Why does recycling have lower emissions than waste prevention for some material types?
In WARM, the recycling emission factors reflect the difference between making a product with virgin inputs and making a product with recycled raw material inputs. This means that the virgin inputs that would have been necessary to create the specific material are no longer required because this material is being recycled. In contrast, source reduction is assumed to displace the current mix of recycled and virgin raw material inputs used to manufacture a given material. This means that when a material is reduced (source reduction), the inputs needed to create this material come from both recycled content and virgin content. • For some materials including aluminum, dimensional lumber, medium-density fiberboard, and carpet, the greenhouse gas (GHG) benefits of recycling are greater than source reduction for the current mix. • In the case of aluminum, this is because recycled production is much less GHG-intensive than virgin production, and the current mix of virgin and recycled inputs use
