Traditionally, industrial economies have continually relied on a single model of resource consumption: a linear economic model that follows a “take-make-dispose” pattern. This has led to ever-increasing resource extraction and excessive waste generation, exerting significant pressure on the environment.
The amount of natural resources used in buildings and transport infrastructure increased 23-fold between 1900 and 2010, and approximately 79% of global greenhouse gas (GHG) emissions are associated with infrastructure. If we continue to follow linear economic models, both resource extraction and GHG emissions will continue to increase in the future as more infrastructure is built to meet the needs of a growing and increasingly urban population.
Circular economic models decouple economic growth from resource consumption by extending the useful life of the things we make, build, and use, and by closing material loops. Thus, “waste” from certain products and processes serves to provide inputs for other products and processes (also known as “industrial symbiosis”). Transitioning to circular economic models will require infrastructure that is fit for purpose. Infrastructure must be planned, built, and operated in a way that maximizes synergies between infrastructure systems to enable industrial symbiosis and closed loops. A shift towards sourcing materials locally, more shared ownership, and flexible models can also help reduce the resource intensity of infrastructure systems. The successful implementation of these concepts requires strategic planning during the early phases of the infrastructure lifecycle, prior to the development of infrastructure projects.
The remainder of this policy brief outlines key opportunities and requirements for mainstreaming circular economy principles into sustainable infrastructure development and elaborates on how infrastructure development can support more circular economies.