Re: [asa] Arctic sea ice and global warming

Yes, the conveyor belt has since long been a very efficient way to
transport heat northward, causing the winters in northern europe to be
milder. The conveyor belt is fueled by the convection of cold water
which is heavier and tends to sink.
The immediate effect of ice melting is that the white surface is
replaced with a darker surface which is more efficient in capturing
heat.
As is the case with almost anything, the interactions are hardly
trivial as there are feedback loops, non-linear interactions and
global rather than local consequences.

See http://www.grida.no/climate/vital/32.htm for the conveyor belt
which runs all the way from the pacific, through the north atlantic
all the way up north.

The impact of fresh water is that it can reduce the forcing and
decrease the strength of the conveyor belt. "Periodic movement of
excessive ice from the Arctic into the Greenland Sea appears to be
responsible for the interdecadal variability of the conveyor belt."

also http://www.davidsuzuki.org/Climate_Change/Science/Conveyor.asp

<quote>A distressing confirmation of the models has recently emerged.
Measurements of the saltiness of the North Atlantic show that the
region has been growing gradually fresher over the past 40 years. The
rapidity and extent of freshening came as a surprise to oceanographers
- the change is equivalent to a 3-4m cap of freshwater appearing over
a broad area of the northern North Atlantic. If this continues, the
resulting loss of density could prevent sinking, and short-circuit the
NADW within decades.</quote>

Somewhat unintuitively, global warming may lead to some very cold
winters in Northern Europe

http://en.wikipedia.org/wiki/Thermohaline_circulation
http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation

On 1/8/07, Charles Carrigan <CCarriga@olivet.edu> wrote:
>
>
> Don,
>
> There is something of a reverse feeback loop here with the melting of arctic
> ice, but it has more to do with salinity than with temperature. The north
> Atlantic is an important point in the global ocean coveyer belt circulation
> system. Near surface currents bring warm water up from the south to this
> point. These waters then cool, and due to the higher density of cool water
> (at least until 4 C), they sink in the north Atlantic and then return to
> southerly lattitudes as deeper water currents. The melting arctic ice
> causes an influx of fresh water into the North Atlantic. These fresh waters
> are less dense than saline ocean water, so the sinking phenomenon can be
> "shut off", in a sense, causing a break in the global ocean circulation.
> This has the effect of causing colder tempertures, especially across Europe.
> It is believed by many that this phenomenon is what lead to the "Little Ice
> Age" that hit Europe between ~1500-1850 AD. So yes, there is something of a
> reverse feedback loop here with the melting of ice causing colder T, and
> therefore more ice. However, I think most climate scientists would argue
> that the warming induced during the 20th century is more than enough to
> overcome this effect and continue the warming trend.
>
> The History Channel had a very interesting program recently on "The Little
> Ice Age: Big Chill" that discussed the science behind this period of climate
> change and the massive cultural effects it had on Western Civilization. It
> was the best 2 hours I spent in front of the TV in 2006, and I highly
> recommend catching it if they air it again.
> http://store.aetv.com/html/product/index.jhtml?id=74653
>
> Best,
> Charles
>
>
> _______________________________
> Charles W. Carrigan, Ph.D.
> Assistant Professor of Geology
> Olivet Nazarene Univ., Dept. of Physical Sciences
> One University Ave.
> Bourbonnais, IL 60914
> PH: (815) 939-5346
> FX: (815) 939-5071
> ccarriga@olivet.edu
> http://geology.olivet.edu/
>
> "To a naturalist nothing is indifferent;
> the humble moss that creeps upon the stone
> is equally interesting as the lofty pine which so beautifully adorns the
> valley or the mountain:
> but to a naturalist who is reading in the face of the rocks the annals of a
> former world,
> the mossy covering which obstructs his view,
> and renders indistinguishable the different species of stone,
> is no less than a serious subject of regret."
> - James Hutton
> _______________________________
>
>
> >>> "Don Perrett" <donperrett@theology-perspectives.net>
> 1/8/2007 11:25:07 AM >>>
>
> I'm curious, if the fresh water ice at the poles melts and lowers the
> salinity of the oceans, will this not cool the oceans and thereby help to
> reduce global temps?
>
> Don
>
> -----Original Message-----
> From: asa-owner@lists.calvin.edu
> [mailto:asa-owner@lists.calvin.edu] On
> Behalf Of PvM
> Sent: Monday, January 08, 2007 11:49 AM
> To: Janice Matchett
> Cc: ASA
> Subject: Re: [asa] Arctic sea ice and global warming
>
> Janice's "argument" is once again one of fallacy. The reason polar bears are
> thriving since the 1970's is because of hunting agreements.
> However, the fact that their habitats are being destroyed is a real
> phenomenon.
>
> Then again, the 'happy polar bears' at Seaworld are an indication that such
> animals can thrive anywhere. ROTFL The level of logic here is just baffling.
> Is this the level of arguments we should expect against those concerned
> about the environment?
> So what about the declining polar extents Janice? Does that not concern you?
>
>
> On 1/7/07, Janice Matchett <janmatch@earthlink.net> wrote:
> >
> > At 12:04 AM 1/8/2007, PvM wrote:
> >
> >
> > Including 2006, the September rate of sea ice decline is now
> > approximately -8.59% per decade, or 60,421 km2/year (23,328 mi2/year.
> > NSIDC Research Scientist Julienne Stroeve said, "At this rate, the
> > Arctic Ocean will have no ice in September by the year 2060." The loss
> > of summer sea ice does not bode well for species like the polar bear,
> > which depend on the ice for their livelihood, she said.
> >
> > But then again, the polar bear was never mentioned in the Bible so
> > why should we care P-) ..." ~ Pim @ Good news is mentioned in the
> > Bible. (So is the one who personifies "bad
> > news") :)
> >
> >
>
>
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Received on Mon Jan 8 14:05:11 2007