In late 1990s, a Texan oilman, George Mitchell, developed an affordable way to extract natural gas / tight oil locked up in shale rock and other geological formations. It involves blasting them with water, sand and chemicals. This technique known as hydraulic fracturing, or “fracking”. Fracking technology is relatively new but is most developed in the United States, where tight oil could add up to 1 million barrels per day to total oil production by 2016, according to a report by the International Energy Association (IEA).

Fracking requires large amounts of water and chemicals, and environmental concerns have led some governments to ban its use or put moratoriums in place. Hydraulic fracturing has raised environmental concerns and is challenging the adequacy of existing regulatory regimes. These concerns have included ground water contamination, risks to air quality, migration of gases and hydraulic fracturing chemicals to the surface, mishandling of waste, and the health effects of all these.