Subject: Re: [Homestead] Holdren on climate change
Date: Sat, 20 Dec 2008 10:41:43 -0800 (PST)
Gerald , I just read through page 9. It is a bit esoteric for m. My wife ,
in my household, the scientific one. But, I have been trying to read and
learn on this subject for a number of years. I have cut and pasted (below)
from his speech an issue which I think brings out the biggest point of
skepticism from laynmen like me. Please tell me what you think.
My problem with this is that they are making educated guesses of the earth's
temperature for the past sevral hundred years. Let's say their guesses are
absolutely correct. How many hundreds of millions of years old is the earth?
That Al gore movie was a bad idea for given this issue credibility. So much
of it has been exposed as being wrong. But, at the same time, I read
recently, I believe in Scientifc American, that next summer, 'all ' of the
Arctic icebergs will melt. 'All of them'. If that happens, we will all
become believers, if it doesn't it will sound like more fearmongering.
As a good steward, what do I do other than that which I have already done to
conserve and protect resources?
And, once again, how are we so sure this isn't a "sun event" that happens
every 100,000 years?
We have another list member named Jerry who really knows this stuff, but he
has been having problems with his internet ability to post messages. I meant
to ask him these same questions once, but procrastinated..........
"Change’s (IPCC) best estimates of the forcings — literally meaning how hard
we’re pushing on the climate, positive in the heating direction, negative in
the cooling direction — including increases in atmospheric carbon dioxide (by
far the biggest factor); methane, nitrous oxide, and chlorofluorocarbons
(combined,slightly less impact); contributions from ozone, absorptive
particles, some partially counteracting effects from reflective and
cloud-forming particles, and a little bit of influence from landuse change.
And what you see, very interestingly given the skeptics who still claim the
sun is doing this, is that the best estimate of the warming influence of
greenhouse gases and absorbing particles from 1750 to 2005 is about 30 times
the best estimate of the warming influence"
of the estimated change and input from the sun over this period."