World agriculture towards 2030/2050: the 2012 revision - Fao

PROOF COPY
tonnes/ha (average 2005-07). On average it has been growing in a nearly perfect linear
fashion with increments of 44 kg/year on average, as it can be seen in Figure 1.9. A linear
growth pattern implies a falling growth rate: 44 kg was 3.1 percent of the 1.44 tonnes/ha of
the early 1960s, but it was 1.8 percent of the 2.4 tonnes/ha of the early 1980s and only 1.3
percent of the current 3.4 tonnes/ha. Recently, this has become a source of concern about the
capacity of world agriculture to produce enough food for the growing population. Is this
concern justified?
Up to about 2006 the world was abundantly supplied with cereals, while the growth rate
of yields kept falling. This is evidenced by the trend towards decline of the real price of
cereals, at least up to the mid-1980s, and its near constancy thereafter up to the major rise in
the price index in the years 2007-08. While the price rise was the result of confluence of many
factors, a major one has been the sudden spurt in demand caused by the diversion of
significant quantities of cereals to the production of biofuels (Alexandratos, 2008; Mitchell,
2008). If such spurts in demand from the non-food sector were repeated in the future
(something not foreseen in these projections), the falling growth rate of yields could prove to
be significant constraint to meeting projected demand.
However, with the projected slowdown in the growth of demand a further decline in the
growth rate of yields, unless it were nearly catastrophic, would be compatible with the need to
produce the quantities required. If the linear growth of cereal yields continued at 44 kg/year,
by 2050 the growth rate would have fallen further to 0.8 percent p.a. Yet the world would be
producing more grain than required by the projected demand even if there were no increase in
the area cultivated. This is because even with this falling growth rate of yield, in 2050 the
average would have grown to 5.42 tonnes/ha by 2050, and world production would be 3.8
billion tonnes, hence more than our projected demand of 3.28 billion tonnes. 10
While global averages is fairly meaningless, but nonetheless instructive for illuminating
the debate on the significance of the decline of the global yield growth rate for food security
in the long term future. What matters, however, is what individual countries can achieve in
the light of their prospective needs for increasing production, their resource endowments and
initial conditions. Several countries and regions have a long history of near stagnant yields
and resource endowments and policy environments that are not very promising. Based on a
country by country and crop by crop examination, and distinguishing between rainfed and
irrigated production, we estimate that global cereals yields could grow from 3.3 tonnes/ha in
the base year to 4.30 tonnes/ha in 2050 (Figure 1.9).
10 These cereal quantities include rice in paddy – as is appropriate when we discuss yields –and the 3.28 billion
tonnes is equivalent to the 3 billion tonnes for 2050 we presented earlier which includes rice in milled form as is
appropriate when we discuss consumption.
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