Following measures were taken to combat air pollution by Delhi Government:
1. All the city buses were converted to run on CNG (i.e. compressed natural gas) by year 2002. CNG causes less pollution and is less expensive fuel.
2. There was new fuel policy drafted by the Government.
3. The norms were set to reduce sulphur and aromatic content of petrol and diesel.
4. Engines of the automobiles were upgraded.
5. Bharat stage emission standards (BS) were set. These standards are equivalent to Euro norms and have evolved on similar lines as Bharat Stage II (BS II) to BS VI from 2001 to 2017.
