Climate Red - News and Views on Climate Change Issues.

Today, the main coal fire areas stretch along the coal mining belt in China, which extends for 5000 kilometers (km) from east to west along the north of the country. Here more than 50 coal fields affected by coal fires have been identified. At present in China an estimated 20-30 million tons of coal burn each year. This corresponds to the amount of Germany’s annual hard coal production. Actually, the tenfold amount of the resource is lost, since coal adjacent to a coal fire becomes inaccessible. The economic loss of the valuable resource in China is estimated to sum up to total 4.2 billion tons since 1960. Thus, China faces the world’s biggest problem of coal fires both in terms of the spatial area affected and the amount of coal lost each year.


The picture shows a geologist collecting temperature measurements of hot gases emitted by an underground coal fire. Temperatures at these cracks and vents in the bedrock surface can exceed 500°C. (Photo taken by Claudia Kuenzer, September 2003, Wuda coalfield, China.)
Besides the economic loss, coal fires pose many environmental threats. The fires produce large amounts of greenhouse-relevant and partially toxic gases including carbon dioxide (CO2), methane (CH4), nitrogen oxides (NOx), nitrous oxide (N2O), carbon monoxide (CO) and sulfur dioxide (SO2). According to most recent estimations coal fires in China contribute about 0.1% to 0.2% of the annual human induced CO2 emissions globally. They contribute 12% of all Chinese coal-based carbon emissions in the form of CO2. In addition, coal fires lead to the degradation of their direct surrounding area through significant aerosol input to water sources and agricultural areas. Additionally, the toxic fumes released pose a threat to the health of the local inhabitants. Furthermore, land subsidence can occur due to the loss of volume underground, when a coal seam, supporting several layers of overlying strata, turns into ash.