This group brings together the best thinkers on energy and climate. Join us for smart, insightful posts and conversations about where the energy industry is and where it is going.


EPA confirms high Natural Gas leakage rates

David Lewis's picture
  • Member since 2018
  • 353 items added with 44,390 views
  • Dec 7, 2010


The latest EPA study confirms that its original “seminal” study of methane leaks from natural gas use, i.e. “Methane Emissions from the Natural Gas Industry (GRI/EPA 1996) was in errorThe GRI/EPA 1996 study was the holy grail.  The IPCC used GRI/EPA numbers when it assessed the climate impact of gas.  

The old figures drastically underestimate the climate impact of the use of natural gas. 

This confirms the work of Dr. Robert Howarth, the Cornell professor whose work I described in two recent posts (first, here, and later, here) in a most authoritative way

The original GRI/EPA study was regarded as so good it served as “the basis for most CH4  [methane]  estimates from natural gas systems”.  These include:  the main EPA Inventory of US GHG Emissions and Sinks, the American Petroleum Institute (API) Compendium, the studies done by the Interstate Natural Gas Association of America, the protocols developed by the California Climate Action Registry, and “many of the emission factors included in the Intergovernmental Panel on Climate Change Guidelines for National Greenhouse Gas Inventories.” 

The EPA page that refers to the study is here.  The study in question is: “Technical Support Document:  Petroleum and Natural Gas Systems“. 

Gory details follow.  (Noises of busy newsroom in background) 

Actually this isn’t some news flash.  EPA posted the study on a webpage that looks like it was created in November 2010.  The document I dug out was an obscure looking link only a demented wonk would click on, late at night, near the bottom of the page.  How could something this old, stuffed here, have news in it?  Gas gets such a free ride from the usual suspects who scrutinize this type of thing something like this can be hidden in broad daylight.  I quote: 

“Although the GRI/EPA Study has been the cornerstone for estimating CH4 emissions from the natural gas industry to date, the data on which the study is based are now over a decade and a half old and in some cases (e.g., wells, compressors), not always reflective of current conditions in the United States. In recognition of the fact that existing methane emission factors were becoming quickly outdated, in 2007 EPA funded a 4-year cooperative agreement with UT Austin to support research and, as appropriate, measurement studies to update selected CH4 emission factors from the 1996 GRI study”

So it isn’t even a final paper from a completed study yet.  They didn’t get enough funds to completely revamp GRI/EPA 1996, even though they know its data is invalid.  They are now in the process of “evaluating the most efficient use of the remaining resources”. 


epa logo


But the paper used new data on methane leakage its authors believe supercede the old GRI/EPA numbers.  There are drastic changes. 

Howarth and the EPA are in the process of changing how the world views natural gas.  


Table 1, Table 2, and the explanatory note to Table 2, say it all. 

On Table 1, note the Revised Emissions Factors.  One is more than 8,000 times higher than the old one.  Its the figure for new shale gas well completions :

Table 1













The explanatory note under Table 2 was the clue for me.  I wanted to put the data into the basic form Howarth uses when he assesses how bad methane emissions from gas are.  I.e. what percentage of the overall production was leaked to the atmosphere as methane?

Table 2

In that explanatory note I saw that for 2006, they are breaking out the data for just the gas industry that isn’t separated in the Table.  So they say “the natural gas industry emitted 261 MMTCO2e of CH4 in 2006.

A  GAO report I’ve been studying had a conversion factor to convert MMTCO2e to billions of cubic feet of natural gas.  Total US gas production for 2006 is available from EIA in cubic feet.  The conversion figure GAO-11-34 published in 2010 page 41 is”.4045 million metric tons of carbon dioxide equivalent per billion cubic feet of vented natural gas“.   So I took the 261 million metric tons of CO2e, divided by .4045 and got 645 billion cubic feet.  I took this 645 Bcf and divided by the 2006 marketed production of around 20 trillion cubic feet.  This gave me:

 3.25 % of US natural gas production leaks into the atmosphere as methane gas. 

The industry has been saying the leaks are tiny, less than a fraction of 1%. 

Howarth wrote in an email to me that his figures were much higher than old EPA data: “at least 1.9% and perhap 5.6% or greater”  Howarth’s to be published paper will have more detail.  Howarth was saying EPA was low and he had a number of solid studies showing why.  Now EPA is saying they agree – their own figures are much higher than old EPA data.  This EPA data is in the range of gas is worse than coal.  David Hone said on the Natural Gas Webinar recently aired by The Energy Collective that leaks in Europe are essentially “zero”.  Hone called Howarth’s work “unimpressive”.   

This is a big can of worms

And, as I analyse this new EPA document I see there is potential for the number to be greater.

E.g.:  EPAs new reporting rule allows an estimated 15% of emissions to go unreported – it isn’t clear whether they then jack up or intend to jack up what’s reported by 15%.  “Engineering” calculations such as some the EPA still seem to rely on have proven to be in error compared to what actual measurement of what’s in the air surrounding facilities shows.  And I didn’t include US gas flaring CO2 because it was too late at night.  I just wanted to calculate long enough to get the drift of what EPA was saying. 

One reason I explained how I derived my 3.25% figure up there is because it seemed odd I have to calculate at all.  I thought they hired the people preparing these reports to do the calculating, so people like me won’t misunderstand what they’ve discovered.  It was the same thing with the GAO study on venting and flaring I just studied.  If I want data in a form that is meaningful to compare the climate impact of gas to coal, I have to calculate.  Everyone involved understands that there are some who see climate as serious, even though the denial campaign has been a splendid success. If I was guessing, I’d say if an agency expresses itself too clearly about what it has discovered about US gas, the report is taken by industry to be antagonistic.)

But the fact that the EPA now estimates methane venting to be this high is the end of the fantasy world for all those who were saying gas is “green”.  Its one thing to say some professor must be off his head.  This is the agency that came up with the reference data everyone was using.  EPA clearly states the reference data was bad all along.  

The gas industry can’t clean up their act overnight, and the fact that it is this bad at this moment speaks volumes about what their attitude to climate science has been and is now.  They believe greenhouse gas emissions don’t matter.  Its been economical for them to just fill the atmosphere with methane rather than make even more money than they were making already by collecting it and selling it.

What proves this is the way BP cleaned up its US operation in the San Juan Basin starting just after their CEO declared he believed climate was a problem during the runup to Kyoto.  BP and Royal Dutch/Shell, #2 and #3 biggest non state sponsored oil and gas companies in the world, split away from the Exxon-Mobil denial campaign in a break historians will see as significant.  BP’s CEO, then John Browne, announced BP would no longer deny,  in 1997 in this way:  “over time we can move towards the elimination of emissions from our own operations and a substantial reduction in the emissions which come from the use of our products”.  The word came down from BP’s senior management starting from then on in a way that simply did not happen with Exxon-Mobil and most of the rest of the US oil and gas industry:  BP started to do something about their own emissions.  BP made money doing something about methane.  BP CEO Hayward in 2007 called on world governments to put a price on carbon, saying “although the challenges of climate change are grave, they can be solved.  Human ingenuity knows no bounds – and human kind will solve its biggest challenge to date”.  

Basically, I’m more cynical than the next guy.  But it is obvious.  If US Big Oil would throw in the towel on the denial campaign, everyone would feel better and we could move on.  We could aim for stabilization.  General Accounting Office data shows BP’s words were translated into action in the San Juan Basin, and the same dataset proves US industry could care less. 

If gas industry people want to know how bad this leak problem is, they can ask BP, who are in a position to say how much of this can be eliminated, how long it will take, and what it will cost. 

Clearly, the use of natural gas in the entire world up to now has been worse than coal. 

E.g.:  in 2004 the GAO accepted the US gas industry line that leaks were lower than 1%, and looked out at the mayhem going on in the rest of the world (Russia announced it was not flaring at all even as NOAA satellite data proved they were doing “significant” flaring) and in comparison estimated world leakage at 3%.  Maybe world data was actually beyond 6%.  Why is 10% out of the question?  This industry is using natural gas in areas where there is no electric grid as a power source, not by burning it, but as a substitute for compressed air.

In the US, past gas use must have been worse than coal and may even now be worse than coal.  It may add up that the historic use of gas in the US to the present has been worse for the climate than if coal had been substituted all along, even if the climate impact is viewed over 100 years.



1. EPA/GRI (1996) Methane Emissions from the Natural Gas Industry. Prepared by Harrison, M., T. Shires, J. Wessels, and R. Cowgill, eds., Radian International LLC for National Risk Management Research Laboratory, Air Pollution Prevention and Control Division, Research Triangle Park, NC. EPA-600/R-96-080a.

2 EPA (1996) Methane Emissions from the U.S. Petroleum Industry (Draft). Prepared by Radian. U.S. Environmental Protection Agency. June 1996.


Geoffrey Styles's picture
Geoffrey Styles on Dec 7, 2010


Thanks for digging through the details of the EPA’s latest study on methane emissions from natural gas production.  I agree that a figure of >3% leakage is surprisingly high, though as I’ve noted in other comments the solution is not to abandon gas drilling, but to make sure those leaks are addressed, the gas captured (and marketed) and the emissions converted from CH4 to CO2 in the course of using energy that would otherwise be wasted.  However, these figures don’t seem to support your contention that “gas is worse than coal.” 

Take the 261 MMt of CO2e referenced in your posting and substitute it for the figure of 103.1 MMt for CH4 emissions of natural gas systems in 2006 from the EPA’s latest National Greenhouse Gas Inventory.  Then add that to the 29.5 MMt of CO2 from natural gas systems and 85% of 1,141.4 MMt of CO2 from natural gas combustion (to count only the combustion emissions of domestic gas)  to get a grand total of 1,261 MMt CO2e attributable to domestically produced natural gas in 2006, after accounting for the newer leak estimate. (This over-counts the contribution of domestic gas by attributing all the transportation, storage and distribution emissions to it, and none to imported gas.) That’s 20.7% of net US emissions in 2006 of 6,101 MMt, resulting from that 85% of gas’s 24% of US energy consumption in 2008, per the EPA, or a domestic gas contribution of 20.4% of US energy.  Now compare that to coal.  From the same EPA GHG inventory, methane emissions from coal mining in ’06 were 58.3 MMt CO2e, ignoring abandoned mines.  CO2 emissions from coal combustion were 2077 MMt, for a total for coal of 2,135 MMt, or 35% of net US emissions, for a source providing 22.6% of US energy. 

So after accounting for the extra emissions from leakage shown in the latest EPA study, in the context of its latest US emissions inventory, gas emits 65% as much CO2e per BTU as coal.  The only way I can see to make gas look worse than coal using these figures is to apply the much higher short-term GWPs to methane emissions, as you suggested in a recent posting.  If that’s the key to your argument, it’s a bridge too far for me, because climate change is not generally regarded as just a 20-year problem, but a long-term problem, and the extra CO2 emitted by all the coal we’ll burn if we turn our backs on gas now would be influencing the climate long after the short-term kick from any extra leaked natural gas–gas that we are largely capable of collecting rather than emitting–has faded out. 

David Lewis's picture
David Lewis on Dec 8, 2010

You’d have to add 30%+ to your calcuation when it comes to anything involving GWP for methane the way I see it.  EPA and the IPCC for that matter have yet to adopt Shindell’s figures for GWP.  I did n’t have to compensate as all I was interested in finding out what the raito of leaks was to the overall production.  I didn’t look deeper than what I needed to do to get an approximate, and lower than I could have found figure. 

The EPA 2006 National GHG inventory data doesn’t take into account new data on GWP for methane.  Howarth says “several” IPCC authors who did the IPCC methane assessment say is “appropriate” to use this now.  (Shindell says uncertainties which will become more certain as research goes on, which can only add to the power of CH4 were left out because he was considering a number of gases). 

Re:  imported gas

There is NETL, what they say they’ve just published is the “first” lifecycle GHG analysis of several types of gas generation technology.  They have studies on separate technologies and a compilation report.  I looked at their NGCC report and briefly at the Compilation report.  They do separate studies based on whether the gas was imported or is domestic.  The imported gas is taken to have more of a climate problem.

Industry says US leakage is best in the world.  Interior said that to GAO citing GAO 2004 in reply to GAO 2010.  GAO didn’t say that in 2004 I thought, but…

If industry wants to insist, let’s say all imported gas is worse.  I’m not sure what you are saying about imported gas.  I’m not certain what is in the figure EPA gives for US gas leaks.  They broke it out of the combined data for gas and oil without saying how. 

As far as I could tell, what I’m looking at is a combined gas and oil production industry that gets some gas and some oil out of a lot of wells.  How anyone is supposed to separate out what is happening to the level of detail industry demands as they seek to stuff that last molecule of CO2 into the atmosphere that anyone will possibly let them get away with I don’t see. 

If you say we might think about subtracting imported gas from pipeline data assigned to US gas, but we won’t, maybe we should start asking questions about where the meters are, i.e. if they are there, how many and where.  Gas starts coming up out of the well, and until it gets to the meter it is sort of hard to “estimate” how much there is (was).  It is in the interest of the operator to be not that interested in leaks until a meter has recorded how much was there to start with compared to how interested he is in leaks the authorities have fined others for in the past.  The leaks that are penalized are not very many of the leaks, and the oversight seems less than what we’ve got for speeders on the freeways near Seattle.  I’ve worked in industry.  It isn’t necessarily squeaky clean.  I thought everyone got a fresh snapshot of exactly how industry practice might tend to vary a bit from regulation, when BP lost that platform out in the Gulf.  Where do people get the idea industry is not like this?  Its industry  

There’s a guy who says the only way they got governments to sign the Nuclear Test Ban treaty was by developing new scientific capability to distinguish earth tremors from bomb tests at very long range.  There were people who thought it couldn’t be done.  It was done.  Because verification was possible, the treaties were signed.  Now people are saying let’s develop the capability to measure by satellite and in other ways detailed and accurate GHG emission data so the self reporting, by operators in US gas and oil fields, by countries and by anyone anywhere can all stop. This guys says these calculated national GHG inventories are a joke.  He tests parts of them by going around measuring with what’s available now. 

One reason GAO gave me when I asked why they did in 2010 what their 2004 report should have made unnecessary, because in 2004 they looked at this same issue and said clean it up and industry said yes that’s what they were doing, just as they are saying now, was because new technology has arrived in the form of IR cameras, etc.  GAO’s report on gas venting and flaring issued 2010 says leaks of a magnitude thought “larger than previously thought possible” were found in a way industry could not deny because of these things. Cynics might interpret this this sudden discovery in other ways.  “We didn’t know”,  lacks conviction.  How are you supposed to not know gas is pouring out from your equipment?  Its flammable.  There is stuff out there  now that is well tested that can directly measure the concentration of gases in air from long range.  DIAL is one technology. As people zero in, funny thing, they are discovering things industry “didn’t know”.

Anyway, you mentioned imported gas as if it was a point you were conceding, I thought I’d mention something as well.  It doesn’t matter. 

The GWP of methane is 30%+ higher than everyone thought it was until Shindell published.  I don’t see you compensate in your calculation.  I can’t face a load of numbers right now maybe I’ll look at yours later.  30%+ on calculations involving leaks of 3-4% are getting bad, says Howarth.  Beyond 5% leaks it is getting worse than coal at 100 years, he says.  My assertions that historic use of gas in the US and in the world must have been worse than if coal was substituted for that supply of energy if viewed over 100 years are conjecture, based on everyone tells me how they are squeaky clean now that the bad old days are past which are quite recent.  World emissions were said by the World Bank in 2004 to be 3%, EIA said 4%, but that was from people who thought US emissions were less than 1%.  US emissions were greater then than they are now, otherwise I’ll just have to accept that all the industry talk about how they’ve been cleaning up all this time were outright lies because they were actually making things leakier?  This is the implication of finding that US emissions are now between 3 – 4%.  If global was far worse in 2004 and the US was obviously higher than 3 – 4%, what were global?  Where did gas get this “green” rep?  What were people thinking? 

Howarth’s paper is undergoing peer reivew, but it will come out.  If he responds I’ll try him on a general question involving math like yours. 

Industry wants to pretend nothing is actually real until years of bureaucratic infighting takes place.  If this was a battlefield, the commander would be taking a report like EPA, Shindell and Howarth and acting on it.  There is nothing real at stake of course, just the viability of the planet to support life.  

By the time the climate impact of gas compared to coal is not one half of coal but its 85% – 115% depending on whether I thought the next 50 years wouldn’t be getting too close to the brink of some tipping point or something and I’m supposed to be fine with calculations to the precision of significant figures to the speed of light that say something bad is slightly better than something worse if viewed over 100 years, and its radioactive, I don’t know.  I’ll have to ask my Mom. 

This GWP thing is not that well understood by your average climate guy, including me. Its a calculated value that would change depending on how much of what you are calculating the impact of accumulates, as it accumulates.  The “lifetime” doesn’t mean it isn’t there after its “lifetime”, its a description of a decay rate, you can ask what is the impact at 25 years, 50 years, 75 years,  not just 20 and 100 years, the impact doesn’t suddenly disappear at the end of the period which is what the calcuation assumes.  Its a thing I don’t have a handle on to describe in a few words.  The climate impact of coal is also modified by the aerosol that comes along with it, more or less.  I’ve seen a paper that would have me believe all that Chinese coal hasn’t really affected global conditions yet because all the aerosol that comes out with it compensates. You substitute gas for that coal and the air looks cleaner and but all that CO2 that was hidden by aerosol until now suddenly makes itself felt.  Boom. 

There will be a number someone more versed in this than I am can come up that’s better than yours or mine when the dust settles on this where we can roughly look at gas and say it can be said to have about the power of coal in a certain country given its aerosol policy, if viewed over the next “x” years.  My feeling is that will be way more than 20, and I don’t rule out 100.  As I said when I first exchanged views with you here, no one listens to me.  I’d stop investing in any more fossil infrastructure starting twenty years ago.  I was calling for stabilizing the atmosphere at less than 350 ppm starting twenty years ago.  I’d be moving to power sources that emit what wind and nuclear emit.  This arguing about whether gas is green seems like arguing about whether I should let someone keep feeding arsenic to my mother now that I’ve discovered someone doing it, because they claim they’ve got some that is “less” harmful. 

The closer I look the more iffy that “green” case for gas is. 



Charles Barton's picture
Charles Barton on Dec 8, 2010

Geof, I understand why you believe that the natural gas leak problem can be solved, but you appear to rest your belief on a hypothetical argument, the does not take into account the actual conduct of the Natural Gas Industry.  When I checked into the causes of a number of recent natural gas explosions in North Texic, I discovered that natural gas leaks from defective compressors were repeatedly mentioned as part of the problem.  Texas gas companies have known about the defective compressors for some time, but have not moved to replace them.  There are 360,000 miles of natural gas pipeline in Texas alone, and it seems unlikely that all willl be well maintained.  It is known that there are 3 million defective natural gas compressors in Texas.  Gas companies have not announced plans to replace them, and appear to be draging their feet. 

Geoffrey Styles's picture
Geoffrey Styles on Dec 8, 2010


Two quick points.  First, re import issue.  EPA’s stats for emissions from US natural gas in 2006 included the emissions associated with transporting, storing and distributing the 15% or so of net gas consumption that we imported, mainly from Canada.  By applying all of that to domestic gas production as a first approximation, I was over-counting the resulting emissions effect.  That has nothing to do with the non-US emissions associated with imported gas, which aren’t the issue here.

Two, re GWPs.  From what I read in your postings and comments, inflating the GWP for methane by 30% depends on the findings of one paper and is a matter currently under discussion by some in the IPCC, but not yet in the category of official policy and “settled science.”  Even so, for argument’s sake let’s take EPA’s 261 MMt of CO2e and ratchet it up by 30% to 339 and add in the indirect and combustion CO2, to get 1339 MMt of CO2e for domestic gas’s 20.4% of US energy consumption.  Then we also have to up the impact of the methane emissions for coal, increasing its total to 2153 MMt for coal’s 22.6% of US energy. That still leaves total CO2e emissions from gas 31% lower per BTU than those from coal.  And note that this doesn’t factor in the consumption side efficiencies of gas in the power applications that are the main focus of coal displacement, which has CCGTs at better than 50% efficiency, compared to coal in the mid-to-high 30s.  No matter how you slice this, it still doesn’t come up supporting your assertion that “gas is worse than coal”.

Geoffrey Styles's picture
Geoffrey Styles on Dec 8, 2010


The conduct of the companies in question is one thing, but are you claiming that capturing a much larger fraction of that leaked gas is not possible from an engineering and/or cost perspective?  And if so, on what basis?  It might be expensive and require changes in practice and process, but there’s also a nice reward attached to it. The 650 BCF of annual leaks David calculated from the EPA report equate to $ 2.6 B/yr at current wellhead prices. Producers and pipeline companies might not be able to prevent all leaks, but I’ll bet they can cut them substantially with that kind of incentive and a bit of public scrutiny on the issue.

David Lewis's picture
David Lewis on Dec 8, 2010

This industry is risking the “green” image its product has that it is a “bridge” fuel, as if it knows nothing matters except what can be forced through a political system it believes forces it is allied with have under control.  Its going to find out that you actually can’t fool all the people all the time. 

The shills who made the argument that the leaks are under control:  do you think we’d just leak what we sell as if we didn’t know we could capture it and make money,  knew it was bogus.  One of them called me:  she’s still making the argument.  You are either one of those people or you were taken in by them too.  It is inconceivable that a CEO competing with BP did not know what BP was doing on this front for the last decade.  Decisions were made to concentrate capital investment on getting access to more product rather than to make the most of what had been discovered.  The rest of it, how long it takes EPA to change its reference document, how long it takes to percolate up to the IPCC, how long industry can keep the lid on Shindell’s findings, how long they can keep up their campaign to discredit Howarth, the people doing it may even be on automatic pilot, going home to the families they care about where they teach their kids not to lie. 

Dr. Howarth has worked for months studying the literature and calculating.  I have only examined the issue for a few days.  I read some of the references he gave me, and I looked for things he may not have included to see if the smoke he says he’s seeing is this big fire.  When I saw the paper EPA put out I discussed in this post showing methane leaks are 30 times what industry claims, which says that EPA put out the reference the IPCC used and EPA is now saying its original assessment was that far out of whack, I realized this isn’t a question of wondering how solid Dr. Howarth’s work will prove to be.  There’s a lot of interest in what he’s doing.

 This idea that everything has to percolate up to the IPCC won’t wash.  US Big oil and gas has been cheering on the attacks on IPCC credibility even though the most casual inspection shows no intent to deceive existed.  Meanwhile their spokespeople are still claiming their operations do not cause what the EPA has found. The gas industry was reported by the NY Times to be still insisting the leakage is 0.1% of production. 

If NASA found aliens on Mars, if US Big gas and oil treated the information in the same way its people are doing with this, they would deny it saying its only one paper published by a NASA staffer no one heard of before.

Industry spokespeople argue like lawyers protecting a client they know a court can’t pronounce guilty until there is proof beyond reasonable doubt.  That’s fine for individuals and a society that is prepared to face the cost of letting a lot of what look to be obviously guilty people go free in the interest of not depriving a far fewer group of innocents of their liberty. 

This adversarial system is not working when it comes to minimizing how far planetary destabilization proceeds as civilization expands its activities. 



David Lewis's picture
David Lewis on Dec 8, 2010

Erik’s been on this case for years.  He pointed out the EPA study I wrote about here to me. 

I think the nuclear crowd would find what he says about natural gas to be more palatable than what they’ve been seeing over at Climate Progress or from the Sierra Club. 

I don’t know what Erik’s position on nuclear is.

David Lewis's picture
David Lewis on Dec 8, 2010

Howarth says he had to use the latest data from Europe on the leakage from transmission pipelines, because “there are no data in the US“.  He wrote that the European data is

“low, since they do not include accidents, etc.  Note that these pipelines are newer than the average for the US.  For our high end estimate for leakage from pipes, we used accounting data for Lost and Unaccounted For Gas in Texas.  Note this gives us a range that is within that reported by one of the only other peer-reviewed papers out there. See:  Hayhoe Substitution of Natural Gas for Coal:  Climatic effects of utility sector emissions Climatic Change 54: 107-139″

The “dragging their feet” part is hard to believe but it is proven fact.  They appear to have political support.  Interior responded to the fact GAO’s latest study on gas leaks appears to buy EPA data rather than the Industry line by saying GAO bought the industry line in 2004, as if Interior still believed industry is going to get somewhere as it keeps on selling that, as if it can’t understand that EPA studies will withstand scrutiny.  BLM, who control most of the gas production was reported by the Associated Press as having “resisted calls for change, saying the emissions from gas produced on federal lands are impossible to link directly to climate change“.  I contacted BLM for comment, referring them to these posts I’ve been doing on gas and the AP report.  They responded instantly with a guy saying he’d get right on it and get me a statement that either confirmed AP got their position correctly or that they’d restate their position. I framed the query by saying industry is risking its “green” image over something they could be making money on, it looks suicidal to me, are you enabling them or are you going to try to help them see what would be best for them?, sort of thing. 

I never heard from them again.  I imagine a news headline:  Gas Industry commits suicide.  BLM has no comment. 

Gideon Polya's picture
Gideon Polya on Jan 3, 2011

I was interested in your estimate that “3.25 % of US natural gas production leaks into the atmosphere as methane gas” whereas “The industry has been saying the leaks are tiny, less than a fraction of 1%..”

I have done a simple calculation to show that with 3.7% methane leakage the greenhouse effect of the leaked methane is the same as the greenhouse effect of the CO2 from complete oxidation of the 96.3% remaining methane  (see “Gulf oil & gas disaster, lobbyists, Obama & huge threat of natural gas (methane) to Humanity & Biosophere” ).


Methane (CH4) has a molecular weight of 16 and carbon dioxide (CO2) has a molecular weight of 44.

When you burn CH4 you get CO2: CH4 + 2O2 -> CO2 + 2 H2O.

Accordingly burning 16 tonnes of CH4 yields 44 tonnes of CO2 and burning 100 tonnes of CH4 yields 100x 44/16 = 275 tonnes of CO2.

However if there is industrial leakage of CH4 (estimated to be at least 2.2% by the US EPA) then one must consider the greenhouse gas effect of the released methane (72 times worse than CO2 as a greenhouse gas on a 20 year time scale).

Of our 100 tonnes of CH4, how much CH4 leakage (y tonnes) gives the same greenhouse effect (in CO2 equivalents or CO2-e) as burning the remaining CH4?

y tonnes CH4 x (72 tonnes CO2-e/tonne CH4) = (100-y) tonnes CH4 x (2.75 tonnes CO2-e/ tonne CH4).

72y tonnes CO2-e = (100-y) 2.75 tonnes CO2-e

72y = 275 – 2.75y

74.75y = 275

y = 275/74.75 = 3.68 i.e. a 3.7% leakage of CH4 yields that same greenhouse effect as burning the remaining CH4.


3.68 tonnes leaked CH4 corresponds to 3.68 tonnes CH4 x 72 tonnes CO2-e/ tonne CH4 = 265 tonnes CO2-e . Burning the remaining 96.32 tonnes of CH4 corresponds to 96.32 tonnes CH4 x 2.75 tonnes CO2/tonne CH4 = 265 tonnes CO2.

You may be interested in this detailed and documented draft report written for people who are threatened by a proposal for a 1,000 MW gas-fired power plant 1.5 km from the town of Gatton (population 6,000) in the fertile Lockyer Valley, SE Queensland , Australia  and entitled  “A detailed resource to stop the Gas Boom, Gas Rush, Gasland obscenity devastating Australia and America”, Bellaciao, 27 December 2010: .

Dr Gideon Polya, Melbourne, Australia.

David Lewis's picture
Thank David for the Post!
Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.
More posts from this member

Get Published - Build a Following

The Energy Central Power Industry Network® is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »