WORLD population has been rising and the comfortable assumption that – as the standard of living rises – the increase would diminish has not worked out.

We find that, particularly in continents such as Africa, the fertility level remains high and we have the double disadvantage of living standards remaining low at the same time as the world population has been rising.

It seems that the introduction of condoms is not on its own the solution, and there is the attitude of powerful religions which seem to think that the human race should continue to multiply in the face of the fact that it can become so numerous as not to be sustainable.

In their own way the Chinese have found an answer with the one-child per family policy, but this is going to create demographic problems in the longer term.

It is odd that we are having to think again about the prognostications of the British scholar Malthus (1766-1834) which, for most of my life, I had thought had been disproved.

If, through the economic crisis, nations are going to confer together to find world solutions to problems, I hope that population growth will be high on their agenda.

Geoffrey Bulmer, Billingham.