SRES Emissions Scenarios

In 2000 the Intergovermental Panel on Climate Change (IPCC) published a set of scenarios for use in the Third Assessment Report. These SRES scenarios are possible images of the future under different future developments. Factors such as economic development, technological development, energy use, population change, and land-use change were all included in the SRES scenarios. Four story lines were constructed. These four include A1, A2, B1 and B2 story lines (see image below). These 4 story lines differ on how global and regional policies relate, how new technologies evolve, how economic activities evolve, and how population growth changes. There are 40 different scenarios based on the 4 story lines looking at different possible futures. Nakicenvoic et al. (2000) describes the SRES scenarios in the Special Report on Emissions Scenarios (SRES). We are distributing data from 3 of these scenarios.

SRES scenario B1 is a lower end emissions scenario. Scenario B1 assumes :

  • population that peaks in the mid-century and declines thereafter
  • rapid changed in economic structures
  • introduction of clean and resource-efficient technologies

SRES scenario A2 is the higher end of the SRES emissions scenarios. Scenario A2 assumes:

  • increasing global population
  • regionally oriented economic growth
  • technology development is slow

SRES scenario A1B is a middle of road scenario. Scenario A1B assumes :

  • very rapid economic growth
  • global population peaks at the mid century then declines
  • introduction of more efficient technologies
  • energy sources not relying too heavily on one particular energy source



Nakicenvoic et al., 2000. Special Report on Emissions Scenarios. A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press: Cambridge.