Manabe & Wetherald (1975)
Also: Manabe & Wetherald 1975
The effects of doubling the CO2 concentration on the climate of a general circulation modell
Manabe, S., & Wetherald, R. T. (1975). The effects of doubling the CO2 concentration on the climate of a general circulation modell. Link to PDF
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.