The phenomenon of shale gas is both topical and controversial. Its proponents claim that it is a clean, environmentally friendly and abundant source of cheap natural gas; its opponents believe the opposite. In several countries it is a fast-growing industry and operations have begun in the UK. With conventional reserves of natural gas being quickly depleted, gas prospecting is turning to “unconventional resources”, one example being gas found in shale. Uncommon technologies, notably hydraulic fracturing and horizontal drilling, are necessary for shale extraction to be economical. Shale gas has faced some difficulties over concerns regarding environmental pollution. In the US, Gasland, an influential film was released alleging that waste fluid from hydraulic fracturing, “flowback water”, was polluting groundwater. While it is possible for methane to enter groundwater through a faulty well completion, in the UK it is the responsibility of the Environment Agency and HSE to ensure regulation is adequate to prevent risks to the environment or human health. There have been two earthquakes in Lancashire thought to have been caused by shale gas operations. The results of an investigation into these have been accepted as revealing that they were caused by hydraulic fracturing operations and new guidelines are being proposed to reduce the risk of this happening again. With insufficient public information and sometimes animosity towards shale gas, drillers need to consider developing corporate social responsibility programs tailored to the needs of the communities local to drilling, with especial consideration towards environmental initiatives. Worldwide, shale gas has had a significant and growing impact on gas production and looks likely to rapidly transform the energy situation. In Europe, Poland and France have the largest reserves; Poland has embarked on a program to exploit its shale gas reserves. France, on the other hand, has outlawed the hydraulic fracturing technology vital to shale gas on environmental grounds. The UK's shale gas reserves are unlikely to be large enough to be a “game changer”; however, they would contribute to gas security and the UK's energy mix, as well as being perceived as a lower-carbon alternative to coal-fired electricity generation. There are already substantial reserves of gas available worldwide; however, the development of these unconventional gases, which are often in more politically stable parts of the world, may provide a greater security of supply to the Western World going forward.