Decades of research have gone into creating new kinds of plastics from fossil fuels, and only a proportionally tiny amount into what happens to those plastics at the end of their lives. But many companies, including Twelve, are building on new research to do just this kind of transformation, using renewably sourced energy to turn water and atmospheric carbon dioxide back into hydrocarbons. Building momentum as fast as we can will limit the materials bill for the huge changes that decarbonization will entail.