I Read your article in The London News, and I would like to tell you what i think about it.
You wrote that in your opinion using cars should be prohibited in big cities. I have to disagree with you: this would 'cause a big chaos occur. I think that people would do everything to break that rule, and police would have to do lots of work to make it work.
And do you really think that all people would agree to use buses and taxis? Not everyone can afford taxis, and buses are not comfortable, especially for older people, or anyone who needs to transport anything. Also, the good side of that is a nonsense, I think. I don't believe that it would save any oxygen: Buses also produce CO2, and other pollution. If everyone would use them, they will make just as much of it as cars does nowadays.
So, concluding, I think this would be a bad law to prohibit cars in cities.
Mam nadzieje że jest dobrze :)