It should also be noted that the larger regional increases and decreases in crop
yields witnessed under S550 and S750 by the 2080s fall outside the range of
previously reported results from the ensemble of unmitigated HadCM2-driven
experiments. Table 1 summarizes global cereal production (under realistic
assumptions about trade liberalization) in the absence of climate change and
under the three emissions scenarios.
Implications for Food Security and Hunger
The changes in total global cereal production shown in Table 1 appear small, but
can have significant effects on global food prices and the consequent risk of
hunger. Food prices are simulated in the Basic Linked System, and are projected
to rise relative to the baseline case with no climate change because of the lower
production. This increase in prices exacerbates the stress of regional shortfalls in
production, leading to an increase in the risk of hunger. More cases emerge where
populations are not only unable to grow enough food due to a sustained
deterioration in their resource base, but are also unable to reduce the food deficit
by purchasing additional foodstuffs on the world markets because of regional
inequalities in economic growth.
Table 2 shows the number of people at risk from hunger in the absence of
climate change and under the three emissions scenarios. With no climate change,
the number of people at risk from hunger, following historical trends, decreases
from more than 500 million in 1990 to about 270 in the 2080s. This is the result of
increased agricultural production due to technological advances combined with
the assumption that living standards will rise while the incidence of poverty in
developing countries will continue to fall. Under the unmitigated emissions
scenario, it is estimated that the additional number of people at risk from hunger
due to climate change would be around 20 million by the 2050s, increasing to
around 80 million by the 2080s. The numbers of people affected are smaller by
the 2050s, largely because the effects of climate change on prices are lower at this
time, which is itself because at this time horizon — unlike the others — grain
production increases in the United States under two of the four ensemble
members. Stabilization at 750 ppmv reduces the unmitigated impacts by around
75%, while stabilization at 550 ppmv achieves a more modest mitigating
reduction of around 50% in the number of additional people at risk of hunger due
to climate change.
Global figures, however, hide considerable regional variations. The vast
majority (:65%) of the people at additional risk of hunger in the future are in
Africa. This partly reflects the greater-than-average reduction in yields, but is also
due to higher levels of vulnerability caused to some extent by the lower incomes in
Africa. Increasing this regional disparity, it appears that the beneficial effects of
stabilization are also less in this region. Under an S750 world the additional
number of people at risk of hunger is only reduced by :30% while under an S550
future the reduction in the climate induced impact is only 20%.
M. Parry and M. Livermore
136
yields witnessed under S550 and S750 by the 2080s fall outside the range of
previously reported results from the ensemble of unmitigated HadCM2-driven
experiments. Table 1 summarizes global cereal production (under realistic
assumptions about trade liberalization) in the absence of climate change and
under the three emissions scenarios.
Implications for Food Security and Hunger
The changes in total global cereal production shown in Table 1 appear small, but
can have significant effects on global food prices and the consequent risk of
hunger. Food prices are simulated in the Basic Linked System, and are projected
to rise relative to the baseline case with no climate change because of the lower
production. This increase in prices exacerbates the stress of regional shortfalls in
production, leading to an increase in the risk of hunger. More cases emerge where
populations are not only unable to grow enough food due to a sustained
deterioration in their resource base, but are also unable to reduce the food deficit
by purchasing additional foodstuffs on the world markets because of regional
inequalities in economic growth.
Table 2 shows the number of people at risk from hunger in the absence of
climate change and under the three emissions scenarios. With no climate change,
the number of people at risk from hunger, following historical trends, decreases
from more than 500 million in 1990 to about 270 in the 2080s. This is the result of
increased agricultural production due to technological advances combined with
the assumption that living standards will rise while the incidence of poverty in
developing countries will continue to fall. Under the unmitigated emissions
scenario, it is estimated that the additional number of people at risk from hunger
due to climate change would be around 20 million by the 2050s, increasing to
around 80 million by the 2080s. The numbers of people affected are smaller by
the 2050s, largely because the effects of climate change on prices are lower at this
time, which is itself because at this time horizon — unlike the others — grain
production increases in the United States under two of the four ensemble
members. Stabilization at 750 ppmv reduces the unmitigated impacts by around
75%, while stabilization at 550 ppmv achieves a more modest mitigating
reduction of around 50% in the number of additional people at risk of hunger due
to climate change.
Global figures, however, hide considerable regional variations. The vast
majority (:65%) of the people at additional risk of hunger in the future are in
Africa. This partly reflects the greater-than-average reduction in yields, but is also
due to higher levels of vulnerability caused to some extent by the lower incomes in
Africa. Increasing this regional disparity, it appears that the beneficial effects of
stabilization are also less in this region. Under an S750 world the additional
number of people at risk of hunger is only reduced by :30% while under an S550
future the reduction in the climate induced impact is only 20%.
M. Parry and M. Livermore
136