Q837. What factors influenced the trend in emissions for metals production?
A837. Reported emissions from the metals sector decreased significantly from 112.0 million metric tons (MMT) CO2e in 2011 to 94.1 MMT CO2e in 2018, a decrease of 16 percent. Reported emissions decreased between 2011 and 2016, with the largest decrease occurring in 2015 (13%). Although emissions have remained below 2015 levels, annual emissions from the metals sector increased in 2017 and 2018, with 2018 emissions 6.9 MMT CO2e higher than 2016.
Iron and steel production is responsible for approximately 80 percent of the reported emissions in the sector. Crude steel production is closely tied to economic conditions and can vary from year to year, with corresponding fluctuations in emissions. From 2011 to 2016, emissions from iron and steel production decreased. As shown in the table below, there was a decrease in production during this period due to restructuring of the industry, technological improvements, and increased scrap steel utilization, which resulted in a corresponding drop in emissions.The number of reporters in the iron and steel subsector also decreased during this period from 129 facilities in 2011 to 122 facilities in 2017. In 2017 and 2018, however, the industry has seen an uptick in both pig iron production and steel production, leading to a corresponding increase in emissions in 2018. Annual emissions increased by 3.5 MMT (5 percent) in 2017 and by 2.4 MMT (3.3 percent) in 2018, while the number of reporters remained steady at 122.
Annual Production (million metric tons)*
Pig Iron Production
*United States Geological Service Mineral Commodity Summaries 2019, 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