Fracking is a technique used to fracture rocks using high pressure fluid so that oil and natural gas can be exploited where conventional techniques cannot be used. As it plays a major role in the exploitation of unconventional gas sources, the two terms have come to be seen as synonymous.
Exploitation of unconventional gas sources in general is of concern as it is likely it will result in burning more gas than is compatible with avoiding catastrophic climate change. Renewable alternatives may be ignored rather than transitioning to a low-carbon energy system. There are also many concerns regarding the use of fracking, these include: contamination of groundwater, methane pollution, concerns about the chemicals used in fracking, waste disposal and safety issues.