The Inconvenient Skeptic: The Comprehensive Guide to the Earth's Climate

by John Kehr

After the Earth started to warm up, the CO2 level also started to increase. While it is interesting that the CO2 level changed after the temperature did, what I find more interesting is what happened when the Eemian started to dramatically cool down 118,000 years ago. The CO2 level stayed the same. The Earth cooled down while the CO2 level was at the “warm” level of 270 ppm. In fact the CO2 level stayed nearly constant at 270 ppm from 128,000 to 112,000 years ago. In that same period of time the global temperature dropped 8 °C (14 °F). So while CO2 did go up after the temperature went up, the CO2 level didn't do anything to stop the Earth from cooling down. So it could be argued that CO2 “might” have contributed during the beginning of the Eemian, but the Earth cooled down as the insolation dropped. It is also interesting to note that the temperature of the Earth during the Eemian was warmer than it is today, while the CO2 level was only 285 ppm. A temperature projection based on the CO2 level during the Eemian would indicate that the temperature anomaly of the Earth today should be 1.6 °C warmer than it was at the peak of the Eemian which would put the modern temperature anomaly at 5.4 °C. That is ~5 °C higher than the current temperature. If the modern insolation anomaly of -13 W/m2 is used to predict the modern temperature anomaly, then the prediction would be 0.6 °C which is almost exactly what the modern temperature is. In fact the Earth is 0.2-0.4 °C cooler than the ...