Natural gas as a ‘bridge fuel’?

I have mentioned methane before in the context of agriculture (specifically the meat industry) and in terms of the so-called “dash to gas” in Europe.

More broadly, the desirability or undesirability of gas is a major issue in environmental politics. On the basis that electricity produced using gas produces fewer emissions per kilowatt-hour than electricity from coal (or that natural gas vehicles pollute less per kilometre than gasoline or diesel ones), some have argued that more widespread use of natural gas can be part of a transition to a low-carbon future, with some identifying it specifically as a “bridge fuel”.

The case against gas is multi-faceted. First, there is an argument about fossil fuel dependence. Gas may be less polluting per unit of output than other fossil fuels, but building new infrastructure to extract, transport, and burn gas arguably perpetuates fossil fuel dependence. In part, this could be by crowding out investment in options which are better from a climate change perspective including renewables and, possibly, nuclear. A second major argument is that natural gas, which is primarily composed of methane, is a powerful greenhouse gas itself. One estimate recently cited in The Economist is that 2-2.5% of all the methane produced in America leaks into the atmosphere (“fugitive emissions” – “much higher, and that would endanger the argument that natural gas is over all time periods cleaner than coal”. A third argument centres on how most new gas production in North America comes from hydraulic fracturing (fracking), which in turn contaminates ground water and causes health and environmental problems. On this basis, numerous environmental groups have called gas “a bridge to nowhere”. A paper by Robert Howarth concludes:

Using these new, best available data and a 20-year time period for comparing the warming potential of methane to carbon dioxide, the conclusion stands that both shale gas and conventional natural gas have a larger GHG than do coal or oil, for any possible use of natural gas and particularly for the primary uses of residential and commercial heating. The 20-year time period is appropriate because of the urgent need to reduce methane emissions over the coming 15–35 years.

A last argument might be that since the fossil fuel industry is implacably opposed to the kind of government action which would keep temperatures to less than 2 ˚C or 1.5 ˚C of warming, the profits they derive from gas maintains financial and political strength which will continue to make climate action impossible.

Perhaps the most plausible argument in favour of gas doesn’t concern rich states like Canada and the U.S. but rapidly developing states like India, China, and Brazil which continue to deploy new coal-fired generation. If the choice really is between coal and gas, and methane leaks can be controlled, then gas may be an improvement in some situations. Rich states that are looking to build energy systems which can be counted on indefinitely, however, need to be working to move beyond fossil fuels entirely, reducing the policy-blocking power of the fossil fuel industry and avoiding the imposition of new forms of social injury through fracking.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here.

15 thoughts on “Natural gas as a ‘bridge fuel’?”

  1. B.C.’s climate targets will be impossible to reach if LNG Canada project goes ahead, critics say

    Environmentalists are warning that it will be impossible for British Columbia to reach its climate targets if a Shell-led liquefied natural gas project forges ahead along the northern coast.

    Attaining B.C.’s target of the equivalent of 13 million tonnes of carbon dioxide in 2050 isn’t credible, given that GHG emissions from LNG Canada alone could be 8.6 million tonnes a year, Ms. Askew said. That estimate for the project is based on total emissions that include producers drilling northeast B.C. natural gas wells and LNG Canada operating the export terminal in Kitimat.

  2. And the above is ignoring the main climate-relevant impact of this LNG project, which arises when the gas is burned. New gas infrastructure is as unacceptable as coal and oil if we are going to avoid catastrophic climate change.

  3. A blowout turned an Ohio natural gas well into a methane ‘super-emitter’

    Using satellite data, scientists have confirmed that a 2018 blowout turned a natural gas well in eastern Ohio into a “super-emitter,” leaking more methane in 20 days than all but three European nations emit over an entire year.

    Methane, a potent greenhouse gas, escaped from the well at a rate twice as fast as the Aliso Canyon leak in California in 2015, a four-month incident that became the nation’s largest accidental release of methane, according to the group of 15 scientists.

    The blowout in rural Ohio took place Feb. 15, 2018, at a well owned by XTO Energy, a subsidiary of ExxonMobil, and it took 20 days to get it under control. The well had been “fracked,” or hydraulically fractured, before the blowout took place. Workers had been completing the well, according to news reports at the time, a job made more difficult by heavy rains and a crane that collapsed when the explosion took place.

  4. The uncertain role of natural gas in the transition to clean energy

    MIT study finds that challenges in measuring and mitigating leakage of methane, a powerful greenhouse gas, prove pivotal

    The study shows that in order for natural gas to be a major component of the nation’s effort to meet greenhouse gas reduction targets over the coming decade, present methods of controlling methane leakage would have to improve by anywhere from 30 to 90 percent. Given current difficulties in monitoring methane, achieving those levels of reduction may be a challenge. Methane is a valuable commodity, and therefore companies producing, storing, and distributing it already have some incentive to minimize its losses. However, despite this, even intentional natural gas venting and flaring (emitting carbon dioxide) continues.

  5. Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era1. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate2,3. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century4,5. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year)2,3 between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year6,7. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago8, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions9,10.

    https://www.nature.com/articles/s41586-020-1991-8

  6. “Currently, natural gas is displacing coal in the United States—and, theoretically, this fossil fuel may have lower carbon emissions. It is also cleaner from a conventional air pollution perspective. Given the boom in hydraulic fracturing, the cost of natural gas has declined precipitously in the United States since 2008.32 Still, there are significant concerns with increasing natural gas in the electricity sector. Leakage, wherein methane escapes into the atmosphere before being combusted, is problematic because methane is an extremely potent greenhouse gas. If natural gas leaks at a rate of 3.2% or higher, scientists estimate that this fuel source is worse than coal from a climate perspective (Alvarez et al. 2012).33 Accurate leakage rates are very hard to estimate, but it is likely that the official Environmental Protection Agency estimates are too low and that leakage may be around 2.3% (Alvarez et al. 2018). While many see natural gas as a bridge fuel, given high leakage rates, it may prove to be a bridge to nowhere.”

    Stokes, Leah Cardamore. Short Circuiting Policy: Interest Groups and the Battle Over Clean Energy and Climate Policy in the American States. Oxford University Press, 2020. p. 22

    32. “Natural Gas: Natural Gas Prices,” US EIA, June 28, 2019.

    33. These estimates are in part a function of assumptions about methane versus carbon dioxide global warming potentials (Edwards & Trancik 2014). (p. 264)

    Alvarez, R. A., Pacala, S. W., Winebrake, J. J., Chameides, W. L., & Hamburg, S. P. (2012) “Greater Focus Needed on Methane Leakage from Natural Gas Infrastructure,” Proceedings of the National Academy of Sciences, 109/17: 6435–40. DOI: 10.1073/pnas.1202407109

    Alvarez, R. A., Zavala-Araiza, D., Lyon, D. R., Allen, D. T., Barkley, Z. R., Brandt, A. R., Davis, K. J., et al. (2018) “Assessment of Methane Emissions from the U.S. Oil and Gas Supply Chain,” Science, 361/6398: 186–8. DOI: 10.1126/science.aar7204

    Edwards, M. R., & Trancik, J. E. (2014). “Climate Impacts of Energy Technologies Depend on Emissions Timing,” Nature Climate Change, 4: 347–52. DOI: 10.1038/NCLIMATE2204

  7. “Even today, this dynamic in market-based electricity systems is generally underappreciated. Take, for instance, how natural gas is often viewed as the complement to renewable energy technologies because it can theoretically adapt flexibly to intermittent sources. While this may be true from a technical perspective, it is not the case politically or economically. As one former Republican staffer put it, ‘There’s always been talk about how natural gas and renewables are friends … but natural gas wants to run everything: vehicles and electricity and manufacturing and everything.’38 More broadly, fossil fuel companies no doubt fear a societal movement away from dependence on their product (Leonard 2019). They do not want to support a clean energy transition that would render their business model worthless.”

    Stokes, Leah Cardamore. Short Circuiting Policy: Interest Groups and the Battle Over Clean Energy and Climate Policy in the American States. Oxford University Press, 2020. p. 137

    38. Interview 54, lobbyist for renewables industry, February 14, 2014, Texas.

    Leonard, C. (2019) Kochland: The Secret History of Koch Industries and Corporate Power in America. New York: Simon & Schuster.

  8. Natural gas – friend or foe of the environment? Evaluating the framing contest over natural gas through a public opinion survey in the Pacific Northwest

    A fierce debate is raging about the role of natural gas in North America’s energy mix. Once viewed as a bridge fuel for renewable energy, it is increasingly being characterized as hindering the energy transition. We explore public opinions about natural gas, its use and export, among residents in Oregon, Washington and British Columbia. While many of our respondents supported the continued use of natural gas in electricity generation and viewed it as relatively environmentally friendly, they did not feel that the benefits of fracking (increasingly the main source of natural gas production) outweigh its risks. Males, political conservatives, those who prioritized the economy over the environment, and those who didn’t subscribe to anthropogenic global warming felt more favorably toward natural gas. Furthermore, those who saw gas as more environmentally friendly were more supportive of gas usage and export, while those with pro-environmental views were less likely to support it.

  9. Regulations in Canada are mostly based on surveys that use optical gas imaging (OGI) cameras at oil and gas sites to detect sources of methane leaks. But the study suggests there is a “stark difference” between what the OGI surveys find and what the new airplane-mounted technology can see, and “policy and regulations relying on OGI surveys alone may risk missing a significant portion of emissions.”

    More than half of methane emissions were attributed to storage tanks, reciprocating compressors and unlit flares, according to the study. Storage tanks were found to be a particularly concerning source of emissions, since they alone accounted for a quarter of methane emissions at oil and gas sites.

    https://www.cbc.ca/news/science/methane-regulations-oil-gas-climate-greenhouse-1.6102806

  10. As the energy transition gathers momentum, no fuel’s future is hazier than that of the least grubby hydrocarbon.

    Proponents see gas as the “bridge fuel” to a greener world. They include the five largest international oil firms: ExxonMobil, Chevron, Royal Dutch Shell, Total and bp. These supermajors saw gas rise from 39% of their combined hydrocarbon output in 2007 to 44% in 2019 (see chart 1). That year producers approved a record level of liquefied natural gas (lng) capacity. Those projects will come online in a few years. Shell, which in 2016 paid $53bn for bg, a British gas group, now says its oil production peaked in 2019, but that it will expand its gas business with annual investments of about $4bn. Total expects its crude output to sink over the next decade, but for gas to rise from 40% to 50% of sales. In February Qatar Petroleum, a state-owned giant, said it would begin the largest lng project in history.

    Yet debate is intensifying over whether gas will be a bridge or a dead end. Mr Biden and his counterparts elsewhere appear to be serious about achieving net-zero emissions by 2050. That would require accelerating the phase-out of all fossil fuels, gas included, unless paired with technology to capture and store emissions. Inexpensive wind and solar power already threaten gas-fired electricity, particularly in America and Europe. Even as demand looks uncertain, cheap gas from state-owned firms such as Qatar’s will add to global supply. Some companies’ bets will go bad.

    “To put it mildly,” Werner Hoyer, president of the European Investment Bank, declared in January, “gas is over.” John Kerry, Mr Biden’s climate envoy, warned in January that natural-gas assets risked becoming stranded. The International Energy Agency, an intergovernmental group, reckons that demand growth will slow to about 1.2% a year until 2040, from an average of 2.2% in 2010-19. If governments move more aggressively to restrain temperatures, demand could be lower in 2040 than it was in 2019

    Already, about two-thirds of the world’s population lives in places where power from new wind and solar farms is cheaper than from new gas plants, according to Bloombergnef, a data provider.

    https://www.economist.com/business/2021/04/22/oil-supermajors-mega-bet-on-natural-gas

  11. In a paper published this March researchers from Stanford with access to that data estimated that the amount of methane being lost to the atmosphere was equivalent to just over 9% of the methane being produced. Roughly one tonne of methane was being lost for every nine tonnes that were not.

    That is not just a waste. It is an assault on the climate. Methane absorbs some infra-red wavelengths very nicely. That makes the leaks spottable by Kairos’s cameras; it also makes it a very powerful greenhouse gas. Over a 20-year period, a tonne of methane released into the atmosphere provides as much greenhouse warming as about 80 tonnes of CO2. Burning nine tonnes of methane releases only about 25 tonnes of CO2. If the companies in the Permian do lose one tonne of methane for every nine that they capture, those leaks warm the climate three times more, over the next 20 years, than burning the gas the companies actually sell.

    https://www.economist.com/technology-quarterly/2022/06/23/new-technology-can-help-monitor-manage-and-minimise-methane-leaks

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