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.
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