Experts agree, each in his or her narrow field, that there is degradation of environment, but there has been no common ground for them. The Natural Step offers, again through the unifying theme of the tree's trunk, a set of core beliefs to which all can agree and from which business and technological decisions can flow that will ensure sustainability. We are all born with this ability. Therefore, it is our natural ability to filter, hypothesize and prioritize that, according to Rob rt, constitutes the key to our survival-if we focus on principals. Nothing disappears, it simply changes form.
Earth is an open system.
Fueled by the sun, our planet can, given wise use of resources and sufficient time, continue to redirect the energy we need to create a prosperous, but not wasteful, world economy. Substances from the Earth's crust must not systematically increase in nature. Fossil fuels, metals, and other materials cannot be extracted at a faster pace than they are redeposited in the Earth's crust. To do otherwise results in an inevitable spread of their waste and accumulation as well as their eventual depletion in the earth's crust. Substances produced by society must not systematically increase in nature.