Reuters: With the world population rising, demographers are grappling with one of the most pressing issues of the century - will there be enough food for an extra two to four billion people?
Projections of global population growth vary widely with the United Nations last month forecasting numbers rising to 9.6 billion in 2050 and around 10.9 billion by the end of the century from 7.2 billion currently.
That is about 1.5 billion more people than another estimate calculated by the International Institute...