Walker et al (1981)
Also: Walker et al 1981
A negative feedback mechanism for the long-term stabilization of the Earth's surface temperature
Walker, J. C., Hays, P. B., & Kasting, J. F. (1981). A negative feedback mechanism for the long-term stabilization of the Earth's surface temperature. Journal of Geophysical Research, 86(C10), 9776-9782.
http://users.unimi.it/paleomag/geo2/Walker+1981.pdf
DOI: 10.1029/JC086iC10p09776
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.