marginal effect of that externality. If that results in only a small reduction in fossil fuel emissions then that is still the socially optimal policy, it is just taking into account the inelastic demand for fossil fuels (which it should).

This is reality. People who are harmed complain endlessly and when there is a public good they often have to be compensated. In this case, any "benefit" from warming will not be attributed to CO2 - only the harms will be attributed because that is the way the media/scaremongers work. So in the scenario with no benefit that people will acknowledge, no cost to reduce emissions and obvious harm the then it would be impossible to argue against CO2 reductions. But that is an imaginary scenario.

You are confusing 'what is an optimal policy' with 'what is likely to occur due to the nature of politics'. This doesn't refute what I wrote.

As for no one 'acknowledging' a benefit, if no one acknowledges a benefit then why believe that it exists? Or are you saying just the majority of people don't acknowledge it but at least 1 person does, in which case you 'scenario' is flawed/misleading.

With trade agreements people are willing to accept the premise that there are winners and losers but such thinking is absent from the climate debate because the scaremongers have dominated the field for so long.

Why not just refute the ridiculous assertions that the scaremongers are making and change public opinion via reasoned argument? I get the stranglehold that the 'progressives' have on the media and that it would be difficult, but I can't agree that it is impossible.

Explain why Canada has the highest per capita emissions despite a >$300/tC tax on gasoline and >50% of electrical power produced by hydro and nuclear?

I already did. Canada is a cold, empty, developed country.

The short answer is carbon taxes don't reduce emissions unless there is a viable alternative.

Uh, no. Even without alternatives there is a reduction.

When there is no alternative carbon taxes can only work by slowing economic growth and that is not politically viable.

What do you mean it's not politically viable? We have Obama delaying keystone XL for ~7 years, we have Germany going full on solar to the point of insanity, we have Portugal mass subsidizing solar, we have Denmark going wind (which is very viable given their location), we have Ontario going insane with this green trend to the point of having the highest electricity prices in North America and the loss of many jobs, etc. It's completely politically viable. It's all the rage!

I don't see a carbon tax as a mitigation policy because, as I noted above, their effect at politically acceptable levels is negligible.

You really think the insane politically accepted policies in countries such as Germany is negligible?

A mitigation policy is where targets are set for emission reductions and incentives/regulations designed to force people to reduce emissions are adopted.

No,

Mitigation - noun - the action of reducing the severity, seriousness, or painfulness of something.

A carbon dioxide emission tax reduces emissions. Therefore it is a mitigation policy.

Edited by -1=e^ipi

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Why not just refute the ridiculous assertions that the scaremongers are making and change public opinion via reasoned argument? I get the stranglehold that the 'progressives' have on the media and that it would be difficult, but I can't agree that it is impossible.

Good idea. Publish your breakthrough, for the sake of the economy, humanity and bandwidth please publish.

You get the vast vast majority of scientists onside and it'll be easy to present a reasoned argument to the lay public.

Op-ed pieces heavily peppered with advanced calculus and snide comments probably won't fly too far.

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The fact that many people are making dubious assumptions (that are often politically motivated) in their cost benefit analyses does not make the approach of cost benefit analysis incorrect. It just has to be done properly.

Define "properly". Even people who are not motivated by an agenda need to make assumptions which may not be true. These models cannot represent a "truth" - they are only an opinion. The best they can offer is a min/max range for the variable in question and from what I have seen the SCC has such a wide range that it is effectively useless as a policy guideline. In the end people decide what tax they want to impose and go find the the SCC calculation that will justify their choice.

The fact that the demand for fossil fuels is highly inelastic is not an argument against implementing a tax. If there is a negative externality then in a competitive market one of the ways to solve this issue is to implement a Pigouvian tax equal to the marginal effect of that externality. If that results in only a small reduction in fossil fuel emissions then that is still the socially optimal policy, it is just taking into account the inelastic demand for fossil fuels (which it should).

I completely agree with your theory. I am arguing that, in practice, the effect of a carbon tax is negligible. I am also not opposed to carbon taxes for the reason you state and see them as a useful tool to shut people up about CO2. However, I also believe they are useless as a policy if your intent is to reduce CO2 emissions.

Why not just refute the ridiculous assertions that the scaremongers are making and change public opinion via reasoned argument? I get the stranglehold that the 'progressives' have on the media and that it would be difficult, but I can't agree that it is impossible.

Climate change is a religion for many people. Asking them to talk about it rationally about it is like asking the Pope to have a rational conversation about god.

What do you mean it's not politically viable? We have Obama delaying keystone XL for ~7 years, we have Germany going full on solar to the point of insanity, we have Portugal mass subsidizing solar, we have Denmark going wind (which is very viable given their location), we have Ontario going insane with this green trend to the point of having the highest electricity prices in North America and the loss of many jobs, etc. It's completely politically viable. It's all the rage!

It is politically viable until it starts costing people too much. In Germany the only reason they got away with as long as they did is they protected jobs by exempting industry. Now people are objecting to that exemption and the system is being scaled back. Obama can beat up Keystone XL precisely because it has little economic impact. The areas which have economic impact (like a gas tax) are no-go zones.

You really think the insane politically accepted policies in countries such as Germany is negligible?

Germany was doing well because its plans included nuclear for base load and that alone made up for the mess. But it has since closed down its nukes and is now burning coal and its CO2 emissions are soaring. The curse of the politically viable strikes again. If a nation like Germany is willing to abandon its CO2 commitments because of a misplaced fear of nuclear then what chance does any anti-CO2 policy have in more skeptical places?

A carbon dioxide emission tax reduces emissions. Therefore it is a mitigation policy.

But it is not a useful mitigation policy given the scale of the problem. Edited by TimG

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Climate change is a religion for many people. Asking them to talk about it rationally about it is like asking the Pope to have a rational conversation about god.

So even if the IPCC changed their mind in light of ipi's findings and advised the public to stop being alarmed, the vast vast conspiracy of enviro-freaks, terrorist, commies, LGBTerists etc etc would still be determined to destroy the world's economy?

WOW, that's some vast vast theory.

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Define "properly". Even people who are not motivated by an agenda need to make assumptions which may not be true.

Properly is difficult to define completely, so I will list some of it's properties. It should be made without confirmation bias and the approach should not be dogmatic. It should use the best scientific literature (that is without confirmation bias or dogma) for the best estimates of how the climate will change in response to CO2 emissions. It should use a reasonable and empirically derived discount rate that is justified well. It should try to take into account and monetize all costs and benefits associated with climate change. It should look at various alternatives such as geoengineering. And so on.

With respect to people making assumptions that may not be true, that is necessary, the question is if the assumptions are justified (in the paper I referenced in the original post, I argued that 3 assumptions were not reasonable). I would argue that when one runs out of a priori information then Occam's razor should be invoked to select the simplest model that agrees with the a priori information and the empirical data.

These models cannot represent a "truth" - they are only an opinion.

They might represent truth, you don't know they don't, much like you don't know that there exists a flying spaghetti monster.

But seriously though, you are arguing against the existence of models. Isaac Newton's theory of gravity was a model, and this model was false, yet it still was useful and made reliable predictions.

The best they can offer is a min/max range for the variable in question

Well it's more of a confidence interval, but whatever. That's what people are supposed to do in science, they indicate their uncertainty.

from what I have seen the SCC has such a wide range that it is effectively useless as a policy guideline.

Because people aren't doing proper cost benefit analyses. As I said before, just because you have people producing absurd SCCs doesn't mean that doing this properly can't yield a good estimate of the SCC to make policy decisions.

In the end people decide what tax they want to impose and go find the the SCC calculation that will justify their choice.

Yes, that is dogmatic. And it is wrong. But people doing wrong things doesn't refute anything that I wrote.

Climate change is a religion for many people. Asking them to talk about it rationally about it is like asking the Pope to have a rational conversation about god.

And yet Christianity's stranglehold on Europe was eventually broken.

I agree it is difficult to use reason with people that treat climate change like a religion (as we have seen in these forums). But I don't think it is impossible to sway public opinion to reason in the long run (like over decades).

The areas which have economic impact (like a gas tax) are no-go zones.

Yet most countries have an income tax which has a significant economic impact. Why weren't they 'no-go zones'? Many countries have consumption taxes as well. Many countries have taxes on tobacco.

Germany was doing well because its plans included nuclear for base load and that alone made up for the mess. But it has since closed down its nukes and is now burning coal and its CO2 emissions are soaring. The curse of the politically viable strikes again.

Actually, it is more insane than that. Germany has gone so solar that they have made nuclear unviable even without the crazy anti-nuclear lobby since nuclear plants can't turn on and off quickly enough to deal with the change in solar output during the day. They are even making hydroelectric energy unviable to an extent. Coal is the only thing that can turn on and off quickly enough to be viable in combination with solar panels.

http://theresilientearth.com/?q=content/germanys-solar-failure

If a nation like Germany is willing to abandon its CO2 commitments because of a misplaced fear of nuclear then what chance does any anti-CO2 policy have in more skeptical places?

Germany didn't willfully abandon its CO2 commitments. The idiot environmentalists obtained so much power and imposed such stupid laws that they made hydroelectric and nuclear unviable.

But it is not a useful mitigation policy given the scale of the problem.

Why not? Imposing a global pigouvian tax equal to the scc would yield roughly an optimal response (obviously there are other problems like non-competitive markets and imperfect information). If the optimal thing to do (according to a properly done cost benefit analysis) is to impose a tax which just slows emissions slightly, then what is wrong with doing that?

Edited by -1=e^ipi

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But seriously though, you are arguing against the existence of models. Isaac Newton's theory of gravity was a model, and this model was false, yet it still was useful and made reliable predictions.

Models can show themselves to be accurate if they allow predictions to be made and it is possible to test these predictions. Models used to develop a SCC do allow for predictions which means we cannot determine which is true and which is not. That said, I am not against using these models to say that, for example, the SCC is between 10/tC and 200/tC. It is just that is a rather large range and it is difficult to formulate any coherent policy based on it.

I agree it is difficult to use reason with people that treat climate change like a religion (as we have seen in these forums). But I don't think it is impossible to sway public opinion to reason in the long run (like over decades).

Sure. Pragmatism is the ally of the skeptic. I became skeptical because I found a lot of skeptics would try to follow the data even if the conclusions were not to their liking. This was a huge contrast with most alarmists who refuse to concede the smallest point for fear that they might harm the "cause".

Yet most countries have a significant impact which has a significant economic impact. Why weren't they 'no-go zones'? Many countries have consumption taxes as well. Many countries have taxes on tobacco.

Every country has its bugbears. For the US it is federal taxes and it is looking like that will be the case in Canada too. OTOH, the US has no problems exploiting fracking to reduce the need for coal which is a non-starter in Germany and the UK.

Germany didn't willfully abandon its CO2 commitments. The idiot environmentalists obtained so much power and imposed such stupid laws that they made hydroelectric and nuclear unviable.

I really makes no difference how the policy change happened. The fact is the German anti-CO2 policy lasted less than 20 years before it collapsed under its own weight. Perhaps a more moderate version will emerge that does not include unobtainable targets.

If the optimal thing to do (according to a properly done cost benefit analysis) is to impose a tax which just slows emissions slightly, then what is wrong with doing that?

There is nothing wrong with that. It is a economically and technically sound policy. The problem the UN process has no interest in such a policy. Their primary interest is in a wealth transfer scheme that moves large sums of money from developed countries into the hands of developing countries after the UN bureaucrats get their cut. I would bet on a low energy fusion process before I bet on the UN changing. Edited by TimG

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TimG, I am not in disagreement in what you wrote in your last post. I just think that the way you framed arguments in your earlier posts is incorrect. If you think certain cost-benefit analyses are flawed, or that the UN is flawed, or whatever then just say that rather than claim that doing a proper cost-benefit analysis or whatever is impossible.

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Okay, so I decided to delve into some more extreme ‘low sensitivity’ estimates. This time the claim of an equilibrium climate sensitivity of 0.58 K that Christopher Monckton has made (he’s the semi-climate-change-denalist guy with the googly eyes that appears on conservative talk shows and ‘skeptic’ conferences).

http://scienceandpublicpolicy.org/images/stories/papers/monckton/climate_sensitivity_reconsidered.pdf

Wow does it have some major holes. It makes a few reasonable criticisms such as climate alarmist James Hansen rounding up his calculations and then other alarmists taking Hansen’s calculations and rounding them up, and so on. But overall this paper is nonsense.

The first hole is that Monckton decides to confuse the forcing effect of CO2 with the overall anthropogenic forcing effect (so includes things like aerosols) in order to magically ‘lower’ the forcing effect of a doubling of CO2 from Δf = 3.71 W/m2 to Δf = 3.41 W/m2 (so magically makes 9% of the warming disappear).

Then he goes on further and arbitrarily divides the CO2 forcing by a factor of 3. He claims this is justified because the ‘anthropogenic fingerprint’ of the mid-upper tropical troposphere warming ~2.5x faster than the surface the tropics, which is predicted in 4 general circulation IPCC models, is ‘missing’. He then refers to an MIT paper by Lindzen to justify slashing the forcing by a factor of 3.

http://www-eaps.mit.edu/faculty/lindzen/230_TakingGr.pdf

There are a few problems with slashing the forcing by a factor of 3. For one, Lindzen’s paper suggested that recent warming has only been 1/2 to 1/3 anthropogenic, yet Monckton purposely chooses the lower value to obtain the lowest estimate of climate sensitivity. Secondly, recent warming being 1/3 anthropogenic is not the same thing as CO2 forcing being 1/3 the value of what the IPCC thinks it is. Thirdly, the ‘fingerprint’ is not just predicted from increasing atmospheric CO2, but from other forcing effects as well (such as an increase in solar irradiance warming the earth, which increases water vapour, which makes the mid-upper troposphere more opaque to the Earth’s radiation, particularly in the tropics, which causes the mid-upper tropical troposphere to warm faster than the surface); so the absence of the ‘fingerprint’ does not imply that the IPCC is overestimating CO2 forcing. Rather it shows that better climate models are needed. Fourth, there is some evidence of this ‘fingerprint’ in the empirical data, it is just not as pronounced as expected; or perhaps the data set used is not a good data set because the interval of change is small and natural variation is not accounted for (1998 was an El Nino year). Fifth, an alarmist might look at the lack of this ‘fingerprint’ and go ‘omg, the lapse rate feedback is not as strong as we thought it was! Therefore, climate sensitivity is even higher than predicted!’. Why would Monckton’s interpretation that climate sensitivity be slashed due to the lack of this ‘fingerprint’ be more valid than the alarmist interpretation? Without further information, I see no reason to modify the Δf = 3.71 W/m2.

Hot-spot-vs-observations-650.jpg

Furthermore, Monckton includes the CO2 feedback effect when trying to determine equilibrium climate sensitivity for CO2, which does not make sense. As a result, he over estimates the feedback parameter b as 2.16 W/m2/K instead of 1.91 W/m2/K.

His criticisms of the IPCC’s overestimation of the climate sensitivity parameter κ might have some validity. However, it was explained earlier in this thread that the non-feedback climate sensitivity should be about 1.15 K for a doubling of CO2 (see post #14). If the CO2 forcing effect is 3.71 W/m2, then this would imply that κ = 1.15 K/3.71 W/m2 = 0.310 Km2/W. This is higher than the 0.242 Km2/W used by Monckton, but lower than the 0.313 Km2/W used by the IPCC. Mockton claims that κ should be lowered by ~10% due to non-uniform latitudinal distribution of incoming solar radiation and his supporting evidence is that Dr. Evans told him in an email; but without any proper justification or source, it is difficult to verify this claim.

In any case, if one goes with 0.310 Km2/W, then this means that the feedback multiplier is f = 1/(1-bκ) = 2.4516.

If you put all this together, then the overall equilibrium climate sensitivity is Δf*κ*f = 3.71 W/m2 *0.310 Km2/W *2.4516 = 2.82 ⁰C. This seems consistent with the 2.95 ⁰C estimate I got from making corrections to the Loehle paper (which I have admitted might be a slight overestimation due to assumption of constant decay rate to equilibrium).

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do you actually think anyone is going to take the time to read all that?

It's not even that much... I read far more than that every day.

Edit: Also, no one is obliged to read it. If people want to read it, they can. If scientific illiterates that refuse to even acknowledge the basics of cellular respiration and photosynthesis do not, then so be it.

Edited by -1=e^ipi

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I actually read that last one in full (though I did not read the OP in full). Interesting stuff, thanks. Also, while I myself have pointed out that this likely is not the best audience for original scientific research, it seems ridiculous that "On Guard for Thee" would complain about it so hard... is it really so bad to have some science on this board compared to the usual trolling and insults?

One thing that is interesting is how much BS is really out there in published scientific papers. My own field are more related to plasma physics, space propulsion, fusion energy, etc, and people publish all kinds of stuff that is just flagrantly wrong. They use the same technique as you show here... go through a bunch of estimates, then pick the extreme end of the range of each estimate and multiply them all together to get an answer closer to what they want. This is very common with over-optimistic promises of small groups claiming to be "just a few years away" from unlocking fusion in some novel way, for example: Well the plasma density is anywhere in the range of 10^19 to 10^24. The confinment time is in the range of 10 ms to 1 s. The temperature is somewhere in the range of 1 keV to 10 keV. Headline: We have a device that can plausibly contain a 10^24 density plasma for 1 s at a temperature of 10 keV. Eureka! Give us money!

Edited by Bonam

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is it really so bad to have some science on this board compared to the usual trolling and insults?

No, it really underscores the sentiment that scientists truly are out to lunch and really are the last people anyone should be listening to, bar none.

Who knew?

Edited by eyeball

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No, it really underscores the sentiment that scientists truly are out to lunch and really are the last people anyone should be listening to, bar none.

Ok, go listen to politicians, priests, and celebrities instead. That'll get you far in life.

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I'm afraid scientists were my last hope. I'd probably given up on your other suggestions way back before you were out of diapers.

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I'm afraid scientists were my last hope. I'd probably given up on your other suggestions way back before you were out of diapers.

The first person you need to be able to listen to is yourself. If things make sense in your own head, then starting to make sense of what others are saying becomes easier.

As for diapers, where I grew up, they didn't exist.

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Well the plasma density is anywhere in the range of 10^19 to 10^24. The confinment time is in the range of 10 ms to 1 s. The temperature is somewhere in the range of 1 keV to 10 keV. Headline: We have a device that can plausibly contain a 10^24 density plasma for 1 s at a temperature of 10 keV. Eureka! Give us money!

Yeah, I know what you mean. In a field that I worked in 3 years ago as a graduate student, I saw lots of people making ridiculous claims in order to get funding. In my research I saw those around me throwing out 95% of their data that did not agree with their predetermined conclusions in order to get the conclusions they wanted and publish them. I also saw terrible methodology and even blatantly untrue claims published in scientific journals. Because of that experience, my career path has been seriously sidetracked.

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96.999% more to go and maybe we'll start taking you seriously too.Maybe even sooner if the rate of scientists abandoning the consensus position takes off.

Dare to dream, keep up the good work .

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