Zeebe et al. (2009)
Also: Zeebe et al. 2009
Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming
Zeebe, R.E., Zachos, J.C. & Dickens, G.R. (2009). Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming. Nature Geoscience. 2(8),576-580. PDF
https://doi.org/10.1038/ngeo578
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.