Papers on gas leakage from natural gas industry

This is a list of papers on gas leakage from natural gas industry. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (February 5, 2012): Howarth et al. (2011), Cathles et al. (2012), and Howarth et al. (2012) added.

Venting and leaking of methane from shale gas development: response to Cathles et al. – Howarth et al. (2012) “In April 2011, we published the first comprehensive analysis of greenhouse gas (GHG) emissions from shale gas obtained by hydraulic fracturing, with a focus on methane emissions. Our analysis was challenged by Cathles et al. (2012). Here, we respond to those criticisms. We stand by our approach and findings. The latest EPA estimate for methane emissions from shale gas falls within the range of our estimates but not those of Cathles et al. which are substantially lower. Cathles et al. believe the focus should be just on electricity generation, and the global warming potential of methane should be considered only on a 100-year time scale. Our analysis covered both electricity (30% of US usage) and heat generation (the largest usage), and we evaluated both 20- and 100-year integrated time frames for methane. Both time frames are important, but the decadal scale is critical, given the urgent need to avoid climate-system tipping points. Using all available information and the latest climate science, we conclude that for most uses, the GHG footprint of shale gas is greater than that of other fossil fuels on time scales of up to 100 years. When used to generate electricity, the shale-gas footprint is still significantly greater than that of coal at decadal time scales but is less at the century scale. We reiterate our conclusion from our April 2011 paper that shale gas is not a suitable bridge fuel for the 21st Century.” Robert W. Howarth, Renee Santoro and Anthony Ingraffea, Climatic Change, DOI: 10.1007/s10584-012-0401-0. [Full text]

A commentary on “The greenhouse-gas footprint of natural gas in shale formations” by R.W. Howarth, R. Santoro, and Anthony Ingraffea – Cathles et al. (2012) “Natural gas is widely considered to be an environmentally cleaner fuel than coal because it does not produce detrimental by-products such as sulfur, mercury, ash and particulates and because it provides twice the energy per unit of weight with half the carbon footprint during combustion. These points are not in dispute. However, in their recent publication in Climatic Change Letters, Howarth et al. (2011) report that their life-cycle evaluation of shale gas drilling suggests that shale gas has a larger GHG footprint than coal and that this larger footprint “undercuts the logic of its use as a bridging fuel over the coming decades”. We argue here that their analysis is seriously flawed in that they significantly overestimate the fugitive emissions associated with unconventional gas extraction, undervalue the contribution of “green technologies” to reducing those emissions to a level approaching that of conventional gas, base their comparison between gas and coal on heat rather than electricity generation (almost the sole use of coal), and assume a time interval over which to compute the relative climate impact of gas compared to coal that does not capture the contrast between the long residence time of CO₂ and the short residence time of methane in the atmosphere. High leakage rates, a short methane GWP, and comparison in terms of heat content are the inappropriate bases upon which Howarth et al. ground their claim that gas could be twice as bad as coal in its greenhouse impact. Using more reasonable leakage rates and bases of comparison, shale gas has a GHG footprint that is half and perhaps a third that of coal.” Lawrence M. Cathles, Larry Brown, Milton Taam and Andrew Hunter, Climatic Change, DOI: 10.1007/s10584-011-0333-0. [Full text]

Methane and the greenhouse-gas footprint of natural gas from shale formations – Howarth et al. (2011) “We evaluate the greenhouse gas footprint of natural gas obtained by high-volume hydraulic fracturing from shale formations, focusing on methane emissions. Natural gas is composed largely of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the life-time of a well. These methane emissions are at least 30% more than and perhaps more than twice as great as those from conventional gas. The higher emissions from shale gas occur at the time wells are hydraulically fractured—as methane escapes from flow-back return fluids—and during drill out following the fracturing. Methane is a powerful greenhouse gas, with a global warming potential that is far greater than that of carbon dioxide, particularly over the time horizon of the first few decades following emission. Methane contributes substantially to the greenhouse gas footprint of shale gas on shorter time scales, dominating it on a 20-year time horizon. The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years. Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.” Robert W. Howarth, Renee Santoro and Anthony Ingraffea, Climatic Change, Volume 106, Number 4, 679-690, DOI: 10.1007/s10584-011-0061-5. [Full text]

Future development of the upstream greenhouse gas emissions from natural gas industry, focussing on Russian gas fields and export pipelines – Lechtenböhmer & Dienst (2010) “Natural gas makes an increasing contribution to the European Union’s energy supply. Due to its efficiency and low level of combustion emissions this reduces greenhouse gas emissions compared to the use of other fossil fuels. However, being itself a potent greenhouse gas, a high level of direct losses of natural gas in its process chain could neutralise these advantages. Which effect will finally prevail depends on future economical as well as technical developments. Based on two different scenarios of the main influencing factors we can conclude that over the next two decades CH₄ emissions from the natural gas supply chain can be significantly reduced, in spite of unfavourable developments of the supply structures. This, however, needs a substantial, but economically attractive investment into new technology, particularly in Russia.” S. Lechtenböhmer, C. Dienst, Journal of Integrative Environmental Sciences, Volume 7, Issue S1, 2010, Pages 39 – 48, DOI: 10.1080/19438151003774463.

Study on Methane Emission Reduction Potential in China’s Oil and Natural Gas Industry – Liu et al. (2008) A review report of China’s situation with natural gas methane emissions. Junrong Liu and Jun Yao, Michael Gallaher and Jeff Coburn, Roger Fernandez, RTI Project Number 0208702.027, Prepared for U.S. EPA, April 2008. [Full text]

Tapping the leakages: Methane losses, mitigation options and policy issues for Russian long distance gas transmission pipelines – Lechtenböhmer et al. (2007) “The Russian natural gas industry is the world’s largest producer and transporter of natural gas. This paper aims to characterize the methane emissions from Russian natural gas transmission operations, to explain projects to reduce these emissions, and to characterize the role of emissions reduction within the context of current GHG policy. It draws on the most recent independent measurements at all parts of the Russian long distance transport system made by the Wuppertal Institute in 2003 and combines these results with the findings from the US Natural Gas STAR Program on GHG mitigation options and economics. With this background the paper concludes that the methane emissions from the Russian natural gas long distance network are approximately 0.6% of the natural gas delivered. Mitigating these emissions can create new revenue streams for the operator in the form of reduced costs, increased gas throughput and sales, and earned carbon credits. Specific emissions sources that have cost-effective mitigation solutions are also opportunities for outside investment for the Joint Implementation Kyoto Protocol flexibility mechanism or other carbon markets.” Stefan Lechtenböhmer, Carmen Dienst, Manfred Fischedick, Thomas Hanke, Roger Fernandez, Don Robinson, Ravi Kantamaneni and Brian Gillis, International Journal of Greenhouse Gas Control, Volume 1, Issue 4, October 2007, Pages 387-395, doi:10.1016/S1750-5836(07)00089-8.

Greenhouse gases: Low methane leakage from gas pipelines – Lelieveld et al. (2005) “Using natural gas for fuel releases less carbon dioxide per unit of energy produced than burning oil or coal, but its production and transport are accompanied by emissions of methane, which is a much more potent greenhouse gas than carbon dioxide in the short term. This calls into question whether climate forcing could be reduced by switching from coal and oil to natural gas1. We have made measurements in Russia along the world’s largest gas-transport system and find that methane leakage is in the region of 1.4%, which is considerably less than expected and comparable to that from systems in the United States. Our calculations indicate that using natural gas in preference to other fossil fuels could be useful in the short term for mitigating climate change.” J. Lelieveld, S. Lechtenböhmer, S. S. Assonov, C. A. M. Brenninkmeijer, C. Dienst, M. Fischedick & T. Hanke, Nature 434, 841-842 (14 April 2005) | doi:10.1038/434841a.

Estimate of methane emissions from the U.S. natural gas industry – Kirchgessner et al. (1997) “Global methane emissions from the fossil fuel industries have been poorly quantified and, in many cases, emissions are not well-known even at the country level. Historically, methane emissions from the U.S. gas industry have been based on sparse data, incorrect assumptions, or both. As a result, the estimate of the contribution these emissions make to the global methane inventory could be inaccurate. For this reason the assertion that global warming could be reduced by replacing coal and oil fuels with natural gas could not be defended. A recently completed, multi year study conducted by the U.S. Environmental Protection Agency’s Office of Research and Development and the Gas Research Institute had the objective of determining methane emissions from the U.S. gas industry with an accuracy of t 0.5% of production. The study concluded that, in the 1992 base year, methane emissions from the industry were 314 t 105 Bscf or 6.04 t 2.01 Tg (all conversions to international units are made at 15.56 °C and 101.325 kPa)” David A. Kirchgessner, Robert A. Lott, R. Michael Cowgill, Matthew R. Harrison and Theresa M. Shires, Chemosphere, Volume 35, Issue 6, September 1997, Pages 1365-1390, doi:10.1016/S0045-6535(97)00236-1. [Full text]

Methane emission measurements in urban areas in Eastern Germany – Shorter et al. (1996) “We have investigated methane emissions from urban sources in the former East Germany using innovative measurement techniques including a mobile real-time methane instrument and tracer release experiments. Anthropogenic and biogenic sources were studied with the emphasis on methane emissions from gas system sources, including urban distribution facilities and a production plant. Methane fluxes from pressure regulating stations ranged from 0.006 to 24. l/min. Emissions from diffuse sources in urban areas were also measured with concentration maps and whole city flux experiments. The area fluxes of the two towns studied were 0.37 and 1.9 g/m2/s. The emissions from individual gas system stations and total town emissions of this study are comparable to results of similar sites examined in the United States.” Joanne H. Shorter, J. Barry Mcmanus, Charles E. Kolb, Eugene J. Allwine, Brian K. Lamb, Byard W. Mosher, Robert C. Harriss, Uwe Partchatka, Horst Fischer and Geoffrey W. Harris, et al., Journal of Atmospheric Chemistry, Volume 24, Number 2, 121-140, DOI: 10.1007/BF00162407. [Full text]

Indirect chemical effects of methane on climate warming – Lelieveld & Crutzen (1992) “METHANE concentrations in the atmosphere have increased from about 0.75 to 1.7 p.p.m.v. since pre-industrial times1,2. The current annual rate of increase of about 0.8% yr-1 (ref. 2) is due to increases in industrial and agricultural emissions. This increase in atmospheric methane concentrations not only influences the climate directly, but also indirectly through chemical reactions. Here we show that the climate effects of methane’s atmospheric chemistry have previously been overestimated, notably by the Inter-governmental Panel on Climate Change (IPCC)3, largely owing to neglect of the height dependence of certain atmospheric radiative processes. Using available estimates of fossil-fuel-related leaks of methane, our results show that switching from coal and oil to natural gas as an energy source would reduce climate warming. A significant fraction of methane emissions cannot, however, be accounted for by known sources; should leakages from gas production and distribution be underestimated for some countries, then it might be unwise to switch to using natural gas.” Jos Lelieveld & Paul J. Crutzen, Nature 355, 339 – 342 (23 January 1992); doi:10.1038/355339a0.

Gas leakage in United Kingdom – Wallis (1992) No abstract. M. K. Wallis, Nature 359, 355 (01 October 1992); doi:10.1038/359355a0.

Leaking gas in the greenhouse – Wallis (1991) “Greenhouse gas emissions by the United Kingdom could be significantly reduced by replacement of old and leaking gas mains. Such a programme could even be cost-effective for the utility concerned.” Max K. Wallis, Nature 354, 428 (12 December 1991); doi:10.1038/354428a0.

Leaky answer to greenhouse gas? – Wallis (1990) No abstract. Max K. Wallis, Nature 344, 25 – 26 (01 March 1990).

A study of leakage from the UK natural gas distribution system – Mitchell et al. (1990) “This paper studies leakage from the UK natural gas distribution system. British Gas maintains that the leakage rate is around 1% of supply. This paper estimates a Low, Medium and High Case leakage rate of 1.9%, 5.3% and 10.8% respectively. The authors are confident that the leakage rate is above 1.9% and consider it more likely that the leakage rate is between the Medium and High Case. This investigation has been very cautious in that only leakage from the low pressure, medium pressure and service pipelines has been calculated. No estimates of leakage from the broader supply system have been included because of lack of verifiable information. The implications of these leakage rates for energy policy are considered.” Catherine Mitchell, Jim Sweet and Tim Jackson, Energy Policy, Volume 18, Issue 9, November 1990, Pages 809-818, doi:10.1016/0301-4215(90)90060-H.

Methane leakage from natural gas – Okken (1990) “Carbon dioxide (CO₂) emissions from fossil fuels are a major cause of the global greenhouse effect. Fuel switching is one of the options to reduce emissions. However, CO₂ is not the only greenhouse gas. This paper addresses the question whether greenhouse effect mitigating strategies such as fuel switching would change if methane (CH₄) is taken into account, by calculating the global warming from current energy related CH₄ and CO (carbon monoxide) emissions as ‘CO₂ equivalents’.” P. A. Okken, Energy Policy, Volume 18, Issue 2, March 1990, Pages 202-204.

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