If you’re interested in the big forces driving the global economy and geostrategic landscape over the next 40 to 50 years, then it’s well worth having a look at Sarah Harper’s fascinating TED talk on global demographic trends.

She explains how fertility rates are falling, which means the world’s population will peak at around  10 billion. This, one might think, is good news as far as the depletion of the Earth’s natural resources goes. But the problem is that while the population may begin falling, aggregate consumption will continue to rise as developing nations increase their prosperity. Perhaps the only solution will be for the West to offset this growth by decreasing its own consumption. This will be one of the key economic and political questions of the next decades.

The other major trend is populaton ageing. Science and technology mean we are living loger and longer – by 2050 Europe will have over 3 million people at 100 or over. This will have a fundamental impact on social norms and practices that we usually take for granted. For example, will people have to remain economically productive for longer, or will the burgeoning population of old people need to be supported by a relatively smaller number of people in work? If we are living longer, how will this affect when we choose to leave home, have children, marry etc?

Much food for thought!