From: J. Andrew Rogers (andrew@ceruleansystems.com)
Date: Fri Nov 25 2005 - 21:34:30 MST
On Nov 25, 2005, at 2:45 PM, Martin Striz wrote:
> The IPCC concluded that about half of the 1 degree centigrade rise in
> temperature in the last 100 years can be attributed to human activity.
> When something accounts for 50% of the variance, that's signficant to
> me.
For historical data in absolute terms, that variance is almost below
the noise floor. It may be significant to you, but that opinion is
pretty irrelevant in the context of what typical variances and rates
of change have looked like over the last million years. The climate
does not ask your opinion of whether or not a variance is
"significant" before doing what it does. I have no problem with the
idea that humans are significantly contributing to the variance, but
I do have a problem with the idea that this variance is extraordinary
when there is ample evidence that this variance is well within normal
parameters for the system that is earth. From a systems perspective,
the global climate really does not care where the variances come
from, and this particular variance is not extraordinary. I would be
far more worried about extreme variances that happen naturally with
moderate frequency.
My issue, illustrated in your response, is that many people have
strong opinions on this matter but they are frequently based on
intuitions that are divorced from the context of the system those
opinions are nominally about. I really don't have an opinion or
prediction about climate change, but I've made a lot of observations
that most self-styled definitive opinions are of highly suspect
quality based on the evidence we currently have.
That said, why exactly is all this even important? Solving problems
a hundred years in the future today seems like a fruitless use of
resources. Even the most catastrophic climate shifts in the
historical record took a couple decades to occur, and those were a
couple orders of magnitude more extreme than the variances we've seen
over the last century.
J. Andrew Rogers
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