Fracking is the popular term for hydraulic fracturing, the process of injecting liquid to put cracks in certain deep rock layers and coal seams so that they release the natural gas they hold.
The physics is similar to what happens when a bottle of soda water is opened for the first time — as pressure is released so too is gas.
That we can achieve such major environmental engineering is remarkable in itself for it requires knowing where the gas bearing rocks are and how deep. Then to drill down sufficiently to inject liquids sufficient to compromise the integrity of the rock layers so as to break the pressure seal that holds the gas within the rocks. The borehole then becomes a pipe to bring the gas to the surface.
Something very similar happened in the 1800s in the Middle East, US and then many other parts of the world. We sank boreholes to capture oil that became the fuel must regularly used for vehicles that soon proliferated into myriad shapes on wheels, wings and keels.
The only real difference with hydraulic fracturing is that the fuel is natural gas that only releases if the rock layers are broken.
boreholes used to dynamite rock layers — note that the rock layers have shifted along fracture lines so the bores no longer line up
Natural gas is predominantly methane, an efficient fuel source and a feedstock for the manufacture of plastics and, crucially, fertilizers.
In 2010 global production reached 120 trillion cubic feet increasing its proportion of global energy use to nearly 24%.
It is a fossil fuel considered cleaner than coal from the greenhouse gas perspective and a lot less messy when spilled.
Proven and probable reserves of natural gas are large and sufficient to support current rates of extraction for up to 200 years.
It can be hard to see why the extraction of coal seam gas should be an environmental issue.
1. Climate issue
Yes, natural gas is a fossil fuel that when burnt will add carbon dioxide [a key greenhouse gas] to the atmosphere. Only burning natural gas releases fewer greenhouse gas emissions than oil or coal and none of the particulates. In fact burning methane captured from landfills can generate carbon credits.
The environmental issue could be the disturbance and potential pollution that drilling and especially the injection of liquid to fracture rock might cause to groundwater. Many jurisdictions have stopped the use of harmful fluid lubricants so that most operations now inject water into the shale beds.
But our knowledge of groundwater is patchy at best despite the vital role it plays in irrigation, industrial water use and even domestic use in many countries. Breaking rock layers without knowing the consequences for water movement screams for the precautionary principle.
It is possible that weakening rock layers could result in subsidence or instability at the surface. Not too much of a problem if the fracking occurs in rural areas but many shale beds and coal seams are close to built up areas.
4. Land use conflict
Making fracking about land use has created a heated environmental issue. Gas extraction has been painted as displacing agriculture so that the issue is about land use and the values people place on each type of use.
But if farmers can herd livestock beneath vast arrays of solar panels and earn income from both meat and energy, there is no reason why boreholes and bullocks cannot coexist. Alloporus posted on ‘farming not fracking’ to highlight how odd this situation has become.
This, of course, is the real reason for the environmental issue with fracking. The current model in most countries is that rights to resources belowground are separate to rights for resources aboveground. A mining company with a gas extraction lease trumps the farmers rights to graze livestock on the paddocks above the gas reserve.
And this is the age-old issue — who owns what.
upland wetlands like this one in New South Wales, Australia are at risk if water drains through fractured rock layers
Until usable alternatives to fossil fuels are invented, then we are stuck.
We feed and clothe ourselves via an economic system that requires energy and unless there is an economic paradigm shift — a revolution of biblical proportions — we are stuck with that too.
Energy is a huge business opportunity. There is big money for anyone who can supply energy at reasonable cost and if all you have to do is to dig it up or pipe it out of the ground, there is a good chance of a tidy profit. When there is 200 years worth of supply in the ground and the knowledge and means to bring it to the surface, there must be very good reason why you wouldn’t do it.
But fracking is dangerous. It could easily create local instability, pollute vital groundwater reserves, and take land away from farmers and out of vital food production
Plausible arguments that can be translated into “ the common good is all good until it requires a compromise”
So we do have a conundrum of how much local compromise there must be to satisfy wider economic benfit.
Here’s a possible solution using estimates from Australia where coal seam gas and fracking have been hotly debated.
Estimates are that natural gas will deliver 25% of energy over the next 10 years. At 2013 prices in Australia that is roughly $20 billion worth of energy each year.
Now if fracking is banned then we forgo perhaps 50% of that production, equivalent to $10 billion worth of energy production, and there is a shortfall to make up.
Australia could burn more coal. However, this would further increase greenhouse gas emissions and make it almost impossible for Australia to meet its Kyoto commitment.
Instead alternative energy sources could be used – solar, wind, wave and biomass — that are currently more expensive and would have to be subsidized to be viable.
Create the subsidy by imposing a one-off ‘no coal seam gas’ levy of $500 per family on the 7.8 million Australian households that will generate a little less than $4 billion revenue to be spent on alternatives.
Except that this is not enough money to cover the shortfall and also big NIMBP problem — not in my back pocket — and hugely unpopular too.
And so we have another glimpse at the true root of environmental issues.
borehole through rock layers showing how easily rock fractures and hen shifts
Jul 26, 15 07:19 AM
Global environmental issues fall into three broad categories based on the extent of their effects. Thinking this way helps us to know when the issue is real.
Jul 26, 15 06:59 AM
The GFC hit hard and fast, reverberating through economies everywhere. There are a number of ways that this impact fuelled environmental issues.
Jul 26, 15 05:47 AM
Fracking is drilling and injection of liquid to fracture deep rock layers and release natural gas. It is similar to drilling for oil but far more controversial — find out why.