Few people today muck around in earth, and when on international flights, I often find I have the only decently dirty fingernails.

If and when the whole world is secure, we have won a right to explore space, and the oceans. Until we have demonstrated that we can establish a productive and secure earth society, we do not belong anywhere else, nor (I suspect) would we be welcome elsewhere.

The value of land must, in the future, be assessed on its yield of potable water. Those property-owners with a constant source of pure water already have an economically-valuable "product" from their land, and need look no further for a source of income.

We have to let nature put what's left together, and see what it can come up with to save our ass.

One of the great rules of design is do something basic right. Then everything gets much more right of itself. But if you do something basic wrong - if you make what I call a Type 1 Error - you can get nothing else right.

I'd come into town from the bush - after 28 years of field work in natural systems - and become an academic. So I turned my attention to humans, much as I had to possums in the forests.

We're only truly secure when we can look out our kitchen window and see our food growing and our friends working nearby.