Natural gas has garnered a lot of attention, but the research reveals it is anything but clean. To increase domestic energy production and reduce reliance on coal, there is a natural gas boom in the U.S. and elsewhere. However, reliance on natural gas is not a panacea to our energy woes. According to a February 2012 study published in Nature, extracting and producing natural gas releases enough methane into the atmosphere to negate any greenhouse gas advantages that its somewhat cleaner burning chemistry provides.
Approximately 85 percent of natural gas is composed of methane, which is 105 times worse than CO2 as a greenhouse gas (GHG). Based on EPA data, methane leaks at a rate of 3.3 percent and that number more than doubles (7.9 percent) when fracking is employed to extract natural gas. Extrapolating from this data, gas burning for electricity is much dirtier than coal burning in terms of GHG emissions.
Dr. Drew Shindell and colleagues (NASA’s Goddard Institute for Space Studies) have published a paper in the scientific journal Science (US), in which he said:
“We found that gas-aerosol interactions substantially alter the relative importance of the various emissions. In particular, methane emissions have a larger impact than that used in current carbon-trading schemes or in the Kyoto Protocol. Thus, assessments of multigas mitigation policies, as well as any separate efforts to mitigate warming from short-lived pollutants, should include gas-aerosol interactions.”
The Nature News part of the prestigious scientific journal Nature (UK) has summarized the key findings of Shindell and colleagues as follows:
“a range of computerized models to show that methane’s global warming potential is greater when combined with aerosols — atmospheric particles such as dust, sea salt, sulphates and black carbon. The International Panel on Climate Change (IPCC) and treaties such as the Kyoto Protocol assume methane to be, tonne-for-tonne, 25 times more potent than carbon dioxide at warming the planet. But the interaction with aerosols bumps up methane’s relative global warming potential (GWP) to about 33, though there is a lot of uncertainty around the exact figure.”
Dr. Shindell has summarized the findings by saying: “What happens is that as you put more methane into the atmosphere, it competes for oxidants such as hydroxyl with sulphur dioxide. More methane means less sulphate, which is reflective and thus has a cooling effect. Calculations of GWP [Global Warming Potential;] including these gas-aerosol linkages thus substantially increase the value for methane.”
Major systemic gas leakage from the hydraulic fracking of shale formations has led Professor Robert Howarth, Cornell University, Ithaca, New York, to conclude:
“The large GHG footprint of shale gas undercuts the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming. We do not intend that our study be used to justify the continued use of either oil or coal, but rather to demonstrate that substituting shale gas for these other fossil fuels may not have the desired effect of mitigating climate warming”.
The February 2012 study of air samples revealed high emission levels from gas fields. The study explains that methane leaks during production may offset any benefits of natural gas. In 2007, National Oceanic and Atmospheric Administration (NOAA) researchers noticed pollutants including methane, butane and propane, in air samples from a tower north of Denver, Colorado. They linked the pollutants to a nearby natural-gas field. Their investigation produced the first hard evidence that the cleanest-burning fossil fuel might not be better than coal when it comes to climate change.
In 2008, NOAA researchers and the University of Colorado, Boulder, estimated that natural-gas producers in an area known as the Denver-Julesburg Basin (where more than 20,000 oil and gas wells have been drilled during the past four decades) are losing about 4% of their gas to the atmosphere. Additional emissions come from the storage tanks and pipelines.
Natural gas emits about half as much carbon dioxide as coal per unit of energy when burned, but separate teams at Cornell University in Ithaca, New York, and at the US Environmental Protection Agency (EPA) concluded that methane emissions from shale gas are much larger than previously thought.
Robert Howarth, a Cornell researcher whose team raised concerns about methane emissions from shale-gas drilling in a pair of papers, said “I’m not looking for vindication here, but [the NOAA] numbers are coming in very close to ours, maybe a little higher.” Howarth said natural gas might still have an advantage over coal when burned to create electricity, because gas-fired power plants tend to be newer and far more efficient than older facilities that provide the bulk of the country’s coal-fired generation. But only 30% of US gas is used to produce electricity, with much of the rest being used for heating, for which there is no such advantage.
Natural gas is touted as a cost effective energy, but capturing and storing gases that are vented during the fracking process is feasible, but considered too costly to adopt. An EPA rule that is due out as early as April would promote such changes by regulating emissions from the gas fields.
A major 2011 study by Tom Wigley of the Center for Atmospheric Research (NCAR) concluded:
The most important result, however, in accord with the above authors, is that, unless leakage rates for new methane can be kept below 2%, substituting gas for coal is not an effective means for reducing the magnitude of future climate change.
As explained by Gabrielle Pétron, an atmospheric scientist at NOAA and at the University of Colorado in Boulder, “I think we seriously need to look at natural-gas operations on the national scale.” The findings surrounding natural gas has far reaching consequences, not the least of which is the emerging understanding that natural gas is not the bridge energy solution many had hoped for.
Howarth’s online version of his new 2012 paper concludes: We reiterate our conclusion from our April 2011 paper that shale gas is not a suitable bridge fuel for the 21st Century. Even without a high-leakage rate for shale gas, we know that Natural Gas Is A Bridge To Nowhere. The International Energy Agency, in its big June 2011 report on gas, said “Golden Age of Gas Scenario” Leads to More Than 6°F Warming and Out-of-Control Climate Change.
These studies demonstrate the urgency to radically reduce our fossil fuel consumption. Even with large and early cuts in emissions, the indications are that temperatures are likely to rise to around 2 °C above pre-industrial levels by the end of the century. Currently the world’s overall emissions are increasing at a rate of 1 percent every year.
We need to shift away from fossil fuels including natural gas. We need to rapidly adopt renewable forms of energy energy like wind, solar, geothermal, and tidal. We must rapidly move toward an economy based on renewable fuels. Studies by Mark Z. Jacobson and Mark A. Delucchi and Robert Howarth indicate that the U.S. and the world could rely 100% on such green energy sources within 20 years.
We need to expose the subterfuge of the fossil fuel industry, which falsely asserts that “gas is clean energy” or that “gas is cleaner energy” than coal burning. Natural gas does not reduce GHGs compared with coal and therefore it will not minimize the impacts of global warming. In fact, as revealed by a growing body of research, increased reliance on natural gas will actually hasten catastrophic climate change.
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