The Anthropocene Equation: Collective Human Impacts Pushing Change @ 170X Natural Rate
Homo sapiens now rivals the great forces of nature. Humanity is a prime driver of change of the Earth system. Industrialised societies alter the planet on a scale equivalent to an asteroid impact. This is how the Anthropocene – the proposed new geological period in which human activity profoundly shapes the environment – is often described in soundbites. But is it possible to formalise such statements mathematically? I think so, and believe doing this creates an unequivocal statement of the risks industrialised societies are taking at a time when action is vital.
Following the maxim of keeping everything as simple as possible, but not simpler, Will Steffen from the Australian National University and I drew up an Anthropocene equation by homing in on the rate of change of Earth’s life support system: the atmosphere, oceans, forests and wetlands, waterways and ice sheets and fabulous diversity of life.
For four billion years, the rate of change of the Earth system (E) has been a complex function of astronomical (A) and geophysical (G) forces plus internal dynamics (I): Earth’s orbit around the sun, gravitational interactions with other planets, the sun’s heat output, colliding continents, volcanoes and evolution, among others.
EDIT
The rate of carbon emissions to the atmosphere is arguably the highest in 66 million years, when the (non-avian) dinosaurs slipped off this mortal coil. The staggering loss of biodiversity in recent decades prompted researchers in 2015 to argue that the Anthropocene marks the third stage in the evolution of Earth’s biosphere, following on from the microbial stage 3.5 billion years ago and the Cambrian explosion 650 million years ago. Pulling this together, we conclude that the rate of change of the Earth system over the last 40 to 50 years is a purely a function of industrialised societies (H).
In the equation, astronomical and geophysical forces tend to zero because of their slow nature or rarity, as do internal dynamics, for now. All these forces still exert pressure, but currently on orders of magnitude less than human impact.
EDIT
https://www.newscientist.com/article/2120951-simple-equation-shows-how-human-activity-is-trashing-the-planet/