On May 6, 2000 in Montreal a full Plenary Meeting of the IPCC (Intergovernmental Panel on Climate Change) accepted the Special Report on Emissions Scenarios (SRES).

Nebojša Nakicenovic served as the the Convening Lead Author with Arnulf Grübler, Keywan Riahi and R. Alexander Roehrl contributing as Lead Authors of the SRES Writing Team.

The IPCC first developed long-term emission scenarios in 1990 and 1992. In 1995 the 1992 scenarios were evaluated, and in 1996 the IPCC Plenary commissioned a new set of scenarios. The result is 40 new "SRES scenarios" presented in this report. The 40 new scenarios are grouped into four families, each based on a distinct qualitative "storyline."

• A1: Rapid economic growth, technological progress, globalization, and convergence.
• A2: Regionally oriented economic development resulting in less convergence and more fragmented and slower technological progress and growth than in A1.
• B1: Global cooperative solutions to economic, social, and environmental sustainability, including improved equity.
• B2: Local and regional solutions to economic, social, and environmental sustainability, resulting in more fragmented and slower technological progress and growth than in B1.

The report identifies six scenarios as representative of the range covered by all 40. These are one "marker scenario" for each family, plus two additional scenarios from the A1 family - one in which technological progress focuses on non-fossil technologies and a second in which the focus is fossil technologies. Consistent with the terms of reference specified by the IPCC, none of the 40 scenarios includes policies designed to limit greenhouse gas emissions.

The report compares its new scenarios to a database of over 400 previously published emission scenarios. Results are presented principally in terms of projected emissions of CO2 and other gases related to possible global warming.

Six models from around the world were used to develop the new scenarios, including the ECS Project's MESSAGE model. Among other contributions, ECS provided nine of the 40 SRES scenarios, including one of the markers (B2) and one of the illustrative A1 scenarios (non-fossil technologies A1T scenario).

Quick Links:
A set of transparencies describing key SRES results is accessible here.
Link to the SRES Summary for Policy Makers (in pdf format/full text).