Global warming, caused by the greenhouse effect, is probably the greatest ecological
threat we face, and about half of this effect is being caused by the increase of carbon di-
oxide in the air. We can reduce the amount of carbon dioxide we produce by burning less
fossil fuels and destroying less forest; but we can also grow new forests which will convert
it to solid compounds of carbon, i.e. wood.
Clean water is becoming so rare and valuable a commodity that it will soon be more ex-
pensive than petrol. Already a litre of spring water in a supermarket costs as much as a litre
of petrol at the pump outside.
Water flowing from forests is clear and clean. The flow is constant, with the extremes
of flood and drought evened out by the sponge effect of the vegetation. Trees also create
more rain, by absorbing water and releasing it to the sky to form new clouds, rather than
allowing it to flow away across the surface, taking the soil with it. By contrast, water from
farmland is always contaminated to some degree and the more trees are cleared, the more
droughts and floods occur.
So a permacultural vision of the future might be one where the present landscape of pre-
dominant farmland is changed to one of woodland and gardens.
But this vision is not going to happen overnight. It will only come about when a large
number of us have decided to change to a more sustainable lifestyle. So for some time yet,
the majority of our food will continue to come from farms, and there is a great deal we can
do to make them run more efficiently and sustainably.
The idea of zoning, putting things which need the most attention nearest the centre of hu-
man activity, is just as important on a farm scale as it is in the garden. For example, a
chicken house needs to be visited at least twice a day, while a plantation of timber trees
may not need visiting even once a year, so it is clear which should be placed closest to the
farmhouse. The difference between, say, a lambing shed and an orchard may be less ob-
vious, and some careful thought about where to place them will be well rewarded. Even a
very small advantage in efficiency will be multiplied up to a big gain over the lifetime of a
building or of trees.
Zoning has its most obvious application when laying out a new farm or installing
something new on an existing one. But it can be worthwhile to move an existing structure,
if the increase in efficiency is going to be more than the cost of moving it. It can even be
worthwhile expending some fossil fuel to make this possible.
An example comes from a smallholder in Wales who decided, after taking a course in
permaculture, to move his polytunnel closer to the house. To do this it was necessary to
create a new terrace in the hillside, and this meant using earth-moving machinery. This was
a one-off expenditure of fossil fuel, an investment in a structure that will in its lifetime pro-
duce far more energy than was used to make it. It is a very different matter to the constant