Now, excavations at a Bronze Age site in northwestern China show people were burning coal on a large scale up to 3600 years ago, 1 millennium earlier than previously thought.

In a new study, archaeologists found that Bronze Age societies in northwestern China were using coal as an energy source over 3600 years ago — a millennium earlier than previously believed.

Coal became more important in the Chinese Song Dynasty about 990 to 670 years ago, and later played an instrumental role in the European Industrial Revolution.

And perhaps it always did: it seems coal was routinely burned 3500 years ago in what is now China – the earliest evidence we have for the practice.