As someone who has followed the BC LNG debate pretty closely, I can’t count the number of times I have heard the expression “natural gas is a bridge to nowhere“. This expression derives from an infamous article by Cornell Biologist Robert Howarth. I have repeatedly argued that Dr. Howarth’s research is not applicable in the context of BC LNG. My opinion is consistent with the peer-reviewed academic literature on this topic. Today I was directed to a new research article that I hope will finally put a stake into the heart of this horrible metaphor. This new article concludes that, even in the Marcellus Shale, natural gas “exerts a net climate benefit compared to coal” or as I put it: the climate math says that BC LNG has the potential to help in the global fight against climate change.

Let’s start this piece with a brief discussion of BC natural gas. When it comes to issues around natural gas, geology matters. In BC, most of our natural gas is very deep and sour. As the BC Oil & Gas Commission puts it:

B.C.’s geology provides a natural advantage over other areas of the world where hydraulic fracturing takes place closer to the surface, as natural gas in B.C. is found deep underground, in some cases over four kilometres, and beneath impermeable layers of rock.

Look at that sentence again. I admit one thing I often fail to really comprehend in geology is just how deep these formations are. In the Montney the gas is located 4 kilometers beneath the surface. Think of that number again. We are talking about 4000 m of rock. If you were to start walking down the street at average human walking speed it would take you 48 minutes to travel the depth of this gas…all through layers and layers of virtually impermeable rock. This is why fracking really can’t do anything to affect our drinking water aquifers which are typically very shallow. Sour gas, meanwhile, is poisonous and as a result it is dangerous to vent. As a consequence, venting and flaring of gas is strictly controlled in BC.

These two considerations are very important because the deeper the gas the more buffer zone to prevent infiltration of methane and fracking fluids into our drinking water aquifers and the nature of sour gas means that our regulators are far more cautious about fugitive emissions as any releases can have serious medical consequences for anyone near a drill site. So when someone from places where the gas is much shallower complains about fracking all I can do is to shake my head and say “geology matters”.

But one of the biggest arguments against BC LNG has been based on the research by Dr. Howarth at Cornell. As I noted, Dr. Howarth is a Biologist by training but has made a name for himself criticizing natural gas development. Most of his work has been heavily critiqued (as I detail in a previous blog post) with some of his biggest critics being his own colleagues at Cornell. Arguably they aren’t really his colleagues because unlike him they are trained geologists. Even though actual geologists sharply critique his work, his most famous paper, the Bridge to Nowhere article, seems to always be part of the arguments used by opponents of BC LNG.

Because of its apparent importance in the debate I keep a look-out for newer research on the topic and was very interested in a new study by Ren et al. “Methane Emissions from the Marcellus Shale in Southwestern Pennsylvania and Northern West Virginia Based on Airborne Measurements“. This new study effectively puts a stake in the heart of the “Bridge to Nowhere” argument and hopefully will put to bed the argument that BC LNG is worse than coal for powering Asian economies.

The new study uses airborne measurements combined with direct sampling to calculate an estimate of the methane emission rates of the Marcellus Shale. Their plain language summary says:

In this study methane (CH4) emission rates were estimated for the southwest Marcellus Shale based on airborne observations. A mean emission rate of ~21 kg CH4/s was observed from a 4200 km2 study area. A significant portion (~70%) of the emitted CH4 was found to originate likely from coalbeds. Our mean estimated emission rate of 1.1% of total natural gas production indicates a climate benefit of natural gas combustion compared to coal, but the full range includes values above the 2.4% break-even point for the CH4 global warming potential over a 20-year time horizon.

So what does that mean? Well the numbers they get are about a third of what Howarth uses in his paper and their best estimate is less than half of the 2.4% necessary for natural gas to be an effective alternative to coal in our fight against climate change.

What is even more interesting is that their study doesn’t even consider another recent paper titled Temporal variability largely explains top-down/bottom-up difference in methane emission estimates from a natural gas production region by Vaughn et al. This paper came out while the Ren paper was in production and makes the cogent observation that the flights used by researchers (like Ren et al.) to measure methane only happen during the day (usually in the middle of the day). This coincides with when maintenance on natural gas facilities (which requires that they flush their systems) are typically occurring. As such, it is likely that this type of sampling overestimates total emissions.

For an analogy it would be like traffic counters only working during rush hour and then extrapolating that rush hour conditions exist over the entire 24 hour day including the middle of the night.

In particular, it would explain why sampling often finds intermittent super-emitters that drive the averages higher. It is likely that many of the “super-emitters” cited in other reports simply represent one-time flushing being done for maintenance purposes. This is important because these outliers have a massive effect on the statistics and may grossly overestimate total emissions.

The interesting additional feature of the Ren et al. paper is that as part of their work the authors collected air samples for further chemical analysis. By comparing the chemical composition of the collected gas (specifically the correlation between methane and ethane/propane) the authors were able to determine that as much as 66% of the observed methane in their observations were derived from coal beds and not from oil and natural gas operations.

This new analysis helps explain the discrepancies between the work that was done in bottom-up analyses and the top-down work. In particular it explains the recent NASA research showing increases from fossil fuel sources in global methane budget. It appears that in the Marcellus Shale, at least, coal mining may actually be the primary source of anthropogenic methane in the atmosphere. The serves as another reason, (as if we need one) to reduce or eliminate the mining of coal in that area.

As someone who believes in evidence-based decision making the recent research makes it abundantly clear that the climate math strongly supports BC expanding its LNG industry. As I have noted in the past, the most recent research on this topic demonstrates conclusively that when replacing coal in Chinese energy facilities, BC LNG produces lower total, life-cycle emissions.

Even more importantly, in the current market, BC LNG would not be replacing coal when exported to China. Instead BC LNG would mostly be replacing Chinese synthetic natural gas (SNG) and on that topic the climate math is even more categorical. BC LNG is much, much cleaner than Chinese SNG from a life cycle perspective. 

Finally as this new research shows, the alternative argument used by the opponents of BC LNG, that natural gas is a bridge to nowhere, has been staked in the heart. Using the activists’ own top-down methodology these independent researchers have confirmed that even in the Marcellus Shale natural gas is a climate benefit over coal. The anti-LNG activists simply don’t have a leg to stand on.

Addendum:

I posted a comment about the Ren paper on Twitter and was surprised to receive a very quick reply from Dr. Howarth himself. Needless to say, he was quick to discount my initial analysis. When I asked him to correct me, (even going so far as to give him the benefit of the doubt that I might not have interpreted the article correctly) he blocked me. His response made it clear that I had indeed hit the nail on the head.

Credit: cover image from BC Oil & Gas Commission