Shannon and I have been writing about demographic issues for nearly a decade now. In that time we have tried to do our small bit to change the lingering population bomb/explosion narrative from the 1970s. Instead of a planet that was facing impending doom due to too many people, we argued that the biggest demographic story of the 21st century is demographic decline and, in some cases, collapse.

We focussed on a number of countries which were the canaries in the coalmine: Japan, Russia, South Korea, Bulgaria, Italy, China. Countries where the population was rapidly ageing, the workforce was rapidly sinking and the population was in imminent danger of decline, if it had not already tipped over that edge. We have tried to draw out the economic, social and spiritual dimensions of a demographic winter and, at the very least, have tried to show why the demographic decline in the 21st century is a big deal.

Now, not to put too fine a point on it, we told you so. Relatively imminent demographic decline is in the news and it’s not confined to one country: it’s global in scope. According to this research funded by the Bill and Melinda Gates Foundation and published in The Lancet, the world’s population is expected to peak at below 10 billion people in 2064. By 2100 it will have declined to about 8 and three-quarter billion people. One hundred and fifty-one countries would have below replacement fertility rates in 2050, and this would rise to 183 countries by 2100.

More dramatically, 23 countries would see their populations drop by more than 50 percent by the end of the century, including Spain, Thailand and Japan. China would not be far behind with a population decline of 48 percent.

The fertility rate decline that these projections represent is astonishing. In 1950 women had an average of 4.7 children in their lifetimes. By 2017 this had halved to 2.4 and it is projected to subside to almost a third (1.7) by 2100. As researcher Christopher Murray states with some understatement this is “a pretty big thing…I think it’s incredibly hard to think this through and recognise how big a thing this is; it’s extraordinary, we’ll have to reorganise societies”.

The speed at which a number of countries’ populations will shrink is “jaw-dropping”.

Why will we need to reorganise society? Well, think about the global age pyramid: the number of those aged over 80 worldwide will be double the number of people aged under 5 by the end of the century. How will we care for the six-fold increase in the number of the very old? Economically, the consequences could be quite dire: how will societies service the social welfare systems needed in an older world, let alone the piles of debt that we are leaving for the future generations right now?

The answer that so many countries have had for falling fertility rates and natural population decline, immigration, won’t be available since nearly every country in the world will have a falling population. Will we be competing for a shrinking pool of in-demand workers?

At the same time the world’s population concentration will shift from Asia to Africa: the population of sub-Saharan Africa is expected to treble in size to more than three billion people (a third of the world’s population) in 2100. Nigeria will be the second largest country in the world (behind India) with nearly 800 million people living there. If immigration becomes more prevalent, then many countries will probably be home to more people of African descent.

We just have no idea how all of this will play out though. What will it mean to live in a world in which the human race is declining in number for a sustained period? This will be the first time in history that the human race will fail to repopulate itself from one generation to the next and will have sustained natural decrease. Are we ready for what that will mean?

Our entire society, indeed, our way of thinking about the future, is one of hope, progress and the idea that we will want to continue on with the human race. A steadily declining global population is hard to fit with this way of thinking. Once again, we’ve been warning of this on this blog for a long time. We told you so...