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).
