Ever since the Industrial Revolution, we’ve consumed products in largely the same way. A company will extract or collect the resources to create a product, which consumers then buy, use, and ultimately throw away. This is known as a linear model of mass consumption.

We know now that this model of consumption has contributed to the changes in our climate that, if left unaddressed, threaten to make life much more difficult in coming decades. Every year, some $2.6 trillion worth of material in fast-moving consumer goods—80 percent of the material value—is thrown away and never recovered.

Circularity presents an alternative to the linear model. In a circular economy, resources can be used over and over again, often for the same or similar purposes.

Three major principles govern a circular economy:

1. Preserve and enhance natural capital (the world’s stock of natural assets) by controlling finite resources and balancing the flow of renewable resources.
2. Optimize resource yields by circulating products, components, and materials in use at the highest possible levels at all times.
3. Make the system more effective by eliminating unintended negative consequences, like air and water pollution.