There are many ways to judge whether a city is sustainable.
One is to ask if it's carbon neutral. A carbon neutral eco-city
would balance the carbon it releases, for example in the burning of
fossil fuels, with
the carbon it sequesters, for example with the planting of trees.
Another is to look at the ecological footprint of its residents, to
calculate how much land and water their lifestyles require. The
UK's ecological footprint averages somewhere above 5 hectares. But
if we were to share the earth's biocapacity equally among its 6 billion
plus inhabitants, we'd get just 1.8 hectares each. An eco-city
would therefore aim for 1.8 or below.
However, neither of these concepts are particularly useful in
themselves. They offer us broad goals to aim for, but tell us
nothing of how to achieve them.
I believe resiliency to be a far better standard for us to judge our eco-towns
and cities against.
Global warming has yet to wreak the devastation it threatens, but
when it comes we will no longer be able to rely on food and energy
supplies from abroad.
And sooner or later, the oil is going to run out.
We're looking at a future very different to now; a future in which
energy and even food are in very short supply.
Resiliency means accepting that this is going to happen at some point in the
future, and planning for it today.
We all need food to eat and water to drink. We all need to
travel to work to earn money for food, and to the shops (or the farm) to buy it.
And we all need homes to provide us with shelter.
These are our basic needs, and we must still be able to meet them
when resources become scarcer and energy costs rise.
The city detailed in these pages is based on several
levels of resiliency:
Trolleybuses are extremely energy efficient, and a
broken-down vehicle will not stop them.
But if future energy supplies get so bad as to impact on
the trolleybus network, shops and local services are never more
than a 4 minute
walk away. And the city is compact enough to
keep the city centre within a 30 minute walk of every home, and
considerably less by bicycle or on roller skates.
Buildings use minimal energy for heating and cooling, and are
designed to conserve drinking water.
And much importance is placed on local, sustainable farming
so that the city can always feed itself.
For example, a sustainable town may be fully pedestrianised, with
walking and cycling the main modes of transportation, or it may be based
around zero emission cars. But when the energy crunch comes, only
the resilient pedestrian town will continue as normal whilst all those
zero emission cars will grind to a halt.
But what if all those zero emission cars were powered by renewable
The wind doesn't always blow. And, here in England at least, sunny days are
rather less common than
Renewables are also far less productive than our current fossil fuel burning
power stations. Which means when we start the big switch over to renewables, there's going to be less energy to go around, not more.
Hydrogen is not a source of energy, you have to produce it. So
that rules out fuel cell cars, too.
And we'll need all our arable land for food production, not bio fuels.
The first step must always be to reduce.
We need to reduce the energy and water we use in our homes, reduce
the distance our food travels, and reduce the need for cars.