Can fracking help reduce CO2?

Question

The Guardian reports that the UK fracking tsar, Natascha Engel, has resigned and blamed anti-fracking activism for "fear-mongering", saying:

“There is much to be optimistic about how developing technologies – including fracking – can help us accelerate the reduction in CO2 and grow our economy. Sadly today only those who shout get heard.”

To me this seems completely illogical. I would think that fracking can only increase the supply of fossil fuel, that any increase in supply causes some increase in consumption, and that any increase in consumption of fossil fuel causes an increase in CO2.

Is there any validity to her claim?

Answer 1

If it replaces coal mining for power production, fracking reduces CO2 emissions, but that's not the whole story. Burning anything results in increased CO2 emissions, and methane leaks in fracked gas infrastructure result in CO2 equivalent emissions that erase the gains in reduced CO2 emissions compared to coal.

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Engel's argument rests on two key assumptions which have turned out true in the case of the U.S., which leads the world in shale gas production:

1. Natural gas replaces coal as a source of electric power. This is basically true. With an aging coal fleet, increasing natural gas-burning generation capacity, and falling power prices, several economists have looked at the direct effects on coal consumption. Numbers vary, but anywhere from 28% to 49% of the reduction in U.S. coal consumption is a direct result of the influx of cheap natural gas caused by the shale gas boom (see also here and here for more nuanced analyses). This means that a world with shale gas burns less coal than one without it.

2. Per kWh produced, coal-burning plants emit more CO2 than natural gas-burning plants. This is also true. Per unit of energy, coal produces more than twice as much CO2 as natural gas (source) when burned in a power plant.

But Engel ignores something that recent data is confirming more and more: leaks in natural gas production systems are chronically under-estimated and probably eliminate the GHG-reducing gains made by the shift from coal to natural gas.

This was documented in an article in Science published in 2018. The article, "Assessment of methane emissions from the U.S. oil and gas supply chain", can be viewed in manuscript form here. Phys.org has a good summary. Here's the most significant finding (emphasis added):

[R]esearchers found most of the emissions came from leaks, equipment malfunctions and other "abnormal" operating conditions. The climate impact of these leaks in 2015 was roughly the same as the climate impact of carbon dioxide emissions from all U.S. coal-fired power plants operating in 2015, they found.

Net generation from coal and natural gas were roughly equal in 2015, with natural gas increasing and coal decreasing since then.

The reason for this massive impact, and why leakage is such a concern, is that methane as a greenhouse gas is 34 times more potent than CO2 on a 100-year timescale. And that's just the leaks -- the natural gas still has to be burned, which will produced additional CO2 emissions.

Strictly speaking, if you're intent on digging things up and burning them and all you care about is CO2, then shale gas is better than coal. But it's still putting CO2 into the atmosphere, and if you factor in the global warming potential of leaked methane, it stops looking any better than coal.

Answer 2

First, let's agree on definitions. Fracking (or hydraulic fracturing) is a process by which fluids are drawn from the ground. In this context, the fluid would either be oil or natural gas.

From the article that you link:

Engel’s resignation letter said: “The UK is currently spending £7bn a year on importing gas – money that is not being used to build schools, hospitals or fix the potholes in our roads. Developing our own shale gas industry would mean money going into the Treasury rather than out.”

She added: “We know shale gas can be extracted safely. [...]

So she is discussing shale gas which is simply natural gas trapped in shale.

Also from the article:

Fracking, she said, had the potential to create jobs, economic security and provide a cleaner alternative to coal and biomass.

So she is specifically talking about substituting natural gas for coal. Some sources that support natural gas being better than coal in terms of greenhouse emissions:

• Natural Gas Really Is Better Than Coal
• Environmental Impacts of Natural Gas

Note that natural gas itself is a worse greenhouse gas than carbon dioxide. So to be cleaner than coal, they have to be careful not to let it leak.

It also may be worth noting that coal is a base load power, meaning that the plant is started and then run continuously. Turning the plant on and off is a lengthy process and not something that they do in response to variation in demand during the day. Coal power plants have a thermal mass, meaning that they continue producing electricity even after the flame is smothered.

Natural gas is on demand power. The generators can be smaller and turned on to meet demand. As such, natural gas is a more natural method to use with renewables like solar and wind than coal is. This is because those renewables are on supply power. They provide power when the sun is shining or the wind is blowing. But if you want power on a calm night, they don't help you.

Answer 3

The question is if fracking does...

...accelerate the reduction in CO2.

The answer is NO.

Consumption of fossil fuels is rising. (Also [1].)

So there is no reduction, and no acceleration of reduction that fracking could be part of.