Energy. Environment. Economy.

Study: Natural Gas No Bridge to Zero Fossil Fuel Future

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A rainbow is seen over the Galata bridge and Galata Tower after a rainy day in Istanbul on November 23, 2012.

Proponents of natural gas tout new shale deposits, such as Pennsylvania’s Marcellus, as a way to reduce carbon emissions while the world eases itself off fossil fuels, and moves toward alternatives such as wind and solar. Natural gas power plants emit less CO2 than coal, which still dominates electricity generation worldwide. In the U.S., low natural gas prices have allowed natural gas to catch up with coal-fired electricity. But this “bridge fuel” scenario is controversial.

Some say the world is warming too quickly to even consider the concept legitimate. Still others say the process of extracting natural gas at the wellhead emits enough methane, a greenhouse causing gas, to negate any benefits of lower carbon dioxide emissions at power plants.

Climatic Change, a peer-reviewed scientific journal, has just published online a report that has something to make both sides happy and sad. Written by Michael Levi, “Climate consequences of natural gas as a bridge fuel,” is one of the only reports to look at the issue from a vantage point of global emissions reduction goals. The bottom line, says Levi, is that any potential “natural gas bridge” would be useless because it would be so short. He does say, however, that natural gas can play a role in easing nations off of coal.

“Collectively, these results suggest that it may be useful to think of a natural gas bridge as a potential hedging tool against the possibility that it will be more difficult to move away from coal than policymakers desire or can achieve, rather than merely (or primarily) as a way to achieve particular desired temperature outcomes.”

Natural gas opponents will cheer these results. But they won’t be too happy about Levi’s conclusions about natural gas emissions at the wellhead. Levi says when lowering emissions to halt climate change, the methane that leaks from natural gas wells is not enough to offset the benefits of lower CO2 emissions at the power plant.

“Moreover, in most cases where stabilization is near 550 ppm CO2, even high rates of methane leakage do not fundamentally alter the conclusion that replacing coal with gas can substantially lower peak temperatures relative to what they would be if a transition away from coal were instead delayed. In particular, if so-called “tipping points” can be triggered by exceeding particular temperature thresholds, methane leakage in the context of bridge fuel scenarios will have at most a very small impact on the odds that those thresholds will be crossed. This is true even if steps to reduce methane leakage can yield benefits exceeding costs.”


  • TheProspector

    I think your “short bridge” comment was very confusing. I went back to the abstract and figured out that the writer considers a proper bridge to be short, so as to prevent global warming. I believe that his point was that the natural gas bridge was too LONG, to be able to get us to green energy before global warming goes too far

  • Mike Knapp

    I’m very confused by the tone of this story, especially the headline.

    Levi’s point isn’t that natural gas is ineffective at lowering the amount of climate change inducing proponents into the atmosphere. He says that gas won’t do much good in stopping the run to 450ppm, because much like a freight train climate change carries significant momentum, and nothing short of a near overnight deployment of zero carbon energy could hope to stop it short of the 450ppm barrier (which, he also mentions, is not likely, or even feasible). He goes on to say that it could be very beneficial when viewed at the 550ppm threshold:

    “In contrast with the 450 ppm cases, in the scenarios explored here, pathways that stabilize CO2 concentrations near 550 ppm using natural gas as a bridge fuel promise substantially lower peak temperatures than similar ones that differ only by delaying the transition away from coal until zero carbon energy rises in its place.”

    Basically, we’ve already driven too far over the cliff for natural gas to save us from 450ppm, but on a longer term gas could be very beneficial.

    Furthermore, it’s well established that natural gas is by far the best backup source for renewable energy (which needs a backup when the wind isn’t blowing and the sun isn’t shining). Gas fired plants can cycle up on a few minutes notice and be at full capacity, so they can shut down when not needed. Other plants must continue to run to be able to quickly deploy energy should a renewable field suddenly see a sharp reduction in output. In effect, natural gas makes renewables infinitely more feasible, and much cleaner.

  • Patrick Henderson

    Not all proponents of natural gas simply view it as a “bridge” fuel. This statement implies that it is merely temporary; is still not ideal; but is nonetheless better than the alternative. That’s shortsighted and simplistic. To further the analogy, many view it not as a bridge to get you someplace else, but rather as one of the destinations. Issues surrounding fugitive emissions are important, and we have seen new federal rules put in place to address this. But they are not and should not be the sole criteria upon which the value of developing natural gas is measured. It ignores the economic benefits of job creation here; the other environmental benefits; the impact of re-shoring U.S. dollars current exported around the world; and of increased energy security and energy independence (which is not, despite StateImpact’s prior statements on the subject, merely “rhetoric”.) Our resources, including renewable and alternative energy resources, that are and can be plentiful in Pennsylvania certainly exhibit these benefits as well. We do not need to accept an “either/or” proposition when we can pursue a true “all of the above – and below” proposition.

    Patrick Henderson, Energy Executive
    Gov. Tom Corbett

    • Eric Banford

      The “economic benefits” are a fallacy as the rising unemployment rate in PA shows. See James Barth’s details here: Few profit while many pay the environmental consequences. If at some point the gas can be extracted minus the toxic chemical mix, then sure it burns cleaner and could be used, but the current technology of fracking is a disaster and should be banned everywhere.

  • Paul Roden

    All the more reason to begin the transition to renewable energy now. Germany is doing it and will obtain 80% of its energy needs from renewable energy by 2016, while getting off of nuclear energy.. Their economy is growing while their energy usage is declining. The Chancellor and the Bundestag (The German Parliament) is united behind this effort. All political parties are unified behind this plan. If the Germans can do it, so can we. I wonder how the German politicians ignored the fossil fuel, nuclear energy and centralized electric companies lobbying money. Somehow the politicians there, saw the light and where not motivated by greed, not like the politicians in our country at both the Federal and State levels. According to Jacobson and Delucchi in their Nov. 2009 Scientific American article on their plan to transition the planet to renewable energy by 2030, we have the technology and resources to do this now, what we lack is the political will. How can we make our elected representatives in the United States see the light on global warming and the end of fossil fuel and nuclear power? How can ‘we, the people” fight back against the lobbyists who have bought our elected representatives?

  • Dave Meiser

    Renewable energy could fully power a large electric grid 99.9 percent of the time by 2030 at costs comparable to today’s electricity expenses, according to new research by the University of Delaware and Delaware Technical Community College.

  • Eric Banford
  • Dave Meiser

    Also a recent study states that methane leakage may be higher Nature published an article which indicated Losses of up to 9% in CO

  • Richard Edward Dillon

    There is no such thing as “renewable” energy. It is a fiction. Germany is not transforming its entire energy infrastructure into renewable or “green” systems.

    What is true is that France produces most of its power by means of nuclear technology and what is even more true is that Susan Phillips and NPR do not report on France. They do not report on China and its use of ALL energy sources. Phillips is a political operative working for far-Left, statist, interests. These interests are not at all what her slick website seems to represent.

    Phillips’ examples of troubles that Marcellus shale development purportedly create are in truth created by Phillips and her organization. Phillips is an invidious propaganda agent.

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