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Does a Natural Gas Bridge Go Anywhere?

(a few very minor edits have been made since this post was written. -ed).

Michael Levi has a great and provocative new paper on natural gas as a bridge fuel – that is, shifting from coal to gas generation now, with a future shift to zero-carbon renewables. At the risk of oversimplification, the main finding is that natural gas doesn’t matter much if your long-term stabilization target is 450 ppm of atmospheric carbon, since the bridge can’t be very long. A very rapid shift to minimal emissions is needed to meet this target. But if your target is 550ppm or more, it looks much more useful. A secondary finding is that methane leakage is a mostly a sideshow—largely because dangerous warming happens over the long-term, while the high impact of methane relative to CO2 is only short term (it gets broken down eventually).

It’s an interesting set of results since it shows how the inertia of the climate system works against us and for us in different contexts.

Levi’s conclusions on methane leakage contrast with those of others, whose work is more pessimistic (much more so, in the case of Howarth et al.’s 2011 paper). Unlike the other papers, however, Levi looks at stabilization scenarios, under which natural gas is eventually phased out completely. I tend to think this is a better approach. But it’s worth reading Levi’s own explanation, both to capture the detail and to see whether you agree. The bridge scenarios also result in greater peak warming rates over the next century, exacerbating risk of triggering nonlinearities (tipping points) in the climate system, even though long-term temeperatures don’t change much (Levi does note this risk in the paper).

Gas opponents may take heart from Levi’s general conclusions since they likely also view 450ppm (or less) as a critical target. But I look at it as an illustration of just how deep in the hole we already are, and therefore how hard it is to hit a long term target of 450 or less (absent geoengineering). If a big switch from coal to gas doesn’t help much, and short-term big shift to renewables is needed, that target is probably out of practical reach.

If that’s true, then the only basis for opposing gas as a bridge is if you think pursuing it undermines a realistic shot at near-term renewables by pushing them out of the market instead of coal. In other words, whatever you think the chances of a big, fast shift to zero carbon energy are, you might think they are smaller if the world dabbles with gas. See this RFF report for more on how and when this might occur. Some of Levi’s scenarios include gas displacing renewables, but there are constraints, and they don’t (at least directly) consider effects on innovation and learning-by-doing in renewable development.

But there are targeted policy solutions for the problem: direct support for renewable R&D, renewable portfolio standards, European-style feed-in tariffs, or, less optimally, US-style investment subsidies. We may need these tools even without a gas bridge – we certainly will if our target is 450 ppm.

Because those policies are available, I think the debate over gas as a bridge fuel is based on a false dichotomy between gas and renewables. Moving from coal to gas is cheap—the market is already doing it, even without a price on carbon. With a price, the trend will accelerate. That, according to Levi’s scenarios, makes a 550ppm goal easier to reach. But it doesn’t mean giving up on doing better than 550ppm. Renewable breakthroughs – supported by targeted policies where needed – could make that possible. If those breakthroughs don’t come, we’re still much better off than if we had discouraged gas expansion. Levi notes this, characterizing a coal-to-gas switch as a “hedge.” An all-in bet on renewables might be our best shot at 450ppm or less, but it’s a risky bet. If good policies are in place to promote renewables along with a carbon price that promotes gas in the short term, we have an option with similar (if not equal) chance of hitting that target, but much less risk.

It’s also possible that a shift from coal to gas could make renewable deployment easier because gas may be better than coal at filling load gaps when the sun doesn’t shine or wind doesn’t blow. More research (and experience) is needed here.

An all-in bet on renewables is also politically impossible. That could change in the future, but by then we might have already exceeded 450ppm anyway. The real-world options are probably only business-as-usual or a lower-carbon path dependent on gas. Levi admits that his paper does not examine the political or economic plausibility of his various scenarios. Environmentalists are often accused of making the perfect the enemy of the good. I think the charge is often overstated, but here it seems apt. If the goal is minimizing atmospheric CO2, their efforts might be better focused on getting a carbon price (or at least flexible regulation), then preserving and extending policies to support renewables.

All this ignores local environmental impacts of gas development. That’s a tough (and, if you can believe it, more controversial) issue. Prudent regulation and effective enforcement are clearly necessary. But it’s worth remembering that these local impacts have to be compared to the alternative – the local impacts of mining and burning coal, and the global impacts of climate change.

About Nathan Richardson

Nathan Richardson is a visiting fellow at RFF and an associate professor at the University of South Carolina School of Law. A lawyer by training, Nathan's research focuses on energy and climate policy, particularly regulatory tools available under US law.

Views expressed above are those of the author. Resources for the Future does not take institutional positions on legislative or policy questions. All information contained on Common Resources is intended for informational and educational purposes and may only be used for these purposes. Please see RFF's Terms of Use for further information.

Comments
5 Responses to “Does a Natural Gas Bridge Go Anywhere?”
  1. Michael Knapp says:

    Great commentary Mr. Richardson.

    With the huge build out of nat gas fired plants that is on the horizon, what place to do you see CCS technology having?

    I’m assuming that it would be far easier and cheaper to incorporate into a new facility from the get go, rather than trying to retrofit existing facilities? Is it cheaper/easier to implement on a gas fired plant rather than a coal plant?

    If CCS could be implemented now, during the impending construction boom, how do you think that could impact the ability of gas to have a more profound effect?

    Michael Knapp

    • I confess that I don’t know how to rate CCS at this point. I treat it like big renewable breakthroughs, various geoengineering options, even fusion power – exciting, but dependent on technological and in particular cost breakthroughs. Predicting those is near-impossible for experts in each field, and I’m certainly not one.

      You are probably right that building in CCS at plant construction would be cheaper, but it’s not cost-effective right now. Maybe large subsidies could fill that gap, but I don’t see a good argument for spending money there rather than on zero-carbon R&D.

      A carbon price would let the market determine which among these (and other options) is preferable. Many have strong opinions on their favorite renewable tech, CCS, geoengineering, etc. But I think society’s much better off if those advocates are competing for investors rather than subsidy dollars.

  2. Alan Loeb says:

    Interesting analysis. I think the main point that needs to be made is that people who think building something will lead to its opposite (i.e., let’s build out a natural gas infrastructure as a transition to low-carbon energy system) are fooling themselves. The main dynamic is what I like to call “the psychology of sunk costs.” Once someone plunks down billions of dollarls to build out the infrastructure for one energy system, and promises to pay a good portion of the cost out of future earnings, there is not only considerable opposition to moving demand away from that supply, there is a mental state of dependency that naturally forms around it. The reason natural gas cannot be a transitional fuel is that once we build out the infrstructure fo increase the supply of it — more pipelines, more generation, etc. — it is likely to stay in place beyond our own lifetimes, and the capital that might have addressed the climate problem has already been sunk into something that only slows down but doesn’t actually change our date with destiny. The solution to the carbon problem is not — and cannot be — to burn an alternative hydrocarbon.

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  1. [...] http://common-resources.org/2013/does-a-natural-gas-bridge-go-anywhere Michael Levi has a great and provocative new paper on natural gas as a bridge fuel – that is, shifting from coal to gas generation now, with a future shift to zero-carbon renewables. At the risk of oversimplification, the main finding is that natural gas doesn’t matter much if your long-term stabilization target is 450 ppm of atmospheric carbon, since the bridge can’t be very long. A very rapid shift to minimal emissions is needed to meet this target. But if your target is 550ppm or more, it looks much more useful. A secondary finding is that methane leakage is a mostly a sideshow—largely because dangerous warming happens over the long-term, while the high impact of methane relative to CO2 is only short term (it gets broken down eventually)… .fb_iframe_widget { vertical-align: top !important; margin-left: 16px !important; } Tweet Danièle RevelMore Posts  Imprimer ce billet [...]



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