The climate change has to be mitigated by applying a new energy provision system based on renewable energy and materials. Bridging technologies shall help to approach the final goals. One of them is the progressive blending of natural gas with biomethane. Starting material for biomethane is the carbon dioxide of the current atmosphere. Photosynthesis concentrates the carbon in the resulting biomass. Further concentration can be achieved by microbial disproportionation to biomethane and carbon dioxide. Biomethane can be mixed with natural gas without any disadvantage. The mixtures show higher climate agreeability by that percentage, natural gas has been substituted by biomethane.