There's a common story of how the Maya civilisation was wiped out: they fell foul of unstoppable climate change. Several periods of extreme drought withered their crops and killed off thousands in their overpopulated cities. ‘There was nothing they could do or could have done. In the end, the food and water ran out – and they died,' wrote Richardson Gill in 2007. The jungle reclaimed the cities with their palaces and pyramids until they were rediscovered in the 19th century by intrepid explorers.