Mankind leaves mark on the planet with the end of the 12,000-year Holocene age

Landmark in the Earth's 4.7bn-year history as geologists hail dawn of the 'human epoch'

Biologists have their principles of evolution, physicists have their laws of thermodynamics and chemists have their periodic table. For geologists, perhaps the most hallowed reference source is the Geological Time Scale, a complex timeline depicting the entire history of the Earth as a series of distinct periods, epochs and ages, from the birth of the planet 4.7 billion years ago to the present day.

The Geological Time Scale is quite literally set in stone. As geologists dig down through the different sedimentary layers of rock, they go back in time to periods when prehistoric humans with stone tools hunted mammoths, to an earlier time 100 million years ago when dinosaurs roamed the land, and even to a distant era 3.8 billion years ago when life first arose in the ancient oceans of a more primitive world.

Changes to the Geological Time Scale resulted from natural events, whether it was the mass extinction of life from a giant asteroid impact, or an ice age resulting from changes to the orbit of the Earth around the Sun. Now, however, geologists are about to consider whether humans themselves have started to influence the geological history of the world.

They cite human-induced changes to the geology of the Earth in support of such an almost heretical position, pointing to alterations in the landscape caused by the growth of global agriculture, the mass extinction of animals and plants caused by hunting and habitat loss, differences in the composition of the atmosphere resulting from the burning of fossil fuels, and to a corresponding change to the global climate, including rising sea levels and increasing ocean acidity.

On the immense scales of geology, time is measured in tens of thousands, and indeed hundreds of millions of years. By comparison, human life and history are imperceptibly short.

So it is almost inconceivable that the Geological Time Scale should be changed to accommodate the effect that such short-lived human activity has had on the long history of the planet. Yet a significant number of scientists believes there is now a strong case to justify the modification of the Geological Time Scale to take into account the impact of humans on the Earth.

They believe that the current geological epoch, called the Holocene, which has existed since the end of the last ice age some 12,000 years ago, should now be amended. They suggest that the Geological Time Scale should be formally changed to include the start of a new phase called the Anthropocene, meaning the "human epoch".

Next month the International Commission on Stratigraphy (ICS), the body responsible for guarding the integrity of the Geological Time Scale, will meet in Prague where it will receive a preliminary report from its Anthropocene Working Group, a collection of experts charged with the task of considering the case of introducing the new, man-made sub-division. It will be the start of a long process that began in 2008 when the Stratigraphy Commission of the Geological Society of London decided that there "was merit" to the idea of formalising the term. But, ultimately, it will be for the distinguished members of the ICS to decide on the matter, possibly after years of intense discussion.

To gauge opinion among the 50 or so members of ICS, The Independent conducted a straw poll by email asking whether or not these experts believed there was a strong case for making the Anthropocene into a new formal division of the Geological Time Scale – and why. We received just over 20 replies and nearly half of them – nine – agreed that the case was already strong enough to consider the Anthropocene as a new division. Most of them believed it should be classified as a new "epoch", the same classification as the Holocene, which is a subdivision of the Quaternary Period, the most recent of the three periods of the Cenozoic Era.

"There is no doubt the fingerprints of the Industrial Revolution will be clearly marked by distinctive changes in the planet's biotas and environments in the geological record," said David Harper, professor of palaetontology at the University of Copenhagen in Denmark.

Mark Hounslow of Lancaster University, and member of the ICS, agreed: "Wherever future generations look back, be it in climate change, in ice-sediment, or changes to the character of sediments... it will appear to be a dramatic juncture of earth history."

Jan Zalasiewicz, a geologist at Leicester University and chairman of the Anthropocene Working Group, said the case for considering the Anthropocene rests on the changes to biodiveristy, caused by habitat loss and the introduction of invasive species, which is amplified by global warming and ocean acidification. "Such changes leave permanent markers, in the future fossil record in this case," he explained.

Barry Richards of the Geological Survey of Canada agreed: "Human activities, particularly since the onset of the industrial revolution, are clearly having a major impact on the Earth. We are leaving a clear and unique record... in the stratigraphic record."

A small majority of ICS members disagreed, arguing it is far too early to decide whether humans will leave a permanent, geological legacy. Possibly, in some tens of thousand of years from now such a division will be justified, said Professor Jozsef Palfy, head of palaeontology and geology at the Hungarian Natural History Museum in Budapest. "Its signature stratrigraphic record is such a thin veneer just now, that it is not justifiable to distinguish it as a time-rock unit. The Anthropocene is a nice and useful informal term, but I see no need for its formalisation," he said.

Professor Jim Gehling, a senior palaeontologist at the South Australia Museum in Adelaide and another member of the ICS, said the present epoch, the Holocene, began 11,700 years ago and coincided with agriculture, the domestication of animals and crop plants, and the rise of urban settlements. "This is effectively what I understand as the concept of the 'Anthropocene', when humans began the processes that, more recently, seem to be affecting climate change. The onset of the industrial revolution is not particularly significant compared with the shift from nomadic to agricultural lifestyles, and the consequent clearing of woodlands, draining of swamps and burning of fuel."

But this is not what an increasing number of geologists believe. Professor Sha Jingeng of the Chinese Academy of Sciences said the appearance of humans on Earth was the greatest "bioevent" in geological history: "That is why the Anthropocene must be used in the Geological Time Scale."

Start your day with The Independent, sign up for daily news emails
ebooksA special investigation by Andy McSmith
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Ashdown Group: Senior Systems Administrator - London - £50,000

£40000 - £50000 per annum + benefits: Ashdown Group: Senior Systems Administra...

Recruitment Genius: .NET Web Developer

£35000 - £45000 per annum: Recruitment Genius: A fantastic opportunity for a t...

Recruitment Genius: Customer Service Advisor

£14616 per annum: Recruitment Genius: This leading specialist in Electronic Ci...

Recruitment Genius: Pre-Press / Mac Operator / Artworker - Digital & Litho Print

Negotiable: Recruitment Genius: With year on year growth and a reputation for ...

Day In a Page

The difference between America and Israel? There isn’t one

The difference between America and Israel? There isn’t one

Netanyahu knows he can get away with anything in America, says Robert Fisk
Families clubbing together to build their own affordable accommodation

Do It Yourself approach to securing a new house

Community land trusts marking a new trend for taking the initiative away from developers
Head of WWF UK: We didn’t send Cameron to the Arctic to see green ideas freeze

David Nussbaum: We didn’t send Cameron to the Arctic to see green ideas freeze

The head of WWF UK remains sanguine despite the Government’s failure to live up to its pledges on the environment
Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

Set in a mythologised 5th-century Britain, ‘The Buried Giant’ is a strange beast
With money, corruption and drugs, this monk fears Buddhism in Thailand is a ‘poisoned fruit’

Money, corruption and drugs

The monk who fears Buddhism in Thailand is a ‘poisoned fruit’
America's first slavery museum established at Django Unchained plantation - 150 years after slavery outlawed

150 years after it was outlawed...

... America's first slavery museum is established in Louisiana
Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

The first 'American Idol' winner on how she manages to remain her own woman – Jane Austen fascination and all
Tony Oursler on exploring our uneasy relationship with technology with his new show

You won't believe your eyes

Tony Oursler's new show explores our uneasy relationship with technology. He's one of a growing number of artists with that preoccupation
Ian Herbert: Peter Moores must go. He should never have been brought back to fail again

Moores must go. He should never have been brought back to fail again

The England coach leaves players to find solutions - which makes you wonder where he adds value, says Ian Herbert
War with Isis: Fears that the looming battle for Mosul will unleash 'a million refugees'

The battle for Mosul will unleash 'a million refugees'

Aid agencies prepare for vast exodus following planned Iraqi offensive against the Isis-held city, reports Patrick Cockburn
Yvette Cooper: We can't lose the election. There's too much on the line

Yvette Cooper: We can't lose the election. There's too much on the line

The shadow Home Secretary on fighting radical Islam, protecting children, and why anyone in Labour who's thinking beyond May must 'sort themselves out'
A bad week for the Greens: Leader Natalie Bennett's 'car crash' radio interview is followed by Brighton council's failure to set a budget due to infighting

It's not easy being Green

After a bad week in which its leader had a public meltdown and its only city council couldn't agree on a budget vote, what next for the alternative party? It's over to Caroline Lucas to find out
Gorillas nearly missed: BBC producers didn't want to broadcast Sir David Attenborough's famed Rwandan encounter

Gorillas nearly missed

BBC producers didn't want to broadcast Sir David Attenborough's famed Rwandan encounter
Downton Abbey effect sees impoverished Italian nobles inspired to open their doors to paying guests for up to €650 a night

The Downton Abbey effect

Impoverished Italian nobles are opening their doors to paying guests, inspired by the TV drama
China's wild panda numbers have increased by 17% since 2003, new census reveals

China's wild panda numbers on the up

New census reveals 17% since 2003