Photosynthesis limits CO2 in the global air to a pre-industrial 2 parts per million. In the Jurassic, there were 3 natural ice ages – one lasting 650 million years. CO2 levels rose to 4 times higher than the present capped level.
So people saying man burning Fossil Fuels has affected the TRACE of CO2 in the global air have fallen behind on their metal health medication.
CO2 levels rise 4 years into a natural ice-age. And they are twice as high today, over the Poles.