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Re: [LUG] OT: Snow was Why don't they learn

 

Philip Whateley wrote:
> 
> The data from the ice core samples (available for download from
> http://news.bbc.co.uk/1/hi/in_depth/sci_tech/2009/copenhagen/8393855.stm)
> shows an interglaciation spike beginning about 19,000 years bp. The data
> is based on deviation from the average for 1900-2000, as zero. The data
> shows the the current (baseline) temperature some 3 to 5 degrees cooler
> than the last 4 interglaciation spikes.

Thanks for the link. I'd only just recently finished reading the latest
Vostok Ice core paper, which largely shows the same thing but only for
420,000 years.

> The data also shows some other interesting anomolies, such as CO2 peak
> lags temperature peak by around 30,000 to 40,000 years?

You'd expect CO2 to lag warming slightly if the forcing is due to
orbital changes, there is a lot of discussion of same in the literature.
I think the problem with the "Milankovitch cycles" is the orbit changes
don't map in a simple fashion to the climate we've recorded in history,
so you have to introduce sophisticated climate models to relate the
changes in insolation due to orbit shift to the temperature, and you
have to include things like geographical distribution of land masses.
Some folk are also trying to add in orbit inclination, I bet the
climatologist never expected to have to be this good at orbit theory.




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