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Presentation

2nd Revision

Introduction

 
Arguments - Impact
Population Growth
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.
Crucial Issues
To what extent will demographic factors affect China's food demand and supply? For analytical purposes, we have to distinguish five possible impacts:
WB00860_.gif (262 bytes) The direct 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.
WB00860_.gif (262 bytes) Hence, we 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.)
WB00860_.gif (262 bytes) Certainly 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.)
WB00860_.gif (262 bytes) There is also the possibility that other demographic factors such as the age composition of the population might affect overall food demand.
WB00860_.gif (262 bytes) Demographic 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 country’s 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.)
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Discussion
Direct impact of population growth on food demand Tables & Charts
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 uncertainty).
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).

Various Food Demand Projections
Table 1

Results: Food Demand Scenarios (FDS)
Table 2

China's Food Demand
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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 China’s 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.
Population by Age Groups, 1950 - 2050
Table 3

Population Growth in China by Selected Age Groups
Figure 1
Demographic impact on food supply
Demographic factors not only have an impact on food demand, they can also affect food supply. Statistical data from the Chinese State Land Administration suggest that China’s 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.
Land Use Change by Causes
Table 4
Related Arguments

Population:   Trends     Impact    Data Quality    Prediction Error    Intervention Possibilities    Intervention Costs

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Revision 2.0 (First revision published in 1999)  - Copyright 2011 by Gerhard K. Heilig. All rights reserved. (First revision: Copyright 1999 by IIASA.)