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Question

What are most recent, credible studies on methane emissions from natural gas and LNG?

There has been growing debate over the question of whether natural gas and LNG are "better" than coal in terms of their GHG profiles. This debate has been sparked by a couple of studies which seem hgihly dubious in their methodology -- the most notorious being the Robert Howarth study. That one was savaged by his own colleagues at Cornell University.

I have read one more recent study (based on Permian Basin snapshots) that puts the average methane intensity for natural gas in the U.S. at 1.7%, which is about half what the IEA states it needs to be to put natural gas on par with coal (3%).

In British Columbia, the methane emissions rate for natural gas production is said by the provincial government to be very low -- 0.3%. One study funded by the David Suzuki Foundation (again, the methodology was highly questionable in that study) estimated methane emissions in B.C. could be 2.5 times higher than the government and industry estimates. Even if that's true, that still puts it at only 0.7% -- well below the 3% threshold esttablished by the EIA.

I'd like to stay on top of this issue, so if anyone can point to studies done by credible academics with actual expertise in GHG life cycle analysis that deal with this question, I'd appreciate if you could point it out. I'm starting to collect these studies and keep them in a Flipboard magazine for easy reference.

Thanks in advance for any pointers.

Answers

Here you go Nelson. Key takeaways:

• Methane leakage is estimated to be 2.3% of production, suggesting it's been grossly underestimated in prior studies
• Methane's impact on global warming, for the first 20 years, is approximately 80x that of CO2
• With leakage included, the climate impact of natural gas electricity generation is 40% worse than coal

A deal-breaker for both gas-fired electricity, and the "renewable" energy which depends on it.


 

Good question Nelson. The article I sent via link (please tell me if you do not receive it) is by no means a definitive answer. But it may help in your research.  I too will be interested to hear about any other studies.  So called fugitive emissions are aptly named.  They are hard to find, harder to measure and, sometimes, even harder to reduce, much less stop. I imagine you are aware of various EPA studies and methodologies that try to put numbers on fugitives.  All have their shortcomings.  There is a growing realization among some producers that accurate knowledge of fugitives is the first step to recover the considerable value of the gas, even if their efforts are not driven by environmental considerations.

You would be correct to be skeptical of the studies you cite. Even if the data are valid and accurate, they are only points in time.  As facilities age, they leak more. 

And the numbers get even more dubious, for example, for offshore LNG projects that involve drilling, production, processing, liquefaction, loading, shipping, off loading, re-gasification, pipelining, power plant processes

, so called "wells to watts" figures in order to compare GHG emissions to, for example, coal or very heavy oil.  I would be surprised if you see those figures published.  Those I have seen are not pretty.  But please tell me if you find them!

I have read and re-read about a dozen studies in the last 6 months. My findings are:

1) Methodologies are suspect in all cases for example -  4 of the studies used the same measurements from a single well with a cracked seal and came up with very different results. These measurements were admitted to being high and the initial field report indicated that the sensors were out of calibration - meaning the readings could be right, high or low - nobody knows and never will.

2) Assumptions in all of the studies are interesting to read, if I were to take one study and use another's assumptions - I would get very different results. There is no consistent methodology and no consistent assumptions in the reports. 

There is a need for a methodology and set of assumptions to be agreed to, before the research is useful for coming up with answers. Until then I recommend reading carefully any report you want to cite. 

Matt Chester's picture
Matt Chester on Jul 23, 2019 5:28 pm GMT

This is an interesting answer, Doug. The problem is-- whose job is it to determine the 'right' methodology and assumptions. Will it come from a scientific/geological conesnsus? Will it be from an international governing body? Will it come from industry itself? Each stakeholder who could lay a claim to setting an authoritative process inherently has a mission or a bias, so it makes getting agreement on even just the measurement a tough task with no clear process

One conclusion we can take away from these studies is that accurately measuring methane leakage at the source - a diffuse, invisible gas, escaping into the atmosphere simultaneously at tens of thousands of different locations - is impossible. Exacerbating the difficulty are conflicts of interest - with $billions in profit at stake, do gas producers really want the public to know how much gas they're leaking into the air?

A corollary is the impossibility of verifying the toothpaste-back-into-tube fantasy of "carbon capture and sequestration" - that an more ubiquitous, diffuse, invisible greenhouse gas might be stored away for eternity, simultaneously, at tens of thousands of different locations, by those with precisely the same conflicts of interest.

The longer we sidestep the difficult but inevitable solution, the more difficult it becomes. That, of course, is to leave it in the ground.

There is not a lot of disclosure--especially reliable information is not easy to find. And it's also true that according to the world region countries and companies release different level of information.

However, it might be worth having a look at the companies' presentations as sometimes they provide some data. Alternatively, some studies done by international organizations might be useful. 

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