I have been spending this week in Europe at candidate cities for the Academy of Urbanism's European City Award, won last year by Bristol when it was restricted to UK cities.

One of those cities is Bordeaux. It is a remarkable city that largely escaped damage in the war, and maybe more remarkably has, with one or two noticeable exceptions, largely escaped planning damage since. As a result it is one of the most desirable cities to visit and live in France.

What distinguishes Bordeaux, apart from its glorious 18th century streets, squares and public buildings is its Mayor Alain Jupee, ex-French Prime Minister. Since being elected in 1995 he has acted with courage and determination to lift Bordeaux into the 21st Century leading with one of the finest new tram systems in the world.

This caused vast disruption to the city for five years, and continues to do so as the lines are extended, but the people stuck with him and he is now clearly a hero in his own city – a rare accolade for any local politician.

He realised that the vast one billion Euro investment would result in a massive change in people's behaviour, that it would encourage the repopulation of the centre of the city, transform social and environmental conditions and attract inward investment.

Bristol has much it could learn from our French twin, the most important being that quality matters if we are to attract people out of their beloved cars, something that will be capped by the planned high-speed rail connection between Bordeaux and Paris.

A very different city is Freiburg in southern Germany, which is half the size of Bristol but has some vitally important lessons to teach us all. We were welcomed by charismatic Mayor, Dieter Salomon, Green Party member, who is responsible for continuing the great green agenda for which Freiburg is so famous.

So I should not have been surprised to bump into a team from UWE who were studying the link between city planning and health. It seems that Freiburg's biggest industry is as a showcase for sustainability, a status they have undoubtedly earned.

Their Director of Planning, Wulf Daseking, who showed us Freiburg's remarkable achievements, another tram system being at its heart, has a passion for what they have achieved in his 25 years.

Wulf is on a mission to take the lessons of radical change and quality of life to other cities. They have no fear of others taking on the mantel, as Bristol surely must do if we are to have any hope of realising our ambitions of becoming European Green Capital.

What is particularly remarkable about Freiburg is its new low and zero carbon neighbourhoods, two of which we visited and were struck by the high level of satisfaction and environmental awareness. This was not hair shirt energy saving but a real demonstration of how such a green lifestyle can be so much more fulfilling.

Even the architecture award-winning new church is one that is shared by Catholics, Protestants and the wider community – something that might seem impossible elsewhere. This is an exemplar that Hengrove and other new or extended neighbourhoods in Bristol must learn from – it would be criminal not to do so.

The green attitude penetrates everything that Freiburg does. It is done by consensus by a politically diverse population and council where right and left seem united behind a strong environmental agenda.

We have wasted the past 25 years not doing what Bordeaux and Freiburg have had the courage to do. We have to start now.