Witkowski et al. (2018)
Also: Witkowski et al. 2018
Molecular fossils from phytoplankton reveal secular Pco2 trend over the Phanerozoic
Witkowski, C.R., Weijers, J.W.H., Blais, B., Schouten, S., & Sinninghe Damste, J.S. (2018). Molecular fossils from phytoplankton reveal secular Pco2 trend over the Phanerozoic. Science Advances. 4, eaat4556. Link to article.
References
All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.