Greenhouse gas (GHG) emissions data direct from the largest emitters in the US are being made available for the first time ever via a new online database from the Environmental Protection Agency (EPA). The 2010 GHG data released Jan. 11 by the EPA accounts for 80% of total US GHG emissions for the year. Public information from more than 6,700 entities organized across facilities in nine industry groups and 29 source categories that directly emit large quantities of GHGs, as well as suppliers of fossil fuels,” is included, according to an EPA press release.

“Thanks to strong collaboration and feedback from industry, states and other organizations, today we have a transparent, powerful data resource available to the public,” said Gina McCarthy, assistant administrator for EPA’s Office of Air and Radiation. “The GHG Reporting Program data provides a critical tool for businesses and other innovators to find cost- and fuel-saving efficiencies that reduce greenhouse gas emissions, and foster technologies to protect public health and the environment.”

The EPA’s GHG online data publication tool enables users to view and sort 2010 calendar-year GHG data from more than 6,700 facilities in various ways, including by facility, location, industrial sector, and type of GHG emitted. Data for 2010 show that:

• Power plants were the largest stationary sources of direct emissions, with 2,324 million metric tons of carbon dioxide equivalent (mmtCO2e), followed by petroleum refineries, with emissions of 183 mmtCO2e.


• CO2 accounted for the largest share of direct GHG emissions (95%), followed by methane (4%), and nitrous oxide and fluorinated gases accounting for the remaining 1%.


• 100 facilities each reported emissions over 7 mmtCO2e, including 96 power plants, two iron and steel mills and two refineries.

The online GHG database can be used in any number of ways by private and public sector organizations, as well as by individuals, the EPA notes. For example, communities can use it to identify and find out just how much in the way of GHGs are being emitted, as well as their type. Businesses can use it to compare and track emissions and provide information to state and local governments.

GHG Reporting Expanding in 2011

US greenhouse gas emissions rose 3.9% in 2010 to 213 million metric tons, the highest rate since 1988, according to the US Energy Information Administration, as the US economy rebounded somewhat. Total 2010 emissions were lower than in 2005 and 2007, however.

Fossil fuel burning – coal, oil and natural gas — accounted for 80% of total US emissions for the year as factories ran at higher capacity and a hot summer led consumers to use more air conditioning.

The GHG emissions database is the latest result of the EPA’s GHG Reporting Program, which was launched in October, 2009 as stipulated by the FY2008 Consolidate Appropriations Act. The act requires large GHG emitters across a range of industry sectors and suppliers of products that emit GHGs, if released or combusted, to report emission levels.

An additional 13 source categories will begin reporting their 2011 GHG data this year if their emissions meet the EPA threshold. The 13, all in the “Industrial Activity” sector are:

• Electronics Manufacturing


• Fluorinated Gas Production


• Magnesium Production


• Petroleum and Natural Gas Systems


• Use of Electric Transmission and Distribution Equipment


• Underground Coal Mines


• Imports and Exports of Equipment Pre-charged with Fluorinated GHGs or Containing


• Fluorinated GHGs in Closed-cell foams


• Geologic Sequestration of Carbon Dioxide


• Manufacture of Electric Transmission and Distribution Equipment


• Industrial Waste Landfills


• Injection of Carbon Dioxide


• Suppliers of Carbon Dioxide

The Global Warming Potential of Greenhouse Gas Emissions

The concept “’Global Warming Potential’ (GWP) is used to compare the ability of each greenhouse gas to trap heat in the atmosphere relative to another gas,” the EPA explains. In order to make apples-to-apples comparisons, a gas’s GWP is defined as the ratio of heat trapped by one unit mass of the greenhouse to that of one unit mass of CO2 over a specified time period.

To ensure consistency with the international GHG emissions measurement and reporting standard established by the United Nations Framework Convention on Climate Change (UNFCCC), EPA’s greenhouse gas analyses use the 100-year GWPs listed in the Intergovernmental Panel of Climate Change’s (IPCC) Second Assessment Report (SAR).

Carbon dioxide remains the primary source of greenhouse gas emissions that cause atmospheric warming, not only in the US, but globally. Methane ranks a distant second, but the absolute amount is misleading, as methane is 21-times as potent a greenhouse gas as CO2.

Moreover, atmospheric methane concentration is now higher than at any time in the past 400,000 years of Earth’s history. The average global atmospheric concentrations of methane have increased 150%, from approximately 700 parts per billion (ppb) to 1,745 ppb between 1750 and 1998, according to a definitive IPCC study. A more recent study indicated the atmospheric methane level had been in a steady state between 1999 and 2002.