An apparatus and method of converting flue gases produced by a fossil fuel burning furnace boiler is disclosed. The flue gas is separated into its constituent parts by cooling and filtering. Carbon dioxide, the main constituent, is then converted to carbon monoxide in a laser powered gas converter in which carbon is a catalyst. The laser powered converter also produces hydrogen from steam, and the two newly produced gases are chemically combined to produce a hydrocarbon fuel product which can then be burned in the furnace boiler. In this manner no harmful greenhouse gases are permitted to escape to the atmosphere.