Past changes to the climate that generated increasingly arid conditions for ancient peoples helped to trigger the rise of the earliest civilisations on three continents, a study has found.
The ancient civilisations of Egypt, Mesopotamia, south Asia, China and northern South America all owe some of their initial success to significant changes in rainfall and temperature, a climatologist said yesterday.
The conventional view of how early civilisations developed is that they benefited from the steady conditions of a predictable period of climate constancy.
However, Nick Brooks, a researcher at the University of East Anglia in Norwich, believes there is mounting evidence to show that past civilisations grew in response to climate change rather than being the result of climate stability.
"The earliest civilisations developed as a by-product of adaptation to climate change, and crucially that they were the products not of a benign environment, but of a hostile one," Dr Brooks told the British Association.
A study of the early Garamantian civilisation that developed 3,000 years ago in what is now the Sahara showed that increasingly dry conditions had led to an acceleration in the technological innovation and monumental architecture that are the hallmarks of civilisation. The Sahara was undergoing a dramatic change from a fertile region to one where most of the water was being concentrated around a series of lakes.
The change in the climate was matched by a change in the way of life of the local inhabitants, who began to congregate in relatively large population centres around the lakes. …