On Apr 15, 2:48 am, Alastair <[EMAIL PROTECTED]> wrote:
> ...
> You define inter-glacials as the time of maximum temperature
> between glacials, then by definition they do not show warm events.
But the time of maximum temperature is an 'instant', not an
interval. I would prefer another definition, one which agrees
with the Eem has having had warm-cool-hot-cool-warm subintervals
and something roughlly similar for the Holocene.
> ... So there is still a
> possibility for a rapid change if either of those should suddenly
> disappear.
Is not the Arctic sea ice 'rapidly' disappearing?
> ... It depends whether you
> define the Holocene as a normal inter-glacial or as a cold inter-
> glacial.
The Holocene is a remarkable intrglacial in two respects:
(1) No other interglacial had as stable a climate as the
Holocene (so far).
(2) There is only one other long interglacial in the paleo-
record. (Unfortunately, I disremeber the termination number,
but it was long enough ago that little is known about it.)
> ...
> OTOH, if it is correct that we only see rapid changes during glacials,
> then that implies that climate sensitivity during glacials is
> different from that during inter-glacials. Whichever is true, climate
> sensitivity is a chimera!
I suspect that the climate sensitivity may well be different under
these two conditions, now that you mention it.
Thank you for a most informative post.
Also thanks to James Annan.
>
> One final point, just to return to the subject of this thread. We know
> that the Eemian was warmer than the Holocene, so how could that happen
> if Spencer's Iris operates? Surely that would have prevented
> temperatures in the Eemian rising above those we now experience?
Alastair, that is an excellent point! (Especially with the CO2
concentration at only a maximum of only 287 ppmv, from the Petit
et al. analysis of the Vostok ice core.)
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