Shale gas: The pros and cons of an unconventional energy source

摘要

The search for new and alternative sources of energy continues as the global demand for energy increases. In the past 5 years, developments of unconventional oil and gas sources, such as shale gas, have advanced. Shale gas as an energy source is not a new development, having been extracted since the 1820's. However, fracking (hydraulic fracturing) was not carried out until the late 1940's and full scale production of shale gas did not begin until the 1970's.