Life Cycle GHG Emissions of LNG
Recent Scientific Research Results
The important role of natural gas in reducing global greenhouse gas (GHG) emissions and conventional air pollutants can be better appreciated by comparing the emission profiles of the world’s primary energy sources—coal, oil, and natural gas.
When natural gas displaces coal and oil for electric power generation, it not only cuts GHG emissions, it also reduces nitrogen oxides (NOX), sulfur dioxides (SO2), and particulate matter (PM). Furthermore, when using a full life cycle analysis and comparing natural gas fired power generation to coal and oil, natural gas results in half or less of the GHG emissions.
Two recent articles in Environmental Science & Technology (an American Chemical Society journal) illustrate the clear advantages of liquefied natural gas (LNG) in a full life cycle context:
- The peer-reviewed study Life Cycle Greenhouse Gas Impacts of Coal and Imported Gas-Based Power (2019) found that “on average, life cycle GHG emissions from LNG imported into India are 54% lower than those associated with Indian coal.”
- In the peer-reviewed paper Country-Level Life Cycle Assessment of Greenhouse Gas Emissions from Liquefied Natural Gas Trade for Electricity Generation (2018), the authors found that LNG imported to China, India, Japan, South Korea, and Taiwan from the West Coast of North America would produce net reductions in GHG emissions in all cases, up to a maximum reduction of 2.9 million tons per year (of CO2 equivalent) for each million tons of LNG imported.
These research reports align with the results of three important studies conducted in 2014-2015:
- Skone, T. J.; Cooney, G.; Jamieson, M.; Littlefield, J.; Marriott, J. Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States; Report for U.S. Department of Energy/ National Energy Technology Laboratory: Pittsburgh, PA, 2014.
- Coleman, J.; Kasumu, A. S.; Liendo, J.; Li, V.; Jordaan, S. M. Calibrating Liqueﬁed Natural Gas Export Life Cycle Assessment: Accounting for Legal Boundaries and Post-Export Markets; CIRL Occasional Paper No. 49; Canadian Institute of Resources Law: Calgary, AB, 2015.
- Abrahams, L. S.; Samaras; Griffin, M. W.; Matthews, S. H. Life Cycle Greenhouse Gas Emissions from U.S. Liquefied Natural Gas Exports: Implications for End Uses. Sci. Technol. 2015, 49, 3237-3245.
 Mallapragada, D. S.; Naik, I.; Ganesan, K.; Banerjee, R.; Laurenzi, I. J. Life Cycle Greenhouse Gas Impacts of Coal and Imported Gas-Based Power Generation in the Indian Context. Environ. Sci. Technol. 2019, 53, 539-549.
 Kasumu, A.S.; Li, V.; Coleman, J.W.; Liendo, J.; Jordaan, S.M. Country-Level Life Cycle Assessment of Greenhouse Gas Emissions from Liquefied Natural Gas Trade for Electricity Generation. Environ. Sci. Technol. 2018, 52, 1735-1746. The 2.9 million tons per year figure cite above is derived by dividing the maximum value of 52.6 million tons per year of CO2 equivalent divided by an estimated level of 18.4 million tons of LNG exported from Canada to Asia.