‘The Age of Humans has begun’ say scientists

Rock on: Blue — Earth’s most recent periods. Red — the epochs of the current Quaternary period.

Nuclear tests. Mass extinction. Climate change. Experts say we have entered a new geological era, defined by humanity’s actions. But could the Anthropocene be a golden opportunity?

Imagine aliens have been watching the Earth for billions of years, writes the astrophysicist Martin Rees in The Guardian this week. In all that time, the planet has moved slowly from its volcanic beginnings, through ice ages and drifting continents and the evolution and extinction of various plants and sea creatures and dinosaurs. Finally, 11,500 years ago, the last ice age melted away and the Holocene epoch arrived. A more stable climate allowed humans to thrive and spread. To those imaginary aliens, this latest age has been the shortest by far.

But this week, some of the world’s top geologists argued that we have entered a new epoch of Earth’s history: the Anthropocene, or the ‘age of humans’. Since 1950, the Earth has witnessed a ‘great acceleration’ in its population, production and consumption, and the concentration of carbon dioxide. Meanwhile, nuclear bomb testing has spread radioactive elements far and wide. Humans have fundamentally changed the Earth’s geological make-up, say the experts — and the evidence will be found for millennia to come.

The new epoch is still unofficial for now. First the scientists must decide which ‘golden spike’, or specific geological change, will identify it. The most likely is the increase in nuclear material. But it could also be the billions of tiny plastic beads filling the oceans, the soot leftover from decades of burning fossil fuels, or even the bones of domestic chickens which have become the most common bird on the planet.

Then there is the deforestation. The 6,000ft holes dug for oil. The nitrogen pumped into the soil by fertilisers. The consequences of all these changes have already been huge, from mass extinction to rapid climate change.

Formally declaring the start of the Anthropocene would force us to confront the impact that we are having on our planet, say scientists. If humans are now officially in charge of nature, it is up to us to decide what kind of home we really want.

What on Earth?

‘We are playing with fire,’ says Chris Rapley, a climate scientist at University College London. He compares living on Earth to flying a spaceship, where ‘it would be unthinkable to interfere with the systems that provide us with air, water, fodder and climate control.’ We must find a way to reverse the damage we have done to our precious planet — and fast.

Yet Rees is more optimistic. Yes, we should be careful — but the Anthropocene is also an opportunity. ‘Human societies could navigate these threats, achieve a sustainable future, and inaugurate eras of post-human evolution even more marvellous than what’s led to us.’ If our destiny is in our own hands, future technology could change our lives in ways we have not yet even dreamed of.

You Decide

  1. Do you agree with Martin Rees that this could be an amazing opportunity?
  2. Does humanity have a duty to preserve as much of nature as possible?

Activities

  1. Imagine you are a science student in the year 2100, looking back at the beginning of the 21st century. What will be the three most important changes to the environment from this time?
  2. Choose one of the effects of the Anthropocene mentioned in this piece. Write your own news story, in the style of The Day, which discusses what should be done about it.

Some People Say...

“Mass extinction is the sin that future generations will least forgive us for.”

American biologist E.O. Wilson

What do you think?

Q & A

Will declaring a new epoch actually change anything?
Perhaps. It would certainly give a more accurate description of the planet within scientific communities. But the geologists are hoping it will also have an impact on the wider world as well, by making it abundantly, unquestionably clear that the Earth is now humanity’s responsibility. In turn, this could affect the decisions we make about how to treat it.
Is it definitely going to happen?
The process is underway, but it takes time. This week the geologists involved presented their most up-to-date research, but they still have to choose exactly which geological change will define the new epoch. This will take a couple of years, as they collect more evidence. Eventually the final decision will be made by the wider geological community.

Word Watch

Epoch
Earth’s history is divided into units. From longest to shortest these are: eons, eras, periods, epochs and ages. We are currently in the Quaternary period, and — if it is confirmed — the Anthropocene epoch will be a sub-division of that.
Top geologists
There are 35 geologists in the team behind the report, known as the Working Group on the Anthropocene.
Radioactive elements
Nuclear weapons testing in the 1950s and 60s left traces of a rare isotope, Plutonium-239, across the Earth’s surface.
Most common
There are 50 billion chickens in the world, according to the RSPB.
Deforestation
According to the Food and Agriculture Organization of the United Nations, around 18m acres of forest are lost every year, an area roughly the size of Panama.
6,000ft holes
According to the US Energy Information Administration, in 1949 the average depth of oil wells was 3,635ft, or 1,108m. By 2008 it was 5,964ft, or 1,818m.
Fertilisers
These have doubled the amount of nitrogen and phosphorus levels in soil over the last century. That is the biggest change to the nitrogen cycle in 2.5 billion years.

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