Dahl, T. W., Harding, M. A. R., Brugger, J., Feulner, G., Norrman, K., Lomax, B. H., & Junium, C. K. (2022). Low atmospheric CO2 levels before the rise of forested ecosystems. Nature Communications, 13(1), Article 7616. https://doi.org/10.1038/s41467-022-35085-9