Humans are now the dominant force in changes to the Earth. This is according to a new equation, drawn up by scientists at the Australian National University.
This “Anthropocene equation” looks at the impact that humans have on the planet. It comes at a time of growing calls for a new epoch to declared; the anthropocene, or the era in which humans have the greatest impact on climate and the environment.
That momentum – driven by things such as this equation – is likely to see the holocene declared as having ended in 1950, with the International Geological Congress in 2016 calling for the anthropocene to replace it after that date.
But the rate of that impact has not been quantified, until now. The new equation, published in The Anthropocene Review looks at what has driven changes in the world’s climate and environment over the last 4.5-billion years.
It notes that astronomical and geophysical forces – from excess heat coming off the sun to melting ice and shifting tectonic plates – have been the main reason for changes for much of the Earth’s history.
The research concludes that, on average, these forces have cooled and warmed the world by an average of 0.01°C per century.
This, however, changed in the 1950s: “In the last six decades, anthropological [human-driven] forces have driven exceptionally rapid rates of change in the Earth System.” This, the researchers say, is “purely a function of industrialised societies”.
In the six decades since the 1950s, the world has been warming by 1.7°C a century, or 170 times the natural rate of climate change. The researchers say this means natural forces now play a “negligible” role in changing climatic conditions. In comparison, the impact of humans is so dramatic and sudden that it could be compared to what happens when a meteor crashes into the world.
They note that for the last 2.5-million years, the Earth has “settled into a rather unusual period”, where it regularly moves between ice ages and warm periods. The last 11 700 years have been part of a warm period, with temperatures allowing for extensive agriculture and industrial growth.
But the sudden and rapid impact of humans is changing this: “Remarkably and accidentally, we have ejected the Earth system from the interglacial envelope [between ice ages] and are heading into unchartered waters.”
Echoing the more dire warnings that are increasingly coming from the scientific community, the researchers conclude that if little is done to curb global warming and the extreme rate of climate change, “societal collapse” will ensue.
This, the researchers note, is looking ever-more likely because the dominant economic logic of today – that of neoliberal market economics – is based on the idea of “endless resources on an infinite planet”. But this is not an infinite planet.