This week’s piece, a little different from usual, is a short explanation of a term increasingly used in talk about climate change to describe the times we are living in.
Since the end of the last ice age, c11,700 years ago, the earth’s climate has been relatively stable and mostly benign, allowing humankind to flourish and multiply in a geological epoch known as the Holocene.
But many scientists argue that we are now in a new epoch, the Anthropocene, though there is much debate about how, and indeed if, the term should be used.
But first, what are its origins?
The term was coined in the 1980s by American ecologist, Eugene Stoermer, though it never caught on. Then Nobel Laureate, Paul Crutzen, a Dutch atmospheric chemist, revived it at a conference in Mexico in 2000. This he followed up with a 2002 paper co-authored with Stoermer.
So, what does it mean? It is used to describe the period of time in which humankind has become a planetary force, with sufficient agency to change the complex geophysical and biochemical systems within which we all live.
The name comes from Ancient Greek: ‘anthropos’ means ‘human’ and ‘cene’ (‘kainos’) means ‘new [epoch]’. When Stoermer, then Crutzen, proposed it they argued that so great has become humanity’s impact on the earth and earth systems that we have unwittingly entered – created – a new geological epoch, the Anthropocene.
However, to have a geological epoch formally designated requires the agreement of the International Union of Geological Sciences (IUGS) who, when they met to discuss it in March 2024, blocked ratification. That, though, has not stopped the word taking off both inside and outside academia.
But amongst the many academics who, in spite of the IUGS ruling, want to use the term there is no consensus on when the Anthropocene began. Some argue for the birth of agriculture c11,000 years ago, when human beings first started to transform landscapes through cultivation.
Others, including Crutzen, propose the start of the Industrial Revolution, but there is debate about when that was.
Quite recently, in 2019, the Anthropocene Working Group, an interdisciplinary body founded in 2009, which ultimately reports to the IUGS, proposed the mid-20th century. This is based on clear markers in the geological record, specifically radioactive fall-out from nuclear weapons testing.
The mid-20 century also marked the start of what is called the ‘Great Acceleration’ – the exponential increase – in population, fossil fuel use, plastics, concrete, fertilisers and CO2 emissions. This is the date most favoured by earth system scientists.
Whether the IUGS approve or not, the Anthropocene seems here to stay in both academic and popular discourse.
But should you be in any doubt, consider this: during the Holocene atmospheric CO2 remained relatively constant at around 280ppm. Now it is above 430ppm. Research shows nothing comparable for the last two million years.
On that count alone we are in a new timeframe.
Joe Human
sustainablekeswick@gmail.com
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