Harvard fracking study rings methane alarm bells in Australia by Peter Hennam, November 27, 2013, The Sydney Morning Herald
Australia’s coal seam gas industry has rejected a peer-reviewed report that suggests greenhouse gas emissions from drilling and fracking are 50 per cent worse than thought. The Harvard University-led study found methane leaks from the US fossil fuel industry were far higher than official estimates.
The Australian Petroleum Production and Exploration Association (APPEA) said it had no implications for the local industry, which claims coal seam gas is far cleaner than coal. The result, published in the US journal Proceedings of the National Academy of Sciences, contradicted a move by the US Environmental Protection Agency to cut its estimates of methane emissions from fossil fuel extraction and processing by 25 per cent to 30 per cent for 1990-2011. ”We find that [methane] data from across North America instead indicates the need for a much larger adjustment of the opposite sign,” the report said. … APPEA chief technical officer Rick Wilkinson said the new results ”add to a growing body of data”. He said the results compared with ”conflicting work” from the University of Texas, published in the same journal in August, that found measurements of 190 onshore natural gas sites in the US showing methane emissions at completed wells were lower than estimated. Estimates of emissions from Australia’s rapidly expanding coal seam gas industry remain limited.
A 2012 study by researchers at the Southern Cross University found significant amounts of methane appeared to be leaking from the country’s largest coal-seam field, near Condamine on Queensland’s Western Downs. Testing inside the Tara gasfield showed some greenhouse gas levels were three times higher than nearby districts.
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The latest US study estimated emissions in 2007-08, using measurements on the ground, in telecommunications towers and from aircraft. The study’s authors are examining more recent data to take into account a boom in oil and gas drilling in the US in recent years. [Emphasis added]
Bridge Out: Bombshell Study Finds Methane Emissions From Natural Gas Production Far Higher Than EPA Estimates by Joe Romm, Climate Progress, November 26, 2013, Resilience.org
Fifteen scientists from some of the leading institutions in the world including Harvard, NOAA and Lawrence Berkeley National Lab have published a seminal study, “Anthropogenic emissions of methane in the United States.” Crucially, it is based on “comprehensive atmospheric methane observations, extensive spatial datasets, and a high-resolution atmospheric transport model,” rather than the industry-provided numbers EPA uses.
Indeed, the Proceedings of the National Academy of Sciences study by Scot Miller et al takes the unusual step of explicitly criticizing the EPA:
- The US EPA recently decreased its CH4 emission factors for fossil fuel extraction and processing by 25–30% (for 1990–2011), but we find that CH4 data from across North America instead indicate the need for a larger adjustment of the opposite sign.
D’oh!
How much larger? The study found greenhouse gas emissions from “fossil fuel extraction and processing (i.e., oil and/or natural gas) are likely a factor of two or greater than cited in existing studies.” In particular, they concluded, “regional methane emissions due to fossil fuel extraction and processing could be 4.9 ± 2.6 times larger than in EDGAR, the most comprehensive global methane inventory.”
This suggests the methane leakage rate from natural gas production, which EPA recently decreased to about 1.5%, is in fact 3% or higher.
This broad-based look at methane emissions confirms the findings of 3 recent leakage studies covering very different regions of the country:
- NOAA researchers found in 2012 that natural-gas producers in the Denver area “are losing about 4% of their gas to the atmosphere not including additional losses in the pipeline and distribution system.”
- A 2013 study by NOAA found leaks from oil and gas exploration and extraction in the L.A. basin representing “about 17% of the natural gas produced in the region, similar to the leak rate estimated by the California Air Resources Board using other methods.” Almost all the gas produced in the basin is “ associated” with oil production (rather than, say, fracked). Associated gas is still about a fifth of total U.S. gas production.
- Another 2013 study from 19 researchers led by NOAA concluded “measurements show that on one February day in the Uinta Basin, the natural gas field leaked 6 to 12 percent of the methane produced, on average, on February days.” The Uinta Basin is of special interest because it “produces about 1 percent of total U.S. natural gas” and fracking has increased there over the past decade.
The comprehensive nature of this new study strongly suggests these earlier findings were not anomalies, as some have suggested. Indeed, all of these findings taken together vindicate the concerns of high leakage rates raised by Cornell professors Howarth, Santoro and Ingraffea, which I reported on back in 2011. I asked Ingraffea to comment on the new study. He wrote:
- The results presented by Miller and his team are another serious challenge to an “all of the above” energy policy that relies on negotiated estimates of methane emissions, rather than actual and representative emission measurements, while at the same time claiming serious concern about climate change. A growing series of regional, top-down measurements by this team and others, now on a national scale, is proving to be a more rational approach to accounting for the highly skewed distribution of methane emission sources.
- He added, “That methane bridge is starting to crack.”
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Yes, it’s true a recent study finds the best-fracked wells have low methane leak rates but that study ignored the super-emitters that are responsible for the bulk of the fugitive emissions. … Finally, natural gas makes little sense as a short-term sustainability play, since we know that each fracked well consumes staggering amounts of water, much of which is rendered permanently unfit for human use and reinjected into the ground where it can taint even more ground water in the coming decades. [Emphasis added]
High US methane emissions blamed on leaks by New Scientist, November 25, 2013
Emissions of methane…are 1.5 to 1.7 times higher in the US than current estimates. … To work out how much methane the US was emitting, Scot Miller of Harvard University and colleagues took a “top-down” approach – measuring how much methane was in the atmosphere and then deducing its source. They did this by using data from research flights that monitor the chemical make-up of the air, as well as taking daily readings of methane concentrations from the tops of 10 telecommunication towers across the country. “If you are measuring methane at the top of these towers you are really seeing an amassed signal from across a broad region,” says Miller. “You can really get a good sense of emissions nationwide.”
Gas, gas everywhere
The team made nearly 13,000 measurements between 2007 and 2008. They then plugged the data into atmospheric models that factor in things like wind speed and direction, to figure out where the emissions came from. … Emissions in the south central US, which includes Texas, Oklahoma and Kansas, were 2.7 times higher than recorded in existing emissions inventories. The higher methane levels correlated with elevated concentrations of propane, a gas that is only emitted during fossil fuel extraction and refining. Methane emissions from the region’s fossil fuel production alone were nearly five times higher than prior estimates. … According to the US Environmental Protection Agency, the US’s greenhouse gas emissions have fallen over the last few years. …
Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1314392110
[Refer also to:
Radon gas leaks in coalbed methane fields in Australia spark call for probe