Ice age - Wikipedia, the free encyclopedia
Variations in temperature, CO2, and dust from theVostok ice core over the last 400,000 years
An ice age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of cold climate are termed "glacial periods" (or alternatively "glacials" or "glaciations" or colloquially as "ice age"), and intermittent warm periods are called "interglacials". Glaciologically, ice age implies the presence of extensiveice sheets in the northern and southern hemispheres.[1] By this definition, we are in an interglacial period—the Holocene—of the ice age that began 2.6 million years ago at the start of thePleistocene epoch, because the Greenland, Arctic, and Antarctic ice sheets still exist.[2]
Note that the steepness of the temperature increase leading to an interglacial period is much steeper than that of the descent into an ice age.
You look at those interglacials and some of them were a heck of a lot shorter than ours. But as they say on Wall Street -- past performance is no indication of future returns..
OR IS IT????