Mike Coslo wrote:
May I assume that you believe that glacial cycles are the sole
source of global warming or cooling?

Not the sole source - just the primary source.
120,000 years ago, temperatures peaked higher
than they are presently. These cycles occur in
100k-120k year intervals. CO2 levels always
zoom up and trail off gradually during the peak
temperatures. There is some sort of feedback
mechanism that takes the CO2 levels down.
--
73, Cecil http://www.qsl.net/w5dxp