Natural Gas Is A Bridge To Nowhere Absent A Carbon Price AND Strong Standards To Reduce Methane Leakage

Photo by Walter Disney

A new journal article finds that methane leakage greatly undercuts or eliminates entirely the climate benefit of a switch to natural gas. The authors of “Greater Focus Needed on Methane Leakage from Natural Gas Infrastructure” conclude that “it appears that current leakage rates are higher than previously thought” and “Reductions in CH4 Leakage Are Needed to Maximize the Climate Benefits of Natural Gas.”

Natural gas is mostly methane — a very potent greenhouse gas, though with a much shorter lifetime in the atmosphere than CO2, which is emitted by burning fossil fuels like natural gas. Recent studies suggest a very high global warming potential (GWP) for CH4 vs CO2, particularly over a 20-year time frame.

The new Proceedings of the National Academy of Sciences study introduces the idea of “technology warming potentials” (TWPs) to reveal “reveal time-dependent tradeoffs inherent in a choice between alternative technologies.” In this new approach the potent warming effect of methane emissions undercuts the value of fuel switching in the next few decades, exactly the timeframe we need to reverse the warming trend if we are to have any chance at triggering amplifying feedbacks and preventing multiple catastrophes.

For instance, the new study finds that a big switch from coal to gas would only reduce TWP by about 25% over the first three decades — far different than the typical statement that you get a 50% drop in CO2 emissions from the switch.

Note that the conclusion above is based on “EPA’s latest estimate of the amount of CH4 released because of leaks and venting in the natural gas network between production wells and the local distribution network” of 2.4%.

Many experts believe the leakage rate is higher than 2.4%, particularly for the fastest growing new source of gas — hydraulic fracturing. Also, recent air sampling by NOAA over Colorado found 4% methane leakage, more than double industry claims.  The study notes:

We emphasize that our calculations assume an average leakage rate for the entire U.S. natural gas supply (as well for coal mining). Much work needs to be done to determine actual emis- sions with certainty and to accurately characterize the site-to-site variability in emissions. However, given limited current evidence, it is likely that leakage at individual natural gas well sites is high enough, when combined with leakage from downstream operations, to make the total leakage exceed the 3.2% threshold beyond which gas becomes worse for the climate than coal for at least some period of time.

In short until we have far more actual data showing low leakage rates — or regulations to ensure low leakage rates — it is hard to claim that switching from coal to gas plants has a substantial warming benefit in the near-term (that is especially true for reasons I’ll touch on below).  It’s even harder to claim that simply shoving massive amounts of natural gas into the energy supply system is a good idea at all, given that some of it would inevitably replace new renewables — and  if even a small fraction of new gas plants replace renewables, that eliminates any warming benefit that  switching from coal to gas might have.

I had previously argued that you need a rising carbon price to ensure that any new natural gas plants replace coal and not renewables (see here). Indeed, I first made that argument three years ago — see “Why unconventional natural gas makes the 2020 Waxman-Markey target so damn easy and cheap to meet.”

But now it’s increasingly clear that a carbon price alone doesn’t address the full problem. You are going to need enforceable national standards to bring the leakage rate way down. Such standards could in fact be a very quick way to reduce the rate of global warming.

Indeed, the other shocker in this study is how bad natural gas vehicles (NGVs) are for the climate. In particular, many are trying to pass legislation for switching heavy duty diesel vehicles to natural gas. The study concludes that such a switch sharply increases Technology Warming Potential for many decades, and no one alive today would ever see a climate benefit from that switch.

This new research, coauthored by two EDF scientists as well as other leading scientists, appears to have led EDF to strongly oppose NGVs. As the National Journal reported last month:

“The president has proposed we switch trucks to natural gas, and I’m here to tell you today that every truck we switch to natural gas damages the atmosphere,” Fred Krupp, president of the Environmental Defense Fund, said at the IHS Cambridge Energy Research Associates annual conference here. Krupp said the little data available about how much methane — a greenhouse gas 20 times more potent than carbon dioxide — escapes during the production of shale natural gas compels him to refuse to support a shift toward more natural-gas vehicles.

We’re against what the president called for in the State of the Union until they [the natural-gas industry] can demonstrate they can get the leak rate down below 1 percent,” Krupp added. The Environmental Defense Fund’s opposition to the proposal is notable; it is one of the only environmental groups willing to work with industry on the concerns surrounding shale natural gas, which has been discovered in vast amounts all over the country in the past few years.

The problem for NGVs, as study coauthor and EDF chief scientist Steven Hamburg explained to me, is that the extra steps involved in using natural gas as a transport fuel — including fueling and onboard storage, increases the system leakage rate significantly. And these leaks are probably much harder to address. So the possibility that, say, the entire leakage rate for the heavy-duty vehicle infrastructure, from fracking to fueling, could ever be brought down to below 1% is pretty darn small.


The concept of natural gas as a “bridge fuel” was pushed by the American Gas Association as far back as 1981. It’s the longest bridge in history!  Heck, the Golden Gate Bridge only took 4 years to build!

But the window where gas can be a major bridge fuel to a world with a livable climate appears to be almost completely closed, now. Had we acted back in the 1980s or even 1990s as climate scientists and world leaders had been urging, then, yes, an expansion of gas use might have made sense.

The fact that natural gas is now a bridge fuel to nowhere was first shown by the International Energy Agency in its big June report on gas — see IEA’s “Golden Age of Gas Scenario” Leads to More Than 6°F Warming and Out-of-Control Climate Change. The IEA’s well-named GAG scenario assumes that not only does oil  production peak in 2020 — but so does coal!

Remember, warming beyond 6°F (3.5°C) is “incompatible with organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems & has a high probability of not being stable (i.e.  4°C [7F] would be an interim temperature on the way to a much higher equilibrium level),” according to Professor Kevin Anderson, director of the Tyndall Centre for Climate Change in Britain (see here). We would be self-destructively irrational to risk even 5°F warming.

If your goal is a livable climate, we need to transition off of all fossil fuels ASAP.

September saw the publication of a remarkable study by Tom Wigley of the National Center for Atmospheric Research (NCAR), which concluded:

In summary, our results show that the substitution of gas for coal as an energy source results in increased rather than decreased global warming for many decades.

What NCAR’s new study added was more detailed modeling of all contributors to climate change from fossil fuel combustion — positive and negative.  Reducing coal use reduces sulfate aerosols that have a short-term cooling effect.

The new study does not consider the potential drop in sulfate aerosols from switching off coal. It discusses Wigley’s work and argues that he overestimated the impact. But it seems likely that a significant impact remains and further undercuts the benefit of a major switch from coal to gas.

Analyzing the switch from coal to gas is certainly complicated. I’ve discussed it at length with coauthor Steven Hamburg. And I’ve run this new study by climatologist Ken Caldeira, who stands by his approach that finds basically no benefit in the switch whatsoever — see You Can’t Slow Projected Warming With Gas, You Need ‘Rapid and Massive Deployment’ of Zero-Carbon Power.  Caldeira certainly supports efforts to reduce methane leakage, but as he has said before, “Natural Gas Is ‘A Bridge To A World With High CO2 Levels’.” I cannot do justice to his comments on this study by excerpting them, so I’ll post them in full tomorrow.

Doing in situ studies of actual methane leakage under different conditions is valuable. It’s great that groups like EDF are working with industry to get a better grip on this.

Cutting methane leakage sharply makes a lot of sense, but, realistically, it is all but certain to require federal standards that the industry will oppose. And who precisely is going to achieve such standards globally as the technology for fracking is exported around the world?

Building lots of new gas plants simply doesn’t make much sense since we need to sharply reduce greenhouse gas emissions and the rate of growth of warming in the next few decades if we’re to have any chance to avoid catastrophic global warming.  We only want an outcome, which doesn’t exist yet, where natural gas only replaces coal. We don’t want new gas plants to displace new renewables, like solar and wind — since that would negate what little benefit switching from coal to gas might bring. That requires a carbon price.

So the only scenario I can see in which more gas makes sense is the one I laid out 3 years ago.  We have a rising price for carbon. We have a short-term transition — lasting to about 2020 — to fill the existing underutilized gas-fired capacity and replace coal cheaply.

In this scenario, very few new natural gas plants are built. And, of course, during this time we still push hard on efficiency and all forms of renewables to keep bringing them rapidly down the cost curve. Post-2020 it needs to be pretty much all carbon-free power.

What this new study adds is that even this approach doesn’t make much sense without an additional effort to cut methane leaks sharply.

BOTTOM LINE:  If you want to have a serious chance at averting catastrophic global warming, then we need to start phasing out all fossil fuels as soon as possible.  Natural gas isn’t a true bridge fuel from a climate perspective. Carbon-free power is the bridge fuel until we can figure out how to go carbon negative on a large scale by the end of the century.

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23 Responses to Natural Gas Is A Bridge To Nowhere Absent A Carbon Price AND Strong Standards To Reduce Methane Leakage

  1. What’s most annoying was the sad cry of foul in the mainstream that came from first reports of natural gas fracking posing an emission risk approaching and potentially worse than coal. Are these sources so desperate that they’re taking fossil fuel money under the table? But before I get too far into conspiracy theory, I’d like to note that fracking is turning into an enormous boondoggle. At this point, the cost of nat gas is around 2.20 per unit. Most fracking operations can’t make a profit unless the cost of the gas is around $4.00. Chesapeake is, even now, requiring huge influxes of cash to keep going even as it sells off its drilling acreage. So it looks like we’re in another bubble, this time in fracking. And for what? To kill solar and wind energy just in time to hand advantage to the Chinese and risk wrecking the US economy again? Good job guys.

    Oh, and one last thing, Citigroup just issued the most unrealistic projection for oil production figures I have ever seen. So you’re an energy investor, I’d run as far from a Citigroup oil and gas portfolio as possible. Snake oil doesn’t even begin to describe these figures.

  2. DRT says:

    Presuming a carbon tax can be established, could another approach in lieu of leakage standards be to include both the direct GHG content and the indirect GHG content of the fossil fuel. By direct GHG gas content I mean the amount of GHG produced when the fuel is burned. By indirect content I mean the amount of GHG content released in order to get that fuel in a state where it can be burned. So…slightly off topic here but..the carbon tax for tar sands oil should include the GHG cost to get it out of the ground and to the point of import, as well as the tax on the direct content. Similarly the carbon tax for natural gas should include the GHG cost to get it out of the ground including the leakage there at the well along with the GHG cost of all the leakage that occurs along the chain to the point where its finally burned.

  3. I truly hope that this is the kind of information that is getting around to state, provincial and federal level governments. I know that in Prince Edward Island (Canada), our government is looking at natural gas as a source of electricity and heat (for food processing). It doesn’t seem like it is the great idea they imagined.

  4. M Tucker says:

    This morning I woke to CNBC’s Rick Santelli pitching diy natural gas conversions for pickup trucks. The video of this can be seen on the CNBC site. Santelli makes my head hurt whenever he opens his mouth but I was captivated by the whole diy, screw Detroit if they will not meet the demands of the public, message. The big issue is: Where will you fill up? Santelli says if you have a gas meter, if you already have gas appliances, you can rig your own filling station in your own garage. And that sounds like safe proactive American ingenuity to him. I was appalled and visions of garages going up in fireballs filled my imagination.

  5. prokaryotes says:

    Lawsuit against the state of Oregon and Gov. John Kitzhaber, accusing them of violating their duties to uphold the public trust and to protect the state’s atmosphere, water, land, fisheries and wildlife from the impacts of climate change.

  6. Sasparilla says:

    I saw the same as well. Santelli is very good at bond analysis but get beyond that and ideology (Ayn Rand flavor of things) trumps reality where everything is twisted to fit that worldview. It was interesting to see them do the conversion process.

    As a matter of record there have been natural gas refueling devices (that I knew about) since the 90’s – it does make one pause to think about it flowing in the garage. The biggest issue is the cost. Its $5k – $7.5k for the garage fillers and it was $10k to convert the truck – it’d only really make sense for high mileage fleet folks.

    For electric vehicles, a garage level 2 charger for a plug-in (twice the rate of normal 110volt) is normally about $1.5k with installation. And of course electricity is still cheaper than natural gas.

    It’s a little ironic Santelli talking about the automakers, besides the Honda Civic NGV, starting this summer both Chevy and Dodge will be offering gasoline / natural gas pickup trucks (highest end ones ~$50k in price):

  7. Lou Grinzo says:

    I think the analysis is much simpler: Switch a given vehicle from gasoline to natural gas, and your CO2 savings are typically 20%. That’s all. Twenty lousy percent. Compared to the size of improvement we need to make and the deadline we’re stuck with, and taking into account the time needed to replace a large portion of the US vehicle fleet to anything besides gasoline (and then convert it all again to something much better), natural gas is a disaster. Trying to use it in motor vehicles means we’ll be converting to yet another fossil fuel, and one that strands us above the needed level of emissions.

  8. Sasparilla says:

    Great analysis and definitely true about the non bridge fuel that natural gas is. I only wish our federal government was using it to make energy generation policy decisions. Of course having natural gas being chosen as a bridge fuel would imply we were actively “choosing” a bridge fuel – I wish that were the case.

    Natural gas prices are at record lows in the U.S. (way below break-even for drillers) and much cheaper than coal (or gasoline) so it gets chosen in the U.S. as the default fuel, where applicable, for the foreseeable future.

    While many natural gas drillers are shutting in wells etc., many are also going after oil via fracking which is profitable – the other side of that is that natural gas is part of the output of the oil wells and this adds to the glut of natural gas (and natural gas flaring). Most analysts seem to be assuming natural gas prices won’t recover some until after serious demand next winter (this past winter and spring in the U.S. did not do that with the warmth). Beyond that we have to wait for the market to get prices back up so Wind can become competitive again (4-5 years?).

    One comment of note, I heard again on CNBC today, that several folks from industry believe we’re currently flaring more natural gas at US wells than we’re burning in the U.S. (this is because its so cheap and we don’t have the ability to store it – most storage facilities for next winter that fill up during the summer have been full for weeks).

  9. Sasparilla says:

    So nicely put Lou – its crazy and shortsighted – so we’ll go for it.

    Fortunately the greed of the oil companies will save us at the large scale, as they actively do not want nat gas as a transportation fuel choice since it would impact their profits – Exxon is one of the biggest US nat gas owners these days but won’t put it at its stations because of this).

    The silver lining in the cloud is that natural gas prices will get back up again (4 years?), plug-ins / EV’s will gets seriously less expensive over this decade and vehicles on natural gas don’t last near as long as power plants.

    If we can just get to ~ 2020 without killing our wind / solar and plug in industries, renewables will kill fossil fuels in the open market on economics alone.

  10. John Tucker says:

    Look at this:

    Consumerism and Its Antisocial Effects Can Be Turned On — Or Off

    Those primed to materialism by exposure to certain words evinced more competitiveness and less desire to invest their time in pro-social activities like working for a good cause.

    “It’s become commonplace to use consumer as a generic term for people,” in the news or discussions of taxes, politics, or health care. If we use term such as Americans or citizens instead, he says, “that subtle difference activates different psychological concerns.” We can also take personal initiative to reduce the depressive, isolating effects of a materialist mindset by avoiding its stimulants — most obviously, advertising. One method: “Watch less TV.”

    After all the framing of Americans as energy consumers its probably time to take it back in the other direction.

  11. Mike Roddy says:

    What you are suggesting is rational and even necessary, but process emissions are variable and not easily quantified as large scale averages, either.

    This makes it a loophole, which the gas companies and others will wiggle through.

  12. Raul M. says:

    Some are coming to realize that they may actually say that becoming carbon negative is not only important but imperative.
    Sort of like saying to have dinner there must be food.

  13. Mike Wagner says:

    Malthus would put birth control on the global warming table, especially at this late date. It’s been discussed a bit (search ‘birth control and global warming’). This very article makes the argument that the GWG-control measures it discusses–carbon tax and methane emission control–aren’t going to reduce GWGs quickly enough.

    How quickly can BC reduce GWGs? Consider the unattainable, but didactically simple, case of zero reproduction for ten years in a population of 7B that is in steady state with an average life expectancy of 50 years. After 10 years, that population will have decreased by 10 * 1/50 = 20%. Assuming that consumption stays constant, the expected decrease in GWG emission by year 10 would be 20%.

    Halving of current birth rates could reduce GWG emissions by 10% in 10 years, 20% in 20 years…

    If inundation and food supply projections are correct, world population will be under downward pressure. There is a decision whether to manage this trend (i.e., do it via birth control, which will maintain current life expectancies and quality of life) or through increased mortality.

  14. DRT says:

    Doesn’t the problem of quantifying process emissions exist whether the incentive for controlling those emissions is a regulatory standard or a tax or fee on those emissions?

  15. Also, the cost of gas extraction will rise if gas companies are required to control methane leaks at the well head.

  16. John Whitelaw says:

    Given political will, semi-arbitrary emission factors could be assigned to given production methods. Of course you wouldn’t precisely fairly capture the emissions associated with a specific operation operating over time, but you could get close enough to legislate if you wanted to. Every one knows that tar sands involve much higher fossil fuel energy input than conventional oil extraction. A multiplier could be picked from a literature review of life-cycle analyses or from fuel consumption data of the operators, or whatever data source and just be assumed to be close enough. It would then add carbon content to the fuel accordingly and associated taxes or fees as well.

  17. Chris Vernon says:

    Indeed. Natural gas leakage rates have been ignored too long. I first wrote about this problem in 2010 for The Oil Drum with a follow up a couple of months ago here.

    The bottom line is that leakage rates of ~3% put gas with coal, more than that, as we are seeing, especially with shale gas mean it’s worse than coal. Also note, these figures are based on 100 year global warming potential – consider only the next 20 years and gas leaks are far more dangerous.

  18. Mulga Mumblebrain says:

    Snake oil futures look good, though.

  19. Mulga Mumblebrain says:

    Wasn’t Santelli the putative Godfather of the Tea Party (with the Kochtopus as midwives)? If so, perhaps the Mad Hatters, if they follow his advice, will get raptured in a chariot of fire, quicker than they anticipated. Does he have any helpful suggestions for DIY backyard ‘fracking’?

  20. Mulga Mumblebrain says:

    Gawdamm you reality-based water-melons, and your Gawdamm facts! Damn you all to Hell!

  21. This all reminds me that Obama’s allegedly far more stringent CAFE standards coming down the road have loopholes for alt-fuel vehicles. Expect to see a bunch of NGVs in the future (along with more E85s.)

  22. Jan Lundberg says:

    Natural Gas: a Bridge to Nowhere? – Oklahoma’s petroleum academia hosts critic – video of lecture
    Oct 3, 2011 – Jan Lundberg, independent oil industry analyst and eco-activist, spoke at the University of Oklahoma’s petroleum engineering school on Aug. 30, 2011.