Sir, - While William Reville's Science Today column (May 26th) brought to our attention some salient facts about the world population explosion, it did not demonstrate an appreciation of the enormity of the problem or what we might do about it.
It took 80 years for the world population to double from 1 billion to 2 billion in 1930. In 19.65 it was over 3 billion and now it is about 6 billion - not near 5 billion, as Dr Reville claimed. A doubling over 35 years corresponds to a 2 per cent annual growth rate.
If we continue behaving in the same irresponsible way, we can predict a probable 12 billion population in the next 35 years - unless, of course, nature intervenes to avert such an apocalyptic situation. There is a limit to the abuse our planet will tolerate. The number of people our world can sustain is finite and, while the actual number is a moot point, the concept is not.
Our future survival is not inevitable, nor assured by any known natural law. A cardinal theme of evolution is that most species eventually decline and pass out of existence. Man may stumble along and blunder himself into oblivion or he may use his intelligence to avoid, or at least postpone, extinction. The quality of our lives is inextricably linked to the choices we make. The choices are often painful and difficult, but necessary.
In view of the problem of over population, it must be clear that every couple have a responsibility - to society, as well as to their own family, not to overburden the world with more lives than it can sustain. A zero population growth rate one in which births balance deaths is not only a desideratum but a necessity. An enlightened government policy, therefore, would be supportive towards couples with their first, and possibly second, child but would have disincentives for couples with more than two children. Yours, etc.,
Seapoint,
Co Dublin.