CO₂ Levels over Phanerozoic Time

 

Another interesting paper I have come across during my reading is by Robert A. Berner and published in Science in 1990, the paper is titled “Atmospheric Carbon Dioxide Levels over Phanerozoic Time”.    Barner (1990) is discussing how atmospheric CO₂ for the past 570 million years can be calculated by making use of, a new at the time, model by making use of "feedback functions for the weathering of silicate minerals".  Overall Berner (1990) was able to establish that during the Mesozoic and early Palaeozoic CO₂ levels were higher than those of the Permo-Carboniferous and late Cenozoic.  Berner (1990) bases his model on that of the Garrels and Lerman 1984 model of carbon mass balance, Berner’s model is an expanded version using a steady state.

Berner (1990) concludes that if it is assumed that the calculations made and the results which were obtained were correct then it would be fair to expect to see evidence that atmospheric greenhouse effects would result in warmer global climates.  The model also shows that CO₂ levels were at a minimum at corresponding times to that of glaciation periods e.g. lower CO₂ = lower temperatures.

 

Illustration of the Phanerozoic Eon. 

http://samnoblemuseum.ou.edu/wp-content/uploads/2015/05/Phanerozoic.jpg

All that being said, are we starting to see the link between CO₂ and global temperatures?  It would seem so, but of course I skim the paper here, just pulling out the basic take home message and one can hardly base an argument on two papers regardless of how far back in Earth’s history they look. 

 

Reference

Berner, R. (1990). Atmospheric Carbon Dioxide Levels over Phanerozoic Time. Science. 249, pp.1382 - 1386.