Atmospheric Methane, Nitrous Oxide Levels Unaffected by Pandemic Shutdown
|Llewellyn Jones||Nov 13|
Measurements of methane and nitrous oxide in the Earth's atmosphere taken by the National Oceanic and Atmospheric Administration's (NOAA) Earth Systems Research Laboratories (ESRL) show little change since worldwide shutdowns have taken place.
The measurements taken from the Mauna Loa Observatory in Hawaii show a steady increase from 2019 to 2020 despite a distinct halt in the production of greenhouse gases—methane, nitrous oxide, and carbon dioxide—on a global scale since May. The increase applies to both averaged and trend data compiled by NOAA.
The Environmental Protection Agency (EPA) posits that 28 percent of methane comes from oil and natural gas production and use, which has plummeted during the crisis as gasoline consumption dried up. Other sources include agriculture, landfills, and coal mining. Nitrous oxide in the atmosphere is largely a result of agricultural soil management, but also comes from automobile exhaust.
A report from the International Energy Association (IEA) forecasts global demand for oil declining by an average of over .1 million barrels of oil per day in 2020. The sharp decline in demand caused U.S. oil prices to turn negative in April, the first time in the history of NYMEX oil futures.
Carbon dioxide has also continued to climb in atmospheric measurements despite the large drop in oil consumption and emissions. Multiple papers in Nature have estimated a drop in carbon dioxide emissions of either 9 or 17 percent beginning in April of 2020 because of decreased energy demand. The World Meteorological Association predicts a 4 to 7 percent decline in CO₂ emissions because of the lockdowns for all of 2020.
But NOAA posted a note explaining why COVID-19 might not have an affect on measured CO₂ levels. There is no photochemical destruction of atmospheric CO₂ as there is for other gases and any change needs to stand out from natural fluctuations of CO₂ in the atmosphere.
But that doesn't apply to other greenhouse gases like methane and nitrous oxide, which are not produced naturally in substantial quantities and degrade in the atmosphere over time. CO₂ may last in the atmosphere for thousands of years, but methane only lasts for a decade and nitrous oxide about a hundred years according to the EPA.
While carbon dioxide is the largest source of greenhouse gases by volume (81 percent) and methane represents only 10 percent, methane is considered significantly more potent in terms of its ability to absorb sunlight.
Methane and Oil Production
According to the Mauna Loa observations, levels of methane in the atmosphere have been steadily for decades now. That trend coincides with the steady growth in global oil production, but not always.
In the early 2000s during a period of rampant growth in oil production and consumption of natural gas according to numbers from IEA, atmospheric methane levels flatlined.