Liquefied Natural Gas - Environmental Concerns

Environmental Concerns

Issues commonly referenced include: focus on climate forcing associated with carbon dioxide production in extraction (however, in reality carbon dioxide emissions in the LNG supply chain are lower than in piping natural gas from remote fields when considering equivalent transport distances), liquefaction, gasification and transport; Some groups have identified the plants' release of nitrogen oxide and particulate matter, known to aggravate asthma and respiratory disease as a particular issue. However, combustion emissions from LNG plants are no greater than from a similar energy-demand industrial plant burning natural gas; environmental justice issues associated with site placement; and that expensive infrastructure investment will displace cleaner alternatives.

A typical LNG liquefaction and export terminal exporting 4.5 million tonnes of LNG can be expected to produce in the order of 1.2 million tonnes equivalent carbon dioxide of direct emissions. The greenhouse gas emissions associated with the combustion of 4.5 million tonnes of LNG is approximately 12 million tonnes equivalent carbon dioxide.

On the West Coast of the United States where up to three new LNG importation terminals have been proposed, environmental groups, such as Pacific Environment, Ratepayers for Affordable Clean Energy (RACE), and Rising Tide have moved to oppose them. While natural gas power plants emit approximately half the carbon dioxide of an equivalent coal power plant, the natural gas combustion required to produce and transport LNG to the plants adds 20 to 40 percent more carbon dioxide than burning natural gas alone. However, this assessment does not consider the life cycle emissions of natural gas production, which include significant carbon dioxide emissions from gas compression and transport. On a per kilometer transported basis, LNG carbon dioxide emissions are lower than piped natural gas emissions.

Natural gas could be considered the most environmentally friendly fossil fuel, because it has the lowest CO₂ emissions per unit of energy and because it is suitable for use in high efficiency combined cycle power stations. On a per kilometre transported basis, emissions from LNG are lower than piped natural gas, which is a particular issue in Europe, where significant amounts of gas are piped several thousand kilometres from Russia. However, emissions from natural gas transported as LNG are higher than for natural gas produced locally to the point of combustion as emissions associated with transport are lower.