coal(The natural, rocklike, brown to black derivative of forest-type plant material, usually accumulated in peat beds and progressively compressed and indurated until it is finally altered in to graphite-like material)
carbon cycle(The cycle of carbon in the biosphere, in which plants convert carbon dioxide to organic compounds that are consumed by plants and animals, and the carbon is returned to the biosphere in inorganic form by processes of respiration and decay)
carbon dioxide tax(Compulsory charges levied on fuels to reduce the output of carbon dioxide (CO2), which is a colourless and odourless gas substance that is incombustible)