Method and apparatus for environment protection (climate change) from toxic elements and subsidence by existing underground coal seam fires by expansion termination of these fires. The method is based on creating, on the path of or around a burning coal seam fire, a subterranean void-barrier, with non-combustible gases (or fluids) and absence of oxidiser. The void-barrier may be substantially free from combustible material. The void-barrier will prevent further expansion of the existing coal seam fire, and may be created by known methods of coal extraction in gasified form, such as Underground Coal Gasification (USG). By-products from void-barrier creation can be utilized to reduce environmental pollution and for production of useful commercial entities such as gas or liquid fuels like: petrol, diesel, jet fuel, avgas, paraffin or electrical power generation and/or chemicals like CO2 for enrichment of coal or which may be sold.