Mauna Loa, the observatory in Hawaii that produces the much-watched chart of the Keeling concentrations of CO2 in our atmosphere, also measures methane concentrations.
While not as monotonic as CO2’s relentless rise, it is clear that the amount of methane in our atmosphere has risen from 1700 nmol in 1988 to about 1830 nmol in 2015. Estimates of pre-industrial levels are 722 nmol.
Climate activist Bill McKibben, the man who called Barack Obama a ‘denier’ of climate change, has an opinion piece in Nation about natural gas and climate change. It is titled ‘Global Warming’s Terrifying New Chemistry,’ which seems odd, as there is nothing particularly terrifying and absolutely nothing new about the chemistry of global warming mentioned or even alluded to in his article.
I came to his article to scoff, and as you see below I scoff aplenty. However, at the end of the day McKibben has fulfilled his mission–although I think he foams at the mouth too much to be an effective advocate, he has caught my attention on the issue of methane and has forced me to pay closer attention to it, just for the sake of catching his errors. So now I will acknowledge that methane emissions are increasing and they do deserve our attention. I wish I could damn with even fainter praise, but let’s give the devil his due.
But before I give him his due, there’s a lot of criticizing that stands in the way. In his article, McKibben gets important things flat wrong, accepts unquestioningly a new metric put forward by an opponent of fracking and consistently looks at worst case scenarios as gospel truth. Nothing new in any of that, of course.
The subhead of his rant is ‘Our leaders thought fracking would save our planet. They were wrong. Very wrong.’
That’s error number one. Actually, our leaders didn’t think that. At most they thought natural gas would serve as a bridge from our dependence on coal to a future filled with renewables. More often, they couldn’t think of a reason to stop fracking and stood aside and let it happen despite objections from other fossil fuel producers, once some of the scare stories about fracking were exposed as propaganda.
McKibben writes, “an explosive paper in Geophysical Research Letters. Using satellite data and ground observations, they concluded that the nation as a whole is leaking methane in massive quantities. Between 2002 and 2014, the data showed that US methane emissions increased by more than 30 percent, accounting for 30 to 60 percent of an enormous spike in methane in the entire planet’s atmosphere.”In February, Harvard researchers published
Umm, error number two. The chart above shows a steady rise totaling 10% in 30 years. I don’t see an enormous spike–do you?
There is a spike in methane emissions, but it began in 1900, long before fracking could be blamed. That was about the time that large cities began using landfills to hold great piles of waste that generated methane. That was about the time that huge herds of livestock were held in confined spaces and their waste was collected and later liquefied.
In fact, methane from cows is the largest source of human-caused production of methane.
But onwards. McKibben is worried about leaks from natural gas production and distribution, as methane emitted from the production and distribution of energy is the second largest source of human-caused methane emissions. (He says nothing about cows.) He does say “These leaks are big enough to wipe out a large share of the gains from the Obama administration’s work on climate change—all those closed coal mines and fuel-efficient cars. In fact, it’s even possible that America’s contribution to global warming increased during the Obama years.”
America’s contributions to global warming are estimates based on sales of emissive products, mileage estimates for the fleet of cars, trucks and buses driving around, etc. As greenhouse gases mix fairly quickly in the atmosphere, there’s no way to say X% comes from America, Y% comes from Mexico and Z% from Canada. So where does he get his estimates?
The Harvard study was done by someone who McKibben admits is ‘an outspoken opponent of fracking’ and part of McKibben’s panic is based on a revised estimate of the impact of methane as a contributor to global warming–the revision being done, obviously, by the ‘outspoken opponent of fracking,’ a man named Howarth.
“The EPA’s old chemistry and 100-year time frame assigned methane a heating value of 28 to 36 times that of carbon dioxide; a more accurate figure, says Howarth, is between 86 and 105 times the potency of CO2 over the next decade or two.”
I won’t classify this as an error, but I think I’ll stick with the old figures for now.
Wikipedia notes “Methane in the Earth’s atmosphere is a strong greenhouse gas with a global warming potential of 29 over a 100-year period. This means that a methane emission will have 29 times the impact on temperature of a carbon dioxide emission of the same mass over the following 100 years. Methane has a large effect (100 times as strong as carbon dioxide) for a brief period, having a half-life of 7 years in the atmosphere. (My bold).”
Error number three. I put that last phrase in bold because McKibben writes “But a methane molecule lasts only a couple of decades in the air, compared with centuries for CO2.”
McKibben offers a solution: “We need to stop the fracking industry in its tracks, here and abroad.” He wants to move to solar.
However, Wikipedia also provides this table showing sources and sinks:
|Mass (Tg/a)||Type (%/a)||Total (%/a)|
|Wetlands (incl. Rice agriculture)||225||83||37|
|Emissions + Sinks|
|Imbalance (trend)||+20||~2.78 Tg/(nmol/mol)||+7.19 (nmol/mol)/a|
Wouldn’t it be more reasonable to work on all the sources of methane emissions? We literally cannot quit using natural gas to generate electricity in the short term unless we return to coal. We cannot put up enough solar even if we want to in a short time frame.
The EPA is already coming out with regulations to make the energy part of methane emissions ‘better’. Geneticists are working on making cows less emissive. Waste to energy plants could make a big difference, but are blocked by McKibben’s spiritual comrades in arms, who just want us to put out less waste.
McKibben’s article contains a lot of what-if estimates that I haven’t gone into here. While it should be clear (if it wasn’t before–they called it a ‘bridge fuel’ for a reason) that natural gas is not an end-state solution (there probably isn’t enough of it to last past the middle of the next century if we dive into it big time), it is a useful temporary solution that gets us off of coal while we figure out what combination of renewables and nuclear will best suit our needs.
So, yeah, okay McKibben. I’m now aware of methane. So would you please just quit foaming at the mouth?