You ranting about it all being inconvenient and finding it easier to drive Futher to make life easier doesn't stop you from making more pollution, which your friend is 100% correct, and what you asked. Simple fact.
Justifying that pollution is upto you.
Maybe talk to your local council and say you're unhappy with their traffic routing choices. I'm sure all the local shop owners would agree.
Get the bus. You live in London. It'll be cheaper than petrol.
Pretend your car is off the road for a week. How do you survive?
Im playing devils advocate incase anyone cares.
It would be boring with 30 pages of "your friends a nob" answers.