Charcoal is one of the most environmentally unfriendly fuels; it is also a source of dangerous indoor pollution in developing countries. According to FAOSTAT about 45 million tonnes are produced world-wide every year. Of that, about a quarter is produced sustainably (from recycled wood) and cleanly (with filters and afterburners to reduce emissions of dangerous gases). The rest is produced in traditional kilns and mounds, using wood cut from rain forests, and with unchecked emissions spewed into the atmosphere.
Charcoal is used as household fuel in many developing countries. Studies show that the smoke from solid fuels, like charcoal, is the eighth leading cause of death in developing countries.