Different Future Socio-Economic Development Paths

Assumptions of future economic conditions have two dimensions:

1. Will future societies be more environmentally oriented or continue on a high consumption path?
2. Will future societies look globally or locally for solutions to economic, social, and environmental sustainability?

Figure 4 shows four families of scenarios depending on these behavioral patterns of future societies as described in the Special Report on Emissions Scenarios (SRES). Each of these four families has a "storyline" that describes the global population and energy consumption patterns and the associated greenhouse gas emissions:

Scenario A1 represents high economic growth and global perspectives to economic and environmental issues. It is further subdivided into a scenario continuing to emphasize intensive use of fossil fuels (A1FI), one being energy intensive but with emphasis on use of non-fossil energy (A1T), and a scenario with a balance of fuel sources between fossil and non-fossil (A1B). Global population peaks about 2050 and then declines.

Scenario A2 assumes self-reliance and preservation of local identities. Developing regions are less influenced by developed countries, so that, for instance, fertility follows local historical traditions rather than patterns of developing countries. Global population does not peak in mid-century. Economic development is linked to regional rather than global patterns.

Scenario B1 has global population peaking around 2050 and declining thereafter. Economic growth is more globally linked but with introduction of clean and resource-efficient technologies. Social equity is emphasized with global attention to economic, social and environmental problems. However, there are no global restrictions on emissions of greenhouse gases.

Scenario B2 has an increasing global population, but somewhat less than A2, which does not peak in mid-century. Emphasis is on a local approaches to addressing economic, social, and environmental sustainability. Emphasis is on environmental protection and social equity through local approaches. Economic development is not as rapid as in B1 and A1 but with more diverse technological change.

Resulting Emissions Scenarios and Atmospheric Greenhouse Gas Concentrations

Each of these scenarios creates a somewhat different pattern of greenhouse gas emissions. The following figures show the emissions corresponding to each of these scenarios and the time record of atmospheric concentrations of greenhouse gases that will result from each scenario.

* Adapted from IPCC, 2001: Climate Change 2001: Synthesis Report. A contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Watson, R.T. and the Core Writing Team (eds.)]. Cambridge University Press, Cambridge, United Kingdom, and New York, NY, USA, 398 pp.

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