U.S. companies routinely revise their own greenhouse gas emissions estimates, researchers have found. And they’re usually correcting upward — meaning their previous numbers were too low.
That’s the takeaway of a recent analysis by a trio of researchers from Harvard Business School and the Ross School of Business at the University of Michigan. The findings were published Nov. 26 in the scientific journal Nature Climate Change.
The team combed through corporate reports produced by 724 S&P 500 firms between 2010 and 2024. These reports included voluntary estimates of greenhouse gas emissions, which aren’t required or regulated by federal law.
As they worked through the reports, the researchers noticed a pattern. Many companies revised their initial emissions estimates in later reports. In fact, 58 percent of all the self-reported estimates reviewed by the researchers were altered in later years.
