Natural gas is a fossil fuel that is produced through the decomposition and heating of organic matter over many hundreds of thousands of years. Conventional gas extraction involves drilling vertically through rock formations into gas pockets, from which the gas rises through the borehole and is captured at the wellhead.
However, as these convenient and relatively easily accessed pockets dry up, the industry has been developing ways of extracting gas that is trapped inside the rock formations – known as unconventional gas. The UK has potentially vast reserves of unconventional gas trapped inside shale rock and coal seams. In Scotland, its largely coalbed methane (CBM) that is being exploited.
Hydraulic fracturing, or ‘fracking’, is a controversial technique used to exploit unconventional sources of gas, such as shale gas and coal bed methane. It’s an expensive process which is only economically viable when the price of fossil fuels are high. It involves drilling deep in the earth (up to 20,000 ft in shale, but coal seams are much shallower) and pumping a mix of water, proppants (such as sand) and chemicals (including in some instances highly carcinogenic benzene and formaldehyde) under high pressure into the bore hole to open up fractures and ease the flow of gas for extraction.
There are many risks associated with unconventional gas extraction around the world. Coalbed methane developments are associated with the risk of leakage of methane – a highly potent greenhouse gas – into the atmosphere and local water environment; the lowering of water tables and subsidence; and problems related to the disposal of contaminated water extracted from coal seams. This is true whether or not fracking takes place.
In developments where fracking is undertaken there is the additional risk of toxic chemicals from the fracking fluid seeping into local water tables, poisoning drinking water for humans and animals, and contaminating agricultural land. Fracking is also known to cause earth tremors which – while unlikely to be felt by people – can cause damage to boreholes and wellheads thereby increasing the risk of methane and chemical leaks.
A key factor of the risks associated with the unconventional gas industry is the ‘multiplier effect’. Unlike conventional gas, coalbed methane and shale gas extraction involves a huge number of wells for each development, meaning that the likelihood of something going wrong is considerably greater.
Energy companies like to promote unconventional gas as ‘natural gas’, claiming that it is cleaner than conventional fossil fuels and the obvious answer to our energy needs. However, unconventional gas extraction is more energy intensive than conventional gas extraction and the added risk of methane leakage means it is far from clean. In fact, gas obtained through fracking could have a bigger greenhouse gas footprint than not only conventional gas but as bad as, or worse than, coal which is the dirtiest fossil fuel around.
There hasn’t been a proper assessment of the environmental and health risks associated with unconventional gas extraction – which include climate change emissions and risks to the water environment – nor of public acceptability of these activities. We think it’s essential that a broad, whole life-cycle assessment is undertaken before the industry is allowed to develop further.
Download our Policy Briefing.
Download our Unconventional Gas Free Zone resource pack: this will provide you with all the information you need to find out more about the industry, and help you set up your own community resistance group.
If you are concerned about any coal bed methane or shale developments in your area, please get in touch.