Emission Trends - FAQ
Emissions trends frequently asked questions.
- Why do the PM2.5 emissions for the electric utilities source category jump up between 1998 and 1999?
- Why do mobile source NOx emissions jump higher between 2001 and 2002 on the emissions trends?
- What is the cause of the large decrease in electric utility emissions, particularly sulfur dioxide, starting in 1995?
- What sources make up the Tier 1 categories used in the emissions trends?