Not a footprint, a flow

We talk about human activity having a “footprint” on the natural world. But the products of our activity aren’t just placed on top of an ecosystem like a footprint—everything we do, what we consume in our homes and emit from them, is part of an ecosystem, and it’s just as important as the processes of all the other plants, animals, and microorganisms.

When a household takes nutrients, they have to come from somewhere. And when we flush or vent other nutrients, or pollutants, they have to go somewhere. The rate nutrients flow to and from our homes can have far-reaching, dynamic effects, something you couldn’t say about a footprint.