Reducing Methane Emissions

As CO2 only accounts for about a third of our influence on the climate, it is fair to wonder if going after the other 67% might be a more effective use of our resources.

Certainly in the short term we would get a better bang for our buck by going after black soot, deforestation… and methane.

Methane is about 23 times more potent as a greenhouse gas than CO2,so eliminating one tonne of methane from the atmosphere is equivalent to drawing down 23 tonnes of the more familiar bogeyman.

Here is a chart showing the sources of human generated methane in the U.S.

gases-methane

All of these sources are amenable to human mitigation.

For example, the U.S. EPA has this to say about methane leaks from natural gas operations: https://www3.epa.gov/gasstar/methaneemissions/ (They go into great detail, much of which concerns using correct and modern equipment.)

Good Housekeeping has this advice for farmers: “Anaerobic “digesters” utilize microorganisms to decompose cattle manure within a huge container. The resulting biogas can be harvested and used for “free” electricity production, rather than be expelled into the atmosphere.”

The EPA has more advice along the same lines:

“Trash decomposes (or rots) in landfills, creating methane gas. Methane rises to the top of the landfill and is collected in pipes. The methane is burned to produce heat or generate electricity.”

They cite some examples of this in use:

  • Putting waste to good use. More than 500 landfill–to–energy projects are currently operating in the United States, and another 500 landfills are good candidates for turning their methane into an energy resource, which would produce enough electricity to power nearly 688,000 homes across the nation.
  • Top producer. In 2009, Germany produced enough electricity from biogas to power 3.5 million homes.
  • A world first! Sweden has been operating a biogas-powered train since 2005. It shuttles passengers between two cities that are 75 miles apart.

Sadly, environmentalists often oppose capturing methane for energy as it ‘takes the pressure off of people to reduce, reuse and recycle…” Sigh.

waste plantHG

Methane often comes out of the ground during oil drilling operations. It is often burnt as it does so. But it can be captured and used as fuel.

The Obama administration has put in place a plan to reduce methane escape from oil drilling and operations by 40% to 45% by 2025. Secretary of Labor Jewell said “I think most people would agree that we should be using our nation’s natural gas to power our economy – not wasting it by venting and flaring it into the atmosphere,” said Secretary Jewell. “We need to modernize decades-old standards to reflect existing technologies so that we can cut down on harmful methane emissions and use this captured natural gas to generate power and provide a return to taxpayers, tribes and states for this public resource.”

Manure management accounts for about 12% of the total greenhouse gas emissions from the Agriculture sector in the United States. Greenhouse gas emissions from agriculture have increased by approximately 17% since 1990. One driver for this increase has been the 54% growth in combined CH4 and N2O emissions from livestock manure management systems, reflecting the increased use of emission-intensive liquid systems over this time period.

This too can be reduced. The EPA suggests:

  • Handling manure as a solid or depositing it on pasture rather than storing it in a liquid-based system such as a lagoon. This would likely reduce CH4 emissions but may increase N2O emissions.
  • Storing manure in anaerobic containment areas to maximize CH4 production and then capturing the CH4to use as an energy substitute for fossil fuels.
  • For more information see EPA’s AgSTAR Program, a voluntary outreach and education program that promotes recovery and use of methane from animal manure.

Enteric Fermentation means the infamous cow belches–ruminant animals produce methane as they digest and they burp it out (they don’t fart it out–that’s a myth.)

cow burping

“Methods to mitigate enteric fermentation emissions are still in development and need further research, but early studies looking at potential mitigation options have yielded some promising results. Most research has focused on manipulating animal diet in an effort to inhibit a rumen environment favorable to methanogens. Diet manipulation can abate methane by decreasing the fermentation of organic matter in the rumen, allowing for greater digestion in the intestines—where less enteric fermentation takes place. This inhibits methanogens and limits the amount of hydrogen (H) available for methane (CH4).”

All of these actions have appropriate technologies designed and available for use. Methane produces (apparently) about one third the effect on our climate as does our emissions of CO2.

Why would we ignore this opportunity? We can use it as natural gas to produce heat and electricity and lower our impact on the planet.

 

 

 

32 responses to “Reducing Methane Emissions

  1. Here is an article on the challenges and benefits of methane digesters.

  2. Do you have data/correlations which allow an estimate of methane emissions from coal mines? I ask because I’ve seen data for the amount of methane adsorbed in coal seams, which indicates coal located near or at the surface has a much lower methane content. This in turn makes me wonder if the large methane emissions in China may not be caused by intensive coal mining and rice paddies?

  3. Is there any evidence that domesticated ruminants produce more methane than wild ones?

    • Just a guess but they probably do. Beef feedlots are the world’s largest consumer of soda bicarbonate (Alka selzer) because cattle have a hard time digesting the corn meal, distiller’s grain and soy used to fatten them.

  4. Agree on black soot, and really agree on deforestation, as well controlling indoor air pollution (biggest killer of them all).
    Methane effects, however, are exaggerated.

    https://rclutz.wordpress.com/2016/03/11/much-ado-about-methane/

    • Ron, you once again make real sense. The real lesson is to challenge the underlying assumptions of the climate imperialists. They are not even wrong. They are not even on topic.

  5. Tom, please research the no -human biological sources of methane. The entire climate basis of concern for anthropological methane is, like nearly all of the concerns of the climate obsessed, wrong.

  6. Have agricultural emissions really increased as much as you say. What happened to the methane output from decomposing livestock manure in the days when they roamed the fields rather than the sheds, surely concentrating the processing only changes the source, not the volume of output.

  7. James Hansen, in his book, talks about huge amounts of methane that have accumulated over time that are sequestered in permafrost and clathrates. He thinks that this has sort of primed the world for another PETM event triggered by Arctic warming. Perhaps this is a long term trend that is made inevitable by the rise of civilization. If so, the only solution may be some sort of mega geoengineering project that will require unprecedented amounts of energy. Nuclear energy may be the only candidate.

  8. “CO2 only accounts for about a third of our influence on the climate”

    Flat wrong. CO2 is about 1.8 W/m^2 out of a total anthropogenic forcing of about 2.3 W/m^2.

    “Certainly in the short term …”

    But why should anybody give a damn abut the short term? The only reason for concern is the long lifetime of CO2.

    “… we would get a better bang for our buck by going after black soot, deforestation… and methane.”

    Do you have any evidence for that?

    • There is a lot of evidence from excellent radioactive decay studies that directly refute the climate consensus on CO2 longevity. Methane risks, like most climate consensus claims, are best taken dubiously, if not derisively.

      • You are mistaken, Hunter, as is catweazle. The evidence merely refutes your misunderstanding of CO2 chemistry. Your error is in assuming that the dissolution of CO2 in seawater is linear. It is not. Not even close.

      • catweazle666

        “Your error is in assuming that the dissolution of CO2 in seawater is linear.”

        Really?

        Please point out where either I or hunter have asserted any such thing.

        When you’ve failed to do that, please explain where the peer reviewed paper I refer to below (which also does not assert that “that the dissolution of CO2 in seawater is linear” (whatever that means – are you referring to Dalton’s law of partial pressures?) is incorrect.

        Meanwhile, you might find this dissertation on the solubility of CO2 in sea water informative.

        http://cdiac.ornl.gov/ftp/cdiac74/chapter2.pdf

        Or perhaps this:

        https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCQQFjAAahUKEwj4ucq4t-DHAhUDXBoKHRieBzE&url=http%3A%2F%2Fwww2.hawaii.edu%2F~kinzie%2Fdocuments%2F470%2FCO2solubility.doc&usg=AFQjCNHi0BZLYQGTCgPjF5v1EgUSg8F2RQ&sig2=S8FLLV9xHGkzOxSX8bDw2Q&cad=rjt

        After that, perhaps you can have a go at teaching your grandmother to suck eggs.

      • catweazle,

        “Please point out where either I or hunter have asserted any such thing.”

        I guess I should have realized that you are much to stupid to understand that. I’ve got all the world’s experts on my side, you’ve got your invincible ignorance on your side. No point in my wasting any more time on you.

      • catweazle666

        Mike M: “I guess I should have realized that you are much to stupid to understand that.”

        I assume that as you are entirely incapable of refuting any of the (peer reviewed) information in my post and have descended straight into personal abuse that you have conceded that your scientific literacy is not up to the task and you are utterly incapable of contributing anything of significance to the debate – in other words, you are nothing more than a troll, and not a particularly competent one of those.

        I can’t say I’m surprised.

      • Nike M.
        You are running away like someone with no arguments but plenty of attitude.
        catweazle posts links, you post bluster.
        Certainly you can do better?
        I did not refer to seawater absorption of CO2 linear or non-linear.
        I referred to the studies done of Carbon isotopes during open air nuke bomb testing.
        The C14 isotope decline rates indicate CO2 cycling through the atmosphere in a matter of years, not centuries.
        http://euanmearns.com/the-residence-time-of-co2-in-the-atmosphere-is-33-years/

      • Tom,

        Not a link, but the numbers are in Table 8.6 and Figure 8.15. I just noticed that Figures 8.16 and 8.17 seem to give different numbers from the earlier Figure and the text.

        Part of the problem is that AR5 is not a critical review. The ranges given tend to cover all values that anyone (at least anyone in the club) has come up with and the mean seems to be some sort of compromise. Not the way science is supposed to work.

      • Hunter,

        Yes, it cycles in years. But that only gives you the removal lifetime if the system is linear.

        For a reference, start with IPCC AR5, Chapter 6 “Carbon and Other Biogeochemical Cycles”. Then maybe look at the references (there appears to be eight or nine hundred).

    • “The only reason for concern is the long lifetime of CO2.”

      Another Warmist canard.

      Atmospheric CO2 does not appear to have a particularly long residence time in the atmosphere.

      From the SEVENTEENTH SYMPOSIUM ON THERMOPHYSICAL PROPERTIES

      Fossil Fuel Emissions and Fossil CO2 in the Atmosphere

      Luciano Lepori S, Gian Carlo Bussolino, Andrea Spanedda and Enrico Matteoli C
      IPCF-CNR, Pisa, Italy

      The comparison of fossil fuel emissions (6.4 GtC/yr) with the growth rate of atmospheric CO2 (3.2 GtC/yr) suggests that about half of the anthropogenic CO2 has not remained in the atmosphere: it has dissolved in the ocean or has been taken up by the land. The isotope ratio C13/C12 of atmospheric CO2 has been measured over the last decades using mass spectrometry. From these data the fraction of fossil CO2 in atmospheric CO2 is straightforwardly calculated: 5.9 %(1981) and 8.5 %(2002). These results indicate that the amount of past fossil fuel and biogenic CO2 remaining in the atmosphere, though increasing with anthropogenic emissions, did not exceed in 2002 66 GtC, corresponding to a concentration of 31 ppm, that is 3 times less than the CO2 increase (88 ppm, 24 %) which occurred in the last century. This low concentration (31 ppm) of anthropogenic CO2 in the atmosphere is consistent with a lifetime of t(1/2) = 5.4 years, that is the most reliable value among other in the range 2-13 years, obtained with different measurements and methods. Contrary to the above findings on the concentration of fossil CO2 and its residence time in the atmosphere, in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change it is stated that almost 45 % of anthropogenic emissions, corresponding to 88 ppm or 24 % of the total CO2, have remained in the atmosphere with a mean lifetime of t(1/2) = 30.5 years. On these assumptions are based both the theory of Anthropogenic Global Warming and the climate models.

      http://thermosymposium.nist.gov/archive/symp17/

    • Hi MikeM,

      Is it possible that your figure is for all greenhouse gases while mine is for all anthropgenic forcings? The graphs I have seen suggest that is the case.

      • Tom,

        If you leave out the negative forcings from particles, the total of all the positive forcings is about 3.1 W/m^2. CO2 is still 60% of that. I don’t know where you are getting your numbers. Mine are from IPCC.

      • Hi MikeM,

        I’ve been searching for this for some time. I can’t find it in AR5. Do you have a link?

  9. I know I’ve read somewhere that methane and CO2 have infrared spectrums that overlap. They are very similar lightweight molecules — a carbon atom connected to four protons and an oxygen atom connected to two protons.

    • Canman,

      Spectroscopically, they are nothing alike. H is much lighter than O, so CH bonds vibrate at very different frequencies than CO bonds. I don’t think there is any significant overlap in their spectra.

      • Aaaargh! I meant methane and water. CH4 and H2O molecules do appear to be similar. That is a carbon atom connected to four protons and an oxygen atom connected to two protons. The one big atom makes them both light. Hydrogen is just protons. CO2, O2 and N2 are both heavier molecules.

      • Should be “are all” instead of “are both”. I added CO2 as an after thought.

      • Canman,

        Yes CH4 and H2O are similar and the absorptions overlap. I should have realized that might be what you meant.

        What Sheahen overlooks is that the greenhouse effect is mostly not about absorbing light emitted by the surface, although simple treatments make it seem that way. The greenhouse effect mostly happens in the upper troposphere, where there is relatively little water vapor. As a result, methane does have an effect, in spite of the overlap with water vapor.

        There are things (CFC’s, liquid water) that absorb in the IR windows and thus reduce the emission directly from the ground to space. They can have a really huge effect on a per molecule basis.

    • The spectra of methane & N2O overlap, such that the formulas for radiative forcing (e.g. from Myhre et al. 1998) involve the concentrations of both. Perhaps that’s what you’re remembering.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s