On 14 Jan, 09:44, William Connolley <[email protected]> wrote:
> 2010/1/13 Alastair <[email protected]>:
>
> > On Jan 13, 10:41 am, DrNickBone <[email protected]> wrote:
>
> >> Reasonable GCMs do sometimes show runaway warming
>
> They show a fully cloud covered earth, similar to the outward state of
> Venus, but they do not show a boiling away of the Earth's oceans.
>
> {{cn}}, both of you.
>
> -William
I was referring to a comment by James Annan earlier in the thread
(post of 4th January)
>GCMs can achieve runaway warming - in fact some informal conversations
>suggest to me that this is rather more common than you might imagine
>based on reading the literature - but this is generally attributed to
>some nonphysical behaviour such as a parameterisation extrapolated
>beyond its valid range. However, I don't believe that Pierrehumbert's
>handwaving with simple approximations can really refute calculations of
>state of the art climate models.
I'm not sure which models James was thinking of. But if he is right
at least some have reached the literature, with others hiding in
the filedrawer marked "Uh-oh".
Personally, I'd consider it an academic point whether the oceans
literally boil away in these models, or the Earth comes back into
a new equilibrium with very high albedo. A cloud-covered Earth with
minimal or no life under the clouds is still an awful thought.
--
You received this message because you are subscribed to the Google Groups
Global Change ("globalchange") newsgroup. Global Change is a public, moderated
venue for discussion of science, technology, economics and policy dimensions of
global environmental change.
Posts will be admitted to the list if and only if any moderator finds the
submission to be constructive and/or interesting, on topic, and not
gratuitously rude.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/globalchange
