An article published in the November issue of the journal Nature reports the findings of the California Air Resources Board, California Energy Commission and NASA study to pinpoint emissions of methane, what they call a climate "super pollutant." The results of the study will be used to help state and local agencies and businesses prioritize investments to reduce emissions and meet California's ambitious goals to reduce their greenhouse gas emissions.
Methane is a powerful greenhouse gas and is 25 times more effective than carbon dioxide at trapping heat over a 100-year period. While it does occur naturally, major human-generated sources include landfills, refineries, oil and gas fields, natural gas infrastructure, dairies and wastewater treatment plants. To reduce methane’s impact on the climate, by 2030 California intends to cut overall emissions in the state by 40%t from 2013 levels.
You have to find the methane sources to cut them. So, from August 2016 to October 2018, California Air Resources Board, California Energy Commission partnered with NASA to survey the state. A research team at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, flew a plane equipped with the Airborne Visible Infra Red Imaging Spectrometer - Next Generation (AVIRIS-NG) instrument over the state.
This survey was designed to detect the largest releases of methane from point sources, a single component or piece of industrial equipment, such as an oil well; and included nearly 272,000 facilities and infrastructure components. The survey excluded non-point sources, such as small natural gas leaks from millions of homes, because even though they probably have a significant collective impact on atmospheric methane levels, their individual emissions are below the detection levels of the instrument that can detect larger plumes of methane. Studies of non-point sources need to be done at ground level.
Over 550 point sources of methane were identified during the “California Methane Survey,” and according to the data, just 10% of the point sources were found to be responsible for 60% of the total methane emissions detected. Researchers believe that statewide, these relatively few super emitters are responsible for about a third of California’s total methane emissions. Landfills accounted for 41% of point source emissions, manure management accounted for 26% and oil and gas accounted for 26% of the point source emissions.
The most startling finding to scientists and regulators, however, was that less than 0.2% of infrastructure in the state was responsible for 34% of total methane emissions in California. Of the 270 landfills surveyed, only 30 were observed emitting large plumes of methane. Those 30, however, were responsible for 40 % of the total point source emissions detected during the survey. The oil and gas production sector also included large sources of methane. Most were concentrated in the southern San Joaquin Valley, the region that produces more oil than any other in the state. Los Angeles and Ventura Counties were next on the list.
"These findings illustrate the importance of monitoring point sources across multiple sectors of the economy and broad regions, both for improved understanding of methane budgets and to support emission mitigation efforts," said JPL scientist Riley Duren, who led the study.
Preliminary results were shared with the facility operators to make them aware of the need to improve their methane leak detection processes and to institute better controls on methane emissions. Although the survey provides a detailed map of methane emissions in the state, researchers caution that this was the first attempt to estimate emissions for individual methane sources from a large population distributed across a large region over multiple years. Some methane emissions were highly intermittent, others were affected by wind, and some were too small for accurate emission rate estimation.
“This new remote sensing technology addresses the continuing need for detailed, high-quality data about methane,” said California Air Resources Board Chair Mary D. Nichols. “It will help us and the Energy Commission develop the best strategies for capturing this highly potent greenhouse gas.”
The data from the survey and other methane projects can be viewed at an experimental NASA data portal at https://methane.jpl.nasa.gov/.
Over 550 point sources of methane were identified during the “California Methane Survey,” and according to the data, just 10% of the point sources were found to be responsible for 60% of the total methane emissions detected. Researchers believe that statewide, these relatively few super emitters are responsible for about a third of California’s total methane emissions. Landfills accounted for 41% of point source emissions, manure management accounted for 26% and oil and gas accounted for 26% of the point source emissions.
The most startling finding to scientists and regulators, however, was that less than 0.2% of infrastructure in the state was responsible for 34% of total methane emissions in California. Of the 270 landfills surveyed, only 30 were observed emitting large plumes of methane. Those 30, however, were responsible for 40 % of the total point source emissions detected during the survey. The oil and gas production sector also included large sources of methane. Most were concentrated in the southern San Joaquin Valley, the region that produces more oil than any other in the state. Los Angeles and Ventura Counties were next on the list.
"These findings illustrate the importance of monitoring point sources across multiple sectors of the economy and broad regions, both for improved understanding of methane budgets and to support emission mitigation efforts," said JPL scientist Riley Duren, who led the study.
Preliminary results were shared with the facility operators to make them aware of the need to improve their methane leak detection processes and to institute better controls on methane emissions. Although the survey provides a detailed map of methane emissions in the state, researchers caution that this was the first attempt to estimate emissions for individual methane sources from a large population distributed across a large region over multiple years. Some methane emissions were highly intermittent, others were affected by wind, and some were too small for accurate emission rate estimation.
“This new remote sensing technology addresses the continuing need for detailed, high-quality data about methane,” said California Air Resources Board Chair Mary D. Nichols. “It will help us and the Energy Commission develop the best strategies for capturing this highly potent greenhouse gas.”
The data from the survey and other methane projects can be viewed at an experimental NASA data portal at https://methane.jpl.nasa.gov/.
No comments:
Post a Comment