There are many ways to judge whether a town is sustainable.
One is to ask if it's carbon neutral. A carbon neutral eco-town
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-town
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.
Resiliency
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 then, of course, there's peak oil.
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.
For example, a carbon neutral town may be fully pedestrianised, with
walking and cycling the main modes of transportation, or it may be based
upon 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.
Reduce First
But what if all those zero emission cars were powered by renewable
sources?
Resiliency shows us that we cannot depend on renewables either.
Wind and solar power provide energy only some of the time, whilst biofuel requires enormous amounts of land;
land we should be growing food crops on.
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.
