Someone suggested asking the question, “What would change your mind about Anthropogenic Global Warming?” I replied that I’m hesitant to ask in general, as I know that it would be an open invitation to obstinate skeptics to sling mud and spread misinformation. The discussion would probably quickly degenerate into pointless bickering.
Still, it’s a fascinating question, and one which spurs us to examine our belief and the reason behind it. So instead of asking everybody, I’ll ask the question of the believers.
So, IF AND ONLY IF you believe that AGW is true (i.e., that global warming is happening as a result of human activity), then: What would change your mind?
Note: Inel has already posted an answer. You should definitely read it; but post your response here before doing so, so that her response (which I consider to be excellent) doesn’t bias your own.
Update: Clearly I should be more precise in delineating what I’m asking. So, please limit comments to “What would make you change your mind?” regarding the following:
1. The globe is warming, and will continue to do so in the future.
2. The primary cause is the addition of greenhouse gases from human activity.
3. The negative consequences of this will far outweigh any positive consequences.
I’m interested in discovering the basis for believers’ confidence in the science, not policy strategies (perhaps that’s a topic for a future post, but not this one).
37 responses so far ↓
Article Feed » Question for Believers // February 24, 2007 at 3:40 am |
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Glen Raphael // February 24, 2007 at 9:36 am |
Tamino, by your definition above even *I’m* a “believer”. :-)
The full set of claims related to AGW is more like this:
(1) warming is happening…
(2) …and some of it is human-caused
(3) …and the expected costs of future warming of this sort outweigh the expected benefits enough that we should be seriously concerned
(4) …and we should try to stop it
(5) …and we should try to stop it NOW, when doing so is difficult and expensive, rather than wait 50 years or so for better technology, better understanding of science, and a wealthier humanity to make addressing the issue relatively trivial and cheap.
(6) …and the government should force people to do this.
[Response: there are several propositions with which I disagree, especially that waiting 50 years or so will make addressing the issue trivial and cheap. But for the moment, I'm interested in what makes believers believe the science, not the policy recommendations. So, I've updated the post to give a more precise definition of what I'm asking.]
Dano // February 24, 2007 at 7:50 pm |
Tamino,
IMHO human activities account for the bulk of the recent climate change, not just GHGs.
Best,
D
guthrie // February 24, 2007 at 10:57 pm |
1. A decade or more of temperatures holding steady or declining, coupled with new evidence suggesting everything so far is wrong.
2. The uncovering of other factors that have never before been properly explained, that happen to account for the observed warming.
3. The production of credible evidence and arguments for this position.
THis one is the most entertaining, since I have read of various studies suggesting declining rainfall, major habitati losses and destruction of ecosystems, due to global warming. In contrast the “warming is good for you crowd” point to longer growing seasons and CO2 fertilisation. What they leave out is that the temperature changes will mean crops will no longer be able to be grown in their current geographical locations. Unless we do something about it, which would be a cost. They are strangely quiet on costs.
Furthermore, future technological development, beyond the next decade, is to my mind so impossible to forecast, that hoping they will be able to magically deal with in 50 years time, is incredibly silly.
Peaseblossom // February 24, 2007 at 11:13 pm |
Quite simply, I’d have to see scientific evidence from the likes of NASA and NOAA that sharply refutes what’s been found already.
CraigM // February 25, 2007 at 11:25 am |
(i read inel before i posted…I couldnt help myself)
Ok, the default position for me is basically what the vast majority of scientists are saying, and we all know what that is. I’m just your average joe. I dont have the time to learn everything and go into endless detail. On the one hand I have the world’s scientists telling me one thing. On the other hand I have weirdo’s, a few sensible people, and a few fringe scientists (though most arn’t climatologists) telling me another. Since I cant become a climatologist over night and evaluate all the stuff out there in all it’s technical detail, I’m therefore faced with a choice: Who should I trust? Who should I defer to? I choose the scientists – thats the logical choice for me. That’s why i’ve believed from for some time.
What would change my mind. Well, if scientists stopped saying what they are would be one. But, recently I’ve become more involved in the climate change debate. I’m spending time evaluating the actual evidence. I want to be able to explain my belief with science, rather than just say ‘oh, the world’s scientists say so’. I find the case for AGW more far more convincing. I find some of the real conspiracy claims by denialists a real turn off. But what would a denialist have to produce to convince me that man isnt doing anything to climate. They would have to prove via some strong science that c02 and other GHGs dont have any heating effect whatsoever; or perhaps that the atmosphere is so saturated with these gases that adding more makes no diff whatsoever. That would make a big difference for me.
Having said that, can i perhaps suggest a future topic Tamino. I’ve been buggering with solar forcing (and your posts on this topic were extremely good BTW). But I want to move off that and go through the evidence for the enhanced greenhouse effect in more detail..
Ok. Im told that c02 absorbs infrared. Thats easy to prove with basic experiments. Science fairs do this stuff all the time.
Im told that c02 absorbs certain wavelengths of infrared. Im told this is basic physics. But how they determine this I have no real idea. I need to do more reading.
Im told that c02 is 9-26% (3-9oC) of the greenhouse effect. I ASSUME they somehow measure the backradiation from earth, and the amount of infrared escaping at the top of the atmosphere with satellites or something. Then they do some calculations. How they are really doing this I’m not totally sure.
And…I’m told that the atmosphere is not saturated with c02. I believe (I could be really wrong here) that the lower atmosphere is more saturated than the higher atmosphere? How are they determining how saturated the atmosphere is? I assume they measure it somehow and then do some funky maths. But I have no idea again.
And I’m told that scientists are pretty confident about how much direct forcing 2Xco2 will provide, and how much temperature would increase if we just doubled c02 while leaving all other things the same. Why they are so confident I have no idea. The models say so, I’m told. Why the models say so I have no idea. There are still a lot of gaps in my knowledge.
Anyway…sorry for going off topic here.
reasic // February 25, 2007 at 1:26 pm |
Glen,
I think what you’re not considering is that while we may have technology in 50 years that could make handling the situation much easier and cheaper, in 50 years, the problem will have gotten much worse, therefore making it much more difficult and expensive to deal with. Now which one trumps the other and by how much is surely hard to determine at this point. I would tend to say that it is more of a certainty that the problem will be much worse than it is that we will have some technology that will save us.
The IPCC will release information later this year on recommendations for remediation, I believe, but for now, we can look at examples like the UK, who have lowered their emissions by 14%, and whose economy is still trucking along at 2.8% or so, just barely less than the US. Kyoto has not ruined their economy. The US, on the other hand has increased its emissions by 16%. While it is very convenient for those who are opposed to taking action to imagine doomsday scenarios in which our economy is ruined, the fact is that it would not be as they say, and taking action later rather than sooner is only going to make it a more difficult problem to deal with.
There is also the advantage in putting it off that you are passing it off to the next generation(s), but that would not be the responsible thing to do.
What Would Make Me Change My Mind? « Reasic // February 25, 2007 at 7:41 pm |
[...] change , debate , science , politics , government , news Tamino at Open Mind, has asked the question, “What would change your mind about Anthropogenic Global Warming?” Before I start, I [...]
guthrie // February 25, 2007 at 9:41 pm |
Possibly a gruesome analogy, and I am also no medic, so its all hand wavy, but anyway:
I suggest that one way of thinking about it would be that you have a horrible infection in your hand. It is slowly eating up your arm and dropping toxins into your blood. Your choices are to eitehr have your hand amputated immediately, or else wait several days for the antibiotics and antitoxins to arrive, by which time the situation will have gotten worse, but then if they pump lots of them into you you might not lose your hand.
Which do you choose?
Losing your hand now will be painful, but short and sharp and prevent any more deterioration. If you wait a few days, you might save your hand, but it will be a very painful few days, and the toxins might cause widespread damage before you are treated, and you may well lose your hand anyway.
Real life is not of course quite like that.
It is perhaps more like this:
http://www.bbc.co.uk/sn/hottopics/climatechange/climate_challenge/
A game on the BBC website about making decisions about climate change etc:
http://www.bbc.co.uk/sn/hottopics/climatechange/climate_challenge/
(Oddly enough I found it because it was mentioned on the blog of a YEC.)
britandgrit // February 25, 2007 at 9:52 pm |
Hi tamino,
That is a mighty fine question. Generally, my answer would be that, if in ten years the predictions made today are reasonably close, I’ll buy it. Oh, and since we moved to our own domain, we were able to add a forum / discussion board area. Please feel free to use it if it will help further the conversation. We even have an area for people who just can’t help screaming at each other :)
reasic, you have your figures off on UK vs US reductions in CO2. Even though the UK signed onto the Kyoto treaty, the US has, without Federal regulation, reduced its increase in CO2 emissions more than the UK that regulated reductions. You need to be aware of political speak, since the inflections are difficult to keep straight. None of the countries who signed the Kyoto Accords have actually reduced their pollution. Everything now is being measured against their projected increase in this area. It’s much the same as the US Congress considers a reduction in the projected rate of funding increase to a program a “cut” in funding, even though the actual budget for that program goes up.
the Grit
John // February 26, 2007 at 12:04 am |
Hi britandgrit:
Excellent clarification and well worth noting. There has been a reduction in the increase in CO2 emissions without regulatory dictate and that reduction has been greater than any reduction by the next best reducer & Kyoto signer. From an economics perspective, taxes and regulation should always be last choices, never first choices. Increases in either bear an uncanny inverse relationship to increases in GHGs: they cool their environment (economies). Decreases in taxes and regulations spur growth of capital, sales, profitability, earnings, productivity, tax revenues – and ‘environmental sustainability’. Thank you.
Glen Raphael // February 26, 2007 at 1:55 am |
[tamino: Having stirred a hornet's nest with my offhanded "50 year" comment I feel some obligation to clarify and respond, but feel free to delete this if it's too out-of-scope. Thanks.]
reasic,
Suppose you could press a button and magically make the CO2 level of the planet anything you wanted it to be, at zero cost, knowing it would stay at that level from then on. What would you set it to? Would you change it from what it is right now? I suspect most people wouldn’t. We have a strong status quo bias. The prospect of change scares us, but we quickly get used to each new situation after change happens. So we are likely to think the current level of CO2 is fine, whatever it is.
Intuition tells me that even if the IPCC is right about everything, that will still be the case 10, 25 or 50 years hence. It may be warmer than now, but people will feel like they have adapted and are fine with it. They may still be scared about future warming, but won’t feel compelled to “fix” that which has already occurred and has become familiar.
If I’m right, the perceived magnitude of the problem – this notion that temperature now is okay but temperature in the future might be a problem – won’t really have changed in 50 years. The benchmark level will have changed, is all. That is to say: it won’t be necessary to undo any change between now and then.
But in 50 years, people will be much wealthier and will have much better technology available to them and will have much better understanding of the science and a longer, better observation record than now.
So the problem of anthropogenic global warming is getting a bit worse over time (mainly due to population growth), but our ability to address it is getting better over time at a faster rate (due to population, economic, technologic, and scientific growth). Given that dynamic, the longer we wait, the easier the problem will be to solve. As it gets cheaper and easier, it’s likely the problem will eventually solve itself without anyone really noticing, just in response to changing social tastes and newer, less wasteful technologies naturally replacing older, more expensive ones.
The “horse-manure” problem of 1900 disappeared by 1950 as one form of motive transportation replaced another. This problem will solve itself in a similar fashion, probably well before 2050. But heck, if I’m wrong and it does turn out to require a political solution, our kids will be so much richer and smarter than we are that anything we would do now, they’ll be able to do better then. So there’s really no cause for alarm, no urgency. Plenty of time to clarify the science, to map a course before we start the race and thereby avoid driving the wrong way.
Petro // February 26, 2007 at 3:48 am |
Glen wrote:
“The prospect of change scares us, but we quickly get used to each new situation after change happens. ”
Surely change will scare those people and nations, which have adapted to climate prevailed for hundreds and thousands of years. The adaptation for changed pattern of rain, which collapse agriculture in tropic does not really happen in decades, especially since the change is still going on.
Global climate change is not just about little bit of warmess, it is the drastic changes is whether patterns all over the world affecting hundreds of millions people now.
Andrew Dodds // February 26, 2007 at 10:21 am |
Glen -
Although the ‘Horse Manure’ problem went, it is interesting to note that traffic speeds are largely where they were 100 years ago in London..
And on many measures, western populations haven’t grown much waelthier since the 1970s. This isn’t a great surprise, since the underlying technology hasn’t really changed that much; we still, fundamentally, burn coal and oil. We do it more efficiently, more people work more hours and we have better electronics, but drastic advances haven’t happened. So to simply assume that fast forwarding 50 years will certainly mean that we’ll be able to change climate on a whim appears unjustified.
We first went to the moon in 1969. It’s still not a holiday resort; we haven’t even got a permanant base there. That’s 38 years progress in one field. And don’t even ask about supersonic passenger transport.
Given the above, there is indeed no reason to suggest that progress will be made in the relevant fields, especially if there is no commercial interest.
A lot of technological optomism appears to come from extrapolating a single process – the linear shrinkage of electronic components (leading to an exponential number on a chip, of course) – to the entire field of human endevor.
stewart // February 26, 2007 at 1:38 pm |
Tamino;
Thanks for posting this. My intention was to raise this as a science question, as your site is science-based. Preposterous responses indicate the reader is not science-based, hence their responses are noise, not signal.
Inel, your response was elegant. Since we can’t know it all, and we’re almost all non-specialists, why not let the specialists do the work. Then, if they change their mind (like on plate tectonics, bacterial infections causing ulcers, not much else comes to mind right now) we can rely on normal mechanisms. We don’t have to consider every high school math teacher who has a novel theory, just as we don’t for AIDS, evolution, astrophysics, or the conservation of energy. The loons in those areas also claim conspiracy when they don’t get the keys to the candy store.
John // February 26, 2007 at 3:20 pm |
Andrew Dodds:
Read ‘It’s Getting Better All The Time’ by Julian Simon, 2000, Amazon available. Comment. Stewart:
Tamino does a good job on the site; let him do the moderating, we shall participate, at his discretion.
tamino // February 26, 2007 at 4:07 pm |
There’s been a lot of discussion lately on subjects which are essentially policy-related and/or economic. I encourage such discussion, but I have no special knowledge to contribute. Also, although I encourage such discussion (and indulge in it myself), I prefer the science of global warming.
So, discuss away. But keep it at least reasonably polite. And if some comment really angers you, take time to cool off before launching a response. You’ll be glad you did.
reasic // February 26, 2007 at 4:29 pm |
Grit,
I actually think you’re the one that is incorrect on the UK vs. US numbers. I’ll have to find the charts I looked at when I got those figures and provide some links so we can figure that out.
reasic // February 26, 2007 at 4:58 pm |
okay, Grit. I’m back and I’m armed with stats, so watch out! :P
I may be reading these charts and graphs wrong, so you guys help me out. It looks to me, from this data, that the US has increased overall, over 16%, while the UK has decreased significantly and the EU has decreased slightly:
US stats
Go to page 9. It says that in 2005, the US emissions are 7,147.2 MMT CO2e, compared to 6112.8 in 1990, making it an increase of 16.9%.
UK stats
I could only find this table, which goes to 2003, for the UK. It looks to me that they started with 762 MMT CO2e in 1990, and were at 656 MMT CO2e, for a decrease of 14%. I don’t think this is a decrease in a proposed increase. It looks like it is a straight decrease in overall emissions. Am I wrong?
EU stats
This also shows an overall decrease, however slight, for the EU. It also seems to me to be total emissions.
Help me out here, guys. I know the US talks in decreases of increases, because it makes it sound like we’re doing something when we’re really not. However, I was under the impression that the UK was actually decreasing total emissions. If I’m wrong and somehow the US is actually doing more than the UK is, I need to seriously re-evaluate my position on this.
reasic // February 26, 2007 at 5:00 pm |
Sorry, Tamino. I think I messed up that UK link somehow. could you edit it for me?
[Response: All the links work except the "UK stats." That's because there's no URL! Send the URL, and I'll put in in the post itself.]
John Cross // February 26, 2007 at 5:00 pm |
John: I have not read the book you quote (only a review of it) so I stand to be corrected but I believe it looks at changes in America over the last 100 years (give or take). It takes certain standards (e.g. health, environment, etc) and says that things are getting better all the time.
Now, let me ask you, assuming I have the idea of the book roughly correct, how many researchers were involved in the work? How many sources of data did they draw from? Most importantly, how much checking of other causes did they look at and how much peer review did it go through?
To me it seems inconsistent to take the results from this book and project it out 50 to 100 years and predict that we will have wonderful solutions, but at the same time detract from the global climate models so much. The models have undergone much more rigorous testing and have much firmer science behind them than the book you reference, yet you feel that the book makes a much stronger case.
As I said, to me it seems inconsistent, but I would be interested in your thoughts and comments.
John
John // February 26, 2007 at 9:59 pm |
John Cross:
First, the data base of the text can be viewed in the bibliography as well as on each graph. It is, simply, 265 pages of tables and figures, with less than 10% of the text devoted to scribblings. The data sets are primarily, but not exclusively, US. It invites readers to draw their own conclusions. Beware: it is published by The Cato Institute…
Second, I am not offering it as a panacea for the future, simply as a counterpoint to Mr. Dodd’s assertions regarding ‘the horse manure problem’ and lack of progress in the Western world.
We cannot state with certainty whether scientific progress, or any other kind of progress (or regression) will have a negative, positive or neutral effect on the future of humanity. We may observe the facts of the case – the significant progress that humanity has experienced over the preceeding decade, half century and whole century. We may also observe that if a similar delta of progress were to continue, then there is a higher statistical probability that answers to today’s questions may be found. A contribution to that delta may come from an ever increasing number of science students, applicants to university, tenures, peer reviewed documents, etc. An excellent source of such a surge is the currently ill fed, malnurished, rights-less women and children in the thirld world. Feed, cloth, nuture and rights them and let’s see what happens…
Thus, the economics of affluence and wealth may be a pathway to answers to the climate issues so admirably forumed here by Tamino. Of course, a personal carbon tax may also be a pathway, but as students of economics, we doubt it. Statistical evidence of tax/regulate behavior points in other directions.
Tamino,
If these economics strings are excessive, I shall be glad to back off. The Stern report has brought us into the AGW debate, so here we venture…
[Response: So far the dialogue has been quite civil, so I don't mind. Just don't expect me to add intelligent commentary very often! Now if you want to talk about ice ages...]
Change my Mind? : Atmoz // February 27, 2007 at 1:54 am |
[...] a partial response to Tamino: Question for Believers So, IF AND ONLY IF you believe that AGW is true (i.e., that global warming is happening as a result [...]
Andrew Dodds // February 27, 2007 at 11:09 am |
John –
Well, I was giving a counterpoint to the idea that everything is always improving. Plus I was looking over the last 30 or so years, rather than the past 100.
The thing is, we’ve had the technology to stop AGW (Or cut emissions of CO2 by 95% or so, anyway) for several decades now; it’s essentially a breeder reactor program. The problem is that on one side, the environmentalist-left automatically dislikes nuclear power (somewhat irresponsably in my view), and the free marketeer-right refuses to counternance the fact that energy supplies are better organised by engineers than markets.
My contention would always be that removing CO2 generation at source – by making electric grids all-nuclear, households all-electric, and the introduction of synthetic liquid fuels, GHG emissions can be massively reduced without people having to make personal sacrifices – indeed, given the likely shortages of fossil fuels generally, this is almost certainly a cheaper option over the medium to long term.
And if that makes you say ‘well, then the market will find it anyway’, then you are forgetting the problem of investment lifecycles; once, for instance, you have spent the capital to build a coal plant, replacing it before the end of its service life 50 years hence implies writing off the whole investment; so even if prices spike, you don’t replace it with nuclear. Yet even if you can predict that prices for coal (or especially Natural gas) will be vastly higher 20 years hence, any company investing in that fact will be outcompeted to bankruptcy in the short term.
reasic // February 27, 2007 at 1:21 pm |
I’m still looking for that link, Tamino. I’ll be at work in a bit. Maybe it’ll be in my IE history there. I’ll post it when I get it.
John Cross // February 27, 2007 at 1:48 pm |
John: Thanks for the description of the book. However you have not addressed the second part of my question – which is teh lack of faith in the GCMs.
You will forgive me I am confused, but I see that you are willing to accept the concept that our past performance is some sort of prediction of the future. I would argue that we can only say this if we can determine the underlying drivers of scientific and technical progress and then only if we can predict (with confidence) that they will remain effective into the future.
To counter your points about contributions “to that delta” I would say that our technical progress is based on a more rigorous (I didn’t say better) educational system. The fact that our future scientists can’t use a slide-rule is a step in the wrong direction (but some have called me hopeless old fashioned).
But none the less, looking at your points, how much of an effect will educating the third world have? When you say it will improve the statistical probability of solutions, from what to what and with what confidence? I don’t see any answers to these questions.
Yet when I look at the GCM, I see models that are not perfect but have strong theoretical underpinings and data sets to work with and have been under development for over 30 years.
So, after all that, what is my point? Simply that the GCM have a much stronger basis for their predictions than the idea that technology will solve everything.
Regards,
John
reasic // February 27, 2007 at 3:37 pm |
I finally found the UK stats link. It’s:
http://www.environment-agency.gov.uk/commondata/103608/i1_ems_air_a8_dt1_154217.txt
[Response: I've confirmed that the link works, and put it in your previous post.]
inel // February 27, 2007 at 3:56 pm |
Does this post with UNFCCC GHG inventory data help, reasic?
re: the Grit’s assertion …
… how do you explain the negative numbers on these graphs, the Grit?
Are you, the Grit, referring to the fact that the total percentage change in emissions for all Annex I Parties in 2000-2004 is 2.9%, which is positive? If so, in this particular time period your statement is verging on correct, but you also need to change your statement to refer to the total instead of saying “none of the” individual countries.
Unless of course, you do not trust this data …
P.S. Not all of the companies are reporting all their GHG emissions data in detail, so we could debate the numbers on these charts till the cows come home, and then find we had missed something that had not been reported. However, as long as people are making an honest effort to combat climate change, they should be applauded, imho.
John // February 27, 2007 at 4:52 pm |
Andrew Dodds:
Thank you for your reponse. You points are well made. Much of the technology exists today to address the issues; applied science (engineering) can further contribute. Markets will price, inefficiently short term, efficiently long term, the answers.
These are the types of ways that, in our opinion, can ’sell’. Fear does not ’sell’. For a variety of complex reasons, the US culture adopts a “can do” attitude. If we are presented with an issue to which no solution is evident, proscribed, or possible (e.g., the challenge of very long timelines to a psyche), then it becomes irrelevant. Present the same problem in a context we can understand (breeder reactors, all nuclear, all electric, engineering, etc.) and then we get it. Julian Simon trumps the Erlichs far more often than not.
John Cross:
Thank you. No doubt you may be right on the GCMs. We suggest a reliance upon a variety of solutions, in addition to a description of the oncoming event. However scientists (& financial guys) are trained in the future (with or without slide rules, which we learned from too…), an increasing number of them may be another solution. Lifting folks from poverty may increase that number. This cannot be proved, any more than the GCMs can be proven. They are each working within the realm of probability (reames-stokes equations ??, sorry, not mathematicians). GCMs demonstrate the issue. Wealth (food, shelter, clothing, health, land, education) may allow for solutions.
Some perspective. 2B+ Chinese, Indians, etc. are coming up the ladder, quickly. The ladder is made of wealth, pollution, cars, at el. That number is 3x the current western world’s population (europe & N. Am.). If AGW is a problem, then it is getting bigger. Mr. Dodds has a vairiety of answers to the obvious problems. Wealth creation has a few more. Leap frogging tehnologies … new ideas…
Tamino:
Thank you. Ice Ages, hmmm… Our knowledge is quite limited – Ice Ages (Imbrie), 2 Mile Time Machine (Alley), Meltdown (Michaels), A Matter of Degress (Segre), Ubiquity (Buchanan) as well as the Gold and Singer books previously mentioned. Any suggestions for further reading?
Jay Alt // February 27, 2007 at 8:12 pm |
Expected global warming relates to the sum of the extra CO2 emissions. It is not a rate or flux problem like radiation, athough it is good that U.S. rates finally dropped. But that is certainly not evidence we are doing anything close to Europe.
That claim is an Enron-style accounting trick by someone who wants to reframe the problem and derail Kyoto-style cooperation. The US is responsible for putting ~30% of the total excess CO2 in the atmosphere and that ratio won’t change much for quite some time.
They pick 2000 as the base year, because doing so gives the biggest drop:
http://www.eia.doe.gov/oiaf/1605/ggrpt/figure_1.html
This is similar to global-warming denialist’s claim that the world has cooled since 1998, as that year had the highest average global temperature through ~2005. Note height of single sharp red spike:
http://www.cru.uea.ac.uk/cru/info/warming/
Slioch // February 27, 2007 at 11:08 pm |
What would make me change my mind about AGW?
It seems to me, belief in AGW is a three-legged stool.
The first leg is the huge amount observational data, including: both historical – eg. the polar ice cores showing temperature and CO2 etc. variations going back some 800,000 years; the more recent records of GHG emisions and temperature changes; and the melting of glaciers and ice caps.
The second leg is the physical theory and climate models that provide a coherent explanation for the observed effects.
The third leg (necessary for a non-specialist at least) is the strong consensus (!) amongst climatologists that the physical theory does indeed provide a coherent explanation for the observed data.
One would have to break any one of those legs for the stool to tumble, for example: observational data that showed a significant departure from expected behaviour for a significant time; an alternative hypothesis that could explain present changes without resource to the effects of greenhouse gases/albedo/aerosols and that also showed those effects to be unimportant; or a revolution amongst reputable physicists and climatologists declaring that the previous theories and models had been mistaken.
The stool looks pretty safe. We should continue to sit on it roughly and kick it about a bit and listen for its creaks and groans, but I do not think any of the legs are about to come off.
inel // February 28, 2007 at 10:35 am |
Slioch’s three-legged data/models/consensus stool is brilliant.
reasic // February 28, 2007 at 4:34 pm |
Grit? I was interested to see your take on the emissions stats.
Steve Bloom // February 28, 2007 at 7:10 pm |
Inel and Jay, thanks for locating the information refuting Grit’s sourceless assertion about US progress on CO2 reductions. As with so many denialist claims, it’s a lot more work for folks like us to locate the source material than it is for someone like Grit to make the assertion. I am reminded of the prior “Natural Variations” thread here in which Grit cited an article from the Hindustan Times that seemed to claim (albeit using some slightly elliptical language to do so) that there hadn’t been significant observed melting of Himalayan glaciers in recent years. It took me well over an hour to confirm that the article was bogus and write a properly sourced comment . It also became clear in the course of my research that Grit had simply picked up the glacier item from the wingnut blogosphere. It’s a little sad that he’s willing to take such information on faith while at the same time discounting in advance any information from climate scientists. Tamino at one point commented that he thought Grit had some degree of intellectual integrity, but I’m afraid the evidence points toward a different conclusion.
inel // February 28, 2007 at 10:33 pm |
Steve, it’s my pleasure. Glad you found it, as I just went back to check and my link above is invalid. Sorry. Here is the working model (!) in my quote, in case the Grit would like to comment:
reasic // March 1, 2007 at 2:42 pm |
Yeah, I knew as soon as I saw Grit’s comment that he was probably referring to something like the Horner report, which only references four years of data. So, I went and dug up some links from a prior debate on that subject. I’d still be interested in Grit’s response.
kennebecriver // March 2, 2007 at 11:48 pm |
“What would make you change your mind?”
—
A memo from God saying He’s changed the laws of physics.
Aside from that … nothing.