Quantification of the IS99 Emission Scenario Storylines Using the Atmospheric Stabilization Framework

Abstract

In 1997–1999, an international team of scientists and modelers formulated a set of 40 global greenhouse gas (GHG) emission scenarios. These scenarios were designed as quantitative interpretations of four distinct scenario storylines that described alternative views on the global and regional demographic, socioeconomic, technological, and environmental development in the 21st century. The Atmospheric Stabilization Framework (ASF) was one of the six models selected to develop the scenarios, which are referred to here as IS99 scenarios. The ASF-based (IS99-ASF) results include four GHG emissions scenarios and corresponding changes in the GHG atmospheric concentrations and the global average temperature. The IS99-ASF scenarios were generated by modifying such model inputs as: regional GNP/capita growth; ultimately recoverable fossil fuel resources; supply-side and end-use energy efficiency; the availability of renewable energy resources; and terrestrial carbon sinks. According to the ASF-based analysis, the largest cumulative GHG emissions and climate effects over the next century result from a combination of fast economic growth, a delayed reduction of the energy and carbon intensity of GNP, and an increase of the coal share in the primary energy supply (ASF-A1 scenario). At the same time, a slightly lower GNP growth rate combined with an increased use of renewable energy sources leads to the lowest cumulative GHG emissions and the stabilization of the CO 2 atmospheric concentration by 2100 at about 615 ppmv (ASF-B1 scenario).