Re: [Marxism] (fwd from M Lause) PBS's Nova: " Dimming the Sun"

[Bill Quimby <wquimby@xxxxxxx>]

I watched, and was convinced. I confess though to being most
surprised about not having heard this before, and I think
that I pay slightly better than average attention to science
news. The primary defenders of the "global dimming" thesis
suggested that the scientific community has not gotten as
exercised about it as it has about "global warming", and
neither it would seem has the media.

A scary thought - if the earth's land surface is in a few
decades not able to support agriculture at today's levels
(through drought and desertification) the ocean's food
resources become even more important...but then, given what
we are now doing to the oceans...?

- Bill

Les Schaffer wrote:
> [Mark: not sure why this bounced, i don't see anything
> obvious in the bounce log. Les]
>
>
>
>
> Am I the only one who caught this documentary this week?
>  http://www.pbs.org/wgbh/nova/sun/dimming.html
>
> The documentary provides rather persuasive evidence that
> the amount of sunlight actually reaching us on the
> earth's surface is declining, though it varies from place
> to place.  This is due to more particle pollution in the
> air (around which larger amounts of water can condense)
> and there's stuff up there like jet contrails (satellite
> pictures show how these diffuse to cover a significant
> part of the sky in places-about 75% in the one they
> showed of southern California).  This latter issue became
> evident to the scientists when they observed the skies in
> the days after Sept. 11 when air traffic was grounded.
> The impact of this on the sunlight reaching us has been
> reflected in subtle changes like the rate of water
> evaporation over the last 30 years.  The figures given
> for the overall diminishing of sunlight were unbelievably
>  high--something like 30% in parts of the old Soviet
> Union, 16% less in the UK, etc.
>
> According to the program, this bouncing sunlight back
> into space has masked the actual impact of greenhouse
> gases in terms of heating things up.  So we face a much
> greater potential shift in average global temperature
> than even the more pessimistic of us have expected.
>
> They've also documented greater temperature fluctuations
> in terms of a difference between day and night
> temperatures.  This fits the idea that you have a tension
> between two processes--a global heating up of the planet
> from greenhouse gases and regionally variant factors
> reflecting sunlight back into space.
>
> I'd be interested in what others thought of the program
> and the argument.
>
> Solidarity! Mark L.
>
>
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