Quote:
Originally Posted by HydrogenBond
Part of the problem with the global warming debate is assuming the rise in temperature is due to human action. There is a temperature rise, but the human factor is inconclusive. What I would like to see is longer term data, for the past 100 million years. One can find many warm cycles even when humans were not around. What caused these and why is it not even on the table as part of the reason for this current cycle? The science is not very scientific in that it is using about 50-100 years of the data. The burden of proof should require explaining the past and then eliminating that before introducing a trump card.
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Hi, I'm not going to respond to the "motivation" and funding part; that stuff doesn't work for me.
Scientifically, the logic of 'natural cycles' generally comes down to saying that a person walking out of a burning building with a kerosene bottle and matches is innocent because "fires always happened."
I'm not sure what you're reading, but natural/past variability is intensely studied, and in fact the reason you know about them, is because someone took the time to document it. Greenhouse gases actually play a large role in past climate variability, even in ice age cycles, and in previous extinction events. Changes in solar output, changes in plate tectonics, the oxygenetion of the atmosphere, asteroid impacts, volcanic eruptions, etc all have played a role in past climate variability...and if you want to be more specific on a certain time period, there is going to be a good deal of literature on it until you go back to the pre-Cambrian around 550 million years ago, but then we have much less record.
These things are being studied today, and we don't select 'humans' out of a hat. There is a good deal of understanding that goes into the fact that adding CO2 gives you warming, including well known radiative physics (so even if you're getting some big possible-but-undetectable natural variation, that could only amplify it). But if you want to suggest some natural phenomena that we do not know about, the scientific community is all ears.
Just to self advertise some more, this post may be helpful
(http)chriscolose.wordpress.com/2007/12/18/the-scientific-basis-for-anthropogenic-climate-change/
