ECOLOGICAL PERSPECTIVES.
Frank Notestein, a Princeton demographer, formulated in 1945 the idea
of the three observable stages in the demographic transition that characterizes
the twentieth century. The sequence of the three stages explains the widely
different population growth rates in the world today. In the first stage, represented
by the preindustrial societies of the past, both birth rates and death rates
were high and balanced out close to zero growth rate in a relatively small base
population. In more modern societies, death rates fell because of new developments
in the medical sciences, while birth rates remained high. The difference created
a demographic imbalance and an explosive population growth resulting in an enormous
increase in the size of the base population. This situation represents the second
stage of the demographic transition. As modernization continued, birth rates
fell mostly through contraception and came into balance with the already low
death rates. Once again balance has been reached but at the level of a now large
base population. This population stabilization at low birth rates and low death
rates represents the third stage of the demographic transition.
According to demographic data, all countries today are in either stage two or stage three. As to date some 32 industrial countries have reached stage three. The other 150 or so countries are in stage two. Among these, 39 countries are approaching stage three including China and the United States. In the European Union population stabilized at 380 million while grain consumption and water consumption reached a balanced plateau within the limits of its own land and water resources. This represents an ideal situation today.
It is unfortunate that not all countries can look forward to such bright future as those in the European Union. A number of countries have reached and even passed the limits of their land and water resources and are still facing enormous population growth in the near future. These countries are at risk of falling back into stage one because of a natural increase of death rates. Countries at risk are Afghanistan, Egypt, Ethiopia, Ghana, Haiti, Honduras, India, Myanmar, Nigeria, Pakistan, the Sudan, Tanzania, and Yemen. This falling back into stage one is a devastating experience because a new balance is achieved by a sudden rise in death rates due to famine, water shortage and disease, accompanied by the disintegration of governments, social services, ecological devastation, and ethnic conflicts.
Many people consider our well being in terms of momentary economic progress and are blind to the hidden costs in terms of ecological depletion. The rule is that we cannot aim at unlimited growth in a limited world, be that growth economic or demographic. I list here just a few points to illustrate this statement.
There is no more land to be discovered on the earth to increase grain production. The use of fertilizers to increase yield is either unavailable as in most of the third world countries, or it has been stabilized by the law of diminishing returns as in the United States, Western Europe, and Japan. Grain production per person is now declining proportionally with population increase. Grain consumption per person in India today is less than 200 kg per year.
The available fresh water for domestic, industrial, and agricultural use is on the decline. Some major rivers, such as the Colorado in the United States, the Yellow river in China, and the Nile in the Middle East, rarely reach the sea. Water tables are falling on every continent including in major food-producing regions. Among those where aquifiers are depleted are the U.S. southern Great Plains, the North China Plain, which produces nearly 40 percent of Chinas grain; and most of India. (Brown, Gardner, Halweil) Most of this water is used for irrigation but as scarcity becomes more pronounced industry wins the battle for economic reasons. (Water used to grow $200 worth of agricultural products expands industrial output by $14.000, a ratio of 70 to 1.)
Biodiversity is on a rapid decline. The major cause of this depletion is habitat
loss as the natural world around us yields to human development. Examples are
the gradual destruction of tropical rain forests by settlers and miners; the
destruction of coastal wetlands by developers; the disappearance of coral reefs
by encroachment and pollution, the second highest concentration of biodiversity
after the rain forests; the vast disruption of ecosystems on a global scale
by greenhouse gas emissions.
And one could go on and cite the overfishing of the oceans, the disappearance
of forests, the enormous problems of waste disposal contaminating the soil and
the ground water; the gradual rising of sea level as global warming melts the
polar ice. These are primarily ecological issues and to disregard them in the
name of economic progress implies to spiral into a process of blind self-destruct.
Such attitude is totally contrary to love and respect for life.
Source: World Watch Papers, #143, 1998 by Brown, Gardner, and Halweil.