The Environmental Protection Agency said it would stop updating research that hundreds of companies use to calculate their greenhouse gas emissions after the agency suspended the database’s creator because he had signed a letter criticizing the Trump administration’s approach to scientific research.

The researcher, Wesley Ingwersen, is leaving the E.P.A. to pursue his work at Stanford University. He was one of 139 E.P.A. employees suspended and investigated by the agency after signing the June letter, which charged that Mr. Trump’s policies “undermine the E.P.A. mission of protecting human health and the environment.”

Dr. Ingwersen led work on a statistical model that combines environmental and economic data to calculate the carbon footprints — what experts refer to as emissions factors — of a range of goods and services, from making steel to flying planes to growing apples. The open-source data sets help companies understand the greenhouse gases generated by each step in their supply chains.

The database is the third most viewed of more than 281,000 federal data sets on Data.gov, the government’s public data repository. An earlier version of the database is among the top 10 most viewed. The data sets will remain publicly available but will not be updated to reflect the current state of the economy, rendering them less useful over time.

Dr. Ingwersen will move his work to Stanford through a consortium with two private companies, which has pledged to continue updating the information and making it free to the public.