plz...answer this question plz..
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Answer:
Population is a dynamic field. There have been significant changes in birth rates and the population trajectories of countries and continents in recent years. Global population is still growing by more than 80 million a year, however, and is most likely to continue growing for the rest of this century unless we take action.
Until the time of Napoleon, there were less than 1 billion people on Earth at any one time. Since the Second World War, we have been adding a billion people to the global population every 12-15 years. Our population is more than double today what it was in 1970.
Every two years, the United Nations makes projections for future population growth. Its latest median projection is a population of 9.7bn in 2050 and 10.9bn in 2100. Because many factors affect population growth, it makes a range of projections depending on different assumptions. Within its 95% certainty range, the difference in population in 2100 from the highest to lowest projection is almost 4bn people - more than half the population we have today.
The second graph above shows the UN's projected population if, on average, every other family had one fewer child or one more child than in the median projection ('minus half a child' or 'plus half a child' per family).
This shows the enormous difference in total numbers that arise from just very small variations in family size. If we can achieve that modest reduction in number of children born, we will have more than 3bn people fewer by 2100 - a lower population than we have today.
More than half of the people added to the world's population over the rest of the century will be in sub-Saharan Africa. This is a reflection of four main factors. First, although it is falling, fertility rate (family size) remains high in most African countries. Second, sub-Saharan Africa has a very young population - its average age in 2018 is just 18 years old. That means that many people are entering their childbearing years. Thirdly, people are living longer in Africa. Fourthly, people tend to have children young, meaning there are more generations alive at any one time.
These figures regarding populations of different continents include assumptions about future migration, but are necessarily very speculative. Climate change, poverty and population pressures themselves will lead to a highly mobile global population, with Africa likely to be the largest source of emigrants.