CAC - carbon monoxide, nitrogen oxides, particulate matter, sulfur oxides and volatile organic compounds-are a group of chemicals associated with environmental effects such as smog, acid rain and regional haze, and health effects such as respiratory illnesses. Major sources of CACs are the burning of fossil fuels, as well as natural resource extraction and a variety of manufacturing activities.

GHG - contribute to climate change by trapping heat within the earth's atmosphere. GHGs are the subject of the international Kyoto Protocol, which came into force in 2005. The major gases include carbon dioxide, methane, nitrous oxide and three groups of fluorinated gases. Some of the main anthropogenic sources of GHGs are the burning of fossil fuels, deforestation and agricultural activities.

CAC are reported to Canada's NPRI and GHG are reported to Mexico's RETC, but these pollutants are not subject to US TRI reporting. However, there are other sources of information on emissions of these pollutants in all three countries:

Criteria Air Contaminants:

• Canadian NPRI facility-specific CAC emissions for 2006
• US National Emissions Inventory
• Mexico National Emissions Inventory

Greenhouse Gases:

• Canadian GHG Inventory and facility-specific GHG reporting
• US GHG Inventory 
• US GHG power plant emissions (2005)
• Mexican RETC facility-specific GHG emissions for 2006