The Energy Information Administration (EIA) puts it at around 37tcm of recoverable reserves, two-thirds of which is shale gas and the rest tight gas and coal-bed methane.
"As we can see from the experience in the US, the exploration of shale gas and coal-bed methane has the potential to raise billions of pounds, resulting in reduced energy bills, " he said.
Unconventional sources of oil and gas that are set for further exploitation include Canada's tar sands, shale and coal-bed methane deposits around the world.