Interactive chart time! Over at Axios there is a fantastic interactive graphic that you must go and have a look at. The chart (not the one above) has placed all the countries of the world on an axis: the x axis population growth rate per year expressed as a percentage. This axis runs from -1.5 percent to 5 percent. The y axis plots the total fertility rate ranging from 1.0 children per woman in her lifetime to 8.0 children per woman.

Thus, the graph is split by two lines: a vertical line starting at 0 percent per annum population growth (population stasis), and a horizontal line representing a replacement fertility rate of 2.1 children per woman. A country located at the centre of this graph where the two lines intersect would be replacing itself naturally and would not be experiencing any population growth overall. There are two countries near that position on the graph: Greenland (practically on the intersection) and Georgia (0 per cent population growth and a total fertility rate of 2.0).

These two bisecting lines divide the graph into quadrants. The first contains those countries with above-replacement fertility rates and a growing population (this quadrant contains the most countries and includes India, Pakistan, Mexico and Nigeria). The second most popular quadrant contains those countries which have a below-replacement fertility rate and yet still has an increasing population. Countries in this position are either compensating for natural population decline with immigration, or their decline in fertility rates has not yet produced a drop in population because their populations are living longer. For instance, as Axios notes, even with decades of a one-child policy and little immigration, China’s population is still growing at about 0.6 per cent year. It is expected to start shrinking, but not for another six years or so.

In this quadrant are a large number of countries including the USA, Russia, the UK, France and Spain. Over time, unless these countries move up into positive total fertility territory, they will require more immigration to stop sliding into the left-hand side of the chart: population decline territory. In that category are a number of countries including Japan, Italy, and Hungary. Out on the far left is Lithuania which is shrinking at the fastest rate in the world: 1.4 per cent per year.

The final quadrant is an interesting one, consisting of those countries which have a positive fertility rate and yet are losing population over all. There is only one country in that situation, Syria. A decade-long civil war has driven millions of its population to flee the country while hundreds of thousands more have died, leaving it with an annual population decline of 0.9 per cent.

Over time it will be interesting to see if countries continue to slide to the left (as population growth shrinks or even declines) and slide downwards as fertility rates drop. Certain countries to the right of the chart with the highest population growth per year (all African and Middle Eastern) may slide left due to greater migration from those countries to developed countries with lower birth rates and declining working aged populations. That of course will depend a lot on what the developed nations do in response (if anything).

The downwards trend in fertility and growth rates may even stop and reverse in the years ahead. However, as Global Ageing Insitute President Richard Jackson notes: “each year that goes by with new data showing no rise – or even a decline, as we saw this year – makes a fundamental shift more likely”. One of the key economic, geopolitical and societal questions to be asked will be, how do nations cope with this “fundamental shift” in demographics?

Marcus Roberts is co-editor of Demography is Destiny, MercatorNet's blog on population issues.