If you look at the chart in the first link which is the most accurate interpretation of the climate for the last 20k years yet published you can see some of the natural variability of the planets climate. The radical variability is caused because our sun is not a consistent performer. It has high cycles and low cycles and some times it goes into hibernation for 80k and more years. We have the scientific record of a couple of million years of this extreme climate variability and still really do not know what causes them for sure. A couple of very sharp scientists some years ago came up with a theory stating that solar variability is driven by mineral elements or very sparse gases in space that when encountered cause the sun to increase its output depending on the quantity of the element available. We do not know for sure because Jimmy Carter shut down serious space studies when he was president and the liberals in congress have so far prevented the research from being started up again, even the minor exploratory polar power program Bush got started has been shut down by Obama on orders from his boss David Rockefeller,
Some scientific information revealing the truth about global warming, when it happened and what probably caused it. And as well how many years, centuries or millennia it might be before the world warms up again from the coming ice age.
http://en.wikipedia.org/wiki/File:0Master_Past_20000yrs_temperatures_icecore_Vostok_150dpi.png
http://www.geocraft.com/WVFossils/global_warming.html
http://www.geocraft.com/WVFossils/greenhouse_data.html
http://reasonmclucus.tripod.com/CO2myth.html
http://mc-computing.com/qs/Global_Warming/Atmospheric_Analysis.html
http://en.wikipedia.org/wiki/Solar_variation
Where the heat came from and why it was abnormally cold previously
http://www.ac.wwu.edu/~dbunny/research/global/215.pdf
http://en.wikipedia.org/wiki/Solar_cycle
http://en.wikipedia.org/wiki/Solar_minimum
http://en.wikipedia.org/wiki/Maunder_Minimum
