Q837. What factors influenced the trend in emissions for metals production?
A837. Reported emissions from the Metals sector decreased significantly from 112 MMT CO2e in 2011 to 88 MMT CO2e in 2017, a decrease of 21.4 percent. Reported emissions generally decreased from year to year across the time series but the decrease was most notable from 2014 to 2015 (13.3%). While emissions declined in each industry subsector, the iron and steel production subsector, which represents the more than 70 percent of the reported emissions in the sector, was responsible for the majority of the emissions decrease.
Iron and Steel Production. Reported emissions from Iron and steel production steadily declined from 89 MMT CO2e in 2011 to 73 MMT CO2e in 2017, a decrease of 17.9 percent. Crude steel production is closely tied to economic conditions and can vary from year to year, with corresponding fluctuations in emissions. Generally, emissions from iron and steel production have been decreasing over time, due to restructuring of the industry, technological improvements, and increased scrap steel utilization.
Annual Production (million metric tons)*
Pig Iron Production
*United States Geological Service Mineral Commodity Summaries 2018, available at: https://minerals.usgs.gov/minerals/pubs/commodity/iron_&_steel/
 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2016. U.S. Environmental Protection Agency. April 12, 2018. EPA 430-R-18-003. Available at: https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2016