Quote:
Originally Posted by Superluminal
If there is a 100,000 year cycle, and 100,000 years ago was the last severe round of global warming, could the current global warming be part of that cycle?
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No, the rate of change is too rapid. The average temp has increased by about 1 degree over the last 100 years. For a 100,000 year cycle, that kind of change should take 10,000+ years, unless we are talking about 100+ degree changes over the course of the cycle (not the case, since basically only bacteria could have survived such extreme temperatures).
Pretty much all of the long term oscillations in the global climate (such as those resulting in ice ages) are the result of gradual variations in the orbit of the Earth. Those variations are significant only on the scale of 1000's of years or more, not on the 10's of years for the current global warming. That is why, even though we may be on an upswing in one of those cycles, they are not taken to be a likely explanation for Global Warming.