600 Million Year History
Fig. 1A. TOP: Global Temperature and Atmospheric CO2 over Geologic Time. Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ).
Temperature after C.R. Scotese http://www.scotese.com/climate.htm
CO2 after R.A. Berner, 2001 (GEOCARB III)
Source: Salamatin A.N., V. Ya. Lipenkov, N.I. Barkov, J. Jouzel, J.R. Petit and D. Raynaud (1998). Ice-core age dating and palaeothermometer calibration based on isotope and temperature profiles from deep boreholes at Vostok Station (East Antarctica), Journal of Geophysical Research. 1-3: 8963-87977
Fig. 1B. BOTTOM: Atmospheric O2.
Oxygen after R.A. Berner, 1999: Perspective Atmospheric oxygen over Phanerozoic time; PNAS Vol. 96, Issue 20, 10955-10957, September 28, 1999 abstract*
400,000 Year History
Here is a temperature record for the last 400,000 years. We are now in the last part of the Holocene warm period shown at the right. This plot shows that the earth spends most of its time as an ice ball. The last 12,000 years has been a good time to live.
Source: Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis M., Delague G., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V.Ya., Lorius C., Pepin L., Ritz C., Saltzman E., Stievenard M. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature, vol. 399, N 6735, 3 June 1999, pp. 429-436.
Contributed by William McClenney: