4 million Londoners are breathing cleaner air thanks to a huge low emission zone. In 2021, London expanded its Ultra Low Emission Zone (ULEZ) to 18 times its original size, covering 3.8 million homes. As a result, 21,000 fewer vehicles now drive in the ULEZ every day, and the nitrogen dioxide levels are 44% lower in the very centre of London. London Mayor Sadiq Khan has proposed expanding the Ultra Low Emission Zone even further to cover the whole of Greater London from August 2023. Watch to know more.