On Nov 17, 7:52 am, Alastair <[EMAIL PROTECTED]> wrote:
> On Nov 17, 3:11 am, Tom Adams <[EMAIL PROTECTED]> wrote:
>
>
>
>
>
> > On Nov 16, 9:46 am, Alastair <[EMAIL PROTECTED]> wrote:
>
> > > On Nov 16, 12:44 pm, Tom Adams <[EMAIL PROTECTED]> wrote:
>
> > > > On Nov 15, 4:21 pm, Alastair <[EMAIL PROTECTED]> wrote:
>
> > > > > On Nov 13, 10:15 pm, "Jason Patton" <[EMAIL PROTECTED]> wrote:
>
> > > > > > Eric, I don't disagree that we as a whole should be focused on
> > > > > > current
> > > > > > issues in climate, but running EBMs over long periods appears to be
> > > > > > what these particular scientists do. I don't know if we should get
> > > > > > up
> > > > > > in arms over their work. We cannot expect every scientist to be
> > > > > > working on the same issue, as important as it is.
>
> > > > > > I think what they've done is a valuable exercise, with the caveats
> > > > > > they've taken care to point out. The actual letter to be published
> > > > > > in
> > > > > > Nature actually has some nice details. But, even though as press
> > > > > > such
> > > > > > as New Scientist has to find some way to spice it up (see: title),
> > > > > > this isn't something we need to worry about right now, though it is
> > > > > > a
> > > > > > neat study.
>
> > > > > > Jason Patton
>
> > > > > > On Thu, Nov 13, 2008 at 3:45 PM, Eric Swanson <[EMAIL PROTECTED]>
> > > > > > wrote:
>
> > > > > > > Also note the comment in the article:
>
> > > > > > > "In the model runs best resembling actual climate history, the
> > > > > > > switch
> > > > > > > to a long-lasting ice age happened as early as 10,000 to 100,000
> > > > > > > years
> > > > > > > from now. However, Crowley stresses that not too much confidence
> > > > > > > can
> > > > > > > be placed on the results of single runs out of many."
>
> > > > > > > The CO2 which is now being dumped into the atmosphere would
> > > > > > > likely be
> > > > > > > taken up by the oceans long before the 10,000 year beginning of
> > > > > > > this
> > > > > > > postulated next ice age. As things are going, most of the fossil
> > > > > > > fuels will be burnt before the end of this century.
>
> > > > > > > I'm sorry to say, I think there's still a lot to learn about
> > > > > > > climate.
> > > > > > > And, the focus should really be on the next couple of centuries,
> > > > > > > not
> > > > > > > 10,000 year runs with a simplified model.
>
> > > > > > > E. S.
> > > > > > > -------------------
> > > > > > > Alexandre wrote:
> > > > > > >> "Humans may have prevented super ice age" is the title of an
> > > > > > >> article
> > > > > > >> from New Scientist. According to this article, some researchers
> > > > > > >> argue
> > > > > > >> that "(b)efore we started pumping massive amounts of carbon
> > > > > > >> dioxide
> > > > > > >> into the atmosphere, the planet was on the brink of entering a
> > > > > > >> semi-
> > > > > > >> permanent ice age". Our CO2 emissions may have preventeda long
> > > > > > >> lasting
> > > > > > >> ice age. The article states that "none of the researchers
> > > > > > >> contacted by
> > > > > > >> New Scientist thought the model's predictions are worth taking
> > > > > > >> seriously". However, the idea that something like this might have
> > > > > > >> happened is interesting.
> > > > > > >>http://www.newscientist.com/article/dn16026-humans-may-have-prevented...
> > > > > > >> Alexandre Couto de Andrade- Hide quoted text -
>
> > > > > > - Show quoted text -
>
> > > > > I have put off posting on this subject until I had read the paper, but
> > > > > having done that my opinions have not changed.
>
> > > > > Their idea is not entirely new since both Budyko and Sellers used EBMs
> > > > > to investigate the ice albedo effect on glaciations. But as I
> > > > > understand it, Budyko's problem was why the glaciations stopped, and a
> > > > > Snowball Earth did not happen. In other words, his EBM led to a
> > > > > permanent ice age too, and the question is why it has not happened.
> > > > > Crowley & Hyde cite Budyko. They should have known that. So Budyko,
> > > > > Sellers, and, I am sure, I too could write a model that switched into
> > > > > a permanent ice age.
>
> > > > > My second point is that this hypotheis is not scientific. It cannot be
> > > > > falsified.
>
> > > > It's a counterfactual conditional. It can be falsified, just not with
> > > > the particular experiment you define.
>
> > > > I have seen Newton's First Law described as a conterfactual
> > > > conditional. Hard or impossible to create the conditions for a direct
> > > > empirical confirmation of that one too.
>
> > > > > We cannot undo the damage we have done to the atmosphere
> > > > > and see whether we do end up in a permanent ice age.
>
> > > > > OTOH, Eric make a very valid point when he writes that the fossil fuel
> > > > > will all be completed by the end of this century. Compare that with
> > > > > the conclusion of Crowley & Hyde;
>
> > > > > "Our results therefore suggest that the actualclimate system may have
> > > > > been geologically close ... to permanent bipolar glaciation.
> > > > > (Presumably, future society could prevent this transition indefinitely
> > > > > with very modest adjustments to the atmospheric CO2 levels.)"
>
> > > > > It seems unlikely that this is now true. Where do we get the fossil
> > > > > fuels to burn, or the energy, to create CO2 now that we have reached
> > > > > Peak Oil and the global leaders, such as Gordon Brown, seem determined
> > > > > to maintain this profligracy in order to retain their hold on power.
>
> > > > > Carl Wunch seems to agree with me that this is not
> > > > > sciencehttp://dotearth.blogs.nytimes.com/2008/11/13/more-on-whether-a-big-ch...
>
> > > > > Cheers, Alastair.- Hide quoted text -
>
> > > > > - Show quoted text -
>
> > > AFAIK Newton's first law has been proved to hold in molecular
> > > collisions with photons. It is a physical impossibility to prove that
> > > if we had not added CO2 to the atmosphere we would have entered an ice
> > > age (paraphrasing) because we have added the CO2. There is a
> > > fundamental difference between Newtonian physics which can be proved
> > > in a laboratory, and earth science which excludes experiments which
> > > can be performed in a timely manner.
>
> > > Because of that we rely on computer models, but a computer simulation
> > > is not proof, and as Wunsch points out toy models are not science.
>
> > > But the real question is why has this piece of what Wunsch calls
> > > science fiction caught the public's attention. The answer is that it
> > > assuages their guilt over what they have done to the climate by
> > > driving their Hummers. They can claim that even if the destruction of
> > > New Orleans (and the fires now raging in California) were caused by
> > > climate change, it would have been much worse if we had not burnt all
> > > those fossil fuels.
>
> > > What is inconsistent however is that while they are willing to accept
> > > that we may have avoided catastrophe, they are not willing to accept
> > > that we may be heading for catastrophe. I call this attitude
> > > denialism. And it is not just confined to the general public. Most
> > > scientists seem to have the same attitude, some of them posting on
> > > this newsgroup. Despite overwhelming evidence that both the Arctic sea
> > > ice and the Greenland ice sheet are doomed, even if we do take action,
> > > they still seem to believe, like Mr Micawber that something will turn
> > > up.
>
> > > Obama may change US policy, but it is now too late :-(
>
> > > Cheers, Alastair.- Hide quoted text -
>
> > > - Show quoted text -
>
> > The hypothesis will be used by deniers, and all that.
>
> > I'm just saying that counterfactual conditionals are not unscientific.
>
> > Consider this one: If a 1/4 mile wide meteor hit NYC yesterday, it
> > would have killed >10,000.
>
> I am not arguing that it is untrue that we would have entered an ice
> age if we had not added CO2 tot he atmosphere. What I am saying is
> that it does not meet Karl Popper's criterion of falsifiability for
> scientific theories.
>
> On those grounds, your example of a meteor hitting NYC is scientific
> because we could wait for a meteor to hit NYC and see if more than
> 10,000 people were killed. (In fact it is probable that by the time of
> the impact NYC would no longer he habitated due to sea level rise.
> But \I digress :-)
>
> OTOH, we cannot turn the clock back, not burn all those fossil fuels,
> then wait and see if or if not an ice age happens. Of course you could
> slightly alter the hypothesis and say that if we removed all the extra
> CO2 from the atmosphere then we would return to an ice age, and that
> would be falsifiable, if you believe that we could remove the CO2. But
> of course that is not practical ... and so we resort to climate
> models.
Popper seems to have discoved a way to turn scientists brains to
mush. In my experience, you are not the first to suffer this fate.
Observe that you have just gone from saying that the hypothesis in
question it unfalsifiable, to saying that it is indeed falsifiable,
just not practical to falsify. Collect your brains and consider that
contradiction.
>
> But then this all depends on whether you accept Karl Popper's ideas.
> Judging by Dr Crowley's response to Dr Wunsch
> at,http://dotearth.blogs.nytimes.com/2008/11/13/more-on-whether-a-big-ch...
> Crowley does not.
>
> But climate models are not true experiments, in the sense of that
> pioneered by Galileo when he dropped the balls from the leaning Tower
> of Pisa. Computer models are no better than elaborate mind
> experiments. They still have to be validated by experiences. And
> Crowley's model will never be validated by the experience of a return
> to an ice age.
>
> Anyway, if it is not science why am I wasting my time arguing about
> it?
>
> Cheers, Alastair.- Hide quoted text -
>
> - Show quoted text -
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