On That Methane Bomb Thing
November 26, 2013
I’m on my way to take a dog to the vet, and, well, I need a stool sample. Not mine, his. Anyway, this is not a methane joke, just means, I’m in a rush.
Important: Everyone should know that the Guy MacPherson-imminent-global-doom scenarios are not real, and not helpful.
You should know that the scientists I find most credible and thoughtful are somewhat pissed at the methane-hair-on-fire crowd for overstating what is a real problem.
Methane is a problem, and as these recent studies show, one that is being better quantified and studied now.
This has implications for livestock production, the fracking industry, and dreams of harvesting methane clathrates for energy production.
Emissions of the greenhouse gas methane due to human activity were roughly 1.5 times greater in the United States in the middle of the last decade than prevailing estimates, according to a new analysis by 15 climate scientists published Monday in The Proceedings of the National Academy of Sciences.
The analysis also said that methane discharges in Texas and Oklahoma, where oil and gas production was concentrated at the time, were 2.7 times greater than conventional estimates. Emissions from oil and gas activity alone could be five times greater than the prevailing estimate, the report said.
The study relies on nearly 12,700 measurements of atmospheric methane in 2007 and 2008. Its conclusions are sharply at odds with the two most comprehensive estimates of methane emissions, by the Environmental Protection Agency and an alliance of the Netherlands and the European Commission.
The E.P.A. has stated that all emissions of methane, from both man-made and natural sources, have been slowly but steadily declining since the mid-1990s. In April, the agency reduced its estimate of methane discharges from 1990 through 2010 by 8 to 12 percent, largely citing sharp decreases in discharges from gas production and transmission, landfills and coal mines.
The new analysis calls that reduction into question, saying that two sources of methane emissions in particular — from oil and gas production and from cattle and other livestock — appear to have been markedly larger than the E.P.A. estimated during 2007 and 2008.
One of the study’s principal authors, Scot M. Miller of Harvard University’s department of earth and planetary sciences, said its higher estimates underscore methane’s significant contribution to rising temperatures.
“These are pretty substantial numbers we’re dealing with, and an important part of greenhouse gas emissions,” he said on Monday. “Our study shows that there could be large greenhouse gas emissions in places in the country where we may not necessarily have accounted for them.”
The Arctic methane time bomb is bigger than scientists once thought and primed to blow, according to a study published today (Nov. 24) in the journal Nature Geoscience.
About 17 teragrams of methane, a potent greenhouse gas, escapes each year from a broad, shallow underwater platform called the East Siberian Arctic Shelf, said Natalia Shakova, lead study author and a biogeochemist at the University of Alaska, Fairbanks. A teragram is equal to about 1.1 million tons; the world emits about 500 million tons of methane every year from manmade and naturalsources. The new measurement more than doubles the team’s earlier estimate of Siberian methane release, published in 2010 in the journal Science.
“We believe that release of methane from the Arctic, in particular, from the East Siberian Arctic Shelf, could impact the entire globe, not just the Arctic alone,” Shakova told LiveScience. “The picture that we are trying to understand is what is the actual contribution of the [shelf] to the global methane budget and how it will change over time.”
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.”
We have seen a number of cracks this year in the methane bridge — bringing it to the point of collapse. The Intergovernmental Panel on Climate Change (IPCC) reported recently that methane is a far more potent a greenhouse gas than we had previously realized, some 34 times stronger a heat-trapping gas than CO2 over a 100-year time scale — and 86 times more potent over a 20-year time frame.
With methane having both a higher leakage rate and higher global warming potential than previously thought, the notion of methane as a bridge fuel is falling apart.
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.
And remember, for natural gas to be a bridge fuel to a carbon-free future (rather than a detour around it), gas must replace coal only, rather than replacing some combination of coal, renewables, nuclear power, and energy efficiency — which is obviously what will happen in the real world absent a price on carbon pollution. The most comprehensive modeling to date, by fourteen teams from different organizations, found that abundant and cheap natural gas has little net impact on U.S. CO2 growth (especially post-2020) compared to the case of low shale gas penetration precisely because it displaces carbon-free energy. Globally, the International Energy Agency finds a dash to gas would destroy a livable climate.
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. That’s particularly worrisome considering that fossil fuels destroy the climate and accelerate drought and water shortages.
With this most recent study, our understanding of the limitations of natural gas is now fairly complete. Natural gas is not a bridge to a carbon-free or climate-safe future. In fact, absent both a serious price for carbon and very strong, enforceable national regulations on leakage, natural gas is a gangplank.
The current studies do not address the methane-permafrost connection, which is the topic of the video below: