It has happened again. Another scientific study finds methane emissions from oil and gas production are higher than previously thought, reinforcing the urgent need to reduce emissions of this powerful climate pollutant. The latest study, accepted today to be published in American Geophysical Union’s Journal of Geophysical Research – Atmospheres, measured methane concentrations in the air over Colorado’s largest oil and gas producing region on two days during early 2012 and adds to our understanding of the environmental impact of oil and gas development.
The study—led by scientists from the National Oceanic and Atmospheric Administration (NOAA) and the Cooperative Institute for Research in Environmental Sciences (CIRES) at UC-Boulder—suggests between 2.6 and 5.6 percent of gas produced in the Denver Julesburg basin escapes into the air. That’s nearly three times the amount estimated using data from the Environmental Protection Agency’s Greenhouse Gas Reporting Program. The study also found emissions of smog-forming VOC emissions to be twice as high as estimated based on state data and emissions of benzene, a known carcinogen, to be seven times higher than current state estimates.
Results of this study provide further evidence that methane emissions from oil and gas are a problem, but there is an upside. Progress is being made, particularly in the basin examined in this study. In February, two years after these measurements were taken, Colorado became the first U.S. state—and as of today, is still the only U.S. state—to directly regulate methane emissions from the oil and gas industry. The study confirms that state leaders taking this step made the right call, and it signals to others that protective policies are needed to address oil and gas air pollution in a way that benefits the local environment, businesses and the climate. Thankfully, the Obama administration isn’t far behind. In March, the White House announced—as part of its Climate Action Plan—a national strategy for reducing methane emissions from several industries, including the oil and gas sector, the largest industrial contributor to U.S. methane emissions. The administration recognizes that an effective climate strategy must reduce carbon dioxide and methane, which packs a powerful near-term punch. Methane is 84 times more potent than carbon dioxide over the first 20 years it is in the atmosphere.
Methods of Measuring
Obtaining a complete understanding of methane emissions continues to be a priority for scientists concerned about climate change, and the NOAA-CIRES study provides an important piece in our ever-increasing understanding of these emissions from the oil and gas supply chain.
For this study, the NOAA-CIRES team used a “top-down” approach in which a small instrumented aircraft flew 12 flights around and through the air over the Denver-Julesburg Basin, collecting real-time methane concentration data. They also collected air samples that were analyzed in the lab for hydrocarbons. Methane was attributed to oil and gas activities by subtracting other methane sources in the region as derived from inventory data. These top-down techniques are an important complement to other ground-based, “bottom-up” approaches, including the methods used in another study led by University of Texas researchers which measured emissions during the natural gas production phase. That study, published last fall in the Proceedings of the National Academy of Sciences, identified specific sources and rates of emissions from those sources. Bottom-up estimates of oil and gas emissions are inherently conservative as specific sources could be missed, while top-down approaches tend to be more liberal in their estimates as they may miss non-oil and gas industry sources that need to be subtracted from the overall emissions estimate. National estimates of aggregate anthropogenic methane emissions, such as those reported in the recent Harvard University researcher-led project, help to strike a balance between estimates from top-down and bottom-up approaches, by drawing from both methods of measurement and producing conclusions that fall in the range provided by each.
Every method has its advantages and disadvantages and we need to better understand why they differ in the methane estimates that they generate. To address the observed differences, EDF is collaborating with 12 research teams from across the U.S. that spent two weeks in the Texas Barnett shale applying diverse techniques for measuring methane flux rates at the same time. This project is the largest collective effort to date to measure methane emissions using a wide range of techniques. We are confident that when the results of this effort are released they will increase our understanding of how to best deploy both top-down and bottom-up techniques to reach more precision in estimating methane emissions from the natural gas supply chain.
There is a solution
While the science underlying our understanding of methane emissions strengthens rapidly, we already know enough to act. It’s time for policymakers to commit to reducing methane pollution. The breakthrough in Colorado, along with positive steps in Ohio and Wyoming to reduce air pollution from oil and gas development, demonstrate that some states are getting the message.
Controlling methane reduces waste of a precious natural resource, and it’s a bargain. A recent report by independent consultancy ICF International identified more than a dozen cost-effective emission strategies that oil and gas producers can put in place now that would drastically minimize methane emissions and benefit the local environment and our climate. In fact, they estimated emissions could be cut by 40 percent (below 2018 projections) at a cost to industry of less than a penny per thousand cubic feet of produced gas (a unit that costs between $4 and $5). If the climate benefits of eliminating nearly half of the methane from the atmosphere didn’t get your attention, the economic benefits should. There’s absolutely no reason to wait on establishing policy that pushes operators to cut emissions of methane system-wide and nationwide.
The study released today is one of many that reiterate methane emissions are unnecessarily high –unnecessary because we know this is a problem with an obtainable, cost-effective solution. Colorado leaders understood this. Now it’s time for other policymakers to get on board and press industry to move quickly to fix the problem.