Keywords: Population growth, Cereal production, Yield trends, Harvested area, Food demand and supply.
This paper examines recent trends in the relationship between world population growth and food production and assesses the prospects for this relationship during the period 1990-2020. Data on cereals are used to proxy for food and the analysis is conducted by considering the world in terms of seven major regions.
The paper takes several prominent pronouncements regarding demographic and food production trends as its starting point. It argues that – contrary to what is sometimes claimed – there has been no recent deterioration in world food production relative to population growth. Nor has there been any significant deterioration in aggregate yield trends. It is true that food production in sub-Saharan Africa is failing to keep up with demographic increase but recent developments in the more populous regions of Asia are reasonably encouraging.
Growth in world food demand has become increasingly determined by demographic growth. Likewise, growth in world food supply has become increasingly dependent upon raising yields. These two observations are crucial to any assessment of future prospects.
Using current population projections the paper considers the evolution of global cereal demand to the year 2020. It shows that because those world regions with lower levels of average per capita cereal intake are expected to increase as a proportion of humanity, other things being equal, world per capita cereal consumption will tend to fall in the coming decades. Such a fall could happen even if average levels of per capita consumption were to rise slightly in all regions. However, more plausibly, it is suggested that several world regions probably will experience modest increases in per capita consumption – increases which may be sufficient to offset this effect caused by the changing regional composition of humankind. Therefore we expect that average world per capita cereal consumption will remain roughly constant – or rise slightly – during the next few decades. Turning to supply, a simple linear extrapolation of global cereal yields suggests an average yield of around 4 tonnes per hectare in 2020. With only a modest expansion of area harvested, this should be sufficient to match most of the volume of expected demand. A key ingredient of such yield growth will be raised nitrogen inputs.- from around 80 million tonnes in 1990 to approximately 155-170 million tonnes in 2020.
However, while world cereal output can probably rise in line with demand, this will not hold in all regions. Most of the predominantly developing world regions will need to import significantly greater volumes of cereals – primarily from North America and Europe. Therefore there will be a considerable further expansion of the world cereal trade.
Prof Tim Dyson, London School of Economics and Political Science, London, UK.
35 pages, 2 figures, 11 tables, 22 refs.