Every day starts with water. No, I don’t mean that kind of water. I’m thinking of the first glass of water I drink, and the water I fill the kettle with for my first pot of tea. (I could be content with locally grown food, I think, except that I would still have to have tea, real tea, camellia sinensis.)

When I was first commissioned, in 1988, to write an ecology book, I knew virtually nothing about the subject and my friends were terrified for me. It didn’t reassure them to know that I knew I knew very little; they couldn’t imagine how I could educate myself enough to write a book. One of the first people to help me was an energy expert in London who invited me to his home to use his library. He offered me coffee, and after filling our cups he took a folded towel that was lying nearby and tucked it around the kettle. (In Britain, electric kettles are a way of life.) “It’s a small thing,” he said, “But it keeps the water hot for a couple of hours, until we want another cup.” He was saving both water and energy, in one simple and habitual action.

To make a good cup of tea one needs freshly drawn water, so I rarely use water left in the kettle. But in the morning I find myself ducking and diving not to waste water. As I run the tap–an old habit, from London days when this was a precaution against leaded pipe joints–I catch the water in a watering can, and I toss the water used to warm the teapot in, too, and any dregs from the kettle. I feel a little silly doing this (it is, after all, a very small thing), but the ritual is a good way to remember the more important point, that I need to treat every material thing that passes through my hands as a resource.

And while the kettle is coming to a boil, I can water my houseplants, blooming geraniums and baby-powder-scented heliotrope.