Archaeological excavations at the Bronze Age site of Jirentaigoukou in northwest China have revealed that people were burning coal on a large scale as early as 3,600 years ago, a millennium earlier than previously thought. The study, published in the journal Science Advances, also traces where coal came from and how shortages of other fuels may have prompted ancient people to turn to this new source of energy.
The site, surrounded on three sides by the towering Tianshan Mountains and located near the Kashi River, was a natural gathering place for people who settled in the region. Between 3600 and 2900 years ago, there was a thriving society here, probably consisting of migrants from the Eurasian steppes. These people brought their livestock to the region, as well as their characteristic pottery style and skill in skillful bronze working.
Coal was abundant in the settlement, ranging from simple ash to egg-sized chunks. It was found in large storage pits and inside houses, crushed together with stone tools, and burned in hearths and smelting furnaces. According to Guanhui Dong, an environmental anthropologist and co-author of the study, its versatility in different settings of daily life indicates that it was likely a “common resource” that everyone, regardless of their class or craft, “could use for themselves.”
The findings suggest that these people did not simply burn coal on a sporadic basis. Rather, they built the earliest known system for large-scale consumption. The researchers identified six potential sources of coal within a radius of about 5 kilometers of the settlement. In these areas, exposed seams of coal “easily crumbled” from the cliffs.
According to historian Shellen Wu, knowledge of the use of coal in antiquity was previously based on written sources, but it is “very interesting” to use archaeology to look into humanity’s past use of fossil fuels. Evidence such as fragments of low-quality coal in fireplaces suggests that humans have been burning coal sporadically since the late Paleolithic, more than 10,000 years ago. However, the first reliable written evidence of widespread use of coal did not appear until about 2,000 years ago, during the Han Dynasty of China.
According to environmental archaeologist Jade Guedes, the findings at Jirentaiguku indicate that coal was used quite frequently at the site. The study shows that ancient societies were already using coal to smelt metal or heat water for hot baths long before it became a fuel for the Industrial Revolution.