Author Archives: Steven Hamburg

Measuring Fugitive Methane Emissions

By | Bio | Published: January 4, 2013

In recent days, news reports and blog posts have highlighted the problem of fugitive methane emissions from natural gas production — leakage of a potent greenhouse gas with the potential to undermine the carbon advantage that natural gas, when combusted, holds over other fossil fuels. These news accounts, based on important studies in the Denver-Julesburg Basin of Colorado and the Uinta Basin of Utah by scientists affiliated with the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado (UC) at Boulder, have reported troubling leakage rates of 4% and 9% of total production, respectively —higher than the current Environment Protection Agency (EPA) leakage estimate of 2.3%.

While the Colorado and Utah studies offer valuable snapshots of a specific place on a specific day, neither is a systematic measurement across geographies and extended time periods  and that is what’s necessary to accurately scope the dimensions of the fugitive methane problem. For this reason, conclusions should not be drawn about total leakage based on these preliminary, localized reports. Drawing conclusions from such results would be like trying to draw an elephant after touching two small sections of the animal’s skin: the picture is unlikely to be accurate. In the coming months, ongoing work by the NOAA/UC team, as well as by Environmental Defense Fund (EDF) and other academic and industry partners, will provide a far more systematic view that will greatly increase our understanding of the fugitive methane issue, though additional studies will still be needed to fully resolve the picture. What follows is a briefing on the fugitive methane issue, including the range of measurements currently underway and the need for rigorous data collection along the entire natural gas supply chain.

Why methane leakage matters. Natural gas, which is mostly methane, burns with fewer carbon dioxide emissions than other fossil fuels. However, when uncombusted methane leaks into the atmosphere from wells, pipelines and storage facilities, it acts as a powerful greenhouse gas with enormous implications for global climate change due to its short-term potency: Over a 20-year time frame, each pound of methane is 72 times more powerful at increasing the retention of heat in the atmosphere than a pound of carbon dioxide. Based on EPA’s projections, if we could drastically reduce global emissions of short-term climate forcers such as methane and fluorinated gases over the next 20 years, we could slow the increase in net radiative forcing (heating of the atmosphere) by one third or more.

Fugitive methane emissions from natural gas production, transportation and distribution are the single largest U.S. source of short-term climate forcing gases. The EPA estimates that 2.3% of total natural gas production is lost to leakage, but this estimate, based on early 1990’s data, is sorely in need of updating. The industry claims a leakage rate of about 1.6%. Cornell University professor Robert Howarth has estimated that total fugitive emissions of 3.6 to 7.9% over the lifetime of a well.

To determine the true parameters of the problem, EDF is working with diverse academic partners including the University of Texas at Austin, the NOAA/UC scientists and dozens of industry partners on direct measurements of fugitive emissions from the U.S. natural gas supply chain. The initiative is comprised of a series of more than ten studies that will analyze emissions from the production, gathering, processing, long-distance transmission and local distribution of natural gas, and will gather data on the use of natural gas in the transportation sector. In addition to analyzing industry data, the participants are collecting field measurements at facilities across the country. The researchers leading these studies expect to submit the first of these studies for publication in February 2013, with the others to be submitted over the course of the year. Read More »

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More To Come On Methane…

By | Bio | Published: December 6, 2012

Concerns around the impacts of methane emissions have reemerged in headlines, with the release of a methane leakage study about Boston. Published in the journal of Environmental Pollution a couple weeks ago, researchers from Boston University and Duke University measured atmospheric methane concentrations leaking from natural gas pipelines in Boston many of which are over a hundred years old. Another report issued last week by researchers at the Massachusetts Institute of Technology (published in Environmental Research Letters) looked at the impact of shale gas production on greenhouse gas emissions.

When talking about harmful greenhouse gases, carbon dioxide (CO2) usually gets most of the attention. Yet methane, the main ingredient in natural gas, is a short-lived greenhouse gas many times more potent than CO2 – or around 72 times more potent over a 20-year time frame. Stakes are high for the scientific community to fully understand the implications of methane leakage rates. These reports help elevate the issue that methane leakage matters to the climate and air quality, but this is only part of the story.

Methane is potentially leaking from the entire natural gas supply chain — from wells, pipelines and storage facilities — and no one knows precisely how much is leaking and where the leaks are stemming from. Some reports estimate the total methane leakage rate occurring during natural gas production, transmission and distribution to range anywhere from 1 to 7.9 percent. At the same time, the data that the Environmental Protection Agency (EPA) and everyone else rely on were collected 20 or more years ago.

A challenge for understanding the distribution of methane concentration data in Boston is that no one knows how to interpret the data yet. Maps of methane concentrations in the urban environment can be spurious. They may look scary, but are they? This and many other tough scientific questions still need to be answered, we are very early in the process of understanding how much methane is leaking and from where. The scientific community at large, including EDF and the authors of the Boston study, are committed to collecting the data necessary to addressing these concerns and to understanding the true climate impact of methane emissions.

EDF is working with leading academic researchers and industry leaders to conduct scientifically rigorous measurements of quantitative emissions across the natural gas supply chain from well to the end user. We are developing the methodologies where necessary to move past a ‘he said, she said’ conversation to one focused on data characterizing leak rates. The critical next step for us in using the increasingly robust data gathered from new innovative technologies is to precipitate a clear enough understanding of where the leaks are in the supply chain to catalyze a constructive conversation about what new policies and industry practices will be required to minimize methane leakage.

The first EDF fugitive methane report, focused on field measurements made at natural gas production sites, will be completed early next year under the leadership of the University of Texas Austin. EDF and our partners are using a diverse array of measurement techniques to characterize leak rates. We are also working to make basin-wide measurements within areas of natural gas production. Over the course of 2013 and early 2014, studies of emissions at other key components in the supply chain, including the local distribution system, will be completed and the data and conclusions released to the public.

EDF is actively campaigning to ensure that fugitive methane emissions from the natural gas industry are less than 1 percent of production in order to ensure that the climate benefits of natural gas are maximized. We see development of innovative, cost effective and accurate methane detection technologies and procedures as a necessary part of minimizing leak rates. Our view is that minimizing methane leakage is an important enough issue that we need to take the time to establish a scientific understanding of the underlying issues and by doing so defining effective well-targeted actions.

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New Study To Provide Important, Direct Measurement Data On Methane Emissions From Natural Gas Production

By | Bio | Published: October 10, 2012

While natural gas burns cleaner than other fossil fuels when combusted, methane leakage from the production, transportation, and use of natural gas has the potential to undermine some or all of those benefits, depending on the leakage rate.  Methane is the main ingredient in natural gas and a greenhouse gas (GHG) pollutant many times more potent than carbon dioxide (CO2), the principal contributor to man-made climate change.

In other words, leaks during the production, distribution, and use of natural gas could undermine, and possibly even overwhelm, the greenhouse gas advantage combusted natural gas has over coal and spell major trouble for the climate.

Up to this point, direct measurement data on methane leakage rates has been limited and subject to wide interpretation and debate.  Some studies have estimated the leak rate to be as high as 7.9%, while others have estimated the leak rate to be as low as 1% for some aspects of the drilling process.  Methane leakage matters, and has clear implications on whether natural gas can be seen as a lower carbon energy source.  To help overcome some of the debate, EDF is working with leading academic researchers and industry leaders from across the natural gas sector to take direct measurements of leak rates to help better define the natural gas leak rate across the natural gas supply chain in the United States.

In partnership with the EDF and nine leading natural gas producers, today the University of Texas Austin (UT) announced the first part of this study, focused on emissions from natural gas production.  The study will help provide a clearer picture of methane leakage rates occurring at natural gas drilling sites around the country.  It is particularly relevant because drilling and completion processes have evolved rapidly in recent years – thanks to breakthroughs in horizontal drilling and hydraulic fracturing – and the knowledge about the methane leaked during this shift has not.

The main objective of this study on production emissions is to obtain scientifically rigorous data from multiple gas producing basins. The study will focus on quantifying emissions from well completions, gas well liquid unloading and well workovers, in addition to other more routine well-site fugitive emissions, the areas of the production process with the greatest leak rate uncertainties

The study is unique in that it brings multiple, key stakeholders to the table to make measurements of emissions at the well pad that will be shared when completed. If natural gas is to become an accepted part of an energy independence strategy, while supporting a clean energy future, it is critical to work together to quantify, and where ever possible lower, the existing methane leakage rate. Such an approach could yield enormous added environmental and health benefits from existing and future natural gas infrastructure.

A research team led by UT, including engineering and environmental testing firms URS and Aerodyne Research, is conducting the extensive field study. Project partners include EDF, Anadarko Petroleum Corporation, BG Group plc, Chevron Inc., Encana Oil & Gas (USA) Inc., Pioneer Natural Resources Company, Shell, Southwestern Energy, Talisman Energy, USA, and XTO Energy, an ExxonMobil subsidiary.

For more information on ways to get sustained benefits from natural gas, EDF published a paper earlier this year titled, “Greater focus needed on methane leakage from natural gas infrastructure.”  Find more at edf.org/methaneleakage.

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