hi
thanks, extinct, I think means it isn't in the wild or captivity for 30
years... which is a long time to wait.
The point I'm making is that other terms are created when there is
little sense in waiting for 30 years for non existence to exist...
The point about sea ice, is an important one. Communicating an issue is
key. If, as is possible, that some sea ice remains in pockets or as a
thin film over the Arctic in areas at some times of the year, do we wait
before accepting that the ecosystem is functionally, well, dysfunctional?
I think a term can be adopted in this case, which refers to the sea ice
as so severely reduced that it is no longer performing its critical
previous functions.
Communicating in phrases and terms which are accurate but also readily
accessible is key. I am not sure what the correct phrase for the
diminishing sea ice is, and I am hopeful that we wont need one. I am
optimistic that we will restore the Arctic ecosystem, just as we re
plant a forest when we realise we need it, we clean up an oil spill, and
we clean up a coal spoil heap.
thanks so much,
Emily.
On 18/07/2011 21:50, Mike MacCracken wrote:
For species, I have heard (e.g., from reviewers when I have misused the word
extinct) that when there are no more in a region or in the wild, the
appropriate term is (from biology online):
Extirpation
The act of extirpating or rooting out, or the state of being extirpated;
eradication; excision; total destruction; as, the extirpation of weeds from
land, of evil from the heart, of a race of men, of heresy.
Extinction only applies when there are none either in the wild or in
captivity.
I am not sure that applying this word to sea ice would work very well,
however.
Mike MacCracken
On 7/18/11 3:53 PM, "Emily"<[email protected]> wrote:
Hi,
a term used for species extinctions comes to mind - when a species is
reduced to such a small number of animals in the wild but isn't extinct,
it is sometimes referred to as 'functionally extinct'.
If we consider the functions of the Arctic sea ice - in areas it is
pretty near functionally extinct already... eg in Hudson Bay...
Sea ice performs so many different functions it's hard to even list them.
best wishes,
Emily.
On 18/07/2011 17:24, [email protected] wrote:
Ken (cc list)
I have tried (as a rank amateur observer, not participant) to
follow this retreatjng September arctic ice topic for the last 5
years. I have come to a different conclusion than expressed in your
two articles.. The website I have found most valuable can be located
by remembering the name "Neven" - and googling with "arctic" and "ice"
. This blog averages more than one message per hour - and the folks
commenting there seem to be putting a lot of time into the topic. Not
experts on this blog, but dedicated amateurs, who do seem to be
talking to the ice experts, however.
The key question is what are we to be measuring when we talk of
"gone"? I gather that 10% remainder is considered "gone". One also
has to consider whether one will be talking area, extent, or volume.
I like the volume definition - as thickness is dropping much more
rapidly than area (the smaller number) or extent - and the volume is
easier to find data on than thickness. A good (April 2011)
discussion of these differences is at
http://neven1.typepad.com/blog/2011/04/trends-in-arctic-sea-ice-volume.html#m
ore
This short write-up, using experimental volume data, suggests about
2016 as a best guess to get to this 10% value. This uses a "Gompertz"
model - which has no particular theoretical validity - but seems to
have more validity than a linear or quadratic approach to absolute
zero. It might be overly conservative.
For today's blog exchange (several dozen so far today), go to just
the early part of the above URL.
The modeler who seems (to me) to have done the best job in modeling
this (the subject of Ken's two articles) is Dr. Wieslaw Maslowski who
has supported this 2016 "gone" date since 2008 or so (and again this
year). The following 2008 cite is given in the above URL for a
Maslowski Ppt:
http://www.ees.hokudai.ac.jp/coe21/dc2008/DC/report/Maslowski.pdf
His work doesn't show up in literature comparisons such as in
Ken's articles because his (highly detailed) model is limited only to
the Arctic; it is not a global model, although of course it is linked
to the rest of the world. We should also note that Maslowski has
supported 2013 as not being out of the question. (and still does)
I don't believe we have the luxury of relying on a "gone" date in
the 2030's or even 2020's - and this is based on interpretations of
recent data - not model outputs. It seems to me the lesson is that
the global models need retuning.
Ron
------------------------------------------------------------------------
*From: *"Ken Caldeira"<[email protected]>
*To: *"geoengineering"<[email protected]>
*Sent: *Monday, July 18, 2011 6:41:17 AM
*Subject: *[geo] September sea-ice gone by end of century? (or much
sooner)
Folks,
There has been a fair amount of discussion on this group that talks
about imminent September sea ice loss in the Arctic.
The attached paper indicates that around half of the normal September
sea-ice should still be around in the 2020-2040 time frame.
Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009).
I am not saying that the situation in the Arctic is not dire, however,
are the suggestions that September sea-ice in the Arctic is soon to be
a thing of the past a bit overblown and without foundation?
Best,
Ken
___________________________________________________
Ken Caldeira
Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 [email protected]
<mailto:[email protected]>
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
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