We read with great interest the column by Barney Strobel in The Colorado Sun on March 8, 2020, “Opinion: Ozone is more serious for Colorado than greenhouse gas emissions.“
We agree that the non-compliance of the Northern Front Range Metro Area (NFRMA) with the National Ambient Air Quality Standard (NAAQS) for ozone can have serious health impacts on individuals who belong to sensitive groups, such as the elderly, young children and individuals with respiratory illnesses such as asthma and COPD.
It is therefore important to analyze and address the factors that cause elevated ozone in the NFRMA and provide guidance to the regulatory process.
In fact, the NFRMA is home to one of the largest, world-class atmospheric chemistry research community in the nation (including researchers at CU, CSU, NOAA and NCAR), and much research has been done on the topic of air quality and contributing factors in the NFRMA, and on ozone in particular.
We can therefore assure Mr. Strobel that there is no need to “hire engineers,” because many of us have indeed been “out in the field and measured emissions of ozone precursors to figure out where they are really coming from.”
As members of this local research community, we feel compelled to respond to the column.
While many of the statements made in Mr. Strobel’s editorial are factually correct, the assertion that nothing is known about the origin of ozone in the Northern Front Range Metro Area and that the legislature is obsessed with methane emissions is incorrect.
In fact, in 2014, the state of Colorado through the Colorado Department of Health and Environment funded part of the largest air quality study ever conducted in the Northern Front Range Metro Area (additional major funding for this study came from The National Science Foundation, NASA and NOAA).
Our research clearly showed that the contribution of emissions from oil and gas operations are indeed a major contributor to local ozone production, about equal to motor vehicle traffic when averaged over the entire northern Front Range, and are the dominating contributor for the northern part of the metro area, particularly in areas west of Weld County.
Our research further demonstrated that the available emission inventories for volatile organic compounds (VOC) emissions from the oil and gas industry are underestimated by at least a factor of two, and likely more than that.
Measured VOC emissions from oil and gas operations comprise more than half of the total VOC emissions along the northern Front Range. Just like most of the emission data used in inventories, the recent reductions in VOC emissions overwhelmingly rely on self-reporting by the industry and are still subject to verification.
This publicly available, peer-reviewed publication and the many research papers written by our colleagues cited in it summarize the most recent findings on the origin of ozone in the Northern Front Range Metro Area.
In order to reduce summertime ozone exceedances in the metro area, emissions from oil and gas activities as well as transportation and other mobile sources need to be addressed. There are also significant co-benefits of emission reductions for both air quality and climate change mitigation.
We should use all available research and observations made by teams of scientists and the CDPHE to work with and provide to the legislature all the resources it needs to make decisions that ensure that all people can breathe healthy air and are able to enjoy outdoor activities in our beautiful state.
Gabriele Pfister and Frank Flocke are scientists working in the Atmospheric Chemistry Observations and Modeling Laboratory at NCAR in Boulder.