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Table 2

Population at Risk in 2085 for Hunger

Population at Risk in the

Additional Population at

Total Population

Absence of Climate Change

Risk Because of Climate Change

at Risk

Units

Millions

Percentage of

Millions

Percentage of

Millions

Percentage of

Global Population

Baseline 1990

798 to 872

15.1 to 16.5

798 to 872

15.1 to 16.5

A1FI 2085

105

1.3

0.4

133

1.7

A2 2085

767

5.4

28 to 9

0.2 to 0.1

739 to 758

5.2 to 5.3

B2 2085

233

2.3

11 to 5.0

0.1 to 0.05

222 to 238

2.2 to 2.3

B1 2085

1.1

0.1

100

1.3

Source: M. L. Parry et al., "Effects of Climate Change on Global Food Production under SRES Emissions and Socio-Economic Scenarios," Global

Environmental Change 14, no. 1 (2004): 5367.

the impact of climate change is sec-

Hunger

ondary to the impact of other factors.

The FTA's estimates of population at risk

for hunger in 2085 both with and without

The estimates in Table 2 are based on the

climate change for the various scenarios are

assumption that atmospheric CO2 will

shown in Table 2. These estimates, which

assume CO2 fertilization in the event of cli-

improve crop yields. If that does not prove to

be the case, then climate change would

mate change, show that under every scenario

increase the total population at risk under all

the world will be better off in 2085 with

scenarios. Even so, the additional population

respect to hunger than it was in 1990 despite

at risk of hunger due to climate change

any increase in population.

would still be less than the population at risk

There are three conclusions that one can

of hunger without climate change in all but

draw from Table 2:

the A1FI scenario.30 But such outcomes are

· The cooler scenarios (B2 and B1) do not

unlikely because the probability that direct

CO2 effects on crop growth are zero or nega-

yield markedly less hunger than the

hottest scenario (A1FI). The hottest sce-

tive is slight, particularly since future soci-

nario actually yields less hunger than

eties, especially the A1FI society, should have

two of three cooler scenarios. But for the

a greater capacity to adapt.

FTA's systematic overestimates of the

The Stern Review argues, based on a study

populations at risk of hunger in the

by Long et al., that the beneficial effect of car-

bon fertilization has been overestimated.31

A1FI world relative to the B1 world, the

A1FI scenario might have resulted in the

Accordingly, it uses the results from FTA's

lowest overall levels of hunger with or

hunger study that assumes "no fertilization."

without climate change.

But in fact, Long et al. estimate that the CO2

· For some scenarios (A2 and, possibly, B2),

fertilization effect could be a third to half as

climate change might, in fact, reduce the

large in areas where insufficient nitrogen is

incidence of hunger at least through 2085.

applied or if crops are not well-watered, not

· For each scenario, the additional popu-

zero.32 Even so, a peer-reviewed paper that

lation at risk from hunger because of cli-

evaluated the Long et al. study found that

mate change alone is smaller than the

their analysis was "incorrect, being based in

population at risk from hunger without

part on technical inconsistencies and [lacks]

statistical significance."33

climate change. Through 2085 at least,