So ask yourself the question: where does all the carbon dioxide come from in previous ice ages? (skepticalscience.com)
Based just on orbital forcing, and following previous ice age cycles, we are due for a long period of gradual cooling to the next ice age. (realclimate.org)
Also unclear is why these abrupt climate shifts, also seen in previous ice ages, haven't happened in the past 10,000 years. (ldeo.columbia.edu)