Arguments - Impact
|Population growth is a major
driving force of food demand. However, it is not possible to estimate China's future food
demand simply by multiplying today's per capita consumption by the projected number of
people. In particular, we must take into account a change in dietary preferences,
especially the likely increase in meat consumption. Structural changes within the
population, such as population aging or changes in labor force, might also have a slight
effect on overall food demand. Growing population density in Eastern China also affects
the country's food production capacity, because it leads to the decline of cropland areas.
|To what extent will
demographic factors affect China's food demand and supply? For analytical purposes, we
have to distinguish five possible impacts:
impact on food demand. Obviously, the number of mouths to feed largely determines
overall food demand. With a projected population increase of 260 million people between
1995 and 2025, China would have to increase grain production by at least 20-25%.
This assumes constant per capita calorie consumption and unchanged diet
preferences. However, both assumptions are highly unlikely.
have to take into account a (slight) increase in per capita calorie consumption.
According to the most recent FAO food balance sheet (1996), China has an average food
calorie supply of 2,844 kcal per person per day. This is still somewhat below the average
level of developed countries, which was 3,177 kcal per person per day in 1996. (This issue
is discussed in the chapter on change in diet.)
more important, however, is a likely change in diet. China's population
has not only massively increased meat consumption since 1978, but on average people also
eat many more fruits and vegetables. Direct consumption of grain has leveled off or even
declined. (This issue is discussed in detail in the chapter on change in diet.)
also the possibility that other demographic factors such as the age
composition of the population might affect overall food demand.
factors will not only affect food demand, but they will also have an impact on
the food supply. Growing population density in Eastern China, which has most of the
countrys arable land, will directly lead to a decline of cropland areas.
They will not only shrink because of urban sprawl, but also due to the growing land
requirements of villages and rural infrastructure.
(These issues are discussed in the chapters on urbanization
and arable land.)
|Direct impact of population growth on food demand
projections for China so far have not used very detailed assumptions on population growth.
Usually, only a single-variant population projection is used for the calculations (see
Table 1 for a comparison of various projections). However, a simple back-of-the-envelope
calculation shows that, for predicting China's longer-range food demand (such as to 2025
or even 2050), the unavoidable error range of demographic projections is an important
source of uncertainty. While per capita food calorie consumption has a definite upper
limit (there is only so much one can eat), the limits to population growth are much more
uncertain (see the discussion of demographic
I have developed a simple accounting scheme in which one can specify food demand scenarios
(FDSs) for China by applying various variants of population growth, food calorie increase,
and change in diet to a standard FAO food balance sheet (see Table 2). This gives us
estimates for the domestic demand of various food commodities that have to be supplied by
either production or imports. A detailed discussion of China's future food demand is
available in the in-depth analysis.
With the most recent population projections from the UN Population Division (the 1998
revision) we can show that China's overall cereal (grain) demand in 2025 will vary by up
to 50 million tons between the low and high variants in population growth. Everything else
being constant, we can expect that China's total cereal demand will increase from 379.9
million tons in 1994-1996 to between 434.1 and 481.0 million tons in 2025 (for detailed
results see Table 2). Please note that this is the projected grain demand without diet
change or increase in per capita food calorie consumption.
Of course, it is highly unlikely that only the population will change; we must expect that
the average calorie intake will also increase and that dietary preferences will change
(see the chapter on change in diet).
China's Food Demand
|Other demographic factors affecting food demand
|Not only the number of
people, but also the structure of the population might have an impact on China's overall
food demand. For instance, people with a high average level of physical activity (farmers,
laborers in heavy industry, miners) need significantly more food calories than do people
working at a desk. Due to its rapid economic development, there will be a shift from
agricultural population to nonagricultural population in China; this will reduce the
proportion of people engaging in hard physical labor, while the proportion of those with
urban office jobs will increase. Everything else being equal, this trend could somewhat
lower Chinas overall food demand.
There might also be differences in food demand according to age. Elderly people need fewer
food calories than people of working age. We know that China's population will age
significantly during the next 50 years; a much smaller proportion of the population will
be children and teenagers requiring additional calories for growth. The number of people
aged 50 or above will increase from 209 to 631 million, while the population in the main
working age (aged 20-49) will decline from 595 to 530 million (see Table 3 and Figure 1).
This might also affect the overall food demand.
We can do a quick back-of-the envelope calculation to estimate the possible impact of this
factor on China's overall food demand. Let us assume that in 2050 the average food calorie
demand of the projected 1.478 billion population is 3,183 kcal per person per day
(scenario C). If we now take into account a 10% lower per capita food calorie demand for
630 million people above the age of 50, we have to reduce the average food calorie demand
for the total population from 3,183 to 3,047 kcal per person per day. Ceteris paribus,
this would reduce the national food demand by a little more than 4%. With a total
projected grain demand of 530-630 million tons for 2050 in scenarios A, B and C, we would
"save" some 20-25 million tons of grain annually due to population aging.
|Demographic impact on food supply
not only have an impact on food demand, they can also affect food supply.
Statistical data from the Chinese State Land Administration suggest that Chinas
population growth might have already contributed to a decline in cropland area. Between
1988 and 1995, China lost some 980,000 ha of cropland because of construction projects,
such as for settlements, infrastructure, or water reservoirs. After agricultural
conversion, construction is the second most important cause of the decrease in cultivated
land (see Table 4).
However, this relationship between population growth and cropland loss due to
infrastructure expansion is rather indirect. It greatly depends on the specific legal and
administrative arrangements for infrastructure planning. With adequate zoning laws and
regulations for the protection of cropland areas, these losses could be minimized.
Impact Data Quality Prediction Error Intervention Possibilities Intervention Costs
Revision 2.0 (First revision published in 1999)
- Copyright © 2011 by Gerhard K. Heilig. All rights reserved. (First revision: Copyright © 1999 by IIASA.)