NOVELTY - The improved method for reducing carbon dioxide emissions, comprises carrying out the carbon dioxide to carbon monoxide reduction reaction with or without the conversion of carbon monoxide to hydrogen via water-gas shift reaction using surface or underground reactors. The reduction of carbon dioxide to carbon monoxide is accomplished by contacting the carbon dioxide with hot carbon in specially designed and/or operated reactors, which are operated independently of the primary gasification reactors to accomplish carbon dioxide reduction.    USE - The improved method is useful for reducing carbon dioxide emissions from processes, which use fossil fuels to generate energy and/or processes, which produce low carbon dioxide emission fuel gas, hydrogen fuel, and liquid fuels or fertilizers using synthesis gas as the feedstock.    ADVANTAGE - The improved method increases the yield of products and gasification efficiency, decreases carbon dioxide emissions in an economical manner, controls contaminant migration and reduces potential environmental effects.    DETAILED DESCRIPTION - The improved method for reducing carbon dioxide emissions, comprises carrying out the carbon dioxide to carbon monoxide reduction reaction with or without the conversion of carbon monoxide to hydrogen via water-gas shift reaction using surface or underground reactors. The reduction of carbon dioxide to carbon monoxide is accomplished by contacting the carbon dioxide with hot carbon in specially designed and/or operated reactors, which are operated independently of the primary gasification reactors to accomplish carbon dioxide reduction. The feeds to the carbon dioxide reduction reactor consist of steam, oxidant and fuel gas in addition to carbon to promote both the carbon dioxide reduction reaction and the steam-char reaction. The carbon dioxide reduction reactor is designed and operated to provide high temperature, high carbon surface area and long residence times to promote the reduction of carbon dioxide. The spent underground reactors are used to temporarily store the gases, which are later introduced into the gasification, carbon dioxide reduction and shift reactors to promote the desired reactions by controlling feed flow rates and feed concentrations. The procedure for operating the reactors is modified to incorporate intermittent operation in the combustion mode, the gasification mode, the carbon dioxide reduction mode and water-gas shift mode. The carbon dioxide reduction reaction, with or without the water-gas shift reaction, is coupled with a fossil fueled industrial boiler or an electrical generation plant to co-produce synthesis gas, low carbon dioxide emission fuel gas and hydrogen. The final product stream has a low carbon dioxide emission fuel gas, a synthesis gas and a hydrogen fuel. The method recycles the unreduced carbon dioxide back to the primary gasification reactor and/or the carbon dioxide reduction reactor to accomplish further carbon dioxide reduction. INDEPENDENT CLAIMS are included for:    (1) a method for sequestering carbon dioxide or other wastes in spent underground carbon gasification reactors; and    (2) a method to remediate the water in the still contaminated, underground coal gasification reactors.    DESCRIPTION OF DRAWING(S) - The diagram shows surface based processes, which produce a low carbon dioxide emission fuel gas, synthesis gas and/or a hydrogen fuel.    Carbon gasifier (10)    Gas separation plant (12)    Water-gas shift reactor (14)    Gas to liquids or fertilizer feedstock (16)    Low carbon dioxide emission fuel gas (17)    Hydrogen fuel. (18)