Trends Procedural Documentation
Three separate pdf documents describe EPA's Criteria Air Pollutant Emissions Trends methods from 1900 to 2023.
Current Methods Used to Estimate Emissions for the Years 2002-2023 (pdf)
Methods Used to Estimate Emissions for the years 1985 - 2001 (pdf)
Methods Used to Estimate Emissions for the Years 1900- 1984 (pdf)