According to the first estimate of the healthcare sector's carbon footprint, the healthcare industry emits less than its share of the gases that promote global warming, compared to its size in the economy. Hospitals, nursing homes, drug companies, and the rest of the sector contributed 8% of U.S. emissions, according to an analysis. Healthcare makes up 16% of U.S. gross domestic product. The University of Chicago analysis, based on federal data, takes into account emissions from the manufacture of goods used by the industry and the power needed to run hospitals and other health facilities.