It is shown that there has been only one ice age and that the theories of multiple ice ages are misinterpretations based for the most part on index fossils. Carbon-14 dating and the recession of Niagara Falls are used to demonstrate that the ice age is an extremely recent event. Evidence is presented to show that the ice age was caused by, and that it followed the universal flood. Evaporation of floodwaters cooled the atmosphere below the freezing point. It is proposed that melting of an Arctic icecap that floated northward in the floodwaters lowered the temperature of the ocean from 25" C. almost to zero. Just as evaporation is a cooling process, so is freezing a "heating" process which automatically brought on the postdiluvian "Climatic Optimum" which raised world temperatures 5" above "normal" after the ice age.