Figure TS-9: Global cumulative CO2 emissions (GtC, standardized). The ranges of cumulative emissions for the SRES scenarios are shown. Scenarios are grouped into four categories: low, medium-low, medium-high, and high emissions. Each category contains one marker scenario plus alternatives that lead to comparable cumulative emissions, although often through different driving forces. The ranges of cumulative emissions of the six SRES scenario groups are shown as colored vertical bars and the range of the IS92 scenarios as a black vertical bar.