Similar title to Schrattenholzer, L. & Riahi, K. ORCID: https://orcid.org/0000-0001-7193-3498 (2005). Alternative Scenarios of Greenhouse Gas Emissions. IIASA Research Report (Reprint). IIASA, Laxenburg, Austria: RP-05-004. Reprinted from Encyclopedia of Energy, 3:67-76 [2004].