New Delhi, Liquefied natural gas, or LNG -- used in cooking and in power plants and industries -- leaves behind a greenhouse gas footprint about a third more than that of coal when looked at over a 20-year period, according to a new study. Over a 100-year period, LNG's greenhouse gas footprint was found to be the same as or exceeding that of coal. Greenhouse gas emissions, such as carbon dioxide and methane, are released into the atmosphere, while a greenhouse gas footprint indicates the impact of these emissions on the environment.
Natural gas, an odourless gas primarily made up of methane, is cooled down to a liquid state at about -106 degrees Celsius to form liquefied natural gas, or LNG, thereby reducing the gas's original volume by 600 times. Being liquid, LNG can be shipped efficiently and safely. Although LNG is considered a cleaner, low-carbon alternative to coal, when processing and shipping are taken into account, its greenhouse gas footprint is about a third worse than that of coal, Robert Howarth, a professor of ecology and environmental biology at Cornell University, US, said.
"LNG is made from shale gas (a type of natural gas), and to make it you must supercool it to liquid form and then transport it to market in large tankers. That takes energy. While natural gas and shale gas are all bad for the climate, LNG is worse," Howarth, author of the study published in the journal Energy Science and Engineering, said.
Shale gas is extracted from shale rock formations t.
