Record harvests are unable to keep up with population growth, along with land scarcity, water scarcity are now emerging as serious constraints on effort to expand world food production especially in developing economies.
Growth in irrigation is falling behind population growth leading to a steady shrinkage in irrigated area per person.
In China, the yellow river, one of the northernmost of China’s two major rivers, was drained dry by withdrawal from upstream provinces, failing to make it to the sea for 226 days out of 365 days in a year.
Population growth is not the only source of increasing demand for food but dietary changes over the last century, there has been a growing appetite for animal protein as income increasing noted Lester Brown, of World Watch Institute.
When people have increased their income, they tend to eat more meat. Increasing purchasing power in some areas has led to the consumption of more meat which requires a lot of grains to produce.
World’s demand for protein has increased, world fish catch increase nearly five fold (from 19 million tons to 93 million tons). Meat production (beef, pork and poultry) has climbed (from 44 million tons to 211 million tons).
The enormous growth in world population and economic activity has had its most visible effect on the earth’s rain forest. About 200 million hectares of forests were lost between 1980 and 1995, an area larger than the cropland of the US.
One of the consequence in the destruction of forests and other habitat is the accelerating loss of bird species which already threaten with extinction.