NOVELTY - Producing a glass composition comprises: either providing cullet to a submerged combustion melter, and melting the cullet in the submerged combustion melter to form a molten composition, where the cullet is melted with an aid of heat generated by the reaction of a fuel mixture with an oxidant and the fuel mixture comprises methane from landfill gas, and producing the glass composition from the molten composition; or providing at least 80 wt.% of cullet and a batch comprising a lime-containing material to a submerged combustion melter to form the glass composition.    USE - The method is useful for producing a glass composition such as a glass fiber (all claimed) and vitreous fiber, which is useful to form: various structural components such as glass fiber insulation and wall or attic insulation used in residential, commercial and/or industrial settings; low global warming potential products; composites; panels and duct boards.    ADVANTAGE - The method economically produces the glass composition with reduced energy consumption thus providing low global warming potential and thermal and acoustical insulation in residential and industrial settings in an environmentally friendly manner.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a fuel mixture comprising methane sourced from a landfill and a polymeric material sourced from recycled or post-consumer plastic, where the fuel mixture is capable of melting cullet upon reaction with the oxidant;    (2) a low global warming potential (GWP) glass material having a biosolubility of at least 100 ng/cm2/hour, a difference between the liquidus temperature and the high-temperature viscosity (HTV) value of at least 50 degrees F, and a moisture resistance (Ghyd) more positive than -8 kcal/mole, produced from a verifiable batch comprising greater than 80% post-consumer cullet and a silicon dioxide content of greater than 66 wt.%;    (3) a fibrous glass composition comprising at least 66 wt.% of silicon dioxide and less than 2 wt.% of boron trioxide;    (4) a system for producing a glass composition comprising a submerged combustion melter, where the submerged combustion melter is present in fluid communication with a source of landfill gas from the landfill; and    (5) inerting a tropospheric ozone precursor comprising collecting an ozone precursor resulting from degradation of post-consumer waste, delivering the precursor to a combustion zone under a molten mass, and reacting the precursor with an oxidizer, where the reacting liberates heat and the heat is utilized to generate or maintain the molten mass.