Each of our activities causes consumption of some kind of resource. The consumption may be as simple as the breathing we do during the activity, or the food we ate to have the bodily energy for the activity. The consumption can be complex such as the gasoline and metals and plastics required for cross-country road trips.

Consumption is an innate attribute of all animals including humans.

Each activity can be accomplished several ways. For example, a trip to the neighborhood store for a bar of soap can be done by walking, riding a bicycle, riding a motorcycle, taking the city bus, driving a car, or driving a military tank. It's the same bar of soap in each case, and the distance traveled is the same, but each requires a different sort of and amount of fuel. The resources required to walk are very minimal, but the resources required to build and drive the military style tank are enormous.

The consumption of some resources have enormous negative consequences on the natural world, others don't faze the natural world. For example cutting the grass on your lawn has minimal impact because more grass will grow, and the cuttings can be composted into plant nutrients. On the other hand burning fossil oil releases lots of poisons into the environment, and cannot be replaced for 10 million years or so. Mining metals usually means digging underground where they are, pulling the raw ore out of the ground, refining it, and disposing of the non-metal parts of the raw ore. All other resource extraction activities have their own negative consequences.

The natural world has a capacity to renew itself or repair damage. Some resources replenish themselves automatically, while others take essentially or literally forever. If the impact on the natural world is less than that capacity for self-repair, then the natural world can accommodate the activities of humans. If the impact is greater than the capacity for self-repair the natural world will be unable to keep up, and eventually it will fall behind and become permanently damaged.

Hence, the resource usages to minimize are those with negative impact, or a long time to replenish the resource.