On March 10,U.S. EPA proposed the first nationwide mandatory reporting system for greenhouse gas emissions, addressing a range of industry sectors. U.S. EPA estimates that the proposed rule will address 80 to 95 percent of U.S. greenhouse gas emissions. Once U.S. EPA publishes the proposal in the Federal Register, companies and other members of the public will have 60 days to submit comments. The source categories subject to the proposed rule are as follows:

Upstream Fuel Sources. "Upstream" suppliers of fossil fuels, such as coal and petroleum products, as well as suppliers of industrial greenhouse gases, would be required to report the volume of fuel they introduce into commerce each year and the quantity of greenhouse gases emitted through total combustion of that volume of fuel.

Downstream Stationary Sources. For most categories of "downstream" emission sources, the proposed rule would cover facilities with 25,000 metric tons or more per year of greenhouse gas emissions. Some sources (such as food processing, industrial landfills, iron and steel production, and pulp and paper manufacturing) are individually identified by their source types and by this emission threshold. Others fall into a general category for larger fuel-burning units, such as boilers, that meet or exceed the 25,000-ton threshold. For certain high-emitting business sectors, including cement producers, petroleum refineries, aluminum manufacturers, and power plants subject to the federal Acid Rain Program, all facilities are covered regardless of their emission levels.

Vehicle and Engine Manufacturers. Finally, manufacturers of certain types of vehicles and engines, including passenger vehicles, watercraft, heavy-duty engines and vehicles, nonroad diesel engines, and aircraft engines, would be required to report the quantity of greenhouse gases emitted from the engines and vehicles they produce.

In addition to carbon dioxide emissions, annual reports would be required to track emissions of methane, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons, and other fluorinated gases. Reporting would occur at the facility level for downstream stationary sources and at the company level for upstream fuel suppliers and vehicle or engine manufacturers. Although the proposed rule would not require any reductions in greenhouse gas emissions, data collected would undoubtedly influence the development of future climate change policies.