A group of scientists in China has put forward a proposal to convert abandoned coal mine tunnels into underground farms, aiming to foster a green, circular economy within the country’s extensive mining sector. The research team, based at the Shanxi Province Coal-based Resources Green and High-efficiency Development Engineering Centre, detailed their concept in the journal China Mining Magazine late last month.
China anticipates closing approximately 15,000 mines by 2030. The researchers argue that these subterranean environments, insulated from external weather conditions and natural disasters, possess unique qualities suitable for agricultural development. They suggest repurposing existing infrastructure such as tunnels, power grids, ventilation systems, and groundwater resources to support controlled-environment farming.
The study highlights the growing challenges that climate change poses to traditional agriculture and asserts that underground farming, conducted in closed environments, could offer a practical alternative. While the absence of natural sunlight underground presents an obstacle, the team notes that the mines’ available space and strong power networks would facilitate the installation of artificial lighting systems. Additionally, underground temperatures remain relatively constant throughout the year, and geothermal energy could supply sustainable heat, potentially reducing greenhouse gas emissions associated with crop cultivation.
Transforming decommissioned mines into agricultural sites may also contribute to environmental remediation efforts. After mines close, pollutants like lubricating oils and hydraulic fluids can leak through geological faults or unsealed boreholes, threatening surface water bodies. The researchers propose that establishing underground farming laboratories could indirectly support the treatment and reuse of contaminated mine water.
Specifically, mine water containing high levels of sulfates and heavy metals might be processed using techniques such as adsorption and membrane filtration before being used to irrigate acid-tolerant crops like rapeseed and tea. The paper clarifies that the initiative is not aimed at large-scale food production, but rather at creating experimental platforms for studying key cultivation factors including light, heat, water, air, and carbon dioxide levels deep underground.
These investigations could have broader applications, potentially informing agricultural methods for deep-space missions and the development of extraterrestrial ecosystems. Between 2010 and 2019, China closed about 12,000 mines, and with ongoing decommissioning, underground space available for such uses is expected to reach roughly 7.2 billion cubic meters by 2030.
Similar projects are underway internationally. In Hubei province, researchers are growing butterhead lettuce 245 meters underground in an abandoned copper mine using artificial lighting and low-carbon energy. In North Yorkshire, Britain, scientists operate the world’s deepest underground farm over 1,000 meters below the surface within a working polyhalite mine. Trials there aim to explore new approaches that could transform national food production.
The concept of underground farming in former coal mines dates back several years. As early as 2018, Safaa Riffat, president of the World Society of Sustainable Energy Technologies, advocated for the practice as a cost-effective strategy to meet rising global food demands. The idea has since gained traction among some British mine owners and attracted interest from the Chinese government.