In the UK last week, the findings of an investigation into earth tremors that followed exploratory shale gas* operations near Blackpool in the Northwest of England last year were made known. There had been doubts about the safety of the gas extraction method hydraulic fracturing** (also known as 'hydrofracking' or 'fracking') in areas of known seismic activity. Now, a report compiled by an academic from the Applied and Environmental Geophysics Research Group at Keele University (Staffordshire, UK), an independent fracking expert and the head of seismology at the British Geological Survey has concluded that it's safe to resume shale gas exploration, not just in Lancashire but across Britain, with one or two amendments to procedure.

One of the suggestions in the report concerns 'well integrity'. The second of the Blackpool tremors caused 'deformation' of the well's structure, which obviously raises issues of leakage and contamination. Cuadrilla Resources, the drilling company, have been asked to test whether the well's casings are intact. Seismic and well-structure monitoring surely need to be a permanent and integral part of gas mining procedure.

This report deals with only one of many controversial aspects of fracking, and has been criticised for such. When the findings were published in The Guardian in the UK last Tuesday one of many reader comments described the writer's experience of living in the middle of the shale boom in Pennsylvania. He mentioned the huge water consumption of each well; the large tanker fleets involved in bringing in water supplies and disposing of waste water and its contaminants ('fracking backwash') which include large amounts of salt; the associated escape ('fugitive emission') of some methane (one of the worst greenhouse gases for carbon emissions); the sheer number of wells and pipeline network required to mine a deposit; and the noise and pollution surrounding those wells. Other, wider issues of mining gas include the pollution or depletion of aquifers and groundwater; air pollution by petroleum hydrocarbons produced at fracking sites; and the despoiling of fertile agricultural land and beautiful landscapes (thus affecting tourism).

Much of the debate about this second dash for gasª misses a far more fundamental point, however. Extracting and burning natural gas will produce more greenhouse gases and therefore exacerbate the world's current difficulty in arresting anthropogenic climate change. Shale gas and coal-seam gas* may produce half the carbon dioxide that coal does, but they are by no means 'clean'. A by-product of mining shale gas can be the radioactive gas radon, a consequence not yet fully investigated. Gas is often touted as an interim measure, a halfway house between dirty coal and clean renewable forms of energy, but it is at best a short-term stop-gap rather than the answer to future energy demands in a carbon-challenged world, and will delay the day that renewables come into their own.

The bottom line is that most governments – regional, state or national – cannot resist the enormous profits to be made from the exploitation (including export) of vast reserves of relatively cheap fossil fuels. And with the promise of wealth comes the carrot of employment. I have never heard the threat to jobs being used as deftly as it is in Australia, whenever legitimate concern is expressed about the impact of the mining boom on human health, forests, unique ecosystems, habitats, water systems and even the Great Barrier Reef. Place people in sufficient fear for their livelihood and they will condone their politicians' ostrich-like attitude to a far greater impending disaster.

There are shale and coal-seam gas deposits in every continent on earth, being surveyed, subject to planning consents or environmental impact statements, or already in commercial production. Across the globe there are activists – be they farmers or parents or environmentalists – asking important questions about the loss of strategic cropping land, the noise and dust in their backyards where their children play, or chemical pollution from fracking. Sooner or later, down a lane near you, a rig will trundle into position and there will probably be very little you can do to stop it. Among all the other issues you may raise, one you must ask is what price a clean-energy future?

*natural gas is a naturally occurring hydrocarbon gas composed mainly of methane and associated with oil fields and coal beds. Shale gas and coal-seam gas (aka coal-bed methane) are examples of where the methane has been absorbed into the deposit: they are very similar chemically and produce the same amount of heat and carbon dioxide (roughly half that of brown coal). Shale gas extraction always requires fracking, whereas about half coal-seam gas reservoirs necessitate fracking. Shale gas is exploited extensively in the United States: Australia has huge deposits of shale gas as yet largely unexplored. Both countries have large coal-seam gas deposits, but Australia is closer to commercial production (mostly for export)

**see also Bimblebox, March 2012

ªthe first was the move by newly privatised electricity companies in the UK in the 1990s to generate electricity using natural gas

This post was last updated on 28 April 2012