Although one may be reasonably optimistic about the prospects of adapting the
global agricultural production system to the early stages of warming, the distribution
of vulnerability among regions and people is likely to be uneven. As pointed
out in Section 5.3.3, in the tropicswhere some
crops are near their maximum temperature tolerance and where dryland, nonirrigated
agriculture predominatesyields are likely to decrease with even small
amounts of climate change. The livelihoods of subsistence farmers and pastoral
peoplewho make up a large proportion of rural populations in some regions,
particularly in the tropics, and who are weakly coupled to marketsalso
could be negatively affected. In regions where there is a likelihood of decreased
rainfall, agriculture could be substantially affected regardless of latitude.
However, regional economic analysis (see Table 5-4)
indicates that aggregate impacts on incomes even in the most vulnerable populations
may not be large.
Clearly, in addition to the foregoing generality on productivity, other features
of agricultural vulnerability are likely to vary widely among people, regions,
nations, and continents (see Chapters 10-17).
As noted in several places in this section and elsewhere (Downing et al.,
1996a), the poorespecially those living in marginal environmentswill
be most vulnerable to climate-induced food insecurity. Parry et al. (1999)
assessed the consequences of climate change for the number of people at risk
of hunger as defined by the Food and Agriculture Organization (FAO, 1988) (see
Table 5-4 for details of the study). By the 2080s,
the additional number of people at risk of hunger as a result of climate change
is estimated to be about 80 million. However, some regions (particularly in
the arid and subhumid tropics) may be affected more. Africa is projected to
experience marked reductions in yield, decreases in production, and increases
in the risk of hunger as a result of climate change. The continent can expect
to have 55-65 million extra people at risk of hunger by the 2080s under the
HadCM2 climate scenarios. Under the HadCM3 climate scenario, the effect is even
more severe, producing an estimated additional 70+ million people at risk of
hunger in Africa. It should be noted, however, that these hunger estimates are
based on the assumption that food prices will rise with climate change, which
(as noted above) is highly uncertain as far as 80 years into the future.
Who are these extra people at risk of hunger likely to be? Downing et al. (1996b)
suggest the following classes: rural smallholder producers, pastoralists, rural
wage laborers, urban poor, and refugees and displaced people. In addition, they
point to particular kinds of individuals: rural women, malnourished children,
handicapped and infirm people, and the elderly.
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