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Re: population growth & physics ed



A point about all of this that James Burke makes in his film 'After
the Warming' [which is a very good film to have students view and
evaluate] IS that virtually everyone agrees that continued increases
in the levels of greenhouse gasses will eventually effect the climate.
We can argue about by how much and how soon, but his point (well
taken IMO) is that why take the risk? We insure ourselves from lots
of other hazards so why not take some out some insurance concerning
global warming by cutting back on green-house emissions as soon as
possible. The film describes a Dutch plan from around 1989 that could
be a model for doing so. Other salient points of the film describe
how the dilution of salt in the North Atlantic (by the escape of an
ice age lake in Canada) caused an 8-10 degree drop in the space of
only 100 years--point being that very large temperature swings CAN
happen very quickly. It is the effects of the oceans vis-a-vis global
temperatures that are not well understood, but under SOME models can
lead to cascading effects that could cause very rapid increases in
temperature. Once again a central point here is that reducing carbon
emissions NOW can't hurt but not doing so COULD be disasterous!

Rick Tarara

----------
From: Leigh Palmer <palmer@sfu.ca>
Leigh Palmer says:
...
It should always be pointed out that the rise in carbon dioxide
levels
over the years of monitoring has been very much larger than the
rise in
temperature over the same period.
...

Relative to what? Given that I'm sure that total absence CO2 would
not
translate to an Earth temperature of 0 K, I don't know how to
interpret
this statement.

Relative to the initial temperature and concentartion at the
beginning of
the monitoring period. Sorry, I thought that would be clear from
context.
The (relative) increase in temperature is only about 0.02%, and the
CO2
concentration has increased by about 14% since 1958 (see, for
example,
http://www.science.uwaterloo.ca/earth/waton/mauna.html).