This table originates from the UN global population forecasts. For the first time, it extends to the year 2100 so that we can see what the shape of demographics could be for this century. As always, the figures used are the mid-point figures, around which there is a cone of uncertainty. This cone (of varying degrees of statistical confidence) can be very wide in some areas, and very narrow in others.
The short story is that this century may well belong to Africa rather than Asia. It is interesting to note that not one European country is in the top 10 for 2100. However, 90 years is a long way to go, and there are many factors that may cause these projections to run off course. One of these factors may be that the political units that we have today may change into something radically different by the year 2100.
For example, the current forecasts presume that we have seen the high water mark of European integration. Some question this. They also presume the current territorial integrity of China (i.e. no shrinkage and no expansion). Some question this. As always with long term futures forecasts, the devil lies in the details of the assumptions made. And yet, some assumptions do have to be made in order to derive these very interesting results. That does not invalidate the results, it merely defines the degree of caution that we should exercise when using them.