Upward Spiral

An Upward Spiral is a form of positive feedback loop that produces increasingly beneficial results. Also referred to as a "virtuous cycle" (in contrast with the more common "vicious cycle"), an Upward Spiral can rapidly transition a system from one state to another, e.g. from bare rocky mountainside to alpine forest. Because too much of anything is generally bad, Upward Spirals tend to continue only for finite time.

In his movie The Upward Spiral, Paul Krafel argues that Gaia, far from being merely an advanced planetary thermostat maintaining homeostasis in various environmental properties, is also a prolific generator of Upward Spirals. Perhaps the most dramatic example of this in established Earth history was the oxygen crisis, when cyanobacteria caused the oxygen in Earth's atmosphere to transition from a trace gas to a substantial fraction of the total. While this transition probably took tens of millions of years (still relatively brief compared to Earth's 4.5-billion-year lifetime), smaller-scale examples such as the aforementioned growth of a forest may take mere centuries or even decades. Humans can assist in the process of creating and accelerating Upward Spirals, for example using Paul Krafel's game to help rainwater soak into the soil, described in the movie and in Krafel's TEDx talk.