Showing posts with label Ideology. Show all posts
Showing posts with label Ideology. Show all posts

Monday, October 21, 2013

Joe Romm's cognitive dissonance on renewables, nuclear and shale gas

I used to be an avid reader of Joe Romm's "Climate Progress" blog. However, my enthusiasm has waned dramatically over the years due to his selective presentation of facts and data, stark intolerance for any opposing ideas and dogmatic stance on nuclear power. (On the plus side, his blog remains an excellent repository for climate news and he can be great fun when mocking the likes of Christopher Monckton.)

Probably the biggest problem that I have with Romm, however, is that he appears to suffer from acute cognitive dissonance. For example, the overriding theme of his blog is one of impending climate doom, yet he regularly proclaims that renewables are already at grid parity, getting cheaper by the second and ready for mass deployment. So, problem solved surely? Frustratingly, this is a recurrent theme on many green blogs, where Cassandra complexes are hard to square with wildly overstated -- or misleading at best -- claims about current renewable energy performance.

Such cognitive dissonance is again on display in one of Romm's recent posts, entitled "Major Study Projects No Major Long-Term Benefit From Shale Gas Revolution". The study in question is by Huntington et al, (2013) and contains projections from a broad suite of integrated climate models. In addition to GHG emissions, the researchers looked at the wider economic impacts of shale gas and their conclusions are rather more nuanced than Romm's excitable headline would suggest. In short, the final projections depend on a complex set of model assumptions and variable interactions. This is evident from the following paragraph that Romm actually cites from the study (emphasis his):
…this trend towards reducing emissions becomes less pronounced as natural gas begins to displace nuclear and renewable energy that would have been used otherwise in new power plants under reference case conditions. Another contributor to the modest emissions impact is the somewhat higher economic growth that stimulates more emissions. Reinforcing this trend is the greater fuel and power consumption resulting from lower natural gas and electricity prices.
Does anyone else see the irony here? Romm is lauding a study which questions the climate credentials of shale gas... and yet that largely depends on whether cheap gas displaces nuclear power -- a technology that he maligns at every opportunity.

More importantly, to say that shale gas confers no long-term climate benefits (in of itself) is extremely misleading. It all depends on whether it is complemented by a carbon price, as anyone interested in this debate (at least that I am aware of) readily acknowledges. You get a sense of this from the very figure that Joe Romm chooses to include in his blog post:

Comparison of low shale scenario (light blue), high shale scenario (dark blue), and a scenario depicting a reference case combined with a carbon price (green). This reference case is in between the low and high shale scenarios, while the carbon price starts at $25/tonne in 2013 and increases at 5% each year. Source: Huntington et al. (2013).

The dramatic reduction in emissions due to a carbon price is clearly evident. However, the above figure is still not really comparing apples with apples, since the carbon price is not adapted to the high shale scenario. (It is applied to a reference scenario that is somewhere in between the high and low shale cases.) Luckily, the data that would allow us to make the correct comparison is available here. I have therefore reconstructed the above graph, this time adding a new column that specifically combines the high shale scenario with a carbon price.

Based on Figure 13 of Huntington et al. (2013). The figure now includes a fourth column (purple) where a high shale scenario is combined with a carbon price.

This updated graph makes perfectly clear that the shale revolution can be fully compatible with deep long-term emission reductions, as long as it is complemented by a carbon price. To his credit, Romm does mention this briefly in the article and has also commented on the issue previously. Yet, by continuing to disparage shale gas and pretend that its supporters ignore the need for a carbon price, he simply serves to further polarise the climate debate.

THOUGHT FOR THE DAY: Adapting to the threat of climate change will require a broad suite of interventions. Nobody should claim that the proliferation of shale gas is a sufficient development for de-carbonising the global economy. However, together with a carbon price and other technological breakthroughs, it will likely form a very necessary component.

PS - It probably goes without saying that the economy also benefits from cheap and abundant shale. Huntington et al. state as much in their report (p. 7):
Higher shale resources reduce the costs of natural gas development and expand opportunities throughout the economy. Relative to its path in the low-shale case, [real GDP] is higher in all models that track the economy’s aggregate output. The cumulative aggregation of these GDP gains over all years is significant standing at $1.1 trillion (2010 dollars).
Showing this in graphical form is a little trickier, since some of the models actually take economic growth as an exogenous assumption, or don't extend all the way until 2050. Nonetheless, here is a graph showing a selection of models that compare changes in real GDP up until 2035.

Thursday, January 31, 2013

I was Ayn Rand's lover

Posted this on twitter a few minutes ago, but I've just stumbled on the best piece of satirical writing that I have read in ages: I was Ayn Rand's lover by George Saunders.

Seriously, and while I usually prefer 57 page monologues like any red-blooded male who likes his philosophy dispensed in the guise of fiction, you really should take five minutes out of your day to read this little gem. A snippet:
Not many people know this, but I was once Ayn Rand’s lover. That’s right. The year was 1974. I was a fresh-faced seventeen-year-old, she was a prominent international author—and we were lovers. By “lovers” I mean: we were constantly raping each other. Well, first there’d be a long speech. Usually by her. Then we’d gaze deeply at one another, and our souls would begin speaking the only language a man and a woman ever need: the language of mutual self-benefit.
And, after our poor hero gets jilted for a younger, stronger protégé of greater conviction (Paul Ryan!):
[T]here I was, back in my sock-smelling bedroom, listening to “Photographs and Memories” by Jim Croce, feeling like a total dork. Or, as Ayn might have said, a “parasitic whining parasite.” 

Sunday, January 20, 2013

Review - Extreme Environment (Ivo Vegter)

Extreme Environment (hereafter EE) is a book written by South African journalist, Ivo Vegter. I have mentioned Vegter before on this blog and he generously arranged for me to be sent a free copy of EE after I offered to review it in an online discussion. Given this, and seeing as some of other reviews that I have read are disappointingly superficial, I decided to provide a chapter-by-chapter overview and criticism. I hope that you'll excuse the subsequent length of this post in exchange for some added thoroughness. (If not, a condensed version of this review can be found here.)


The major premise of EE is straightforward: Environmentalists are guilty of making grossly exaggerated claims and the green movement should in general be regarded with extreme scepticism. I fully endorse the more measured observation of the book jacket, which is that we should be just as cautious of the emotive rhetoric of environmentalists, as we are of corporate spin. EE expands on this dictum with varying degrees of success and some parts of the book are undoubtedly more convincing (and fairly presented) than others. It should be said that Vegter is not immune to moments of unfounded hyperbole himself, stating as early on as page 3 that the car could not have been invented in today's world, because it "would never have passed modern safety and environmental rules". (Talk about exaggeration!)

Thursday, April 26, 2012

Quote(s) of the Day - Marxism

Just to prove my even-handedness on this issue of a priorism and empirical validation, here is the father of the falsification doctrine himself, Karl Popper, on Marxism:
[O]ne might say that Marxism was once a science, but one which was refuted by some of the facts which happened to clash with its predictions[...] 
However, Marxism is no longer a science; for it broke the methodological rule that we must accept falsification, and it immunized itself against the most blatant refutations of its predictions. Ever since then, it can be described only as nonscience—as a metaphysical dream, if you like, married to a cruel reality.
HT: Jonathan Portes

F.A. Hayek, who was greatly influenced by Popper and actually parted company from the extreme a prioristic approach of his mentor, Mises, made a very similar point here (see from 04:30):
Both the Marxists and Freudians had the dreadful habit of insisting that their theories were irrefutable; they [were] logically and absolutely cogent. And that led me to see that a theory that cannot be refuted is not scientific.
UPDATE: Jon Catalan has some thoughts here. I left a comment underneath too.

Wednesday, March 21, 2012

Libertarianism and the paleo diet - Natural or strange bedfellows?

I want follow up on the previous post by making a side observation on the paleo diet's marked popularity within libertarian circles -- especially anarcho-capitalists. Certainly, prominent libertarians like Lew Rockwell, Tom Woods and even Russ Roberts have gone "primal" in a very public sense.

Now, sure, this makes sense at the superficial level: It probably comes very naturally to many libertarians that they reject government-endorsed advice, take pride in swimming against the tide of mainstream thought, and so forth. Indeed, here is an article from LRC that openly flaunts the "ideological parallels" that underpin the libertarian-paleo connection. (Thanks Google!)

However, doing something simply because it feels "familiar" is likely to produce counterproductive results sooner rather than later. This is particularly likely to be true when it comes to endorsing heterodox thinking across unrelated topics.[*] After all, there's a reason why certain ideas tend to emerge as dominant over time: They explain the world around us better than the competing paradigms. (Obviously, this can change as we gain more knowledge. Science is a process after all and not an end result.)

More fundamentally, it seems to me that the underlying scientific approach of the paleo movement -- as outlined by Gary Taubes at least -- is at odds with much of what characterizes libertarian economic thought of the Mises.org variety. I've had my say about the dangers of extreme a priorism before and still consider the rejection of empirical testing by some Austrians to be a completely nonsensical dead end. Indeed, the a prioristic approach is antithetical to the empirically-based scientific approach that Taubes so strongly advocates.

Given his popularity among these groups, I wonder what Taubes makes of this?

[*] Rockwell, in particular, seems prone to indulging just about every crank,conspiratorial, anti-science theory around. (They're all there, by the way. HIV/AIDS, evolution versus creationism, vaccines and autism, climate change... Even David Icke, alien technology and unlimited energy!)

===

Speaking of libertarian-based economic research, a good example of why experimental design is so important can be found by looking at Selgin, Lastrape and White's (2010) much-circulated paper, Has the Fed has been a failure?. The study itself is a great piece of historical writing that makes an important contribution to the literature. It also uses some fairly advanced empirical techniques such as GARCH time-series modelling. However, SLW don't provide a compelling counterfactual and, as such, their work can at best be described as a "pre-post" evaluation. Despite some overzealous reviews in libertarian circles then, this study was never meant to provide a definitive answer to the question that it asked. To their credit, SLW actually emphasize right at the outset (p. 1):
These findings do not prove that any particular alternative to the Fed would in fact have delivered superior outcomes: to reach such a conclusion would require a counterfactual exercise too ambitious to fall within the scope of what is intended as a preliminary survey. The findings do, however, suggest that the need for a systematic exploration of alternatives to the established monetary system, involving the necessary counterfactual exercises, is no less pressing today than it was a century ago. 

UPDATE: Dan Kuehn weighs in with some thoughts here.  He's not completely convinced that SLW heed their own warning...

Friday, February 10, 2012

Science and distortion

Below is a video of the late climate scientist, Stephen Schneider. Please watch it and tell me that scientists are the ones trying to polarize this debate and selectively feed us alarmist harbingers of doom. Specifically note Schneider's comment at the 3:35 mark on the false dichotomies, "end of the world" and "good for you".

I see (environmental) economists as making meaningful contributions to this project as well. Cutting through the extreme and distortionist views, so that we can finally settle on some sensible solutions. At times that seems too much to hope for, but every skeptic could do with an optimistic streak...



UPDATE: From 6:04, Schneider provides a great summary of the role that risk management plays in this whole climate debate. I'd refer readers to this post, where I make very similar observations on risk probabilities and insurance decisions.

Thursday, November 3, 2011

Facts vs Beliefs (George Monbiot edition)

When the facts, I change my mind. What do you do, sir? 
- Apocryphally attributed to John Maynard Keynes

A criticism often leveled at environmentalists is that they are far too wedded to their own ideological agendas to ever partake in rational debate.

Ignore, for the moment, that such criticisms are usually dripping in hypocrisy. (My experience is that extremists on both side of the aisle not only deserve each other, but have a remarkable gift for pointing out their own flaws in their opponents.) The unfortunate truth is that such characterisations of blinkered "green" thinking does hit the mark in many cases. While it's hard to fault someone's sincerity in arguing passionately for the environment, too often reason is thrust aside at the alter of Gaia.

All this points towards why I enjoy reading George Monbiot. His essays often provoke, but they always make you think. Alongside his ability to construct compelling arguments using detailed lines of evidence, his honesty makes him a rare commodity in the world of "opinion" columnists. He is not scared to challenge power or orthodoxy, but is also prepared to admit when gets something wrong.

Now, I've praised Monbiot along these lines before (e.g. here). However, he provides some deeper insight into this admirable trait in today's column. [Background: New data made available by a UK researchers show that resource use (at least in the UK) is diminishing with, and may even be caused by, GDP growth.]
Is the 'peak consumption' hypothesis correct?
I won't deny it: my first reaction on seeing the results of Chris Goodall's research into our use of resources was: "I don't want this to be true." Obviously, I'd like to see our environmental impacts reduced, as swiftly and painlessly as possible. But if his hypothesis is right – that economic growth has been accompanied by a reduction in our consumption of stuff and might even have driven it – this would put me in the wrong. I'm among those who have argued that a decline in our use of resources requires less economic activity, or at least a transition to a steady-state economy. 
[snip]
That was what the available research suggested at the time. But if Goodall's findings are correct, they put a coach and horses through something I strongly believed to be true. 
So, for a few minutes, I engaged in what psychologists call protective cognition. I started scouring his findings for reasons to reject them. It took an effort of will to shake myself out of it and remember that the intellectually honest response to new information is to adjust our beliefs to the evidence, rather than adjust the evidence to our beliefs. We must question and test new findings of course, but we must do so as dispassionately as possible. Otherwise we are in danger of doing more harm than good, and of wasting our lives promoting the wrong causes. Anti-vaccine campaigners please take note. 
Starting again, this time reading it as objectively as I could, I saw that Goodall's report appears to be rigorous and unbiased. It answered many of the questions and objections I raised as I read it. People like me have to step back and consider the possibility that Chris Goodall could be right when he states:
"Absolute decoupling of resource use from economic growth may possibly have occurred … GDP growth, because it brings technological progress which is correlated with more efficient use of resources, may help reduce environmental damage."
[...] 
Monbiot does go on to ask some legitimate questions that might challenge the extent to which we can generalise Goodhall's findings. (For instance, by pointing out that declining resource use in the UK is a relatively new phenomenon with much uncertainty over the longer term.) However, the principle is worth repeating: "The intellectually honest response to new information is to adjust our beliefs to the evidence, rather than adjust the evidence to our beliefs."

Monday, August 15, 2011

Ideas, not people

Beyond the specific subject matter of my previous post, I think that the Paul Samuelson article inadvertently highlights something else of value... especially in the current, polarised economic climate.

Samuelson, of course, was arguably the seminal economist to emerge after the Second World War. A (neo) Keynesian first-and-foremost, he revolutionised the field through the application of a common mathematical language to economic problems (co-opting the approaches found in the physical sciences) and is also held as figurehead of the neoclassical synthesis that came to dominate economic thinking in the latter half of the 20th century.

And, yet, he happily acknowledges a seminal contribution of Friedrich Hayek -- whom many would regard to personify something like the antithesis of Samuelsonian economics -- in an important economic issue; namely the role of decentralised prices in allowing viable economic calculation.

I keep seeing people pitting the likes of Hayek versus Samuelson/Keynes as if it's some stark choice: All of one and none of the other. Similarly, there's a tendency for people to slavishly (deride) defend their (non-) favoured thinker no matter what cost or subject. Now, of course, it certainly is true that there are some very different prescriptions on things like fiscal policy that are not going to be reconcilable... However, it's beyond counter-productive to overlook the fact that there are also some tremendously important areas of commonality.

While I can't speak for every economics programme out there, I've certainly been exposed to (and influenced by) Hayekian insights in my classes and syllabus. And, let's not forget, that's coming from someone studying in the socialist nightmare that is Scandinavia! Dum dum daaaa....


Part 2 here.

Humour aside, I have to smile wryly at suggestions that someone like Hayek has been unduly ignored and marginalised by mainstream economics. That type of explanation just smacks of laziness and a lack of intellectual integrity. The man won a Nobel Prize for goodness sake! Beyond the narrow field of professional economists, he acted as an inspiration for Margaret Thatcher among numerous others, influencing many of the most powerful political  and business leaders of the last two generations.

Just as Samuelson expresses his admiration of Hayek for pinpointing the value of decentralized prices in unlocking the socialist calculation debate, he can comfortably dismiss some of the latter's other prognostications and positions.[*] Finding some redeeming feature in your intellectual opponents isn't a pre-requisite for being a serious thinker, but at least it means you aren't an empty ideologue. By the same token, Hayek, Keynes, Samuelson, or anyone else for that matter, didn't need to be right about everything to contribute many profound insights to economic thought.

It is ideas that matter, not the people behind them.

[*] In case you missed it, the money passage was: Hayek has been persuasive -- not in Whig ideology or in declaring that moderate reform of laissez-faire leads inevitably down the road to totalitarian socialism but -- in arguing that experience suggests that only with heavy dependence on market pricing mechanisms can there be realized quasi-efficient and quasi-progressive organization of societies involving humans as Darwinian history has bequeathed them[...]

Monday, July 25, 2011

More on Norway, liberty and labels

UPDATE: Two very good additional posts by Daniel and Gene Callahan. In particular, will Breivik's quoting of Mises and Hayek be cause for reflection among libertarians, and encourage a toning down of the self-righteous attitude of exceptionalism (and a tendency towards "'sic simper tyrannis" rhetoric)?

As most of you know, I have called Norway home for the better part of two years. While I have been on exchange for the last six months, I shall also be returning there shortly to start my PhD. I have offered previous thoughts on the country's approach to liberty and mixed-market economy elsewhere. For example:
[The commentator above] more or less nails it: 
'Recall that the phrase "economic liberty" means different things to different people.'
As a foreigner that has now lived in the Nordics for close on two years, this is the crucial distinction that I keep trying to point out to dogmatic, US-style libertarians. (Actually, there have been a number of interesting articles on this precise matter... See, for instance, here and here.)
From my experiences, Scandinavians place a premium on equality and fairness alongside prosperity. They appreciate the benefits offered by social security (and, by and large, trust their politicians to make sensible decisions). As one example, the State education loan funds in these nations put an excellent tertiary education in reach of virtually every student. This ensures that they preserve a critical mass of human capital that helps maintain the countries’ international competitiveness, say nothing of rewarding student meritocracy regardless of the social standing of their parents. 
Now, I certainly don’t agree with everything that I have experienced here (e.g. the ridiculous state monopoly on selling wine and spirits), and would be cautious for suggesting how replicable their system is given the small size and homogeneity of their economies. However, I will say that their mixed-economy structure works for them, if nothing else, for the simple reason that everyone buys into it.  
An example that was particularly striking to me: You can freely view the full salary and tax contributions of each and every Norwegian citizen (your neighbour, priest, date for next Friday night… even members of the Royal family) on public websites (e.g. here). You can only imagine the cries of “privacy invasion!” if you tried to implement that kind of system in other parts of the world and yet it is consistent with the Nordic view of how a transparent and fair society should be run.
Freedom in terms of "outcomes" is one thing, but it is the premises themselves that form the crucial distinction here.
I have been meaning to write something on the sheer frivolous of trying to pin down the "Scandinavian Model" according to the usual dichotomies that we've grown accustomed to in the Anglo-Saxon west -- capitalism vs socialism -- for a while on this blog. However, in the absence of such extended comments, I suppose that the above quote succinctly summarises my thoughts. The mixed-market economy is exactly that. Those who seek only to find absolute redeeming features of any particular ideology lose the essence of Scandinavia's successful economic and social balance in the process. But then again, what do I know?...

The majority is always wrong; the minority is rarely right. 
- Henrik Ibsen

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Daniel Kuehn and Gary Gunnels are among those commenting on the Norway shootings, attempting to draw out the blurred lines between political ideology and individual psychology. In particular, what labels should we apply to Anders Behring Breivik? (He appears to see himself as a righteous crusader of liberty and Christian conservatism.)

The twisted mind of our present subject notwithstanding, I am pretty uncomfortable with the tendency to simply categorise individuals by the labels that they self-apply. Breivik's quoting of John Stuart Mill no more renders him a disciple of liberty than having a Che Guevara t-shirt makes you a socialist revolutionary.

If self-proclaimed labels leave me uneasy, then I'm definitely sceptical of the tendency to bend major events and characters to our preferred worldview. I was struck by a thought yesterday when chatting to a friend, who holds strict libertarian views of the anarcho-capitalist variety. He mentioned his surprise -- following revelations of Breivik's identity -- that the attacks were not in retaliation to Norway's involvement in Afghanistan and Libya. However, had the killings indeed been motivated by Norway's NATO activities, I've little doubt that we would have seen the likes of Lew Rockwell dot com trumpeting this as horrific evidence of the uncontrollable fallout of aggressive foreign policy.[*] But, if we were being entirely consistent, wouldn't you now have to argue on that lax immigration policy and social integration should be rethought? After all, they too can now be argued as bringing about terrible backlashes of their own. Well, apparently not.

It is convenient to place people in boxes. This applies as much to others as it does ourselves. When those privileged typologies don't gel with the narrative before us, I wonder which is easier to discard or rearrange...

[*] Just to be clear, my opinion is the possibility of a backlash -- terrorist or otherwise -- provides entirely justifiable (utilitarian?) grounds to generally oppose military interventions in other countries. The operative word being "generally", as there may be equally inescapable reasons to enter into war in particular circumstances.

Sunday, November 14, 2010

Facts vs Beliefs

I should really be studying... but my attention has been drawn to several articles and interviews over the last few weeks that coincide with a recurring theme here at Stickman's Corral: The tendency of beliefs to trump facts, and a priori biases to cloud objective decision-making.

For instance, the below radio interview discusses new research on the problem of "backfire". As the name suggests, this is the phenomenon whereby facts don't necessarily have the power to change people's minds... Indeed, quite the opposite, as people actually tend to cling to their beliefs more strongly when presented with opposing evidence!

A related article on the same research can be found here:
The general idea is that it’s absolutely threatening to admit you’re wrong,” says political scientist Brendan Nyhan, the lead researcher on the Michigan study. The phenomenon — known as “backfire” — is “a natural defense mechanism to avoid that cognitive dissonance.
Similarly, this article (which links to this report) discusses the problems of the "Enlightenment Model", which
holds that people make rational decisions by assessing facts. All that has to be done to persuade people is to lay out the data: they will then use it to decide which options best support their interests and desires.
A host of psychological experiments demonstrates that it doesn’t work like this. Instead of performing a rational cost-benefit analysis, we accept information which confirms our identity and values, and reject information that conflicts with them. We mould our thinking around our social identity, protecting it from serious challenge. Confronting people with inconvenient facts is likely only to harden their resistance to change. [HT: WTD]
Regular readers will know that I've been trying to make a similar point on this blog for a while (e.g. herehere and here).  Stickman's Corral tries to abide by the relaxed principles of El Duderino and this approach was motivated by the realisation that: a) Making purely unequivocal statements is a one-way ticket to intellectual stagnation, and b) The fear of embarrassment or being wrong is among the most powerful motivators out there. If you don't offer people a way out that preserves their sense of dignity, you don't really offer them anything all. I'm always taken aback by how many people don't seem to grasp this simple rule of human behaviour. Or, as I've said several times now: Calling someone an "idiot" is not the best way to convince them of your position.

Now, of course, being respectful of someone you disagree with is hardly the same as not having an opinion. I take numerous angles on this blog that I feel are pretty clearly laid out. Further, I abhor false equivalences. Being open to changing your mind is of fundamental importance, but there are many issues where I think the evidence is simply too compelling for any reasonable person not to embrace a particular side. On this topic, it really grates me to see how tautological the defensive arguments against, say, evolution and climate change are. The first of these is well documented, but the latter typically goes something like this: 

Knee-jerk Sceptic: There is no scientific consensus about humans causing climate change.
Response: Well, actually every major survey shows that over 95% of practising climate researchers support this mainstream view...
Knee-jerk Sceptic: Those studies are flawed. [Or: Those mainstream scientists are wrong and the minority who disagree and are correct and have simply been marginalised.]
Response: Come on, that's a real stretch. The dissenting research simply doesn't hold up to scientific evidence and peer-reviewed scrutiny... 
Knee-jerk Sceptic: The peer review process has been corrupted. We can't trust it any more as opposing views have been silenced. Just look at the "Climategate" emails.
Response: Well, actually, the whole thing was blown ridiculously out of proportion and three independent reviews have cleared the involved parties of any significant scientific malpractice. 
Knee-jerk Sceptic: The reviews were just a sham and a cover up.
Response: Seriously? Okay, how about the fact that independent media analyses have come to a similar conclusion and even sceptics have offered compelling reasons not to put stock into the conspiracy theories...
Knee-jerk Sceptic: I don't care about those reviews; they aren't official. And there is a conspiracy: The governments of the world want to institute a new communist world order by imposing a huge carbon tax so to regulate the free peoples of the world.
Response: That is ridiculous. The amount of money spent on fighting climate change pales in comparison to money spent on, say, oil exploration and research. Even if it didn't, why do you suppose governments would sabotage their own economies by potentially depriving themselves of "cheaper" fuel? Think about it: They can't even agree to binding emissions targets!
Knee-jerk Sceptic: Governments are just fighting it out to see who gets greatest share of the pie.
Response: Look, scientists working separately all over the world have arrived at the same basic hypothesis that CO2 is the most likely culprit behind the observed warming of the last 150 years. Yes, there is uncertainty, but that should call for more caution if anything. More to the point, putting a price on carbon is ultimately about saving us money, since it corrects  for the negative costs that climate change is likely to entail.
Knee-jerk Sceptic: Scientists/Economists are part of the global conspiracy.

Etcetera, etcetera...
Sealed argument, much?

THOUGHT FOR THE DAY: Facts are important, but you have to play - and be sensitive - to peoples' emotions and values if you really want to win hearts and minds.