What population explosion?

It is raining outside, again, I'm bored with Facebook, and TV hurts my brain so, as you do, I downloaded the UN 2013 Population report tonight - all 118 pages and that's just the 'highlights' version. I won't pretend I read it all but I was fascinated by the chapter on human global fertility. Take a look at this chart.

I was brought up on all that doomsday stuff about population explosion and all of us standing squashed together until we fell into the sea. But things have changed big time. It all began (according to the UN, and I guess they know) in 1965.  That was the year the fertility rate (number of children per woman) fell below the 'replacement level', which is approximately 2.3, in 'developed regions'.  In other words a couple needs to produce 2.3 children to replace those who die (allowing for those who are childless) to maintain a steady population.  So ever since populations in developed regions have been declining (if you ignore migration which does not effect total global population).

1965 was also the year when fertility rates in less developed regions started to fall rather than increase and the same happened a decade later in the least developed regions. 

What is driving this?  Basically (says the UN) improved economies in places such as China, India and Brazil. The better off people are economically the less children they have (or can afford!)  Poor people cannot afford not to have lots of children. Rich people cannot affort to have children.

Any implications for mission?  I'm just beginning to get my mind around this but I see huge implications.  For a start we are going to have to learn how to share the gospel with 40 year olds and 105 year olds, not just children, youth and students. And in terms of holistic mission, what does the gospel mean in a world where more and more older people have fewer and fewer young people to care for them?

Lot's more thinking to do!