There are only three things that can kill a farmer: lightning, rolling over in a tractor, and old age.

The number of people on whose cooperative efforts your eventual existence depends has risen to approximately 1,000,000,000,000,000,000, which is several thousand times the total number of people who have ever lived.

I wanted to quit and to do this forever, sleep in a bed and in a tent, see what was over the next hill and never see a hill again. All of this all at once, every moment, on the trail or off.

It is a slightly arresting notion that if you were to pick yourself apart with tweezers, one atom at a time, you would produce a mound of fine atomic dust, none of which had ever been alive but all of which had once been you.

We used to build civilizations. Now we build shopping malls.

The whole of the global economy is based on supplying the cravings of two per cent of the world's population.

There is always a little more toothpaste in the tube. Think about it.