Many countries are rerouting energy supply chains and developing alternative fuels. The Russian government started to use energy supplies as a political weapon. The UK is preparing to produce aviation fuel from waste vegetable oils, fats, and greases. The creators of refinery technology assure that their sustainable aviation fuel (SAF) can bring billions of pounds to the British economy, increase jobs, reduce energy dependence on Russia, and help the aviation sector become "green." The Global Britain Commission reported that most UK airplanes are supplied by Russian fuel from Rotterdam. Heathrow chief executive John Holland-Kaye said that supply chains were vulnerable amid the geopolitical tensions and the country had to rely on domestic fuel. The UK may become a leading supplier of green fuels. It leaves at least 70% less carbon footprint and can be used in all aircraft engines. Currently, SAF has been used in 360,000 flights.