It has been forecast that, by the middle of the next
century ____

The dramatic growth of the world's population in the
twentieth century has been on a scale without parallel
in human history. Most of this growth has occurred
since 1950 and is known as the population ‘explosion'.
Between 1950 and 1980 the world population
increased from 2,5 to over 4 billion, and by the end of
the century this figure will have risen to at least 6
billion. Growth of this size cannot continue
indefinitely. Recent forecasts suggest that the total
population will level-out at between 10 and 15 billion in
the mid twenty-first century. Already there are
encouraging signs that the rate of increase in many
less developed countries is beginning to slow down.