A while ago I wrote about Cradle to Cradle by William McDonough and Michael Braungart, a book about remaking the way we make things. Thinking differently about how waste can be seen in a new light, as a valuable raw material for the next process rather than something we should simply get away from.

Here’s what they have to say about closing the loop and looking at all products, biological or otherwise, from a cradle-to-cradle perspective rather than the traditional, and hopelessly unsustainable, cradle-to-grave approach. The world we live in has two essential elements: mass (the Earth) and energy (the sun).

Otherwise, for our practical purposes, the system is closed, and its basic elements are valuable and finite. Whatever is naturally here is all we have. Whatever humans make does not go ”away”.

Go on throwing away our valuable resources they say, and our world will literally become a grave.

If humans are truly going to prosper, we will have to learn to imitate nature’s highly effective cradle-to-cradle system of nutrient flow and metabolism, in which the very concept of waste does not exist. To eliminate the concept of waste means to design things — products, packaging, and systems — from the very beginning on the understanding that waste does not exist.

They divide products up into those that should stay in closed-loop biological cycles (such as food) and those that should stay in closed-loop technical cycles (such as electronics).

Things that go into the organic metabolism must not containe mutagens, carcinogens, persistent toxins, or other substances that accumulate in natural systems to damaging effect.

Materials and products that are designed to return to the biological cycle they call biological nutrients, things that can be consumed by microorganisms in the soil and by other animals. By thinking new products could be designed from the beginning so they could safely remain in this loop.

Worry-free packaging could safely decompose or be gathered and used as fertilizer, bringing nutrients back to the soil. Shoe soles could degrade to enrich the environment. Soaps and other liquid cleaning products could be designed as biological nutrients as well; that way, when they wash down the drain, pass through a wetland, and end up in a lake or river, they support the balance of the ecosystem.

Wouldn’t it be fun if this sort of smart design could help take the guilt out of much of our everyday life. As they say, throwing something away can be fun — and giving a guilt-free gift to the natural world is an incomparable pleasure.