05-02-2019, 04:15 PM
From HERE
Nick,
It doesn’t have to be a coincidence. CO2 could have risen to the mid-300 ppm in all of those interglacial stages and not been resolved by the ice cores.
Plant stomata indicate that CO2 levels of 300-360 ppm were not uncommon in the Early Holocene and Eemian. Greenland ice cores yield similar results; although in situ CO2 production is a possibility. The Antarctic ice cores lack the resolution to negate this. I’m not suggesting that >400 ppm spikes occurred. If I remember correctly quercas (oak) stomata don’t respond to CO2 levels above 400 ppm. So, most stomata chronologies top off between 330-360 ppm.
Pre-industrial estimates of oceanic pH are generally derived from atmospheric CO2 levels.
Nick,
It doesn’t have to be a coincidence. CO2 could have risen to the mid-300 ppm in all of those interglacial stages and not been resolved by the ice cores.
Plant stomata indicate that CO2 levels of 300-360 ppm were not uncommon in the Early Holocene and Eemian. Greenland ice cores yield similar results; although in situ CO2 production is a possibility. The Antarctic ice cores lack the resolution to negate this. I’m not suggesting that >400 ppm spikes occurred. If I remember correctly quercas (oak) stomata don’t respond to CO2 levels above 400 ppm. So, most stomata chronologies top off between 330-360 ppm.
Pre-industrial estimates of oceanic pH are generally derived from atmospheric CO2 levels.