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What is the "political economy forecast" for a carbon tax? What are the benefits of such a policy for containing climate change? ("HFC! CYPHIMU?" Episode No. 1)

In the spirit of CCP’s wildly popular feature, “WSMD? JA!,” I’m introducing a new interactive game for the site called: “Hi, fellow citizen! Can you please help increase my understanding?”—or “HFC! CYPHIMU?” The format will involve posting a question or set of related questions relating to a risk or policy-relevant fact that admits of scientific inquiry & then opening the comment section to answers. The questions might be ones that simply occur to me or ones that any of the 9 billion regular subscribers to this blog are curious about. The best answer, as determined by “Lil Hal,”™ a friendly, artificially intelligent robot being groomed for participation in the Loebner Prize competition, will win a “Citizen of the Liberal Republic of Science/I Popper!” t-shirt!

I have a couple of questions  that I’m simply curious about and hoping people can help me to figure out the answers to.

BTW, I’m using “figuring out the answer” as a term of art.

It doesn’t literally mean figuring out the answer! I think questions to which “the answer” can be demonstrably “figured out” tend not to be so interesting as ones that we believe do have answers but that we agree turn on factors that do no admit of direct observation, forcing us to draw inferences from observable, indirect evidence. For those, we have to try to "figure out" the answer in a disciplined empirical way by (1) searching for observable pieces of evidence that we believe are more consistent with one answer than another, (2) combining that evidence with all the other evidence that we have so that we can (3) form a provisional answer (one we might well be willing to act on if necessary) that is itself (4) subject to revision in light of whatever additional evidence of this sort we might encounter.

Accordingly, any response that identifies evidence that furnishes reason for treating potential answers as more likely or less than we might regard them without such evidence counts as “figuring out the answer.” Answers don’t have to be presented as definitive; indeed, if they are, that would likely be a sign that they aren’t helping to “figure out” in the indicated sense!

Oh-- answers that identify multiple sources of evidence, some of which make one answer more likely and some less relative to a competing one, will be awarded "I'm not afraid to live in a complex universe!" bonus points.

Okay, here are my “questions”:

a. If one is assessing the prospects for enacting a carbon tax (or some comparable form of national legislation aimed at reducing U.S. CO2 emissions), how big a factor is public opinion in favor of “doing something to address climate change”?

b. How much of a contribution would a carbon tax—or any other U.S. policy aimed at reducing the impact of atmospheric concentrations of CO2—make to mitigating or constraining global temperature increases or adverse impacts therefrom?

Some explanation for the questions will likely help to elicit answers of the sort I am interested in:

a. If one is assessing the prospects for enacting a carbon tax (or some comparable form of national legislation aimed at reducing U.S. CO2 emissions), how big a factor is public opinion in favor of “doing something to address climate change”?

This is essentially a political economy question.

Researchers who have performed opinion surveys often present evidence that there is growing public support—and possibly even “majority” support—in the U.S. for policies that would constructively address the risks posed by climate change. This conclusion—and for this question, please accept it as correct even if you doubt the methods of these researchers —is in turn treated as support for the proposition that efforts to enact a carbon tax or similar legislation aimed at reducing carbon emissions in the U.S. are meaningfully likely to succeed.

Of course, we all know that “majority public support” does not necessarily translate in any straightforward sense into adoption of policies. If it did, the U.S. would have enacted “gun control” measures in the 1970s or 1980s much stricter than the ones President Obama is now proposing. We’d have a muscular regime of campaign-finance regulations. We wouldn’t have massive farm subsidies, and tax loopholes that enable major corporations to pay (literally) no U.S. income tax. Etc.

The “political economy climate” is complex—if not as complex as the natural one, then pretty close! Forecasts of what is likely or possible depend on the interaction of many variables, of which “public support” is only one.

So, can you please help me increase my understanding? What is the political-economy model that informs the judgment of those who do believe increased public support for “action on climate change” meaningfully increase the likelihood of a carbon tax? What are the mechanisms and practical steps that will translate this support into enactment of policy?

b. How much of a contribution would a carbon tax—or any other U.S. policy aimed at reducing the impact of atmospheric concentrations of carbon—make to mitigating or constraining global temperature increases or adverse impacts therefrom?

This, obviously, is a “climate science” question, primarily, although it might also be a political economy question.

The motivation behind the question consists of a couple of premises. One is that the U.S. is not the only contributor to atmospheric CO2; indeed, China has apparently overtaken us as the leader, and developing countries, most importantly India, will generate more and more greenhouse gases (not just CO2, but others, like Freon) as they seek to improve conditions of living for their members.

The second is scientific evidence relating to the climate impact of best-case scenarios on future atmospheric CO2 levels. Such evidence, as I understand it (from studies published in journals like Nature and the Proceedings of the National Academy of Sciences) suggests that earlier scientific projections of the contribution that CO2 reductions and ceilings can make to forestalling major, adverse impacts were too optimistic. Even if the U.S. stopped producing any CO2—even if all nations in the world did—there’d still be catastrophic effects as a result of climate change.

As an editorial in Nature put it,

The fossil fuels burned up so far have already committed the world to a serious amount of climate change, even if carbon emissions were somehow to cease overnight. And given the current economic turmoil, the wherewithal to adapt to these changes is in short supply, especially among the world's poor nations. Adaptation measures will be needed in rich and poor countries alike — but those that have grown wealthy through the past emission of carbon have a moral duty to help those now threatened by that legacy.

The latest scientific research suggests that even a complete halt to carbon pollution would not bring the world's temperatures down substantially for several centuries. If further research reveals that a prolonged period of elevated temperatures would endanger the polar ice sheets, or otherwise destabilize the Earth system, nations may have to contemplate actively removing CO2from the atmosphere. Indeed, the United Nations Intergovernmental Panel on Climate Change is already developing scenarios for the idea that long-term safety may require sucking up carbon, and various innovators and entrepreneurs are developing technologies that might be able to accomplish that feat. At the moment, those technologies seem ruinously expensive and technically difficult. But if the very steep learning curve can be climbed, then the benefits will be great.

I’m curious, then, what is the practical understanding of how a carbon tax or any other policy to reduce CO2 emissions in the U.S. will contribute to “doing something about climate change.”

Am I incorrect to think that such steps by themselves will not contribute in any material way?

If so, is the idea that U.S. efforts to constrain emissions will spur other nations to limit their output? What is the international political economy model for that expectation?

Even if other nations do enact measures that make comparable contributions to limiting atmospheric CO2 emissions, how much of a difference will that make given, as the Nature editorial puts it, “[t]he latest scientific research suggests that even a complete halt to carbon pollution would not bring the world's temperatures down substantially for several centuries?”

Thanks to anyone who can help make me smarter on these issues!

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Reader Comments (26)

I see two main arguments for a carbon tax. One is just that it is a Pigouvian tax. There is an externality from CO2 pollution, and people should internalize the cost. The fact that all the reduction accomplished this way is a "drop in the bucket" is irrelevant. The problem is huge, and reducing it by a tiny percentage may still do some good. Although it is very difficult to estimate the benefit of CO2 reduction, some estimate is better than no estimate, and surely there is some benefit.

The second argument is that this is a consumption tax, and consumption taxes are a good way to raise money, and the U.S. government needs money. The politics of passing a carbon tax might be a little less daunting than the politics of a more general consumption tax.

That said, I have been saying for years (e.g., my 1998 book, Judgment Misguided) that it is an absolute scandal how little money is being invested in research on pulling CO2 out of the air. I don't know why the Nature editorial concludes that it is so costly. We really have no idea. Iron fertilization, for example, is studied only by buccaneers. I can't see why it isn't a serious option, and it is relatively cheap. People, including scientists, are against "messing with nature", but it is way too late to worry about that.

January 25, 2013 | Unregistered CommenterJon Baron

Thanks, @JB.

Is it really the case that "drop in the bucket" is "irrelevant" on your account? A Pigouvian tax needs to be set appropriately to force internalization of the harm in question. Don't we need to know, then, how much incremental harm is associated with different levels of CO2 consumption in the US in order to know appropriate tax? Isn't the incremental harm the difference between how bad things will be w/ & w/o the level of reduction associated with a tax of a particular size? If the benefit were "zero" because reduced consumption in the US will not meaningfully by itself affect global temperatures, then the tax would be a pure deadweight loss, right? I'm not saying the benefit would be zero; in fact, I'm asking how much it is -- because it seems to me that that's a relevant question, and despite a modest amount of searching & inquiring, I don't feel I have a satisfactory answer!

Not to jump the gun here, but you are size ... medium? Or small? If the shirt came in "marathon runner's singlet," am I right to assume that you would prefer that?

January 25, 2013 | Registered CommenterDan Kahan

Would you agree that these questions lead to the following question:

(c) Can the answers to (a) and (b) tell us anything about whether abandoning all hope of mitigation, and shifting all effort towards adaptation, would be justified under a pragmatic, consequentialist moral framework?

January 25, 2013 | Unregistered CommenterNeil Stenhouse

@Neil: I would say answers to (a) & (b) are relevant to decisions about how to apportion efforts between mitigation and adaptation. But my *prior* is that *all* the responses within the range of "plausble answers" to (a) & (b) will fit with a *mixed* strategy for mitigation & adaptation. Even if we could do something unilaterally that was super constructive to reduce or reduce the rate of carbon saturatin, many communities will continue to face risks from climate change impacts for decades, and adaptation will be much cheaper (not to mention morally much better) than trying to deal w/ adverse impacts after the fact. Also, all plausible answers to (a) & (b) will be uncertain. In a condition of uncertainty, it is foolish not to diversify responses. So even if one thought "gee, we better concentrate on adaptation, b/c mitigation seems to have limited prospects for success politically or practically" (if that's your position, why do you feel that way? I want some evidence) it would be a *really unwise* to focus solely on adaptation, since it might turn out that the prospects for mitigation are much better than you have reason to think *so long as* one sticks w/ it.

Were you stating your position, btw, in the question? Or making an argument, in effect, against certain answers to (a) & (b)? Say more?

January 25, 2013 | Unregistered Commenterdmk38

First you have to show the correlation between co2 and a warming temp to get a number for the climate sensitivity to co2.

Basic physics says about 1d c for the first doubling of co2 from around 250 to around 500 and another 1d c for the next doubling from about 500 to 1000, all in ppm. The earth will not see 1000 ppm of co2 for a very long time, if ever.

As there has been NO statistically significant warming now for over 15 yrs now, and as co2 is increasing in the atmo at close to a 2x rate, the sensitivity of the earths atmo to co2 must be pretty low. Per NOAA, current atmo co2 is about 390ppm and increasing currently at about 2ppm annually.

More and more studies are showing that many things besides co2 affect climate.

So reducing human co2 use looks to have little measurable and statistically significant affect on the climate. As such, a tax of co2 is another way to tax energy and generate funds, but will do little to change the climate.

January 25, 2013 | Unregistered CommenterEd Forbes

The argument that "we don't know the cost of the CO2 externality, so therefore let us ignore it" seems to me to be a common error in reasoning about policy. If the right answer is 10 +/- 10, then better to assume that it is 10 than to assume that it is zero. In the case of CO2, we need also to consider that the disutility of CO2 concentration is very likely marginally increasing, and the distribution of possible outcomes has "fat tails" compared to the normal, so it is the high side that we need to take into account in an expected-utility analysis.

I agree with you and Ed Forbes that the effect of CO2 reduction is small (and, indeed, it bothers me, as I said, that almost all political discussion is about CO2 production and not about pulling it out, or adaptation, or methane). But a small effect in the amount of warming can have a big effect on people - not as a proportion, but as an absolute effect. So I think we can assume safely that the cost of the externality is positive.

I also agree that we should take into account the effect of a carbon tax on consumption, but it is not a deadweight loss, because, in order to have this effect, it would have to increase total taxes, a result that will have offsetting benefits. Letting my politics hang out, I think that the marginal benefit of taxes is quite a bit greater right now than that of consumer spending, in general.

January 26, 2013 | Unregistered CommenterJon Baron


What you say makes good sense to me but let me probe a bit.

I myself don't mean to be advancing *my* ignorance of the impact of limiting US CO2 producition-- or anyone else's -- as a reason to be against a carbon tax.

But I am wondering if I am right to read the evidence as implying that the best estimate of marginal impact of reducing U.S. CO2 by whatever amount a carbon tax might accomplish is "0 +/- 10"; & if so, then what is the argument for having it?

I think your arguments still apply even then-- that is, even if the impact is 0 +/-10 rather than 10 +/-10? You would say (a) even if the best estimate is nil plus or minus just a tad at 0.95 CI, the >0.05 possibility that the effect of failing to reduce US CO2 production will be an otherwise avertable catastrophy makes the carbon tax justifiable; and (b) since there will be a tax revenue benefit in any case we are hedged or at least cushioned against a truly pointless tax.

I suppose, too, that it's obvious that I'm also curious why the argument you are making is not one that is commonly advanced in public discussions of the carbon tax proposal. Honestly, I've looked for justifications that explicitly address the issue of what the climate-change impact of a US carbon tax would be and found little (at best, only a tiny bit of hand-waving about whether "other nations" will "follow our lead").

The two answers to that question that occur to me (by way, really of hypotheses) is that those advocating a carbon tax either genuinely haven't given any serious consideration to the question of what the climate-change impact of the policy would be or that they believe an argument like the one you are making would be too hard to articulate or would be politically unappealing & so best just to ignore the impact/efficacy issue.

Both of those hypotheses seem so unreasonable to me that I keep coming back to the possibility that I'm simply misunderstanding -- & that in fact there actually is an evidence-based argument for believing that a U.S. carbon tax, on its own or in conjunction with politically realistic coordinated decisions at the international level, would meaningfully reduce the adverse impact of climate change on the U.S. or anyone else in the world.

January 26, 2013 | Unregistered Commenterdmk38

CO2 taxes are having a very positive affect on the US economy now, not in some vague future. though they are European taxes, not US taxes.

As Europe increases taxes on energy, European businesses that require large amounts of energy and natural gas feed stock are moving to the US to stay completive in the world market.

The US is reducing its CO2 footprint while growing it's economy without carbon taxes where Europe is not only becoming less completive due to increasing costs, they are not reducing their carbon footprint. Other nations see these results very clearly. With the fine example of Europe to look at, it is obvious why the push for taxes on energy have stalled.

January 26, 2013 | Unregistered CommenterEd Forbes

@Ed: The "carbon leakage" effect--the prospect that imposing a tax will increase CO2 production elsewhere, both by driving businesses from taxing to nontaxing nations & by lowering demand in taxing nation & hence lowering cost of energy consumption elsewhere--is something I've seen carbon tax advocates address. It's one of the reasons that they say that imposition of such a tax should be coordinated across nations. That raises the "international political economy" issue.

January 26, 2013 | Unregistered Commenterdmk38

There is no reasonable expectation of an international treaty for level co2 taxes with the US joining. China and India, the main co2 emitters, will not kill their economy over this issue and join either.

There is also "leakage" in the US between states. People and businesses in California are leaving the state in large numbers over California's energy and tax policies.

May I also remind you of the US Senate vote on Kyoto that was 100-0 against directly because China and all the developing nations were excluded from the cuts.

The 2010 mid terms showed that this topic is a loser politically for those in favor of cap and trade or co2 taxes. With the next mid term elections already on the political horizon, I do not expect any movement on this issue in Congress.

January 26, 2013 | Unregistered CommenterEd Forbes

@Ed: I agree that the prospects for coordinated international action seem bleak -- or in any case, that the proponents of carbon tax & like policies seem to be failing to address the difficulties as clearly and accessibly as they should.
REad the Sunstein article (see the "update" above) & tell us wha tyou think of his arguments (I'll try to get to it sooner or later!)

January 26, 2013 | Unregistered Commenterdmk38

Cass Sunstein: U.S. Should Act Unilaterally on Climate Change

Cass at least acknowledges one of the main questions:
"..Unilateral action by the U.S. would do nothing about the global stock and little about the global flow. China is now the biggest greenhouse-gas emitter on earth, and in developing nations, emissions are growing at an extraordinary rate. The Sophisticated Objection is that if the U.S. acts on its own, it will impose costs on the American people without seriously addressing the climate problem. What’s the point? .."

But his response to the question is:
"..True, action by the U.S. can’t guarantee an international accord. But it may be a necessary condition for such an accord, and it would certainly increase the likelihood that other nations will act as well. .."

Basically, he proposes that the US follows Europe in becoming uncompetitive in the world market to make a useless point.

I will leave it at "what's the point".

January 26, 2013 | Unregistered CommenterEd Forbes

@Ed: Thanks for the report. The speed w/ which you compiled it made me realzie that Sunstein's "article" was only a very short op-ed. I agree that it is not very compelling; it is less compelling than either the Nat'l Review review of it or @JB's comment (Sunstein won't get the jersey; unless he supplements)

January 26, 2013 | Unregistered Commenterdmk38

I wasn't stating my position in the question - in fact I am strongly in favour of mitigation, for basically the exact same reasons as you stated in your response: it is likely to be cheaper, more moral, and more effective than adaptation alone.

I was trying to put across the idea that framing the questions in the way you did naturally leads to "drop in the bucket" style responses, and for suggestions to give up on mitigation altogether. It's the wrong frame of reference. If every policy is evaluated on the basis of whether or not it will dramatically reduce climate change "on its own", then every policy is worthless.

We should not only consider the effect of a carbon tax on its own, but also its place in the long and complex path that constitutes the transition to a global clean energy infrastructure. As Sunstein suggests in the article that Reihan Salam was responding to, even if a carbon tax is not a massive step on its own, it may be one necessary precondition of bigger steps.

You ask about the international political economy model for why US emission reductions will help persuade other countries to do the same. I'm not sure if this counts as an IPE model, but one framework that has been used to explain similar processes is Finnemore and Sikkink's model of the "life cycle" of international norms. In the first stage, norm entrepreneurs struggle for awareness and recognition, and attempt to recruit other organizations into a transnational network (think of the early abolitionist movement in the UK and USA). In the second stage, there is a "norm cascade" in which the previously radical norm begins to be adopted and legitimated by state governments, and spread to other states by socialization in the international community.

The key question here is whether this "socialization" thing actually works. In Sikkink's recent book The Justice Cascade, she provides quite a bit of evidence that norm-based international socialization via war crimes prosecutions (e.g. at the International Criminal Court) has led to significant improvements in human rights.

So yes - while it's good to avoid too much optimism that enacting federal policy = climate problem solved, I think we should also avoid the idea that the criterion for judging policies is whether or not they make massive contributions, immediately, on their own.

January 26, 2013 | Unregistered CommenterNeil Stenhouse

Just saw the new responses. I definitely agree that many proponents of these policies fail to address the difficulties clearly and accessibly. I'm all for addressing difficulties! Have at it I say.

If we're going to address difficulties however, we should address all difficulties equally. Many opponents of action commit the opposite error: failing to address the difficulties involved with *not* mitigating climate change. We have to weigh the difficulty of reducing global emissions against the difficulty of thriving in a world with temperatures increased by over 2 degrees. Both pretty hard.

Mr. Forbes makes excellent points that meaningful climate policy will impose large (even massive) costs on the US economy. However his broader argument rests on the claim that damage from climate change is almost certain to be minimal. Perhaps he has other evidence to support this, but the evidence he's cited above is false.

"Basic physics" does not say that you get 1 degree increase for each doubling of emissions; it's generally accepted to be at least 2 degrees:

Also the lack of "statistically significant" warming since 1998 is based on the arbitrary cherry-picking of the starting point. The longer-term trend - which is what matters here - is highly significant.

Just ask NASA:

January 27, 2013 | Unregistered CommenterNeil Stenhouse

Good to be back in SC. I was in Boston this past week and missed your blog. At 1F in the morning, I could have used some global warming!

How big the public opinion in favor to a carbon tax is inverse to the tax's size. The favorable opinion of the tax is also directly effected by the economy; better economy, better acceptance by the public of the tax. This makes the policy politically explosive, an exponentially negative political backlash potential. . I would compare the carbon tax failure as the same as Keynesian economic failures: taxing when the economy is good will be opposed as killing the golden goose; and when times are bad, taxes are cut and spending increased. The failure is because of political "will." The carbon tax has the same problem.

What links (a) and (b) is China and India. It is more likely in the scenarios proposed for the "guilty" past carbon users that such a backlash will occur, for example the increased opposition to taxes in the UK. In the US, (a) will face that (b) is giving jobs away to China and India, while taxes increase and the economy shrinks. So, (b) is actually a negative scenario for a sustained committment by the US.

The real problem with (a) and (b) is that we need to grow the economy in order for it to be politically acceptable. This means an increase in carbon, based on what we are currently doing. Just to stay at the same number of quads requires a bit of pollyannaism .

The weakness in proposals to date, besides pollyannaisms, are the technical limitations. An example is wind energy penetration. If one assumes that the producers cannot offload wind energy as Denmark does, only 4% to 6% wind penetration can be accomplished before exponential costs start. At 10% to 13%, technology not in existance is required. Above 13% to 21% or 33%, depending on what can be acheived, requires non existant hardware in major appliances, software, networks, and infrastructure that not only do not exist, but the ability to make such a system work is unknown.

This brings another real problem with (a). Just what is this "something" you are going to try to sell people. Once proposals are made, one can expect that the engineers will come along and start pointing out the problems, since they are already doing so. There is another problem, perhaps the major one.

Having the moral ascendancy is required for the “Citizen of the Liberal Republic of Science” to take from another citizen. At present, moral acendancy is assumed, but the economics show it is a poor assumption. This was the real failure of Kyoto. The senators and the public did not see Kyoto as having the moral ascendancy. This has not changed. In fact, as Dan, IIRC, has pointed out, those whose culture is liberty and freedom of self will be opposed to the takings and the control by the State. In the supposedly doable scenarios, energy use is determined by the regulators. Since self determined energy use is such a fundamental aspect of the American culture, implementation will face continual opposition. This means that the US would not reasonable reduce its own footprint, much less than make a physically measureable effect on world temperatures.

Without moral ascendancy and a working technology that meets the "iron law", the idea that U.S. efforts to constrain emissions will spur other nations to limit their output is based on fallacious veiw of othe countries' desires, as exemplified by China and India. That will give the opposition more reason and argument to oppose (a), since at this point, the taxes are an expensive symbolic gesture.

January 27, 2013 | Unregistered CommenterJohn F. Pittman

Neil Stenhouse "..evidence he's [Ed Forbes] cited above is false.."

OK...lets start with some basic facts brought up in earlier posts to disprove the above statement. I link to IPCC and NOAA papers, not a known activist site with a well documented policy of deleting posts that do not conform with their biased point of view.

NOAA: Special Supplement to the Bulletin of the American Meteorological Society
Vol. 90, No. 8, August 2009
Pg 24 “..Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate…”

IPCC WGI Fifth Assessment Report
10-21:44 “..In summary, while the trend in global mean temperature since 1998 is not significantly different from zero..”

1880 CO2 levels were about 290ppm, so we have to get to about 580ppm to double the CO2 for the 1d increase in temps recognized by the IPCC for a doubling of CO2, and double again to about 1160ppm for and additional 1d increase.

IPCC Climate Change 2007: Working Group I: The Physical Science Basis
1.5.2 Model Clouds and Climate Sensitivity

“…the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain..”

“1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2..”

“..Clouds, which cover about 60% of the Earth’s surface, are responsible for up to two-thirds of the planetary albedo, which is about 30%. An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration. Simultaneously, clouds make an important contribution to the planetary greenhouse effect. In addition, changes in cloud cover constitute only one of the many parameters that affect cloud radiative interactions: cloud optical thickness, cloud height and cloud microphysical properties can also be modified by atmospheric temperature changes, which adds to the complexity of feedbacks, as evidenced, for example, through satellite observations analysed by Tselioudis and Rossow (1994)…”

And I will end on the topic of "cherry picking" with the repost of:

January 2, 2013 | Dan Kahan
"..I don't know why Silver says 1998 is bad faith; do people tussle about starting there? .."
January 2, 2013 | dmk38
" given "record-high temperatures" that year [1998] "associated with the ENSO cycle...." (Signal, p. 403)).

1998 is an interesting data point. One should either toss it out as an outlier or accept as is. As a skeptic of the notion that increasing CO2 will lead to runaway warming, I would accept either position. If one accepts 1998, then the warming from 1980, a common start point, to 1998 show a very worrisome increase in temp. On the other hand, if one accepts 1998, starting at 1998 to date sees a zero temp trend. If one throws out 1998, the trend from 1980 to date no longer looks worrisome.

The remark attributed to Disraeli 'There are three kinds of lies: lies, damned lies, and statistics.” applies to the climate debates. Where one choses the start and endpoints to compute a trend can give quite different answers.

January 27, 2013 | Unregistered CommenterEd Forbes

Ed, thanks for your reply. But I still disagree that what you've cited shows that warming is not happening.

From the NOAA article:

"The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate…”

A discrepancy with the expected warming rate does not mean zero warming: it just means that the true rate of warming may be somewhat lower than previously assumed. There's a long way to go from "somewhat lower" to zero.

On sensitivity: the IPCC AR4 report indeed shows that the *direct radiative effect* is 1 degree. But this is not the same thing as overall sensitivity.

From the very same IPCC report:

"...we conclude that the global mean equilibrium warming for doubling CO2, or ‘equilibrium climate sensitivity’, is likely to lie in the range 2°C to 4.5°C, with a most likely value of about 3°C. Equilibrium climate sensitivity is very likely [i.e. greater than 90% probability] larger than 1.5°C."

So your evidence does *not* provide evidence that warming has stopped, and your figure for sensitivity is incorrect. Indeed, it was not even a figure for sensitivity, but for direct radiative effect, a different concept.

January 27, 2013 | Unregistered CommenterNeil Stenhouse

Neil Stenhouse :"..In the first stage, norm entrepreneurs struggle for awareness and recognition, and attempt to recruit other organizations into a transnational network (think of the early abolitionist movement in the UK and USA). .."

Morality did not kill slavery, economics and capitalism killed slavery with the invention of the horse collar
A horse without a collar can do five times as much work as a man. However, a horse also eats five times as much as a man. But a horse with a proper collar can do ten times as much work as a man while still only eating five times as much... and suddenly slavery becomes economically unviable. The cotton gin and other such mechanization ended the finial gasp of slavery being economically viable.

Neil Stenhouse "..But this is not the same thing as overall sensitivity."
I agree, that is why I noted "basic physics". The basic physics with co2 is only 1d per double of co2, per the IPCC. Sensitivity is where all the fighting is about. Please remember that “…the amplitude and even the sign of cloud feed-backs was noted in the TAR as highly uncertain..” Clouds are 95% of climate. If the science can not tell us the sign (positive or negative) of the sensitivity of the overwhelming driver of climate, one can not say "the science is settled".

Currently, we are well under the range of 2°C to 4.5°C per 100yrs as expected through the models. The models are all running hot and currently the warming in the real world is less than the 2dC minimum from the models. And even the IPCC admits that not all of the little warming we have seen is all due to co2 sensitivity, which reduces the climate sensitivity to co2 even more.

January 27, 2013 | Unregistered CommenterEd Forbes

@Neil & @Ed: Part of your exchange is returning to the issue of how to sort out relationship between (1) experimental test of hypothesized mechanisms & (2) modeling of impact of such mechanisms wi/ complex system; and between (3) validly modeling a complex system through iterative projection, observation, calibration; and (4) using an *invalid* model

I think discussion would progress -- in a way that would educate me, in any case! -- if

A. @Ed ackowledged, if he believes it, that (2) & (3) exist and that erroneous model forecasts, far from discrediting (2) & (3) are an expected, information-generating step toward figuring out how to make better predictions. &

B. if @Neil, assuming he buys all this, would explain at what point bad model forecasts become evidence of (4), which in turn is evidence that we really do need more of (1) & not simply more or (3), & why any incorrect forecasts to date in climate models should be accepted as (3) & not (4). I tried to do this in the earlier discussion & am willing to admit that I did not give supply an answer that I could expect @Ed or any other reasonable person to be satisified w/

January 27, 2013 | Unregistered Commenterdmk38

I'm trying to understand the difference between (3) and (4). Do you mean to suggest that (3) represents the situation where long-term warming is actually happening, and the modelers are gradually getting closer and closer to the precise "true" model of what's happening? i.e. rejecting *particular iterations* of models involving long-term warming?

...whereas (4) represents the situation where long-term warming is *not* really occurring, and the modelers are just post-hoc fitting the curve to the data, and therefore the entire *set* of models in which long-term warming is occurring should be rejected?

January 27, 2013 | Unregistered CommenterNeil Stenhouse

I have little faith in the IPCC models as they have little relation to reality. As such,they are not fit for purpose. The likely reason is that all the IPCC models use a high co2 sensitivity multiplier. The models project 2°C to 4.5°C per 100yrs.or an average of 0.2 to 0.45 dC per decade. Actual temp increases over time do not come within the minimum .2dC per decade, let alone the average of about 0.35 dC per decade.

Over the last 140 years global surface temperatures have risen by about 0.8ºC. However, only the warming from about 1945 to date matters as before this date anthro co2 was minior and also prior to this date the earth was coming out of the Little Ice Age.

For a look at temp vs co2, Wood for Trees provides a nice graphic summary for 1995 temps vs CO2 to date. There is no correlation between temp and co2.

Correlation does not imply causation, but lack of correlation can disprove causation.

To get back on topic, if one can not show a correlation between co2 and temp increases, "whats the point" for a tax on co2?

January 27, 2013 | Unregistered CommenterEd Forbes

Mr. Forbes makes excellent points that meaningful climate policy will impose large (even massive) costs on the US economy.

How do you view such a statement given the existing full cost/benefit context, in that our current energy policies impost costs on the US economy - such as the costs of addressing the geopolitical conditions that enable the flow of oil, the costs in terms of health impacts resultant from the emission of particulates from coal, the costs due to reliance on individual automobile travel as compared to improved public transportation. Of course, a cost/benefit balance must be applied to those items I just listed - but whenever I read about the "cost" of meaningful climate policy change, I feel they are resting on unsupported assumptions without examining the full range of externalities.

January 29, 2013 | Unregistered CommenterJoshua

Joshua, I'm with you 300% on the idea that in the long term, the cost of doing nothing is higher. And yes, far too many people leave out discussion of the costs of inaction, deliberately or otherwise.

The reason I said the points about costs was "excellent" was that pro-action commentators are often scared to talk about what real action will cost - that you have to talk about win-win "green jobs" etc etc and nothing at all negative, otherwise people won't listen.

No matter how good the policies are, and how massive the long term benefits are (economically and otherwise), if you are building a *lot* of clean energy infrastructure that doesn't exist yet, it costs a *lot* of money. Substantially more money than just maintaining/upgrading existing infrastructure.

If anything is worth a lot of money, this is. I just think it's better to be upfront about how much it will cost in the short term. You can't figure out how to convince people big action is worthwhile without talking about *how* big it is.

January 29, 2013 | Unregistered CommenterNeil Stenhouse

Points taken, Neil.

January 29, 2013 | Unregistered CommenterJoshua

Lots of very scholarly points made here - Gotta ask though... making the assumption that the premise is correct (arguing that is not the point of this missive) and that even if everyone on the planet produced zero C02 starting today (can you hold your breath, please?) that things will get very, very bad, then perhaps the best idea is to kiss the girl and enjoy the 1000 or so years we have left assuming that those modeling this thing have got it 100% right. And personally, I'm very uncomfortable with anyone who has things 'all figured out' because they have a computer model that they believe is infallible (as a programmer, you'll pardon my skepticism) screwing around with ideas to try to radically change our climate. These models did not predict the 15 year hiatus in temperatures until AFTER it happened, so why should I trust that NOW they have it right?

All of that aside, I don't know if you've noticed, but it is FAR easier to survive in warm to hot temps than it is to survive in an ice age. Is it possible that increasing arable land by warming the globe would help feed the billions? Let's see. if we raise the sea levels a bit, but increase the amount of water available to the populations, make more land useable for crops (hey, maybe Siberia would be a good place to grow corn for fuel!), expand the growing seasons and reduce the severity of winters, think of how many people we could really help! Perhaps global warming is, in itself, the salvation of much of the undeveloped world. The predicted 'extremes' of weather have not occurred. Take a look at the last 10 years of hurricane data. Even so-called superstorm Sandy wasn't really that bad a storm - it's where it hit. If it had hit the lightly inhabited mid-western coast of Florida, almost nobody would remember it.

Anyway, the issue isn't really the climate, now is it? There is absolutely no way to refute the fact that if you charge a carbon (or any other) tax, it will get passed on to the people by those whom the tax is imposed on. They have to pass it on or the companies cease to be profitable and go out of business. Either way, the people lose. Those in power win because that money goes to them. Maybe some goes into renewable energy and is stolen (remember Solendra?). But government is exceedingly unable to be careful how it takes and spends money. History is my example. Ask yourself: If a solution was really what was being sought, then why 'Cap and Trade'? The trade simply means we can keep doing what we want and people can get rich from the 'trading'.

Sorry - until someone can explain how any of the plans that 'governments' want to put forward will improve my children's and grand-children's lives in the future, I see nothing but a money suck. Any time you TAKE from the people because of something bad that's coming while at the same time saying that it won't make any difference, it's theft and does nothing but hurt the most vulnerable amongst us.

October 17, 2013 | Unregistered CommenterDoug

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