-20
0
20
40
60
80
100
120
2020s
2050s
2080s
Timeslice
Additional Millions of People
HadCM3 HadCM2GGax Range
Figure 7c Global estimates
of the additional number
of people at risk of hunger
due to climate change
compared with the
reference case. HadCM3
estimates are represented
by the grey blocks. Bars
represent the range of
results under the four
HadCM2 ensemble
simulations
the four HadCM2 scenarios. In Africa cereal productivity under the HadCM2
scenarios is estimated to be reduced by about 12% or 30 Mt (<2% depending on
which HadCM2 ensemble member is chosen) from the reference case by 2080
(Figure 8). The figure for South East Asia is ca. 23% (<1%). As a consequence the
number of people at risk of hunger in developing regions is estimated to increase:
in Africa by more than one-third, while in Latin America we might expect to see a
doubling over reference case levels (Figure 9).
4 Reducing Impacts by Stabilizing CO 2 Concentrations at Lower
Levels
In this section we explore the implications for a range of global-scale impacts of
climate change of the stabilization of CO
concentrations at defined levels. These
stabilization scenarios (at 550 ppmv by 2150 and 750 ppmv by 2250) are among
the set defined by the Intergovernmental Panel on Climate Change.
Scenarios
Two stabilization scenarios (stabilizing at CO
concentrations of 550 ppmv and
750 ppmv) are considered, and compared with the IS92a unmitigated emissions
scenario. Figure 10 shows the CO
emissions profiles and atmospheric CO
concentrations consistent with the forcings used in the climate experiments (note
that the Figure does not show the concentration and emissions of other
greenhouse gases). There is little difference in concentrations between the two
scenarios to the 2020s, but thereafter they begin to diverge. The S750 scenario
IPCC, Climate Change 2001: The Scientific Basis. Technical Summary of the Working Group I
Report, Geneva, 2001.
J. Leggett, W. J. Pepper and R. J. Swart, Emissions scenarios for the IPCC: an update, in J. T.
Houghton, B. A. Callander and S. K. Varney, (eds.), Climate Change 1992: the Supplementary
Report to the IPCC Scientific Assessment, Cambridge University Press, Cambridge, 1992, 75—95.
Climate Change, Global Food Supply and Risk of Hunger
129
0
20
40
60
80
100
120
2020s
2050s
2080s
Timeslice
Additional Millions of People
HadCM3 HadCM2GGax Range
Figure 7c Global estimates
of the additional number
of people at risk of hunger
due to climate change
compared with the
reference case. HadCM3
estimates are represented
by the grey blocks. Bars
represent the range of
results under the four
HadCM2 ensemble
simulations
the four HadCM2 scenarios. In Africa cereal productivity under the HadCM2
scenarios is estimated to be reduced by about 12% or 30 Mt (<2% depending on
which HadCM2 ensemble member is chosen) from the reference case by 2080
(Figure 8). The figure for South East Asia is ca. 23% (<1%). As a consequence the
number of people at risk of hunger in developing regions is estimated to increase:
in Africa by more than one-third, while in Latin America we might expect to see a
doubling over reference case levels (Figure 9).
4 Reducing Impacts by Stabilizing CO 2 Concentrations at Lower
Levels
In this section we explore the implications for a range of global-scale impacts of
climate change of the stabilization of CO
concentrations at defined levels. These
stabilization scenarios (at 550 ppmv by 2150 and 750 ppmv by 2250) are among
the set defined by the Intergovernmental Panel on Climate Change.
Scenarios
Two stabilization scenarios (stabilizing at CO
concentrations of 550 ppmv and
750 ppmv) are considered, and compared with the IS92a unmitigated emissions
scenario. Figure 10 shows the CO
emissions profiles and atmospheric CO
concentrations consistent with the forcings used in the climate experiments (note
that the Figure does not show the concentration and emissions of other
greenhouse gases). There is little difference in concentrations between the two
scenarios to the 2020s, but thereafter they begin to diverge. The S750 scenario
IPCC, Climate Change 2001: The Scientific Basis. Technical Summary of the Working Group I
Report, Geneva, 2001.
J. Leggett, W. J. Pepper and R. J. Swart, Emissions scenarios for the IPCC: an update, in J. T.
Houghton, B. A. Callander and S. K. Varney, (eds.), Climate Change 1992: the Supplementary
Report to the IPCC Scientific Assessment, Cambridge University Press, Cambridge, 1992, 75—95.
Climate Change, Global Food Supply and Risk of Hunger
129