Scott: Is natural gas a bridge or barrier to a sustainable future?

Editor’s note: This op-ed is by Bill Scott, a Burlington-based researcher and developer and a volunteer for 350Vermont for which he wrote this piece.

It’s time to rethink our growing reliance on natural gas. Over the past several years research on methane emissions in gas fields and pipelines has raised serious doubts about just how clean natural gas really is. Other studies have shown that the world’s heavy reliance on natural gas is actually leading us down the path to climate disaster rather than across that oft-cited bridge to a sustainable future. Yet these studies have been virtually unnoticed, or possibly just ignored, by President Obama and other elected officials, for whom natural gas provides a convenient cover to continue on with business (mostly) as usual.

Natural gas has long been touted as the “clean” fossil fuel, the cheap and readily available American alternative that can lead us to energy independence while combating climate change and building that bridge to a sustainable energy future. “Powered by clean natural gas” is written reassuringly on municipal buses and utility vehicles around the country. But is it really clean? Should we really be reassured?

For most of us, the first black mark against natural gas came when we realized that our vast new supplies of gas were in shale.[i]  Shale gas is extracted in tens of thousands of fracking sites that endanger drinking water, air quality and human health. This fracking is done by poorly regulated energy companies with the power to industrialize communities and rural areas seemingly overnight.

Now new research is challenging proponents’ claims about the low greenhouse gas (GHG) emissions of natural gas by looking at the “full lifecycle” emissions of this fossil fuel, which include production and transport, not just combustion at the final stage of use. These studies have found that rates of methane (CH4) emissions in the gas fields and pipelines may be far greater than previously believed. In fact, they are so significant that they offset much, if not all, of the savings in CO2 emissions when the gas is burned. A more detailed discussion about natural gas and its GHG emissions is offered below.

Natural gas in its raw state is mostly methane and the gas supplied to customers is close to 100 percent methane.[ii] When burned, methane produces CO2 but less than other fossil fuels. How much less varies significantly depending on what fuel it’s compared to and with differences in technology. When compared to coal in electric generation power plants, natural gas produces about 50 percent of the amount of CO2.[iii] [iv]  However, when compared to heating oil, the combustion emissions rise to about 73 percent.[v] So while natural gas burns cleaner than other fossil fuels, it still emits considerable amounts of CO2. In addition, the emission advantages of natural gas are far lower when compared to fuels other than coal. This is especially important as only 36 percent of natural gas burned in the U.S. is used for electric power generation.[vi]

Perhaps most important, methane is a powerful GHG, 72 times more powerful than CO2 over a 20-year period and 25 times more powerful over 100 years.[vii] Since the next 10 to 20 years is the time frame that is crucial if we are to avoid climate tipping points, it is this shorter period that should especially concern us. To determine just how clean this fuel is – or is not – we have to look at how much methane leaks during production and transportation as well as how much CO2 it emits during combustion.

New studies are finding methane emissions in gas fields and pipelines to be far greater than previously thought, so great that they erode or in some cases even completely offset natural gas’s lower CO2 emission upon combustion. For example, scientists with the National Oceanic and Atmospheric Administration (NOAA), taking direct measurements from ground monitoring equipment, found that 4 percent of the methane production at a Colorado gas field was leaking into the atmosphere.[viii] A NOAA team, using aircraft to supplement ground monitoring equipment, subsequently found 9 percent leaking at production sites in Utah.[ix] These follow earlier studies estimating that 3.6 percent to 7.9 percent of methane from shale gas leaks during production and transportation.[x]

Looking at local infrastructure, a study in Manhattan estimated that about 2.9 percent of the 300 billion cubic feet of natural gas annually supplied by the utility company Con Edison was leaking into the air. (Con Ed has 4,320 total miles of gas pipelines).[xi] A study in Boston also found extensive leaking, with extreme peaking in some locations.[xii] Replacing the aging gas infrastructure in our cities to avoid such leaking would be costly, disruptive, and time-consuming.

These studies contrast with the historically much lower estimates of leaking by the EPA (2.4 percent) and industry.[xiii] EPA national estimates, however, are not based on extensive direct measurement, monitoring and reporting of hard data but are calculated indirectly by applying estimated emission factors to data on the total amounts of gas produced.[xiv]  And, rather than responding to the implications of the new studies, EPA’s draft 2013 GHG Inventory would instead reduce their estimate further based on self-reported industry data on emissions and estimated emissions reductions from the introduction of new green technologies.[xv]

Just what is the rate of methane leakage from our natural gas production and supply systems? The astonishing answer is this: we do not know. As the Washington Post recently put it, “We have no idea how much methane is actually seeping out of our natural gas wells and pipelines.”[xvi] There is no reliable answer, for the simple reason that we lack empirical data over a representative sample of the U.S. natural gas industry. The relatively few empirical studies employing direct measurements look at limited locations over short moments in time. This serious data problem was recently confirmed in an audit by the Inspector General of the EPA that cited the agency for lacking “directly-measured air emission data” and “a comprehensive strategy for improving air emissions data for the oil and gas industry.[xvii] The Inspector General also found that “about half” of the EPA emissions factors were based on insufficient or low quality data.

For natural gas to contribute to solving the climate problem it must produce lower emissions over the next 10 to 20 years than fuels it displaces, and those reduced emissions must be substantial and fast enough to stabilize the climate at acceptable levels.

To rely so heavily on the idea that gas burns cleaner than coal is to set an absurdly low and potentially disastrous measure of success. And, when we take methane leakage into account, we don’t even know with a high degree of confidence that natural gas in fact is cleaner than coal. A recent study by the Environmental Defense Fund (EDF) finds that conversion from coal power plants to natural gas has no net climate benefit over a 20-year period if methane leakage rates exceed about 3.5 percent, a rate below that found in many of the recent studies.[xviii] Moreover, the threshold for a net climate benefit is much higher for natural gas replacement of other fuels. EDF found, for example, that for natural gas replacement of diesel as a fuel for heavy vehicles there was no benefit over 20 years unless the leakage rate was 1 percent or lower.

There is also the real concern that increased use of currently cheap natural gas is resulting in reduced efforts at energy conservation and deployment of truly clean technologies such as solar, wind, and geothermal. The promotion of natural gas is potentially blocking approaches with almost no emissions and delaying the de-carbonization of the economy.[xix]

Even before accounting for the possibility of higher methane leakage, we are falling far short of the GHG emission reductions we need to stabilize the climate. No current forecasts show the world even close to a trajectory to achieve the internationally agreed upon 2 degrees C target. The International Energy Agency (IEA), for example, finds that the world’s “Golden Age of Gas” is leading us to 3.5 degrees C (6.3 degrees F) temperature increases and runaway climate change.[xx] They state that “increased use (of gas) in itself is far from sufficient to reach the 2 degrees C goal.” An MIT forecast estimates median warming of 5.1 degrees C (9.2 degrees F) before 2100.[xxi] Price Waterhouse Coopers recently concluded that achievement of even a 4 degrees C target will require a near quadrupling of the world’s current rate of de-carbonization.[xxii]

Engineering technologies exist to significantly reduce the rates of methane leakage in gas production and transmission.[xxiii] Some of these technologies are currently used by a portion of the gas industry and new “green” technologies have been recently mandated by the EPA to control emissions of volatile organic compounds (VOC).[xxiv] (Reduced methane emissions are a by-product of controlling emissions of VOC but, strikingly, EPA does not currently mandate controls on methane emissions.)

There are currently over 500,000 gas well sites in the U.S. and over 300,000 miles of pipeline; many of these are operated by small companies.[xxv] Federal and state governments have a very poor track record in monitoring and regulating the oil and gas industry. Gas production has expanded and changed dramatically in recent years but there has been no concomitant regulatory response or appropriate allocation of resources at the federal or state levels. Even long-planned emission regulations, such as those for existing coal plants, are being delayed again and again. Loopholes in current law remain on the books and regulation in key gas production states is even weaker than at the federal level. Based on past performance, the prospects for effective and timely regulation and control of methane emissions appear dim. Voluntary industry compliance, especially given the highly decentralized nature of gas production and distribution, is likely to be uneven. If we’re not even reliably measuring methane emissions when we know they are critical to stabilizing our climate, how are we going to control them?

The heavy reliance on natural gas as part of an “all-of-the-above” energy strategy is not part of a comprehensive plan to reduce GHG emissions and stabilize global temperatures. Indeed, unlike countries such as Denmark, we do not even have a plan.[xxvi] Rather we appear to be driven by abundant new supplies of shale gas and a push for “energy independence” and profits coupled with political expediency. While touted as a replacement for coal in electric power generating plants, the use of natural gas is expanding rapidly throughout the economy, while regulations on power plant emissions that would accelerate this conversion continue to be delayed. This relentless expansion is occurring without data and analysis to confirm proponents’ claims that gas is a cleaner fuel, without an understanding of when gas is beneficial and when it is not. And it goes on without effective regulation to protect the public interest.

Our energy policy is a politically convenient roll of the dice, and, as former NASA climate scientist Jim Hansen has often described, the dice are loaded against the climate.[xxvii] Absent a price on carbon, an aggressive strategy to achieve energy conservation and strong incentives to deploy truly sustainable technologies, we are left with expanded oil and gas production and mega-projects like the Keystone pipeline. Based on the available evidence, our growing reliance on natural gas is a very dangerous bet for the climate and the future of humanity. We would do well to follow the precautionary principle that would place the burden of proof on the benefits of natural gas squarely on the gas industry and government and require preventive action to avoid construction of what the European Environment Agency describes as “pipelines of unstoppable consequences.”[xxviii] Failing to do so, we may find, as Vermonters have already experienced, that the waters have risen with no real bridge to a sustainable future.

NOTES

[i] U.S. Energy Information Agency, http://www.eia.gov/energy_in_brief/article/about_shale_gas.cfm

[ii]  Natural Gas Supply Association, http://naturalgas.org/overview/background.asp

[iii] See for example U.S. EPA, http://www.epa.gov/cleanenergy/energy-and-you/affect/natural-gas.html

[iv] Reduced CO2 emissions are primarily due to lower emission of natural gas (53.06) compared to coal used in the Electric Power Sector (95.52), US Energy Information Agency, Emission Factors, Table from Appendix to Form EIA-1605, www.eia.gov/oiaf/1605/emission_factors.html plus the greater operating efficiency of gas power plants compared to coal plants.

[v] U.S. Energy Information Agency, Emission Factors, Table from Appendix to Form EIA-1605, comparison of emission factor for Middle Distillate Fuels of 73.15 to Pipeline Natural Gas Weighted National Average of 53.06, www.eia.gov/oiaf/1605/emission_factors.html

[vi] U.S. EIA, Natural Gas Consumption by End Use, 2012, http://www.eia.gov/dnav/ng/ng_cons_sum_dcu_nus_a.htm

[vii] Report of the Intergovernmental Panel on Climate Change, Climate Change 2007, The Physical Science Basis, Table TS.2

[viii] Jeff Tollefson, Nature|News, http://www.nature.com/news/air-sampling-reveals-high-emissions-from-gas-field-1.9982, http://www.scientificamerican.com/article.cfm?id=leaking-greenhouse-gases-in-colorad

[ix] Jeff Tollefson, Nature|News, http://www.nature.com/news/methane-leaks-erode-green-credentials-of-natural-gas-1.12123

[x] Robert Howarth, Renee Santoro, Anthony Ingraffea, Methane and the greenhouse-gas footprint of natural gas from shale formations, Climate Change (2011), http://link.springer.com/content/pdf/10.1007%2Fs10584-011-0061-5.pdf

[xi] http://www.damascuscitizensforsustainability.org/2013/03/manhattan-natural-gas-pipeline-emissions-2/

[xii] http://green.blogs.nytimes.com/2012/11/20/methane-is-popping-up-all-over-boston/  

[xiii] EPA estimate cited in “Greater focus needed on methane leakage from natural gas infrastructure”, Proceedings of the National Academy of Sciences, http://www.pnas.org/content/109/17/6435.full.pdf+html?sid=962d5849-56f7-4efc-9c7c-08feb6d44a1a

[xiv] IHIS CERA, Mismeasuring Methane Estimating Greenhouse Gas Emissions from Upstream Development, November 26, 2012, Private Report; US EPA, Office of Inspector General, EPA Needs to Improve Air Emissions Data for Oil and Natural Gas Production Sector (2013), http://www.epa.gov/oig/reports/2013/20130220-13-P-0161.pdf

[xv] http://www.huffingtonpost.com/2013/04/28/epa-methane-report_n_3175130.html

[xvi] http://www.washingtonpost.com/blogs/wonkblog/wp/2013/04/04/methane-leaks-are-undermining-the-shale-gas-boom-heres-how-to-fix-it/

[xvii] U.S. EPA, Office of Inspector General, http://www.epa.gov/oig/reports/2013/20130220-13-P-0161.pdf

[xviii] Greater focus needed on methane leakage from natural gas infrastructure”, Proceedings of the National Academy of Sciences, http://www.pnas.org/content/109/17/6435.full.pdf+html?sid=6cf29d83-ee42-458f-a0f0-f8c614dd094e

[xix] Natural Gas Could ‘Muscle Out’ Renewables, MIT Technology Review, http://www.technologyreview.com/view/424220/natural-gas-could-muscle-out-renewables/

[xx] International Energy Agency, Are We Entering a Golden Age of Gas? (2011), http://www.worldenergyoutlook.org/media/weowebsite/2011/WEO2011_GoldenAgeofGasReport.pdf; International Agency Finds ‘Safe’ Gas Fracking Would Destroy a Livable Climate,

[xxi] Probabilistic Forecast of 21st Century Climate Based on Uncertainties in Emissions (without Policy) and Climate Parameters, MIT Joint Program on the Science and Policy of Global Climate Change, http://globalchange.mit.edu/files/document/MITJPSPGC_Rpt169.pdf

[xxii] PwC Low Carbon Economy Index 2012, Too Late for two degrees?, http://www.pwc.com/gx/en/sustainability/publications/low-carbon-economy-index/index.jhtml

[xxiii] World Resource Institute, Clearing the Air, Reducing Upstream Greenhouse Gas Emissions From U.S. Natural Gas Systems (2013), http://pdf.wri.org/clearing_the_air_full_text.pdf

[xxiv] http://www.epa.gov/airquality/oilandgas/pdfs/20130328fs.pdf

[xxv]  U.S. EIA, http://www.eia.gov/dnav/ng/ng_prod_wells_s1_a.htm, http://www.eia.gov/pub/oil_gas/natural_gas/analysis_publications/ngpipeline/index.html

[xxvi] http://www.ens.dk/en-US/policy/danish-climate-and-energy-policy/Sider/danish-climate-and-energy-policy.aspx , http://www.earth.columbia.edu/sitefiles/file/about/director/2009/SciAm_July_2009.pdf

[xxvii] James Hansen, Makiko Sato, Reto Ruedy, Perceptions of Climate Change, Proceedings of the National Academy of Sciences (2012), http://www.pnas.org/content/109/37/E2415.full.pdf+html?sid=722bdbab-b28c-44aa-a263-11429573f8ef

[xxviii] As quoted in Sandra Steingraber, Living Downstream, An Ecologist’s Personal Investigation of Cancer and the Environment, Da Capo Press, Second Edition, 2010, p. 282