Natural gas is primarily methane, which is a major greenhouse gas. Methane is emitted directly to the atmosphere from sources such as leaks in natural gas wells and pipelines and is produced in landfills, sewage treatment facilities and livestock operations. Other major greenhouse gases, carbon dioxide and nitrous oxides are produced when natural gas is burned for heating and electric power production.

Scientists know for certain that human activities are changing the composition of Earth's atmosphere. Increasing levels of greenhouse gases, like carbon dioxide (CO2 ), in the atmosphere since pre-industrial times have been well documented. There is no doubt this atmospheric buildup of carbon dioxide and other greenhouse gases is largely the result of human activities. It's well accepted by scientists that greenhouse gases trap heat in the Earth's atmosphere and tend to warm the planet.

Greenhouse gas emissions are gases that trap heat in the Earth's atmosphere. Without greenhouse gases the average global temperature would go from 59 degrees Fahrenheit to 0 degrees Fahrenheit. The most notable greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halocarbons that contain fluorine such as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) (EPA 2003c). Each greenhouse gas differs in its ability to hold heat.

The greenhouse gas estimates presented here are full fuel-cycle estimates, combining the three major greenhouse gases emitted by motor vehicles: Full fuel-cycle estimates include all steps in the use of a fuel, from production and refining to distribution and final use. This gives a more complete picture of the climate change impacts of using a particular fuel. Some greenhouse gases have greater impacts on climate than others.

Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004. U.S. EPA, Office of Atmospheric Programs. EPA/430/R-06-002. April 15, 2006. This report presents estimates by the United States government of U.S. human-related greenhouse gas emissions and sinks for the years 1990 through 2004. The information provided in this inventory is presented in accordance with the Revised 1996 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories.

Landfill gas recovery projects provide a highly effective means of reducing overall greenhouse gas emissions from landfills, whether the landfill gas is combusted by flare, electricity generation equipment, or another end use system. By using the otherwise wasted methane contained in the collected landfill gas to generate electricity or directly as a fuel, fossil fuels such as oil and coal are displaced.

Carbon dioxide (the key factor in climate change) and other greenhouse gases come mainly from the exhaust pipes of cars, trucks and other vehicles, and from the stacks of power plants and industries that burn coal, oil, and gas. In Canada the biggest source of carbon dioxide is transportation -- approximately one-quarter of the total. Industries are not far behind contributing 19 per cent.

All Canadians need to get involved in reducing emissions of greenhouse gases that cause climate change, as well as air pollution. Making use of the Government's public transit tax credit and increasing your use of public transit to help reduce traffic congestion and air pollution in our cities, and greenhouse gas emissions that impact on our climate. Consulting the ecoENERGY for Personal Vehicles program to help you choose more eco-friendly vehicles.

By 2010, the Climate Savers Computing Initiative seeks to reduce global CO2 emissions from the operation of computers by 54 million tons per year, equivalent to the annual output of 11 million cars or 10–20 coal-fired power plants.5 Under the assumptions detailed below (see footnote No. 6), total power consumption for PCs shipped in 2010 will be reduced by over 50%, for a total savings of 62 billion kWh in 2010, worth more than $5.5 billion (at an average cost of $0.0885/kWh).

EIA provides international natural gas prices for selected countries by sector (electric generation, household, industry).

In 2005, there were 18.2 trillion cubic feet (Tcf) of dry natural gas produced in the U.S. The top producing states are:

Residential consumers in some States have the opportunity to choose their supplier for the natural gas itself. Suppliers are either the local distribution company or approved gas marketers. Regardless of supplier, the local distribution company continues to provide local transportation and distribution services. Learn More: To find out more about States that have "customer choice" programs, see Natural Gas Residential Choice Programs. Yes.

EIA does not collect daily spot price information, but instead relies on a private vendor. EIA publishes daily spot prices for the Henry Hub, Transco Zone 6 NY, Chicago, and an average for selected California locations on a weekly basis and these can be found in the Natural Gas Weekly Update (NGWU). A time series of the daily spot price data for these locations and all others in the Lower 48 States are available from the data vendor, Intelligence Press, Inc.

U.S. residential natural gas prices are projected to average $13.52 per thousand cubic feet (Mcf) this winter , 6.3 percent higher than last winter’s price of $12.36 per Mcf.

In 2006, the U.S. consumed nearly 22 trillion cubic feet (Tcf) of natural gas by the following seven natural gas end users:

There are several ways that total underground working gas capacity may be measured. The Energy Information Administration (EIA) estimated in mid 2006 that, after adjustment for operational considerations that hinder the attainment of full storage at all fields simultaneously, a likely practical estimate for maximum industry-wide working gas capacity is roughly 3.6 Tcf. However, based on design capacity estimates, U.S. working gas capacity was 4.01 Tcf as of the end of 2005.

Numerous underlying factors affect natural gas prices. Depending on the factor-for example, production, imports, demand, oil prices, and natural gas inventories -- each can apply either upward pressure () or downward pressure () or neutral pressure on prices (). Increasing Production - Total domestic production of dry natural gas is projected to increase 1.4 percent in 2007 and is expected to increase an additional 1.3 percent in 2008.

In 2005, nearly 58 percent of all households (residential sector) used natural gas as their primary heating fuel accounting for about 22 percent of total natural gas consumed in the United States.

Major industrial sectors, including electricity produced by combustion, oil and gas, base metal smelters, iron and steel, some mining sectors, cement, forest products, and chemicals production contribute about half of Canada's greenhouse gas emissions that cause climate change. Industry produces about half of Canada's greenhouse gas emissions that cause climate change and our plan sets mandatory targets for them to reduce these emissions.

Businesses that take steps to reduce their greenhouse gas emissions are likely to see an increase in efficiency, helping them save money and setting the bar higher for their competition. Considering that most lawmakers and citizens believe regulatory limits on GHG emissions are inevitable, companies that are early to respond to climate change and pollution will have a technological and economical advantage over their competitors.