InfrastructureNatural gas leaks a significant source of green-house gas methane
Methane, a key greenhouse gas, has more than doubled in volume in Earth’s atmosphere since 1750. Its increase is believed to be a leading contributor to climate change. Where is the methane coming from, however? Research by atmospheric chemist Paul Wennberg of the California Institute of Technology (Caltech) suggests that losses of natural gas – regarded as the “cleanest” fossil fuel — into the atmosphere may be a larger source than previously recognized.
Natural gas leaks a source of greenhouse gases // Source: mit.edu
Radiation from the sun warms Earth’s surface, which then radiates heat back into the atmosphere. Greenhouse gases trap some of this heat. It is this process that makes life on Earth possible for beings such as ourselves, who could not tolerate the lower temperatures Earth would have if not for its “blanket” of greenhouse gases. There is “too hot” as well as “too cold,” however, and the precipitous increase in greenhouse gases since the beginning of the Industrial Revolution induces climate change, alters weather patterns, and has increased sea level.
A Caltech release reports that carbon dioxide is the most prevalent greenhouse gas in Earth’s atmosphere, but there are others as well, among them methane.
Those who are concerned about greenhouse gases have a special enemy to fear in atmospheric methane. Methane has a trifecta of effects on the atmosphere. First, like other greenhouse gases, methane works directly to trap Earth’s radiation in the atmosphere. Second, when methane oxidizes in Earth’s atmosphere, it is broken into components that are also greenhouse gases: carbon dioxide and ozone. Third, the breakdown of methane in the atmosphere produces water vapor, which also functions as a greenhouse gas. Increased humidity, especially in the otherwise arid stratosphere where approximately 10 percent of methane is oxidized, further increases greenhouse-gas induced climate change.
Fully one-third of the increase in radiative forcing (the ability of the atmosphere to retain radiation from the sun) since 1750 is estimated to be due to the presence and effects of methane.
Because of the many potential sources of atmospheric methane, from landfills to wetlands to petroleum processing, it can be difficult to quantify which sources are making the greatest contribution. According to Paul Wennberg, Caltech’s R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering, and his colleagues, it is possible that a significant source of methane, at least in the Los Angeles basin, is fugitive emissions – leaks — from the natural-gas supply line.
