This theory promised, moreover, to give the timing of past changes precisely from basic physical principles, and to predict future ice ages. (history.aip.org)
Dr. Archer has worked on the ongoing mystery of the low atmospheric CO2 concentration during glacial time 20,000 years ago, and on the fate of fossil fuel CO2 on geologic time scales in the future, and its impact on future ice age cycles, ocean methane hydrate decomposition, and coral reefs. (realclimate.org)
Thus the real risk is starving plants and thus endangering life on Earth if CO2 levels can not be stabilized, or better, raised during future ice ages when lower temperatures will lead to lower CO2 levels than currently (as per (1)-RRB-. (carlineconomics.com)