by eric_b » Wed 08 Jun 2005, 19:52:06
$this->bbcode_second_pass_quote('MacG', '')$this->bbcode_second_pass_quote('Sys1', 'M')oreover, global warming will certainly decrease what is left to harvest in the post peak oil world.
Sure. Global Warming might happen. But it will not be because of anthropogenic carbon dioxide. The most prevalent greenhouse gas is... water vapour! Responsible for +98% of the greenhouse effect. It is the sun activity and earths distance and tilting towards the sun which make a difference.
You're correct that water vapor is
the greenhouse gas.
However you're likely incorrect about increasing CO2 levels (fact)
not causing GW. It's thought that CO2 raises temps
indirectly
by how it couples with water vapor. That is, increased CO2 levels will
eventually (if not already) lead to increased levels of water vapor in
the atmosphere. Many computer models seem to bear this out.
The precession of the Earth's axis, distance from sun, seasonal tilting,
etc. are quite accurately accounted for in most computer models -- these
factors are not significant as far as climate (at least for the next few
centuries). The sun's output does vary, but only minutely (fractions of a percent)
and is more than compensated for by the measured 'global dimming'
(up to 20-30 % !!) taking place in many areas of the globe due
to particulate pollution caused by human activities. Ironically global
dimming may be offsetting the warming due to rising CO2 levels.
There's some evidence that solar output is
slightly higher during
the 11 year maxima of the sunspot cycle, and there's some evidence that
increased sunspot activity (charged particles) can effect the extent of
cloud cover on the Earth, but again not enough to offset GW.
Of course, at this point, it's anyones guess as to whether GW is a fact,
though the weight of the evidence (more and more) is pointing towards
it. The 'GW signal' appears to be accelerating.