To extract oil and gas from a facility like this, a series of wells are drilled into the seabed and then the products extracted to a ship moored to the seabed. This offloads the oil onto big ships called tankers, while the gas is sent down a pipeline.

The drilling and anchoring of the ship, as well as chemicals released, have the potential to disturb the seabed and damage habitats - and potentially kill animals living there such as soft corals and sea spiders.

There is also a lot of noise produced underwater when oil is extracted. This is important because many species in the marine environment use sound to communicate.

What Rosebank produces will be sold at world market prices, so the project will not cut energy prices for UK consumers, the Norwegian state oil company Equinor - which is the majority owner of Rosebank - confirmed.