Dear Economist,

I am worried about the damage we wreak on our planet, and I want to do my bit to reduce my personal environmental impact. I was thinking of moving to the country and living a more self-sufficient life. But is there a better way?

-- Jocelyn Hathaway, London

Dear Jocelyn,

You should ask yourself, rather, if there is a worse way. London may not appear to be the model of sustainable development, but it is an organic commune compared with what would happen if the other seven million inhabitants selfishly decided to move to the country.

Tightly packed, rich cities such as London are easily the most environmentally friendly way to enjoy modern life. Wealthy people squeeze into cosy apartments. Cocktail bars and sharp suits are green ways to spend cash compared with maintaining an extensive garden saturated with fertilisers and pesticides.

Denser cities mean more efficient transport. Compare the commuting patterns of London with the sprawling city of Atlanta. Even before the congestion charge, only 10 per cent of commutes into central London took place in cars. In Atlanta, 90 per cent of commutes were in cars, three-quarters with the driver unaccompanied.

Manhattan, the densest and richest city of all, was recently described in The New Yorker as "a utopian environmentalist community" and is vastly more energy-efficient, per person, than any of the 50 American states.

All this without requiring anyone to eat lentils or live like a pauper.

My advice to you is to forget all this self-centred nonsense about moving to the country. Instead, put double-glazing in your flat, travel to work by bike and relax in the smug knowledge that you are living in one of the greenest cities on the planet.

This week's Economist is Tim Harford, www.timharford.com

Send questions to: economist@ft.com