Humanity is ending its Goldlilocks geological era
Republished From: Blue Community Program Coastal Sustainability Best Practices
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In the space of one lifetime, human interference is bringing the conditions of the Holocene - the only ones in which we know we can flourish - to an end, writes Geoffrey Lean.
It has been a Goldilocks geological era. The last 11,700 years have not been too hot, or too cold, too wet or too dry and have witnessed an earth well provided with freshwater and a great array of biomes and life. They have provided almost a planetary ceasefire after a long history of abrupt swings between very much more hostile hot and cold conditions.
So it is not surprising that it has been in the Holocene (the term comes from the Greek words for "whole" and "new") that human civilisation was born, grew and spread. We entered it as a few hunter-gatherers, but have now grown so dominant that scientists believe that we are ourselves bringing the Goldilocks era to an end, with unknown – but deeply worrying – consequences.
At the turn of the millennium, Paul Crutzen – the Nobel Prize-winning chemist who was among the first to call attention to the depletion of the earth’s protective ozone layer – suggested that we had already entered a new area, the Anthropocene, such is humanity’s impact on the world. The idea is increasingly gaining currency and is likely to be endorsed by the International Commission on Stratigraphy next year. Indeed an official Anthropocene Working Group this month suggested that its start was marked by the first atomic bomb test in 1945.
Now a new paper in the journal Science – much discussed at the World Economic Forum in Davos last week – has fleshed out what is happening, and warned that – as a result – the world could cease to become a “safe operating space” for humanity. The paper - by 18 leading scientists from 17 universities and scientific institutions in 11 countries – warns: “The human enterprise has grown so dramatically since the mid-20th century that the relatively stable, 11,700 year long Holocene epoch – the only state of the planet that we know for certain can support contemporary human societies – is now being destabilised.”
The scientists go on: “The precautionary principle suggests that human societies would be unwise to drive the Earth System substantially away from a Holocene-like condition. A continuing trajectory away from the Holocene could lead, with an uncomfortably high probability, to a very different state of the Earth System, one that is likely to be much less hospitable to the development of human societies.”
The paper examines the state of nine "planetary boundaries", identified in a groundbreaking 2009 study, which mark the borders of the safe space for continuing the idyllic conditions of the Holocene. Four of these, it concludes, have already been crossed. It says the most serious, now posing a “high risk” are the integrity of the biosphere - as measured by the loss of species and degradation of ecosystems – and flows of ‘biogeochemicals’ such as the overuse of phosphorous and nitrogen in a few agricultural regions. The other two, presenting an “increasing risk” are climate change and alterations in the uses of land, such as through deforestation and desertification.
Two of the boundaries – the integrity of the biosphere and climate change – are particularly important, it says, because they are “overarching”, connect to all the rest, “operate at the level of the whole Earth System”, and “have co-evolved for nearly four billion years.
But perhaps the greatest surprise to the scientists has been the pace of what is taking place. “Almost all graphs show the same pattern”, says lead author Professor Will Steffen of Stockholm and the Australian National universities. “The most dramatic shifts have occurred since 1950.
“It is difficult to overestimate the scale and speed of change. In a single lifetime humanity has become a planetary-scale geological force. This is a new phenomenon and indicates that humanity has a new responsibility at a global scale.” Indeed so.