Figure TS.2: Comparison
of reference and stabilization scenarios. The figure is divided into six parts,
one for each of the reference scenario groups from the Special Report on Emissions
Scenarios (SRES). Each part of the figure shows the range of total global CO2
emissions (gigatonnes of carbon (GtC)) from all anthropogenic sources for the
SRES reference scenario group (shaded in grey) and the ranges for the various
mitigation scenarios assessed in the TAR leading to stabilization of CO2 concentrations
at various levels (shaded in colour). Scenarios are presented for the A1 family
subdivided into three groups (the balanced A1B group (Figure TS-2a), non-fossil
fuel A1T (Figure TS-2b), and the fossil intensive A1FI (Figure TS-2c)) and stabilization
of CO2 concentrations at 450, 550, 650 and 750ppmv; for the A2 group with stabilization
at 550 and 750ppmv in Figure TS-2d, the B1 group and stabilization at 450 and
550ppmv in Figure TS-2e, and the B2 group including stabilization at 450, 550,
and 650ppmv in Figure TS-2f. The literature is not available to assess 1000ppmv
stabilization scenarios. The figure illustrates that the lower the stabilization
level and the higher the baseline emissions, the wider the gap. The difference
between emissions in different scenario groups can be as large as the gap between
reference and stabilization scenarios within one scenario group. The dotted lines
depict the boundaries of the ranges where they overlap (see Box TS.1).
