Researchers at Carnegie Mellon University are urging companies to broaden their carbon footprint calculations with a new method that estimates the amount of GHG emissions across all tiers of the entire supply chain for all industries.
Carbon footprints are typically reported in “tiers.” Tier one includes emissions by the company’s own activities. Tier two expands to include emissions from electricity and steam purchased by the company. Tier three includes all other emissions from the company’s entire supply chain of goods and services.
Companies usually opt to report only their tier one or tier two GHG emissions, but Carnegie Mellon researchers H. Scott Matthews, Chris T. Hendrickson, and Christopher L. Weber say two-thirds of U.S. industries would overlook 75 percent of GHG emissions if they continue to neglect reporting on tier three emissions.
“By far, most companies are pursuing very limited footprints — toe prints really— instead of comprehensive ones,” said Matthews in a statement.
The average industry has only 14 percent of its total greenhouse gas emissions in tier one and 12 percent in tier two for a total of 26 percent.