One of the reasons why the US appears to be emerging from the credit crunch earlier than the rest of the world is that for the past ten years it has benefited from a boom in cheap energy. This has come from shale gas through a process known as fracking. Fracking also provides a cleaner as well as cheaper source of energy. According to US government figures carbon dioxide emissions fell by 2.4% between 2010 and 2011 and much of the 9.1% fall in US carbon dioxide levels since 2007 is credited to the switch from coal to shale gas in their power stations. The UK government is also anxious to benefit from its shale gas deposits which are said to be considerable. However like any new technology there are concerns as well as benefits. So what is fracking and what are the concerns?

Fracking is shorthand for hydraulic fracturing and refers to how the rock is fractured by using a high pressure mixture. The fracking process consists of drilling down and creating tiny explosions to shatter and crack hard shale rocks to release the methane gas inside. It takes about a month to drill down to the gas-rich shale beds that lie between 1 and 2.5 km below the Earth’s surface. Fresh water aquifers, which typically lie less than 100 m underground, are protected by triple layer steel casings around the bore drill. Water, sand and ‘chemicals’ are injected into the rock at high pressure (about 1,500 lbs. per square inch or 1.034 x 107 N m^-2) which allows the gas to flow out to the head of the well. The process is carried out vertically or, more commonly, by drilling horizontally to the rock layer once the shale layer has been reached. The process can create new pathways to release gas or can be used to extend existing channels. A productive well can produce thousands of cubic metres of gas every day for 20 to 40 years.

Part of the concern comes from the ‘chemicals’ which are injected. In fact more than one hundred substances (including water which is also a ‘chemical’!) have at one time or another been used. A list of those used most often has been published by FracFocus. Essentially they are listed by the function(s) they perform. These functions include acid, biocide, breakers, clay stabilisers, corrosion inhibitors, cross linkers, friction reducers, gelling agents and surfactants etc.  Common chemicals on the list include hydrochloric acid, sodium chloride and methanol but in fact an IB student would recognise almost all of those listed. There are concerns that these chemicals could somehow escape and find their way into drinking water and that some are potentially carcinogenic but there appears to be no hard evidence that this has happened. There are two other main environmental concerns. Burning shale gas in power stations causes much less pollution (carbon dioxide, particulates and sulfur dioxide) than burning coal to obtain an equivalent amount of energy. However the leakage of methane from the shale gas plants into the atmosphere could increase global warming as methane is a more potent greenhouse gas than carbon dioxide. There are also concerns that the drilling may trigger earthquakes, such as those caused by exploratory drilling in Lancashire, UK in 2011, and cause considerable disfigurement to areas of outstanding natural beauty.

Fracking combines both economic and environmental concerns and would seem to be an obvious choice to form part of the new Option C: Energy for the 2014 Programme (for first exams in 2016) as it encompasses the Nature of Science and modern up to date chemical technology. Unfortunately, although a sub-topic on fossil fuels is planned for Option C, it would appear that the opportunity to include fracking as an important component of this has not been taken.