For the last 140 million years, CO2 levels fell precipitously & steadily to within about 30 ppm of the 150 ppm “line of death” below which plants can’t survive. Both the relatively short-term data from ice cores and much longer-term data going back 140 million years (Berner 2001) show an alarming downward trend toward CO2 starvation. The release of carbon dioxide by the use of fossil fuels has allowed humanity to increase concentrations of this beneficial molecule, and perhaps avert an actual CO2-related climate apocalypse.