Global warming science

In terms of the global warming debate, I have generally concentrated on the economics and accepted the consensus of anthropomorphic global warming as a given. The earth is warming, the level of co2 is going up (because of humans), and these things are linked. True, true and true. But recently I’ve been researching the science and the conseqences of these facts aren’t as clear as the global warming fear-mongers would have you believe.

At the heart of the global warming scare is the often repeated message that a doubling of co2 will lead to a temperature increase of 3 (+/- 1.5) degrees. This is possible. It is also possible that a doubling of co2 (from pre-industrial levels) will lead to a temperature increase of 0.4 degrees. Given that temperatures increased 0.6 degrees in the 20th century that implies no further warming. Let me explain.

Doubling co2 (from pre-industrial levels) would give us atmospheric co2 of 560 (2 * 280) ppmv. Using the formula (dF = alpha ln (C/Co) where doubling means C/Co = 2 and alpha is 5.35.) we get a dF (change in “forcing”) of 3.7 WM^-2. No controversy there.

Change in forcing is translated into changed temperatures by multiplying it by lambda. But what is lambda?

As mainstream climate scientist James Hansen explains, compared with today the ice age had about 6.6 (+/- 1.5) WM^-2 less forcing and 5 degrees lower temperature. This implies a lambda of about 0.8 (+/- 0.2). Using this lambda, doubling pre-industrial co2 will produce a temperature increase of about 3 degrees and a range of 2-4 degrees. Another mainstream climate scientist, James Annan roughly agrees with this range and rejects alarmist scenarios of > 5 degree warming.

The skeptical argument comes into play when you consider alternative estimates of lambda. The National Acadamies Climate Change Science Report explains that lambda would be about 0.3 without feedback effects and while noting that 0.8 is the mainstream estimate, also says that “the magnitude and even the sign of the feedback can differ according to the composition, thickness, and altitude of the clouds, and some studies have suggested a lesser climate sensitivity”. Shaopeng Huang estimates 0.4 to 0.7. Sherwood Idso conducted 8 natural experiments and found a lambda of about 0.1.

Another suggested approach is to consider the total forcing from greenhouse gases and the total warming from greenhouse gases. Kiehl and Trenberth indicate a total greenhouse forcing of 324 WM^-2 which gives us 32.5 degrees warming. This implies a lambda of 0.1.

Another approach is to consider the changes in forcing and temperatures since the industrial revolution. Roger Pielke Snr suggests about 27% of recent warming (0.6 degrees) can be explained by atmospheric co2 which implies a lambda of 0.11, but this may be an underestimate because there is a time lag between changed forcing and changed temperatures. *

Taking the above estimates a skeptic might prefer a lambda range of about 0.1 to 0.5, which implies a temperature increase of 0.4 to 1.8 from a doubling of co2 with a best guess of around 1 degree. C8to links to an article by skeptical climate scientist Richard Lindzen which indicates that we might be on track for about a 1 degree increase. This doesn’t seem too scary.

There is lots more that we still don’t fully understand about climate change. The impact of clouds, a potential for a weaker solar impact, consequences and feedback from vegetation growth, or exactly what has happened in the past. Sherwood Idso, President of co2 Science, believes that there are several cooling forces that might offset any co2 based warming.

Further, even if there is some moderate global warming, it is not clear that there will be any significant cost. There is little evidence for catastrophic consequences. Environmental economist Robert Mendelsohn explains that moderate warming will benefit countries in the polar regions and the mid-latitudes while only harming countries in the tropical and sub-tropical regions. He suggests that there will only be a net cost if temperatures increase more than 2.5 degrees when mid-latitude countries start to suffer costs.

In most IIPC scenarios, co2 will not double until late in the 21st century. The actual outcome will depend significantly on the actual level of development in the world and the rate of technological progress. I am a technology optimist and ultimately I think the global warming debate will come be seen in the same way as the food-shortage debate sparked by 19th century economist Thomas Malthus: better energy technology will make the debate irrelevant.

UPDATE 28/11/06: Following a discussion with Tim Lambert (see comments) it became clear to me that I was wrong to use the Pielke co2/total 27% estimate in the way that I did and therefore the 0.11 lambda estimate is not valid. This doesn’t impact on the conclusions of the article.

43 thoughts on “Global warming science

  1. This has already been thoroughly debunked at RealClimate. link.

    See also James Annan.

    The short version is that these low estimates of sensitivity are produced by ignoring basic physics — it takes a lot of energy to warm up the oceans.

  2. You’ve debunked the science. You haven’t debuked the economics of technological change. Malthus was wrong. Get back over to catallaxy and talk about cointegration!

  3. That isn’t a thorough debunking. The RC post was a response to the article by Monckton (full paper) and is not relevant to most of what I have written above. And I already addressed their relevant objection in my article when I wrote:

    “…but this may be an underestimate because there is a time lag between changed forcing and changed temperatures.”

    The Annan article is interesting, but doesn’t say much more than the Annan article I already linked to in my post.

    And for anybody interested, Monckton has responded to some of his critics in a new article, which is being debated here.

  4. Whew!! I was worried there for a while that we might need to cut back on the 70 kg of CO2 that each of us contributes to the atmosphere each day. Now I can sleep easy. Nothing to see here.

  5. fucking excellent post…i’m going to read the idso experiment paper with great interest…have been waiting for that to surface for a while…

  6. Please consider the LDP’s energy policy (http://www.ldp.org.au/federal/policies/energy.html) and tell me if we have got the balance right.
    I wrote the policy, with a bit of help. I also have a background in science, not economics, so I understand the bullshit associated with “consensus”.
    On the other hand I don’t have any expertise in climate science.
    So, please tell me what you think.

  7. The science of climate change is irrelevant to the argument that government intervention is unlikely to acheive any of it’s stated aims. By arguing the science, we are buying into the whole “government needs to do something about it” agenda. Leave global warming debunking to scientists, we need to debunk the idea that carbon trading, emission taxes, subsidised energy production (renewable, nuclear, etc.) and other government programmes will make a lick of difference to the fate of polar bears and how many cyclones lash banana benders’ farms.

  8. David: Please consider the LDP’s energy policy and tell me if we have got the balance right.

    Are you talking to me?

    You already know my view for what LDP policy should be — concentrate on debunking the economics because that’s where the argument is strongest and that’s where we have the most credibility.

  9. John: The RC article was a response to the junkscience piece that you linked to as well and debunks all the stuff you wrote on climate sensitivity. You have not adequately addressed the RC article. There is a defiinitely a lag and you only get the low numbers by ignoring it.

    And I I ike this bit: “Taking the above estimates a skeptic might prefer a lambda range of about 0.1 to 0.5″. Apparantly skeptics prefer lower numbers to accurate ones. Please stop calling yourselves skeptics and start calling yourselves “gullibles”.

  10. The LDP policy on Kyoto and global warming is silly.

    The LDP is an Australian political party.

    There is no policy that Australia could adopt that would make any difference to temperatures or climate anywhere on the planet.

    Therefore, the most rational policy is to do nothing. Favouring “market-based options” if further evidence emerges is beside the point.

    If further evidence emerges, it won’t alter the fact that Australia does not produce a large quantity of emissions, and adopting “market-based options” or anything else would be pointless.

  11. I think the problem with all these people (including you) trying to make amateur observations on climate change is that a) the climate science is much trickier than all the easy to read articles (like, for instance, what part of the maths causes the different models to differ in their predictions and why? etc.); b) by the time anything intelligable for non-climate physicts comes out the newer models have been update increasing their validity; c) lots of the stuff needs to be computer simulated via iterative algorithms on huge supercomputers, so its meaningless to try and interpret parameters in your head — thats the problem of nonlinear interactions with no solution.

    Given these problems (and given that there is now almost unanimous agreement amongst governments that something should be done), my suggestion is that it is a far better idea to try an work on decent economic solutions to the problem than simply pointing person x,y, and z who disagree with each other, or even what a termperature rise of x degrees does. Even if the climate consensus was wrong, you may as well come up with the best economic solution anyway if something is going to be done.

  12. John – no I was not talking to you. I am nonetheless pleased to see you moving closer to my position of sceptical agnosticism on the science.

    I was inviting general comment on the LDP’s policy.

  13. I agree with Conrad. I accept the science, altough I find it very interesting and doubt there is as much of a consensus as Tim would make out – have a look at this guy has to say –

    http://www.opinionjournal.com/extra/?id=110008220

    Most of this article suggests he thinks we should have a more conservative approach:

    http://en.wikipedia.org/wiki/Richard_Lindzen

    Finally, the article concludes with some gentle smearing about funding from oil companies. Where the money comes from is irrelevant to the argument. Real climate has some good articles, but they fall back on this character assassination which does not advance their evidence. His argument is merely that Gore etc are overstating their case.

    However, if we accept a human caused global warming worse case scenario as an assumption towards making a policy to deal with global warming in general, a few things become clear when we actually start applying economic analysis:

    As George says, there is very little Australia can do, and as other have said elsewhere, our firms may simply engage in foreign direct investment to overcome Pigouvian taxes, in which plant facilities may be less efficient, thereby not reducing total CO2 emissions or perhaps making them higher.

    Removal of subsidies will encourage better land management by farmers and the production of more fuel efficient cars. This will facilitate vegetation regeneration and less demand for petroleum fuels. The luxury car tax has a similar effect to that of tariffs.

    Removal of the unsupported bias against alternative forms of energy based on spurious arguments (solar is bad because it uses land, wind is unsightly, nuclear is always unsafe, hydro power always destroys fisheries) through removing planing regulations and ensuring that externalities are minimised by allocating strong and secure property rights will see the prices of alternatives fall significantly. Again this facilitates vegetation regeneration, as would a removal of regulation of GMO, which would require less land use and possibly more efficient harvesting of biofuels.

    Privatisation of power supplies will see the right incentives being given to upgrade transmission networks and to minimise inputs, reducing the demand for energy inputs.

    The long version of my arguments is here:

    http://www.catallaxyfiles.com/?p=2130#comment-5599

  14. Brendan, conrad, Mark — I can’t see why you’re hostile to understanding the science debate.

    I have always said (probably before you guys) that we should be concentrating on the economic debate. I was doing rough benefit-cost analysis of Kyoto back in 2003.

    But that doesn’t make the science debate irrelevant. I am not insisting that the science skeptics are correct — but it never hurts to understand some of the areas of debate.

    And George, if you think the LDP policy of not supporting drastic government action (including Kyoto) without better evidence of a net benefit is wrong, then feel free to support all of the other anti-Kyoto parties in Australia. Oh wait. There are none.

  15. Tim, the only relevant point from the RC article is about lags & as I have already explained to you I didn’t ignore the lag. I wrote: “…but this may be an underestimate because there is a time lag between changed forcing and changed temperatures.”

    Assuming there were no lags gave a lambda estimate of 0.11. RC suggests that if we adjust for lags we need to double this (0.22). But my skeptical range was between 0.1 and 0.5 with a preferred number somewhere in the middle. (Btw, I never said which was my personal preferred lambda and am holding off on making a judgement at the moment.)

    I welcome your contribution to this debate, but please try to cut back on the abuse and stop repeating discreditied arguments.

  16. John,

    I’m not hostile at all to the debate. I think it is good that people try and understand it and are interested in it (I certainly am). I’m sure if more people thought about it (or just thought for that matter) lots of things would be much better.

    I was just pointing out the scientific reality for a lot of areas is that by the time the debate perculates to the level of people not in the area, the debate has already moved on. In addition, in some areas, many people are under the false assumption that the data can be understood meaningfully simply by looking at the numbers/graphs produced by the models, and some people can even recite the coefficients etc. (just look at Quiggin’s Blog). For instance, it looks like you have spent a good deal of time looking at the numbers. However, could you, for instance, now tell me how they relate to the models that generated them, what assumptions are likely to be missing from the models, what assumptions have been tested, why the numbers differ in different models etc., and how these relate to the parameters you are talking about ? These are all questions that you might want to be able to answer to have a fruitful debate about what is right/wrong about climate models.

    I think its just a general thing about complex science — it takes people years to really understand various areas well, and I can’t see why this isn’t true of something as complex as climate change, even if some aspects can be understood at a superficial level quickly. No doubt every so often something relatively simple and brilliant pops up (e.g., relativity) but I don’t think climate models are one of them.

    Another good example that is less politically contentious might be string theory. Everyone likes this so much you can buy popular books on it now , where you can basically learn what it is about. You could probably even have a good conversation about it after. Alternatively, I very much doubt that after reading a book on it you could have an argument with someone that spends their whole life looking at it.

  17. I wasn’t commenting on the virtues of the climate models. They are obviously far more complex than simply plugging in a lambda variable and a forcing change. However the central issue about warming remains the feedback effects which can be understood in shorthand by looking at the lambda (climate sensitivity) variable.

    With no feedback (positive or negative) lambda would be about 0.3. No controversy there. Mainstream science suggests enough positive feedbacks to create a lambda of about 0.8. No controversy there. Skeptics doubt this figure and some have estimated lower values of lambda. I just gave a brief overview of how and why some people disagree. Personally I am still undecided about the issue, but I don’t think the key issues are totally beyond the grasp of a well-informed observer.

  18. Much is made of the “near unanimous agreement” amongst “scientists” and politicians (equally human in their fallibility) about anthropomorphic climate variation.

    So what, unanimity? Same deal on the anthropomorphic Guy In The Sky who made the atom then despitefully used humankind with thorns and thistles. Same deal on Prohibition as a necessary and effective way of dealing with the desire of humans to ease their angst and pain by use of happy herbs.

    Some superstitions, including Flat Earth, respond over generations. Not Sky guy so far. It is a tough one. But plain flow of matter (also known as ‘time’) will deal with the Prepare To Meet Thy Carbon Doom, although nobody will own up to having believed it when it fails to come true.

    mydigest.wordpress.com

  19. John says “Assuming there were no lags gave a lambda estimate of 0.11. RC suggests that if we adjust for lags we need to double this (0.22).”

    This is untrue RC states that 20th century forcing is 1.6 W/m2 and warming is 0.6whicj gives lambda of 0.38 if you ignore lags. But ignoring lags is wrong and gives a bad estimate of lambda. Your description of this issue is misleading.

    And please explain what these “discredited arguments” that you allege I keep repeating.

  20. I think that there is some brilliant science being done in the sphere of climatology and paleo-climatology. The main things that stop me from embracing AGW and that lead me to remain skeptical are:-

    1. The fact that the ice core data shows historical CO2 rises lagged temperature rises. And drops in CO2 levels lagged the coresponding temperature drops.

    2. That the models can’t fully account for all the previous major climatic changes.

    None of this leads me to believe that the AGW theory is wrong, it just causes me to remain very much open to the idea that AGW theory might be wrong.

    Like John I am also a technology optimists. I think that even under the business as usual scenerio there will be much innovation in the area of alternate energy.

  21. Tim, perhaps you haven’t read my original post so I’ll repeat the relevant section:

    Another approach is to consider the changes in forcing and temperatures since the industrial revolution. Roger Pielke Snr suggests about 27% of recent warming (0.6 degrees) can be explained by atmospheric co2 which implies a lambda of 0.11, but this may be an underestimate because there is a time lag between changed forcing and changed temperatures.

    If you assume that you need to double the lambda estimate to compensate for lags then I would double 0.11 and get 0.22. The difference between this and the number that you/RC suggest is that you/RC assume that increase co2 is the only cause of the 20th century temperature increase.

    The discredited argument you keep repeating is that I’ve ignored the lag. As quoted above, I mentioned the issue of the lag in my post. You have twice said I ignored it. Please stop that.

  22. I’m a technology optimitist too — and I think it is one area where Australia might play a role in global policy formation. Some things worth thinking about if there is going to be a global carbon trading scheme are:

    1) Whether you can get credits back for the manufucture of energy saving technology and how it should be calculated– should it be done for an estimated life span, or only via use?
    2) Whether you can get credits back for R & D in energy saving technology.

  23. You have mentioned the lag but you assert that it is possible that there is no lag, which is wrong.

    You write: “If you assume that you need to double the lambda estimate to compensate for lags then I would double 0.11 and get 0.22. The difference between this and the number that you/RC suggest is that you/RC assume that increase co2 is the only cause of the 20th century temperature increase.”

    This is wrong. You get 0.38 if you take all 2oth century forcings (not just CO2) and look at the 20th century increase in temperature. Your 0.11 number appears to arise from a RPSr claim that CO2 FORCING is 26% of 20th century forcings and interpreting as meaning that CO2 is responsible for 26% of the warming but is 100% of the forcing. Which makes no sense whatsoever. If you want to just look at the CO2 contribution and believe RPSr’s claim then you get 26% of the forcing and 26% of the warming and you get exactly the same lambda as before (0.38). And as noted before, this lambda is wrong because it ignores lag.

  24. Tim, this might be up your alley given your background:

    Would you know what happens when you force these baseline/IPCC simulations for different time periods, such as 1930-1970? Would it project a totally different expected future scenario, as they thought at the time (e.g, panic about global cooling)?

  25. Were these guys non-scientists making non-analyses?

    S. Schneider and S. I. Rasool “Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate” (Science 173, 138–141).

    Kukla, G. J., R.K. Matthews & J.M. Mitchell. Atmospheric particles and climate: can we evaluate the impact of mans activities? Quaternary Research, 2, 261- 9, 1972:

    From some less stringently reviewed sources

    http://www.realclearpolitics.com/articles/2006/04/cooler_heads_needed_on_warming.html

    Science magazine (Dec. 10, 1976) warned of “extensive Northern Hemisphere glaciation.” Science Digest (February 1973) reported that “the world’s climatologists are agreed” that we must “prepare for the next ice age.”

    Were the scientists quoted in Newsweek (1975) misquoted? (James Mc Quigg, Mitchell and Kukla again)?

  26. Well that’s pretty sloppy and deceiving that these unsupported arguments keep on propping up. But my point is getting away from me. There was a longer period of observed cooling so than there has been of observed warming. Would an ex ante simulation reinforce the discredited cooling idea?

  27. The thing that gets me is the incoherence of the whole climate change argument.

    Even if human activity is causing climate change – so what? Nothing follows from that. Even if it’s costing future humans dear, so what? How do we know that the benefit to contemporary humans doesn’t outweigh that, all things considered? To say we should stop certain activities now, to preserve some benefit in the future, requires somebody to show who is going to benefit from what, when. No-one is capable of doing that, because it involves the total complexity of both the environment *and* the economy. The whole thing is a moral panic built on hype, presumption, and bullshit.

    The climate change involves the assumption that, if human activity is causing climate change, therefore, it should be stopped. But climate change is made up of all the tiny little temperature variations from every single human activity. Similarly, ecological change means change to every tiny little single critter. Species are comprised of individuals. To make human activity truly ‘sustainable’, you would need to ban all human activity altogether. What kind of extremmist conservatisim is this? The reason we don’t ban human activity in general is because there is no set of values over and above human values, which the climate change morons claim to represent. Their argument only makes sense if they are assumed to be on a higher plane of moral superiority, from which they look down on everyone else, and can decide from superior whether this, or that, human activity should be violently suppressed to produce a better society.

    It is the utter intellectual and moral bankruptcy of the whole stupid belief system that should be condemned. I think the technical arguments are a distraction from the much greater yawning gaps in the ethics and epistemology.

  28. Tim, it appears you were half right about the 0.11 lambda estimate. Or at least, we are both wrong.

    But first on a side-track, you say: “…you assert that it is possible that there is no lag, which is wrong.”

    No I didn’t. I asserted that the 0.11 may be an underestimate. The reason is that it doesn’t take account of the lag. I didn’t bring the existence of the lag into question.

    But on to the real point: it appears I was too quick to accept the 0.11 estimate, but not for the reasons you mention. I did not assume that co2 made up 100% of the forcing. As you say, that would make no sense. My estimate for co2 forcing (1.4 WM^-2) comes from the IPCC, and can be confirmed using the formula dF = alpha ln (C/Co).

    The problem was with the estimate of 27%. While the underlying point of Pielke’s argument remains relevant (ie that non-co2 forcings may be larger than previously thought) the number is not useful for the calculations that I was doing for several reasons. The consequence of the Pielke issue is that lambda would be lower than the number you quote (0.38 unadjusted for lag), but without some more work I can’t say what it would be.

    I will adjust the original post accordingly. However, it is worth noting that this doesn’t change much. There is still uncertainty about the size and direction of the feedback mechanisms, and there are still valid arguments for preferring a lower lambda than the mainstream estimate.

    And it’s worth repeating that I am not arguing for any specific number or picking a side in this debate — but I do think the debate exists.

  29. “No-one is capable of doing that, because it involves the total complexity of both the environment *and* the economy.”

    Bravo.

    Even when it comes to just the economics, some economists still think a Ph.D. is sufficient to know exactly when and where to interfere with the market (eg. through minimum wages). Well it’s not. You’d need to be god for that.

  30. You’d need to be god for that.

    A lot of people claim that we libertarians pursue our politics with a quasi-religious fervour. Perhaps we should just go the whole hog and declare ourselves a religious organisation and get the tax free status.

    In the beginning humans created demand
    And the market saw this demand and saw that it was good
    And other humans provided for this demand, and the
    Markets saw that this was also good and just and fair
    For it is not from the benevolence of the butcher, baker, or brewer
    That we expect our dinner, but from their own self interest
    And then on the seventh day, the markets did not rest
    But continued to serve humanity without need of praise or sacrifice
    Amen

  31. Brendan,

    If we must have scriptures lets at least get it right.

    In the beginning humans created supply. And when they had enough of it to satisfy their own wants they found that the surplus could be traded for other things. Thus supply begat supply and it was good.

    But soon some evil nob invented something called “command” and proceeded to organise society in new ways. But society rebelled against the evil nob. So the evil nob renamed “command” and formulated a false religion in which “demand” is the source of all prosperity. And the people were tricked by the false religion and so “command” still oppressed the people. And a dark shadow was cast across the world.

    Regards,
    Terje.

  32. Lambert. You just stop bullshitting.

    Give us some eovidence that CO2 warms to any substantial degree. And lets not get sidetracked on this Lamda JIVE.

    Annan based 3 degrees as a result of a doubling of CO2…. not on the effect of an increase of CO2 in history. But instead on the effect of a diminution of solar power in history.

    This is junk science, scientific fraud, Its a goddamned lie.

    So you just stop being an idiot Tim and come up with real evidence. Stop your evil propagandizing.

  33. Pingback: GW skeptics, alarmists & denialists « Thoughts on Freedom

  34. “What is truth?” asked jesting Pilate (Lambert)
    And would not stay for an answer.

    Come on Lambert. Where is your positive evidence?

    You and the others have kept this balloon afloat on hot air alone.

  35. The fact that the maths is sophisticated means nothing. The models are of no value. You can model a jet engine, or a rendezvous in orbit. These are simple physical activities with limited variation. But the climate modelling is as doomed to failure as trying to model, say, individual & social human sexual orentation, as affected by environment and behaviour would be.

    You cannot model complicated and interactive organic systems. You may BELIEVE you can, and that you are doing a great job, but you are mistaken. Future generations (if they ever even become aware of your fatuous and ludicrous claims for your models) will hold you in derision and contempt.

    Of course we need to output as little unwanted side-product into our air, water and humus as possible. This needs no silly ‘prepare to meet thy doom’ or ‘we have sinned and must be punished’ priest-like smiting/crusade/holy-war. In the West, clean is seen to be the best policy. Planet Earth is gradually being Westernised. Good.

    But for the healthy journalistic publicising of REAL damaging effects to have become segued into a situation where politians are conned by fake-science and plain cranks is disasterous: road building and oil drilling stopped; the West made vulnerable to theist enemies; hard-won gains seized away.

    Cy Quick at mydigest.wordpress.com

  36. The problem with the commentator who wants all the amateurs to butt out so the complex subject subject of climate control can be handled by the experts it that it was experts like Hitler Stalin and Bush who have created some of the worlds greatest disasters. My view is if the science is so complex the average college graduation cannot understand it, then its probably b.s. anyway and doesn’t deserve much credibility. That is certainly the case with the arguments on global warming and all the “forcing” theory. Basically anyone can come up with complex formulas that explain whatever they want but if a lot of others disagree then it is hardly science. For example, look at basic algebra, nobody but nobody disagrees with how algebraic formulas work so they are unquestionable. Global warming formulas are all over the ball park and everybody but everybody disagrees on everyone as to exact inputs appropriate tweaking etc. In short it is all crap.

  37. “In short it is all crap.”
    One year later, nothing has changed.
    What the big unknown (yet another) is how much of a lag killer the current La Nina / sunspot absence will prove to be. A source of worry for politicians everywhere now dependent on the tax from the co2 warming myth. And the IPCC is still fishing for a global tax in the tens of billions, that they will control should the idiots that rule us cede.
    ’twill make fun reading for kids studying history in the future.
    And what about the poor polar bears eh?

  38. mygest,

    If you are correct then your argument is also true of economics. So what is the point of so much economic modelling?

  39. John, imo mydigest would appear to be responding with overemphasis on the negative with regard to models. I would assume as for climate modeling, so for economic modeling. As new factors are found, more accurate data is accumulated, computer capability improves and models refined, the difference between reality and projections gets smaller. There is no argument that models are improving and for the short term are useful, the bogey, the unpredictables are becoming less unpredictable as understanding increases. That is still very far from saying that pension funds etc should base investments on anything that depends on the accuracy of climate projections that are used as predictions. I would suppose that holds equally for economic projections. The ocean moods are far from predictable, oil price hikes, stock market shifts, deadly disease etc. can all occur unexpectedly, and do. To forge policy on what sums up to good or bad guesswork is insane and continues so.
    But to answer your question, still imo, the continuance of modeling is desirable so it can improve. Its use for long term projection with current understanding and data acquisition, quality, volume and processing ability is fraught with problems. Otherwise there would be no stock market losers.
    I hope mydigest is still around and responds to you.

  40. I agree Clothcap and have no problem with eco or climate modeling. We have to start somewhere and given the amount of research into climate modeling it may be the case that the models have been subject to far more intensive labour than in economics. To give you an example: there was a competition run to see who could best predict economic indicators for each year. Simon Turnbull, the Aus psychic, beat all the economic analysts in two years. This means that the economic models and intuition employed actually made predicting worse or Turnbull really is psychic. Take your pick. The big problem for economists is that human behavior is more chaotic than the weather. Poor bastards.

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