Frack on, or frack off?
Hydraulic fracturing (fracking) has been around since the 1950s and is used across North America to extract natural gas.
The process of fracking involves drilling deep into shale rock to reach untapped reserves of natural gas in very small cracks. Drills can move horizontally so natural gas can be extracted many miles away from a fracking site. Water, sand and other materials are pumped into the hole to open the cracks in the rock, allowing the natural gas to flow out and be used.
Simple diagram of the fracking procedure. The pipes beneath the ground can be many miles long. *Image not to scale.
Proponents of fracking argue that it has helped to secure a reliable source of natural gas in North America, and this technology could be applied to areas such as the UK, South Africa and New Zealand. The US and Canada benefit from around 100 years of gas security because of fracking. For the consumer, a plentiful supply of gas drives down prices, as well as creating jobs.
The horizontal drilling mechanism can allow areas of natural beauty such as National Parks to be protected, by extracting the gas beneath them with no visible effects on the surface. Difficult-to-reach areas such as beneath the sea could also be reached from land with this technology. Furthermore, the burning of the gas itself produces roughly half the carbon dioxide emissions of coal burning.
Despite the reduced carbon dioxide emissions, there are significant pollutants involved elsewhere in the fracking process. The natural gas itself, which is mostly methane, has been found to leak in the production process, and as a more potent greenhouse gas than carbon dioxide, is more important to keep control of. The enormous volume of water, and the infrastructure used to pump it below ground, requires transporting and maintaining at the expense of further carbon dioxide emissions.
There are also legitimate concerns surrounding the leakage of contaminated water into conventional groundwater supplies that are often used as drinking water. This is usually dealt with by sealing the pipe with concrete in the upper portion, but leaks could still occur. Furthermore, public health concerns have been raised about some of the chemicals pumped to keep the cracks open - the details of which are not always fully disclosed.
Fracking and NIMBYism
Are you for fracking or against it? What if large shale gas deposits were found beneath your home, would you then be for or against fracking them? With all proposed energy solutions it is worth considering whether you would be a NIMBY (Not In My Back Yard!) or a YIMBY (Yes in My Back Yard!).
Fracking can release untapped natural gas reserves, providing a relatively cheap and easy to transport source of energy, with less carbon dioxide emissions than coal burning. But, when suggestions of methane release are taken into account, it’s role as part of a zero carbon economy could be questioned.
© University of Exeter