Published July 22, 2020

Sustainable materials management is a systemic approach to using and reusing materials more productively over their entire life cycles. To identify opportunities for reducing environmental impacts, material use and waste generation across the spectrum of goods and services consumed in the US, EPA researchers created a family of models called the U.S. Environmentally-Extended Input-Output models, or USEEIO. These models are designed to bridge the gap between traditional economic calculations, sustainability, and environmental decision-making.

“It’s important to consider not just how to deal with the waste after using a product, but to consider that product from the ‘cradle-to-grave’ to identify where material use, waste, and potential environmental and human health impacts can occur," said EPA researcher Wesley Ingwersen who works on USEEIO. “We want to identify where these wastes and impacts can be reduced and still allow the consumer to get the same service out of a product and have the supply chain thrive.”

The models use data on economic transactions between 389 industry sectors as well as their final consumption and value added in the form of input-output tables from the Bureau of Economic Analysis. These tables are paired with a wealth of environmental data on resource use and release of pollutants, including land, water, energy and mineral use, air pollution, nutrients, and toxics from various public sources, as well as indicators of potential environmental and economic impact, using standard algorithms from input-output analysis.

“With these models, you can see the economic and environmental benefits and concerns side-by-side,” explained Ingwersen.

USEEIO is already widely used across EPA and by other government agencies, corporations, nonprofits, nongovernmental organizations, and academia for applications such as calculating carbon footprints and carrying out environmental assessments. 

Other examples of USEEIO uses include:

• A partnership between EPA and the US Department of Defense’s (DOD) environmental research programs to re-create an input-output model tailored to the specific needs of the DOD, such as life-cycle analysis for military equipment.
• A report developed by Alameda County, CA, called Supply Chain Sustainability Report. This report uses USEEIO to highlight specific activities that occur within the supply chain of the goods and services procured by the County to provide information and recommendations on available opportunities to work with county vendors to improve environmental performance and advance the health and wellbeing of the residents of Alameda County and beyond.

Companies including Amazon, GM, and Merck use USEEIO as a source for life cycle CO2e (CO2e, which literally means carbon dioxide equivalent, allows greenhouse gas emissions other than just CO2 to be expressed in terms of CO2 based on their relative global warming potential) factors in their corporate carbon footprint calculation for estimating part of their carbon footprint related to purchased goods and services and their facilities.

Ingwersen acknowledges that while many organizations are beginning to take these life-cycle considerations into account in their activities, it is much more challenging to do at the community scale because life-cycle considerations are typically made on a product by product basis. At the community scale, life-cycle thinking requires including all products consumed in a community and scaling up to the level of total community consumption. Having a grasp over what all these products are and at what level they’re being consumed in a community is a major challenge, beyond representing life cycle considerations of each individual product.

EPA is working to make USEEIO useful to communities. For example, EPA recently released the Sustainable Materials Management National Prioritization Tool, based on USEEIO, which identifies the biggest opportunities to reduce impacts of products at the national level. A similar state prioritization tool is also under development.

Additionally, EPA is partnering with the Georgia Department of Economic Development Centers for Innovation and Georgia Tech to work with Georgia communities to evaluate economic and environmental outcomes of new technologies, investments, and regional industries through web applications that use a new economy-wide model of industries, households and the environment. From these evaluations, the partners will create a version of USEEIO specifically tailored to the state of Georgia for use by towns, counties, and communities. This means that communities in Georgia can use the modeling tool without needing help from a modeling expert.

“One of the most important things we are doing is partnering with communities to understand their economic development and sustainability goals, and creating tools for them that leverage the life-cycle data in the USEEIO model along with other EPA tools and local data to inform them of the potential environmental and economic outcomes of various development scenarios ,” said Ingwersen. “The goal really is to give local decision makers dynamic and easy-access to rich life-cycle results to inform their development-related policy and decision making. We see this as a productive means of putting sustainable materials management into action.”

By making economic and environmental life-cycle information accessible to government agencies, corporations, nonprofits, nongovernmental organizations, and academic institutions in this model, EPA researchers are better equipping these groups to make choices that support sustainable materials management in the most cost-effective way, benefitting both these groups and the environment.