The choice ofstabilisation level 257Table 10.3Total anthropogenic carbon dioxide emissions in Gt carbon
accumulated from 2001–2100 inclusive for SRES scenarios and for
stabilisation scenarios (calculated using the Bern carbon cycle modela
with no carbon cycle feedbacks)
Case Accumulated CO 2 emissions (GtC) 2001 to 2100
SRES Scenarios
A1B 1415
A1T 985
A1FI 2105
A2 1780
B1 900
B2 1080
Stabilisation scenarios
450 ppm 600
550 ppm 900
650 ppm 1100
750 ppm 1200
1000 ppm 1300
aAdapted from Table 5 of Technical summary. In Houghton, J. T., Meira Filho,
L. G., Callander, B. A., Harris, N., Kattenberg, A., Maskell, K. (eds.) 1996.
Climate Change 1995:The Science of Climate Change. Cambridge: Cambridge
University Press.country to country (Figure 10.2). For developed countries and transi-
tional economy countries in 2000 they averaged 2.8 t (ranging down-
wards from about 5.5 t for the USA) while for developing countries they
averaged about 0.5 t. Looking ahead to the years 2050 and 2100, even if
the world population rises to only about seven billion (as with SRES scen-
arios A1 and B1) under the profiles of carbon dioxide emissions leading
to stabilisation at concentrations of 450 ppm and 550 ppm (Figure 10.1)
the per capita annual emissions averaged over the world would be about
0.6 t and 1.1 t respectively for 2050 and 0.3 and 0.7 t respectively for
210017 – much less than the current value of about 1 t.
The choice of stabilisation level
The last few sections have addressed the main greenhouse gases and how
their concentrations might be stabilised. To decide how the appropriate
stabilisation levels should be chosen as targets for the future we look
to the guidance provided by the Climate Convention Objective (see box