We’ve all seen TV detectives dust a scene for fingerprints. In a study in the journal Nature, a team of scientists did something similar, using carbon isotopes to identify the “fingerprints” of methane– one of the world’s most powerful climate pollutants in the atmosphere.
The study examined the isotopic signature from two types of methane emissions: biogenic (sources like wetlands, landfills and agriculture) and thermogenic (encompassing geologic seepage, activities associated with the oil and gas supply chain or coal mines).
The evidence suggests that not only are we significantly underestimating the share global methane emissions from thermogenic sources, we’re also underestimating how much comes from the production, delivery and use of oil and gas and the production of coal.
According to the study:
“After accounting for geological seepage, emissions attributable directly to the global fossil-fuel industry (natural gas, oil and coal production) are 20–60% higher than in current global inventories.”
The findings mirror results of many of the studies of methane emissions from the natural gas supply chain coordinated by EDF, which also found that overall levels of methane coming from U.S. oil and gas production and delivery infrastructure were higher than previously thought. In one of those analyses – which included the use of diverse types of measurements – emissions were nearly double what the Environmental Protection Agency had previously estimated. It provided some the critical information leading to the agency’s recent 34% upward revision of oil and gas methane emissions..
This latest research published earlier this week indicated that we have also been consistently underestimating oil and gas methane emissions on a global scale as well. This research also adds an important data set to an ongoing scientific debate on the causes of the almost decade-long increase in atmospheric methane concentrations. Resolving the competing explanations for this increase will take some time, but this debate in no way diminishes the importance of taking action now to reduce anthropogenic emissions so we can begin to slow the rate of warming.
Rising Tide of Production Offsets Gain from Better Management
The authors estimate that over the past 30 years, global emissions from the oil and gas industry have fallen from 8% of production to about 2%, and they speculate this decline is the result of better practices and improved technology. But those gains have been overwhelmed as production has soared.
“Natural gas industry improvements associated with management practices, technology, and replacement of older equipment have been credited for reducing CH4 leakage in the past. The global observations used in our study confirm this trend, but the industry improvements have been offset by increased NG production.”
The authors of the latest study concur with our earlier results, indicating that policies are needed to keep the trend in emissions moving downward on a worldwide basis. While the data suggests that the proportion of natural gas lost to the atmosphere has gone down, it is still far higher than is required to reduce the rate of global warming, let alone stop it. The good news is cost-effective technologies are available that can continue to reduce methane emissions from the natural gas supply chain .
Opportunities to Act
Scientists are shining a bright light on a powerful climate pollutant during a time when nations across the globe are taking action on climate. Earlier this week the European parliament approved the Paris Climate Deal, which brought the Paris agreement into force, a critical step toward effectively addressing climate change.
Because methane is the second largest contributor to global warming, for any effort to combat climate change to be effective it must include reductions in methane emissions.
Let’s be clear, oil and gas industry’s methane fingerprints aren’t the only ones causing global warming. But those emissions deserve attention not only because they are significant but because they are among the easiest to reduce.
Mounting scientific evidence – this study included – makes it clear that we have the data to support action to reduce oil and gas methane emissions, and we have the technologies to make significant emission reductions happen now.