- Rate of population growth will slow
With 267 people being born every minute and 108 dying, the worldâ€™s population will top seven billion next year, research groups project. Fears that the worldÂ is overpopulated have been gathering pace, caused both by the continued rise in number of people and by worries about climate change. AccordingÂ WWF, an environmental group, the world will require an extra planet in 20 year’s time if it continues gobbling up resources as it does now.
The human population took roughly 250,000 years to reach 1 billion in about 1800. More than a century passed before it reached 2 billion in 1927. But the next billion took only 33 years (1927-60). The one after that, a mere 14 years. The following two stages, to 5 billion and then 6 billion, took 13 and 12 years, respectively.
However, the era of shortening time lapses is already over, even though the absolute size of the population is still rising. The momentum matters hugely in demography. Large families in an earlier generation mean that there will be more children, even if families are smaller and the underlying impetus towards growth has dropped. It takes another generationÂ before the effect of smaller familiesÂ and lower fertility starts to show up in the overall population figures.
The total fertility rate has been falling for a long time, almost halving from 4.8 in 1965-70 to 2.6 in 2005-10. In some countries the speed of change has been breathtaking.
During the next few years the world will most probably reach another milestone : half of mankind will be living in countries or regions where fertility is at or bellow 2.1, which is the “replacement rate” at which a country is having only enough children to keep the population stable. It will eventually lead population growth to slow down and stabilize.
The increase from 6 billion to 7 billion will be the last to happen in such a short space of time. The next billion will take slightly longer – 13 or more years – and the billion after that, which is supposed to rise the population number to 9 billion, will take 20 to 25 years. Only in few decades, the momentum is very much likely to slow towards zero.