Why is Global warming having a stronger effect in the Arctic(+4
degrees) than in more temperate regions(+1 degree)? I am a teacher and
would like the latest thoughts on this question.

Hi duffer477,
Here is a link to a 2004 report called Arctic Climate Impact Assessment.

http://amap.no/acia/
[Download ACIA Overview report, a 14 Mb pdf file]

It's an extensive reserach report that covers many aspects of the
influence of global warming on the Arctic, including impacts on
wildlife, indigenous communities and effects on the rest of the world.
In page 20 (page 26 in the pdf) you'll find several reasons why the
Arctic is warming faster than other parts of the world.

It appears that the main reason is that "...as arctic snow and ice
melt, the darker land and ocean surfaces that are revealed absorb more
of the sun's energy...".


Google search terms
arctic "global warming" faster
://www.google.com/search?hl=en&q=arctic+%22global+warming%22+faster&spell=1


Best wishes,
elmarto

Global climate is a dynamical system which contains several feedback loops,
the positive one mentioned above (due to high albedo of snow and ice), as well
as several negative ones, like the one in the DaisyWorld model.
http://www.gi.alaska.edu/ScienceForum/ASF12/1220.html

While they all have effect, to consider just one may be too
oversimplified, even for just teaching purposes. What is populary
called 'global warming' is really a change of the temperature
profiles, change in vertical profile in ocean and atmosphere and
time-dependent latitude profile. Climate remains a system far from
equilibrium, driven by variable stream of sunlight, with huricanes,
streams and water cycle.
The question ' why the temerature at time T and location (R l e) is T
-- is a complex question - as any weather forecast shows.

Best way of understanding causal relationships is to work with a
computer model.Small model (to fit a PC) running on a numerical grid ,
may be great teaching tool. Some do exist.

This example may be still too complex to be used in the classroom, but it
list a small number of parameters, which define outcomes:

(This example here is nor Global Warming but Flood model- it shows
feasibility of PC based models. To select a good model would take a
full search).

"..The assumption made in her research was that the oceans were left
warmer than today due to all the heat and energy released in the
events of the Flood. She found that wind speeds were about 25%
stronger with warmer ocean temperatures than today. More precipitation
falls at higher ocean temperatures, with much of it falling in mid to
high latitudes and the polar regions. Precipitation exceeded 20
millimeters a day over large portions of the polar regions and along
continental boundaries. Ice sheets in Greenland and Antarctica could
have accumulated in less than 500 years under the simulated
conditions.."
http://www.icr.org/research/misc/climate_modeling.htm

Another reason why tropical regions are expected to warm less is due
to "latent heat" - a large amount of the heat that goes into those
regions will actually be used to evaporate water rather than
increasing surface temperatures.  This is also part of the reason why
air surface temperatures over land are expected to warm more quickly
than over ocean.  (The other half being that the high heat capacity of
the ocean will provide inertia to warming)

Here is a chart of temperatures changes resulting from various emissions scenarios:
http://www.grida.no/climate/ipcc_tar/wg1/fig9-10.htm

There are other complicated factors involved: possibly differential
changes in cloud cover at different latitudes, or slowing of the
thermohaline circulation (eg, the gulf stream that brings warm water
north), but the retreating ice feedback will probably be the largest
factor, with the latent heat issue being second.

-Marcus

duffer
      
I did (as a free contribution to education :-) looked for   
    PC adaptable models:
 

 NASA Releases Free Global Climate Model Software
EdGCM easily scales for use at levels from middle school to graduate school ..
 http://www.edgcm.org/

 Burt Model is one of the many resources for teaching
climatology/meteorology available at: http://mist.met.ed.ac.uk/calmet


 Dave Bice has an excellent Global Energy Balance modeling module here
... page, and has converted it to a JAVA based on-line ... At present
it runs only on PC platforms
http://serc.carleton.edu/introgeo/models/mathematical/examples/GEBM1.html


 Here is an interesting Distributed model - which runs on a net of
home computers  (SETI - style)
http://dsc.discovery.com/news/afp/20030908/climate.html

SEARCH TERMS: PC based global climate model

adding few words: PC based global climate model, temperature profile,...
brings more specialised studies

hedgie

One more comment - 
since duffer did not came back,
 to comment on the comments, 
 I suspect that ideas presented so far
 are still too complex to be of use to a teacher,
 busy with many other issues.

Is that so, duffer?

If, so, here is an easier way: Visualisation of  scenarios,
computed under different assumptions, which show Temperature profiles at
different times,  predicted by different  models. 

http://ipcc-ddc.cru.uea.ac.uk/cgi-bin/ddcvis/gcmcf

The grid used:
http://ipcc-ddc.cru.uea.ac.uk/asres/scatter_plots/scatterplots_region.html
Research centers cooperating om models
http://ipcc-ddc.cru.uea.ac.uk/scenario_links/model_links.html

Scientific research presented here, by IPCC, should be differentiated from
efforts of various 'think tanks' and political action and industry
lobby groups, which peridocaly flood media with headlines like

Warning Of Repeat Of Historic Climate Catastrophe (left lunatic fringe) or
.confirm that global warming is humbug. ... .(right lunatic fringe)


 Global Warming is "The Quadrillion Dollar Question", as Gina Smith had said..
 it important for public to understand both the research going on and the
 media game which surrounds it to mask and spin the results.

Hedgie