You may be entirely aware by now that the controversy over shale gas resources and their extraction by hydraulic fracturing heated up last week with the publication of an important paper in Climatic Change, a well-respected scientific journal. (Here is a great little video on what exactly the heck hydraulic fracturing is – aka hydrofracking or just plain fracking – and how it works.) The paper in question, “Methane and the greenhouse-gas footprint of natural gas from shale formations”, asserts that the full life cycle of natural gas from hydraulic fracturing through to combustion in a power plant or vehicle generates more greenhouse gas than does conventional oil, gas or coal. The lead author, Robert W. Howarth, is a leading ecologist and Cornell professor.
Why is this important? The assumption has been all along that natural gas, given the enormous reserves that are now recoverable because of fracking, and the fact that gas has just about half the carbon dioxide output of coal when burned for power, thus radically reducing the GHG footprint of the electric power industry if we transition in the near term from coal to gas, so that gas could and should serve as a “bridge fuel” to a decarbonized energy future as we bring more and more renewable energy on line. However, if the extraction process in the case of fracking is particularly prone to the escape of as much as 8% of the total volume being taken out of the shale, as the new paper maintains, then you lose all that lowered GHG advantage in the combustion to the extraction process, and more. Methane, the principal component of natural gas, has a global warming potential (GWP), over a hundred years, 25 times that of carbon dioxide. Methane has, according to recent research at NASA and elsewhere, a much greater overall climate impact than previously thought.
This could break the hearts of the environmentalists, like me, who have embraced natural gas for its potential, not only as a “cooler” fuel, but because it has enormous applicability not only in the power sector, but also for transportation – including to generate hydrogen for fuel cells – and as the principal feedstock for the hugely efficient cogenerating facilities that are popping up around the world.
No less an MSM behemoth than Time had shale gas as a cover story recently: Could Shale Gas Power the World? The extremely astute business and finance journalist, Joe Nocera, wrote a column last week at the NY Times extolling the virtues of natural gas. (Forget all the hoopla about Boone Pickens – this man must have the best PR machine on the planet – he is not the magus for this fuel or for the technologies involved. He is just another rapacious Texas oilman. Not incidentally, John Kerry may have forgiven him for being the driving financial force behind the Swift Boat Veterans for Truth campaign, but I haven’t.) More about Nocera, his column, the response, and his response to that in my next post.
It is important to note that the Howarth shale gas study is not, to say the least, without its detractors. Nature had this article (reposted at Scientific American) in which, among other critiques, we have this: “‘It’s an outlier position,’ says Henry Jacoby, former co-director of the Program on the Science and Policy of Global Change at the Massachusetts Institute of Technology in Cambridge. His overall opinion is that the study is ‘very weak.’” The industry, you will not be surprised to learn, questions Howarth et al in “Five Things to Know about the Cornell Shale Study.” The main critique of the paper, from several commentators, is that the authors get the GWP numbers essentially wrong.
The industry response says: “First, they use a 20-year timeframe to study the GWP of methane in the atmosphere, rejecting the more common 100-year horizon considered by scientists to be more relevant in assessing the impacts of climate change. Second: They ratchet up methane’s GWP value to 105, far greater than IPCC’s recommendation of 72 over a 20-year period, and a staggering 320 percent higher than IPCC’s 100-year benchmark of 25.”
The excellent Kirsten Korosec at BNET’s blog “Carbon Based” notes here that, among other things, the calculations on how much bang you get for the energy buck on gas vs coal are all wrong. She quotes the top climate and energy policy expert Michael Levi from the Council on Foreign Relations: “The per kWh (kilowatt per hour) comparison is the correct one, but Howarth doesn’t do it. This is an unforgivable methodological flaw; correcting for it strongly tilts Howarth’s calculations back toward gas, even if you accept everything else he says.” (See Levi’s thoughts here.)
So, nuff said for now. I have a few more thoughts my ownself coming in the next post.