256 A strategyfor action to slowand stabiliseclimate change03452
1Centimeters6(^87) Sea level rise
2000 2050 2100
(^0200020502100)
4
8
10
12
18
2150 2200 2250 2300
20
16
14
6
2
(a) CO 2 emissions (Gt C)
(^0200020502100)
3
4
2150 2200 2250 2300
5
2
1
(c) Global mean temperature change
(^3002000205021002150220022502300)
400
(b) CO 2 concentration
500
600
700
800
900
1,000
A2 1,100
A1B
B1
A2
A1B
B1
A2
A1B
B1
6
7
WRE 1000
WRE profiles
WRE 750
WRE 650
WRE 550
WRE 450
SRES scenarios
Emissions, concentrations, and temperature changes corresponding
to different stabilisation levels for CO 2 concentrations
Figure 10.1(a) Emission profiles of carbon dioxide that would lead to
stabilisation of carbon dioxide concentration in the atmosphere at levels of 450,
550, 650, 750 and 1000 ppm according to the concentration profiles shown in
(b), estimated from carbon cycle models, without the effects of climate carbon
cycle feedbacks included. The shaded area illustrates the range of uncertainty in
the estimates that includes the effects of climate carbon cycle feedbacks (e.g.
the low boundary of the shading is the profile of the 450 ppm stabilisation curve
with the feedbacks included). Also shown are three of the SRES emissions
scenarios (A1B, A2 and B1) and the concentrations that would result from them.
(c) Global mean temperature changes for the stabilisation profiles in (a)
estimated in the same way as for Figure 6.4. The black spots indicate the year in
which stabilisation of carbon dioxide concentration is achieved. It is assumed
that emissions of gases other than carbon dioxide follow the SRES A1B scenario
until the year 2100 and are constant thereafter. The shaded area indicates the
effect of a range of climate sensitivity across five stabilisation cases (see caption
to Figure 6.4) and the bars on the right-hand side show the range at the year
2300 for the different profiles. The diamonds show the equilibrium (very
long-term) warming for each stabilisation level using average climate model
results. Also shown for comparison are temperature increases in the year 2100
estimated for the three SRES scenarios.