The exploitation of shale gases represents an unconventional form of natural gasextraction. In order to extract shale gas of sedimentary rock, a technology called hydraulicfracturing or „fracking“ is necessary.
The unconventional extraction technology „fracking“ involves possible risks such as the contamination of soil and water and resulting environmental impacts. There is a risk of ground water contamination from leaking methane during the fracturing process. Wether the link between methane emissions and the fracking process is actually causal or only correlated, is subject to an ongoing debate. The movie „Gasland“ (2010) by Josh Fox brought methane contamination that occured near fracking exploitation sites to widespread public attention.
Other environmental concerns involve the impact of toxic chemicals that are pumped into the shales along with sand and water during the drillings.
On the Potential for the Mitigation of Climate Change
Compared to other fossil fuels, natural gas in general has a significantly lower carbon footprint (due to lower impurity). It could thus be considered as a clean energy alternative or a transitional energy source. However, its carbon footprint is dependant on the cleanliness of the extraction process and subsequent transportation to other destinations.
By opening up new possibilities for the exploitation of natural gas, „unconventional“ extraction techniques such as „fracking“ can limit the stateʻs dependence on importing fossil fuels. By boosting a countryʻs energy self-sufficiency, fracking of shale gas could thus contribute to mitigate climate change.
However, there is no clear scientific answer to whether the fracking technology has lower GHG-emissions than conventional natural gas exploitation or not. As the level of advancement of fracking technology used varies to a great degree across countries, it is difficult to determine its actual impact on the climate. It is argued that cutting-edge fracking technology now allows for a very low carbon footprint of shale gas extraction. Considering a low carbon footprint, it might be a suitable bridge technology in the transition to renewable energy supply due to its emission abatement potential. Yet, shale gases remain a petroleum gas and thus a fossil fuel.
It is worth mentioning that most research resources essential to simulate possible outcomes of shale gas extraction lie in the hands of major energy supply companies.
