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 … Continue reading 140-million-year trend of dangerously decreasing CO2.