Current emissions trends data and the documentation of estimation methods are available or linked from here. The latest version of the 1970 - 2016 data shows trends for Tier 1 categories. One of the distinct and natural occurrences in inventory development is the evolution and improvement of emission estimate methods over time. In some cases, an improved estimation method for a source category may be applied 'backwards' to previous year estimates for that same category.

Average Annual Emissions(1 pg, 97 K)  all criteria pollutants National Tier 1 for 1970 - 2016.

State Average Annual Emissions Trend(1 pg, 2 MB)  all criteria pollutants State Tier 1 for 1990 - 2016.

Trends Procedural Documentation -  Any changes in the data or methodologies used to estimate the emissions for a specific time period will continue to be noted in future updates.