Highly sophisticated societies have collapsed (i.e. lost a lot of of their complexity very quickly) in the past, and there is no reason why this couldn't happen to ours. In fact there are a few very good reasons to believe it will happen well within the 21st century, i.e. within the life-expectancy of everybody born in the richer countries from now on. (I do hope Mumsnet are reading this and can still turn things around!)
We're still wrecking the environment we depend on, and the financial crisis has shown how blindly we can run into a disaster, so, well, there may be interesting times ahead.
I've discussed all this in some detail in a feature that has appeared today:
Will our civilisation survive this century?
Current Biology, Volume 23, Issue 23, R1017-R1020, 2 December 2013 doi:10.1016/j.cub.2013.11.028
After writing this feature, I was left with the feeling that we're standing at the edge of a cliff (no pushing at the back!). Since then, however, I've read a book for review that made me think maybe we're already one step further. Like those cartoon characters that stay suspended in mid-air until they realise that they are bound to fall. So I guess it's fine as long as we don't look down. More about that soon, when my review comes out. Now that's what I call a cliffhanger.
Extensive ruins such as those of the Roman colony of Thamugadi (Timgad) in modern-day Algeria remind us that civilisations can and do collapse. (Photo: Wikimedia Commons/PhR61.) I actually visited Timgad many years ago. It does make a big impression.
PS Jan 2017: Oooops, I never did resolve that cliffhanger, did I? The book I was reviewing at the time was "The energy of nations" (review is in C&I Feb 2014, p51, but I forgot to blog about it), in which Jeremy Leggett argues that risk-blindness could lead the energy sector into a crash worse than the financial crisis, and big enough to lead to a collapse of civilisation. Now, as an irascible twitter troll takes over the White House and brings along his fossil fuel cronies, this prospect appears closer than ever.