Temperatures Over Time - Part I

Updated 2/23/09

Quoting this source:

"During most of the last 1 billion years the earth had no permanent ice [as it cycled (NATURALLY) in and out of multi-million year Ice Ages]"

The only reason there is any year round ice anywhere on this planet is because we are currently in one of the three coldest Ice Ages in the last 600 million years:

Click the image to learn more:

NOTE: Unfortunately, the term “Ice Age” is often used (incorrectly, even by scientists) to refer to a glacial period. Ice Ages last millions of years. Glacial periods last tens of thousands of years. Glacial periods only occur during Ice Ages.

The current Ice Age cycle began 30 million years ago.

Some 4 to 5 million years ago, the world cooled enough for cyclical glacial advances and retreats to begin (again).

The last glacial maximum occurred about 18,000 to 20,000 years ago. In general, the glaciers have been melting ever since then!

Within the larger context of an ongoing multi-million year Ice Age, we are currently experiencing one of about 100 perfectly natural, perfectly normal interglacial warming periods known to have occurred “in the last 2.5 million years”.

Sources for the above chart:

Temperature - The Paleomap Project by Dr. C.R. Scotese, a PhD geologist at the University of Texas at Arlington.

CO2 - R.A. Berner, 2001 (GEOCARB III), as published in the American Journal of Science, Vol. 301, February 2001, P.182-204.

The Geocarb III data are found in this file downloaded from this NOAA page.

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