Was 1610 the beginning of a new human epoch?

A new study finds the year to be a key point for the Anthropocene – marking the irreversible transfer of crops and species between the old and new worlds

King James was on the throne, Shakespeare’s Cymbeline was playing in the theatre and Galileo discovered four moons of Jupiter. In future, though, 1610 could be chiefly remembered as the geological time-point at which humans came to dominate Earth.

Scientists have argued that it is time to draw a line under the current geological epoch and usher in the start of a new one, defined by mankind’s impact on the planet.

The year 1610 is a contender for marking the transition, they claim, because this is when the irreversible transfer of crops and species between the new and old worlds was starting to be acutely felt.

Simon Lewis, an ecologist at University College London and author of the paper, said: “In a hundred thousand years, scientists will look at the environmental record and know something remarkable happened in the second half of the second millennium. They will be in no doubt that these global changes to Earth were caused by their own species.”

When Europeans started arriving in the Americas, he added, a cascade of events was triggered that was “as Earth-changing as a meteorite strike”.

The concept of the “anthropocene” is already widely used on an informal basis by writers and environmentalists, but scientists remain divided on whether the designation of a new time period is justified.

Critics argue that the desire to redraw geological boundaries is politically motivated by those wanting to highlight the extent of human destruction on the planet. Others say that it is about 1,000 years too soon to identify the most enduring geological markers of human activity on Earth.

The International Commission on Stratigraphy (ICS), the world body that decides on geological time boundaries, is actively considering the question and a working group is due to report on the issue next year.

The central problem is identifying a permanent and global change that has been captured in natural material, such as rocks, ice or marine sediment – a so-called “golden spike”.

“Global long-term changes to Earth’s system … are required to have one marker that can be precisely dated that is captured in some ancient geological material,” said Lewis.

Lewis and his UCL co-author, Mark Maslin, considered and rejected the earliest use of fire, the dawn of agriculture and the industrial revolution as possible candidates.

Eventually they identified two events – the joining of the two hemispheres and nuclear testing in the 20th century – that met the golden spike criteria.

The year 1610 marks the low-point of a dip in global carbon dioxide levels caused by a drastic reduction in farming in the Americas. This was a knock-on effect of the 50 million or so indigenous deaths that resulted from the introduction of small pox to the continent by European colonialists. A secondary marker of the colliding of worlds is the sudden appearance, in 1600, of fossil pollen maize, a Latin American species, in the European marine record.

The paper, published today in Nature, also considered the year 1964, which saw a peak in radioactive fallout following nuclear weapons testing before the test ban treaty came into force.

The authors conclude that 1610 has a stronger claim because so far the testing of nuclear weapons has not been an Earth-changing event. “I tend to go with 1610 because … the evolutionary consequences of that are pushing Earth onto a new evolutionary trajectory,” said Lewis.

Jan Zalasiewicz, chair of the ICS’s Anthropocene working group, said his committee would consider the authors arguments. However, the working group is converging on nuclear testing as a more universal marker - the CO2 dip and pollen records are patchy and have fuzzier boundaries, he contends.

A potential downside of the nuclear signal is that it will have decayed away within 100,000 years – a blink of the eye in geological time. “Geologists are very pragmatic creatures though,” said Zalasiewicz. “We’re looking for the best signal for dividing strata now, not for geologists a million years in the future.”

The arrival of the Anthropocene would mark the end of the Holocene, the epoch that we currently live in, which itself was only defined in 2008. It is marked by a signal in the Greenland ice cores indicating the end of the last ice age, 11,700 years ago.

Since epochs typically last tens of millions of years, some suggest that the Holocene should not only end, but be scrapped or downgraded. “The Holocene is supposed to last tens of millions of years and it’s several orders of magnitude to short,” said Lewis. “I think we’d have to call that a stage rather than an epoch.”


Hannah Devlin science correspondent

The GuardianTramp

Related Content

Article image
The Human Epoch: when did it start? | @BobOHara & @GrrlScientist
GrrlScientist: A new paper investigates when humans started screwing up the environment, and uses this as the symbol for the beginning of a new geologic age: the Anthropocene, or the Age of Humans.

Bob O'HaraGrrlScientist

11, Mar, 2015 @9:04 PM

Letters: Darwin stood on the shoulders of giants

Letters: The root of the problem lies with our apparent obsession with identifying the role of the individual in the history of science

08, Dec, 2009 @12:05 AM

Article image
Anthropocene: is this the new epoch of humans?
Geologists, climate scientists, ecologists – and a lawyer – to rule on whether impact of human life on Earth has pushed us into a new epoch

Ian Sample, science editor

16, Oct, 2014 @5:00 AM

Article image
Human impact has pushed Earth into the Anthropocene, scientists say
New study provides one of the strongest cases yet that the planet has entered a new geological epoch

Adam Vaughan

07, Jan, 2016 @7:00 PM

Article image
Study casts doubt on human-Neanderthal interbreeding theory

Cambridge scientists claim DNA overlap between Neanderthals and modern humans is a remnant of a common ancestor

Alok Jha, science correspondent

13, Aug, 2012 @11:05 PM

Article image
New species of ancient human discovered in Philippines cave
Homo luzonensis fossils found in Luzon island cave, dating back up to 67,000 years

Hannah Devlin Science correspondent

10, Apr, 2019 @5:00 PM

Article image
Ancient human bone helps date our first sex with Neanderthals
Oldest genome sequence of a modern human suggests Homo sapiens first bred with Neanderthals 50,000-60,000 years ago

Ian Sample, science editor

22, Oct, 2014 @5:00 PM

Article image
Discovery of oldest human DNA in Spanish cave sheds light on evolution
Scientists say DNA strands in thigh bone of 400,000-year-old early human can help build clearer picture of human family tree

Ian Sample, science correspondent

04, Dec, 2013 @6:38 PM

Article image
Shedding our penis spines helped us become human, DNA study hints

Genetic comparison with chimps suggests that losing chunks of DNA – including one associated with penis spines – played a crucial role in making us human

Ian Sample, science correspondent

09, Mar, 2011 @6:00 PM

Article image
Who are you? Royal Institution Christmas lectures will unpick human evolution
Former Time Team presenter and anthropologist Alice Roberts says we ‘overegg the uniqueness of humans compared with other animals’

Nicola Davis

17, Aug, 2018 @4:00 PM