In a report released on Monday, the world's foremost energy watchdog, the International Energy Agency (IEA), said the US would benefit from so-called unconventional sources of oil and gas, including shale gas and shale oil, derived from fracking – blasting dense rocks apart to release the fossil fuels trapped within.

The shale gas boom of the past five years took the US by surprise. Gas prices there have plunged and electricity production is shifting fast from coal to gas-fired power stations. This has had a huge effect on all parts of the US economy, and is changing politics globally.

The UK’s underground shale gas reserves may deliver only a fraction of the gas promised by fracking firms and government ministers, according to a study.

Shale gas

Meaning

Noun