Tag Archives: anthropocene

Better make room: Man-made stuff now outweighs all other living things on Earth

Since the Industrial Revolution kicked off, we’ve built a lot of stuff. That’s just part of humanity most would probably say, from roads and homes to all sorts of vehicles, we need things. But we may have gone a bit over the lin here.

According to a new study, human-made objects now weigh about as much as all of the living beings on Earth and could even exceed it this year.

Image credit: Flickr / Alexandre Macedo

Humanity has gradually become a dominant force in shaping the face of Earth. Its impacts have been so abrupt and considerable that it has been proposed that the current geological epoch, the Holocene, be renamed the Anthropocene. The word comes from the Greek words Anthropos, for “man,” and cene for “new” — so we’ve basically ushered in a new geologic age through our actions.

This led researchers at Israel’s Weizmann Institute of Science to wonder how much material human activities have output, and how this compares to the overall natural biomass. They had already published an estimate of the amount of biomass on Earth and now decided to take it a step further, looking at artificial objects and comparing it with natural mass.

“The study provides a symbolic and mass-based quantitative characterization of the Anthropocene,'” two of the study’s authors, Emily Elhacham and Ron Milo, told Scientific American. “Given the empirical evidence on the accumulated mass of human artifacts, we can no longer deny our central role in the natural world.”

For the study, the researchers divided all the human-made objects into six main categories: concrete, aggregates (including materials like gravel), bricks, asphalt, metals, and “other” materials, which includes plastic, wood used for construction, paper, and glass. They didn’t consider waste in their calculations, which means the total man-made mass is already even higher than the researchers’ calculation.

They found that all the man-made objects weigh in at approximately 1.1 trillion metric tons. This is equal to the combined dry weight of all plants, animals, fungi, bacteria, archaea, and protists on the planet.

For this comparison scale, mankind works on both ends: it’s not just the construction of man-made objects, but also the destruction of natural landscapes. Since the first agricultural revolution, humanity has roughly halved the mass of plants, from approximately two teratons down to the current value of approximately 1.1 teratons. The total mass of domesticated crops is vastly outweighed by the loss of plant mass resulting from deforestation and other land-use change — obviously, a healthy forest with tall trees heavily outweighs the same size covered by wheat or other agricultural plants.

This is also not the end of it. The year 2020 could be when human-made mass surpasses the overall weight of biomass, the researchers estimate. Human-made mass is produced at a rate of 30 gigatons per year. This means materials outweighing the bodyweight of every person on the planet are being produced each week.

“The impacts of human activities have been so abrupt and considerable that it has been proposed that the current geological epoch be renamed the Anthropocene. Our study rigorously and quantitatively substantiates this proposal. In parallel, it adds another dimension to this discussion—a symbolic quantitative demarcation of the transition to our epoch,” the researchers wrote.

Despite the scientists describe the finding as symbolic, they argue the milepost provides humanity with a chance to review how we got here and what the future looks like. It’s a strong message to everyone and brings attention to how modern societies can grow sustainably in the upcoming future.

The study was published in the journal Nature.

Tomorrow’s fossils will be human skeletons “lined up in rows,” domestic animals, and not much else

Humanity is such a central force in today’s world that we’ve likely altered the fossil record of the future in a big way.

Image credits Adina Voicu.

Through technology and sheer numbers, our influence on the Earth now equals or exceeds that of many natural processes. Some researchers call for formal recognition of this fact by declaring a new geologic era: the Anthropocene. However, there’s quite the debate about whether this should happen or not and if it does, when it should begin.

In a new study, paleontologist Roy Plotnick from the University of Illinois at Chicago (UIC) argues that the fossil record of mammals will provide a clear signal of the Anthropocene.

I knew it in my bones

“The chance of a wild animal becoming part of the fossil record has become very small,” said Plotnick, a UIC professor of earth and environmental sciences and the paper’s lead author.

“Instead, the future mammal record will be mostly cows, pigs, sheep, goats, dogs, cats, etc., and people themselves.”

Along with co-author Karen Koy of Missouri Western State University, Plotnick explains that humans and domestic animals greatly outnumber wild mammals. The team cites the example of Michigan, where humans and domesticated animals represent about 96% of the total mass of vertebrates. Chickens and people greatly outnumber everything else.

The situation is likely similar in many other parts of the US as well, the team explains.

Cultural customs are also liable to change the make-up of mammal fossils in the future. The authors explain that while humans have buried their dead in cemeteries for centuries now, how and where animals find their resting place have markedly changed over time.

For starters, human activity is impacting the distribution and properties of natural ecosystems, which will impact fossil preservation. The team highlights land use and climate change as the main culprits, as they impact both wildlife populations and the processes that preserve or break down organic matter (which also govern fossilization).

Soil properties are also shifting across the world, with potential effects on fossilization rates. The creation of new sites of preservation — landfills and cemeteries — are drastically impacting potential fossil distribution. Finally, the team notes that industrial agriculture and increased animal density, through the use of large farm equipment and intensive farming practices respectively, are changing the properties of bones themselves.

Taken together, all these factors will likely have a dramatic impact on vertebrate fossils in the future, the team explains. They add that a hypothetical paleontologist 100,000 years in the future will pick up on the start of the Anthropocene with ease, as today’s fossils will be ‘unique’ and ‘unmistakable’.

“Fossil mammals occur in caves, ancient lakebeds, and river channels, and are usually only teeth and isolated bones,” Plotnick said. “Animals that die on farms or in mass deaths due to disease often end up as complete corpses in trenches or landfills, far from water.”

“In the far future, the fossil record of today will have a huge number of complete hominid skeletons, all lined up in rows”.

The paper “The Anthropocene fossil record of terrestrial mammals” has been published in the journal Anthropocene.

Like fossils: half a century of plastics are buried in layers of sediment

Plastic pollution has become one of the most pressing environmental issues, as increasing production of disposable plastic products overwhelms the world’s ability to deal with them. Now, a new study has found that plastics have been building dramatically in the sediment record since 1945.

Credit: Wikipedia Commons

The research, published in Science Advances Wednesday, looked at a single sediment core that dates back to 1834. However, plastics didn’t really enter the environment until after World War II in 1945 because that’s when its production really ramped up, which became clear in the sediment core analyzed.

The increase in plastics correlates with worldwide plastic production and the population growth along the Southern California coast that feeds the watershed where the team collected this sample. The plastic footprint is so massive that the authors suggest it could serve as a geological proxy in the sedimentary record.

Typically, geologists rely on radioisotopes to flag the beginning and ends of eras. Sometimes, fossils can be used as proxies to assess the age of sedimentary layers. Similarly, the team behind this study thinks plastics can be the marker for when this new type of geological era began. The ocean sediment tells a clear story of the world’s growing reliance on plastic, they argue.

The researchers got their sediment samples from something called a box core, essentially a giant cookie cutter that slices down many years’ worth of layers in the seafloor. Back at the lab, they dried each layer and ran the material through filters to isolate the particles.

Example of geological core (not used in the study).

According to the study, between 1945 and 2009, the rate of plastic deposition doubled every 15 years on average. Most of the plastics—67.5 percent—found in the post-1945 core are white fibers. Microplastics take a much more significant role in most recent layers of sediments, the experts said.

“We barely found trace amounts of microplastics in layers from the 1940s,” oceanographer Jennifer Brandon, lead author on the new paper, said.  “But you can easily see the plastics in the more recent layers. There’s been an exponential increase.”

Not all plastic descends to the seafloor. Much of it floats towards the surface. Scientists helped clarify this point in 2009 when they conducted a landmark study of the Great Pacific Garbage Patch, an immense area of debris roughly 1,000 miles off San Diego.

The concentration of microplastics off the coast of California, where these researchers did their work, might even be relatively low compared to other parts of the world, making it harder to observe their effects on organisms. As coastal populations continue to grow, plastic will continue to pile up in the sea.

“If they were doing the same thing in the Yellow Sea in China, right outside some of the big rivers like the Yangtze and Yellow River, the concentrations would probably be huge and cause adverse effects,” said University of Michigan eco-toxicologist Allen Burton, who studies microplastics.

Today, single-use plastics account for 40 percent of the plastic produced every year. Many of these products, such as plastic bags and food wrappers, have a lifespan of mere minutes to hours, yet they may persist in the environment for hundreds of years. Every year, about 8 million tons of plastic waste escapes into the oceans from coastal nations.

The overall impact of plastics in the environment is one of the several pieces of evidence behind the Anthropocene, Earth’s most recent geologic time period defined as human-influenced, based on the fact that atmospheric, geologic, hydrologic and other earth system processes are now altered by humans.

The ‘Age of Man’ is upon us — Anthropocene period close to becoming official

Mankind is having such a profound impact on the planet that we’ve kickstarted a new geological era: the Anthropocene. A panel of scientists has now taken an important step towards defining this new age, and having it start with the ‘Atomic Age’.

Geologists love to classify things — and they especially love to classify time. The geologic time scale covers the entire 4.5-billion-year history of our Earth, splitting it neatly based on decisive environmental characteristics. You’ve probably heard about Jurassic Park — the Jurassic spans from 201.3 million years ago to 145 million years ago. Before the Jurassic, there was the Triassic, and after it, there was the Cretaceous. The Jurassic itself, like the periods before and after it, is split into smaller subdivisions.

We are currently living in a period of time called the Quaternary, which started 2.6 million years ago and loosely represents the period where recognizable hominids have existed. The Quaternary is also split into several smaller periods, and the current one is called the Holocene.

The Holocene began approximately 11,650 years ago, and includes the development of all written human history, as well as most if not all of our species’ major civilizations. Although it’s a mere blink in the grand scheme of geological time, it is the period when mankind rose to become the dominant species on the planet. Right now, however, the Holocene is coming to an end.

The impact of mankind on planet Earth has become so large that most scientists agree that we should designate a new geological period called the ‘Anthropocene’ — the Age of Man (from the Greek ‘anthropos’ which means”man/human being”). Although the term has not become official just yet, it represents the reality which we are all seeing: the environment, both above and beneath the ground, is heavily affected by mankind. We have produced nuclear explosions which left behind chemical marks that will be visible for millions of years. The plastic we are producing (and dumping into landfills or oceans) takes millennia to decompose. The chemistry of the atmosphere and the oceans has also been substantially altered, and even the bones of the animals we eat are a sign that we are having a dominant impact on the planet — it’s time for all this to get its own period. It is a clearly distinguishable and unprecedented period in Earth’s geological history.

With this in mind, the 34-member Anthropocene Working Group (AWG) voted to establish the Anthropocene as a new type of age. It wasn’t a unanimous vote, but 29 out of the 34 members supported it. The AWG, which works under the tutelage of the International Commission on Stratigraphy (which oversees the official time periods), is now considering what the best starting point of the Anthropocene would be. The first atomic-bomb seems like the most plausible place to start.

The AWG is now looking for the best sites with sufficient sedimentary evidence to support the start of the Anthropocene.

 

Credit: Pixabay.

Five periods of mass extinction on Earth. Are we entering the sixth?

Credit: Pixabay.

Credit: Pixabay.

Our Earth is very old. Based on the estimation of the oldest rock, it’s around 4.5 billion years of age.

Scientists from all over the world use astronomy, geology, chemistry, biology, archaeology and other sciences to investigate the Earth’s formation as well as the emergence and extinction of life on Earth.

…Then there’s life!

Around 13.8 billion years ago, an enormous explosion that scientists call the Big Bang spurred the formation of our planet. The explosion produced increasingly dense, cloud-like masses of hydrogen dust; the biggest turned into our sun, while smaller ones became planets. One of those planets is our Earth.

Some scientists believe around 600 to 700 million years later, meteor showers bombarded the earth, carrying with it large volumes of water and amino acids. Life, in the form of single-cell bacteria, began.

Since then, bacteria has evolved into more complex forms, though different beings have also become extinct.

Geological eras

Geologists divide the periods from the Earth’s formation up until now into a number of eras based on the changes that happened in each of them.

We are currently in the Holocene era, which started around 11,700 years ago when the Ice Age ended.

More recently though, a number of scientists have argued that because of the nuclear bomb testings of the 1950’s and population explosion, humans have entered a new era, called the Anthropocene.

They argue that with more than seven billion people, human activity has drastically influenced nature and the extinction of a number of wildlife.

The Earth is no stranger to disappearing life forms. There are have been many periods of extinction, from when the first organism emerged on Earth until today.

However, according to fossil records, only five eras have drastically reduced the population of living beings on earth to warrant the label of mass extinction.

First period of extinction

Entering early to mid period of the Ordovician Era, the Earth was still warm with an ideal humidity level for living. However, towards the end of the period – around 443 million years ago – everything changed suddenly, when the old continent Gondwana reached the South Pole. The temperature dropped drastically and ice formed everywhere, lowering the water level.

Subsequently, the level of carbon dioxide in the atmosphere and in the sea dropped, causing the number of plants to decrease dramatically and an ecosystem chaos ensued because certain plants, used as sources of food, became scarce.

Some 86% of the population of living beings disappeared within three million years. Some of the organisms affected by the first extinction were Brachiopods, Conodonts, Acritarchs, Bryozons, and also Trilobites that lived in the ocean.

Second period of extinction

The second period of extinction, during the Devon Age, happened around 359 million years ago. A relentless meteor shower is believed to be one of the causes of mass extinction. Other causes include a drastic decrease in oxygen levels globally, the increased activity of tectonic plates, and climate change. These changes caused around 75% of living creatures to die.

Extinction in this period impacted life in the sea which, at the time, was dominated by corals and stromatoporoids.

Third period of extinction

The third period of extinction, around 251 million years ago, during the Permian Age, was the biggest and worst that ever happened on Earth.

The formation of the giant continent Pangea caused immense changes in geology, climate and the environment. Volcanic eruptions that continued for 1 million years released around 300 million square kilometres of lava while more than 1750 metres of sediment was formed in the Siberian Traps.

The eruptions burned forests four times the size of Korea. It produced large volumes of carbon dioxide that caused global warming. As a result, frozen methane below the sea melted, producing a global warming effect 20 times more powerful than carbon dioxide.

The global warming lasted for approximately 10 million years. A terrible mass extinction was inevitable. Only 5% of the population of life on Earth survived and 95% perished from massive drought, lack of oxygen and acid rain that made plants unable to survive.

Fourth period of extinction

The fourth period of extinction happened around 210 million years ago, during the Late Triassic Age.

The slow splitting of Pangea caused volcanoes to form in the Central Atlantic Magmatic Province. After a spike in atmospheric carbon dioxide, global warming started again, with scientists speculating it lasted as long as eight million years.

This caused coral and conodonts, an eel-like ancient sea creature to face serious crisis. Coral-based creatures did not survive.

A meteor rain also hastened the destruction in this period: Around 80% of living creatures, including reptiles died, with some 20% of the creatures that became extinct sea-based lifeforms.

Additionally, a number of creatures that lived on land that died in this period were pseudosuchia, crocodylomorphs, theropods and several large amphibians.

Fifth period of extinction

The fifth period of extinction happened around 65 million years ago and is more popularly known as Cretaceous-Tertiary extinction. It was the fastest period of mass extinction, occurring over one to 2.5 million years.

It’s possibly the most known period of mass extinction because this was when dinosaurs were wiped out from the face of the earth. Scientists believe a meteor fall in today’s Gulf of Mexico compounded with high volcanic activity which produced a significant amount of carbon dioxide, killed half of the earth’s living population.

How does the future look?

Some scientists believe that we have entered the sixth period of extinction since 2010. The massive emission of carbon dioxide from fossil fuels has affected the lives of many plants and animals. Scientists predict that this will affect many life forms on Earth in the next three to four decades. Who knows?

Mirzam Abdurrachman, Lecturer at Department of Geology, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung; Aswan, Lecturer in Geology, Institut Teknologi Bandung, and Yahdi Zaim, Professor in Geology, Institut Teknologi Bandung

This article was originally published on The Conversation. Read the original article.

Technosphere

There are 30 trillion tons of human-made stuff all over the planet

The mass of humanity’s footprint on Earth, all the structures, vehicles, infrastructure, garbage dumps, everything — collectively known as the “technosphere” — comes down to roughly 30 trillion tons, a new study estimates.

Technosphere

Image credits Kasuma F. Gruber / Pexels.

If my last dorm room taught me anything it’s that people have a lot of stuff. And if each one of us has a lot of stuff, then just how much stuff do all of us have put together? It must be a huge pile of stuff — one that would weigh about 30 trillion tons, according to an international team of researchers.

So it would be a pretty impressive pile. But that’s to be expected; everything processed, altered, or made by humans is counted here — every bit of rural and urban infrastructure, all buildings as well as vehicles and other machinery on land, sea, or air, all the computers, smartphones, and all the garbage in landfills. All this makes up the technosphere.

“It is all of the structures that humans have constructed to keep them alive, in very large numbers now, on the planet: houses, factories, farms, mines, roads, airports and shipping ports, computer systems, together with its discarded waste,” study Jan Zalasiewicz, professor of palaeobiology at the University of Leicester, UK, and study co-author said in a statement.

It’s not the largest of the spheres, but it’s definitely big. If we were to distribute the total mass evenly across the Earth’s surface, the technosphere would cover every square meter (11 sq-feet) of the planet in about 50 kilograms (110 pounds) of man-made stuff, the researchers say. And it’s bound to grow in size as time passes.

The technosphere is in a way the sum of our action on the planet. As such, it has a close connection to the newly-declared geological age Anthropocene — a period in which human activity has the power to shape the whole planet. But unlike the other sphere of life, the biosphere, our system does a very poor job at re-using and recycling the materials and energy used to create it. It doesn’t break down to power further growth (think of how animals digest plants into dung which then provides fertilizer for other plants,) instead it just adds to itself, taking more space as new buildings, new cars, or in landfills.

“The technosphere is a system, with its own dynamics and energy flows – and humans have to help keep it going to survive,” Zalasiewicz said.

“The technosphere may be geologically young, but it is evolving with furious speed, and it has already left a deep imprint on our planet.”

Right now, the study concludes, the technosphere outweighs humans 3 to 1. Considering that the “present human biomass is more than double” that of all large terrestrial vertebrates before us and that the primary source for technospheric growth comes from the transformation of the biosphere and other natural resources, the sustainability of further growth under a business as usual model comes into question.

But then again, people need houses, food, roads, and all that good stuff. With the huge population growth we can expect in the future, the technosphere will need to expand to accommodate these needs — putting further pressure on natural resources already spread thin. Some new technologies will also require more resources and energy to implement.

The strain this growth requires might be dampened by re-using materials already available in landfills or infrastructure we don’t need anymore, but that won’t cover all the demand. In the end, there’s a limit to how much the technosphere can expand.

“While the long-term development of the technosphere remains uncertain, its scale and accelerating diversification of form means that it already represents a distinctive new component at a planetary scale,” the study concludes.

The full paper “Scale and diversity of the physical technosphere: A geological perspective” has been published in the in the journal The Anthropocene Review.

Scientists believe humans have started a new geological epoch: the Anthropocene

Our impact as a species on the Earth has become so profound that we need to declare the start of a new geological epoch defined by us, the Anthropocene, experts believe. The proposal was presented to the International Geological Congress in Cape Town on Monday.

Image credits kakuko / pixabay.

The new geological epoch should begin roughly in the 1950s, the experts said, and will most likely be defined by the radioactive elements blown across the planet by our nuclear weapons tests. But there’s no shortage of signals being considered — including plastic pollution, soot from power stations, concrete, even the bones left worldwide by the domestic chicken could prove to be valid delimiters.

New times

Among the first things they teach you in geology is the time scale — our attempt to organize and make sense of the immense periods of time involved in geological processes. One of the main divisions of geological time are called epochs, and the one we’re living in now — the Holocene — has been going on for about 12,000 years. It’s marked by a period of climate stability after the last ice age, and all human civilization up to now has developed in this epoch.

The Holocene is the latest part of the latest part of the Cenozoic. You couldn’t even see the Anthropocene here with a microscope.
Image via Wikimedia.

But conditions are changing. The 20th century has seen a huge increase in free carbon dioxide levels in the planet’s atmosphere, coupled with sea level rise, global extinctions and significant transformation of the land in the form of deforestation, mining, and other development. The planet has changed so much so fast that conditions now don’t match conditions a few thousand, even hundreds of years ago — a window of time that’s barely significant in geological terms. This, the experts believe, means that the Holocene must give way to the Anthropocene.

“The significance of the Anthropocene is that it sets a different trajectory for the Earth system, of which we of course are part,” said Prof Jan Zalasiewicz, a geologist at the University of Leicester and chair of the Working Group on the Anthropocene (WGA), which started work in 2009.

“If our recommendation is accepted, the Anthropocene will have started just a little before I was born,” he said. “We have lived most of our lives in something called the Anthropocene and are just realising the scale and permanence of the change.”

We’re the main players now

Now, before you start celebrating that we’re no longer just a geological force, but one that defines a whole epoch in our planet’s development, take a second and consider what sort of responsibility this puts on us. We’re no longer a group of primates scared hairless at the world around it — we’re safe from predators, safe from the cold or heat, reasonably safe from disease, and there’s plenty of food to go around (we still have to work on the “around” part, though.) We’re no longer at the mercy of the world around us — we shape the world around us.

“Being able to pinpoint an interval of time is saying something about how we have had an incredible impact on the environment of our planet. The concept of the Anthropocene manages to pull all these ideas of environmental change together,” added Prof Colin Waters, principal geologist at the British Geological Survey and WGA secretary.

“The Anthropocene marks a new period in which our collective activities dominate the planetary machinery,” said Prof Chris Rapley, a climate scientist at University College London and former director of the Science Museum in London, who is not part of the WGA.

“Since the planet is our life support system – we are essentially the crew of a largish spaceship – interference with its functioning at this level and on this scale is highly significant. If you or I were crew on a smaller spacecraft, it would be unthinkable to interfere with the systems that provide us with air, water, fodder and climate control. But the shift into the Anthropocene tells us that we are playing with fire, a potentially reckless mode of behaviour which we are likely to come to regret unless we get a grip on the situation.”

Martin Rees, the astronomer royal and former president of the Royal Society, said that the dawn of the Anthropocene was a significant moment.

“The darkest prognosis for the next millennium is that bio, cyber or environmental catastrophes could foreclose humanity’s immense potential, leaving a depleted biosphere.”

“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. The dawn of the Anthropocene epoch would then mark a one-off transformation from a natural world to one where humans jumpstart the transition to electronic (and potentially immortal) entities, that transcend our limitations and eventually spread their influence far beyond the Earth.”

[panel style=”panel-default” title=”Evidence of the Anthropocene include:” footer=””]

  • Rising plant and animal extinction rates. If conditions don’t improve, our planet will lose 75% of species in the next few centuries.
  • CO2 levels in the atmosphere rising faster than ever in the last 66 million years. The level was 280 ppm before the industrial revolution and it’s gone up to 400ppm and rising today.
  • Huge amounts of plastic in oceans and waterways. Microplastic particles are now virtually ubiquitous, and plastics will likely form geological structures identifiable in the future.
  • Nitrogen and phosphorus levels in agricultural soils have doubled over the past century (chemical fertilizers.) This likely constitutes the largest impact on the nitrogen cycle in 2.5bn years.
  • A layer of airborne particulates in sediment and glacial ice such as black carbon from fossil fuel burning.

[/panel]

While humanity’s effect on the planet is highly evident, the short window of time in which they’ve taken place — epochs usually span tens of millions of years — was used to criticise the idea of an Anthropocene.

“One criticism of the Anthropocene as geology is that it is very short,” said Zalasiewicz. “Our response is that many of the changes are irreversible.”

Each geological epoch needs a marker that can be used to differentiate between it and the previous one, a signal that can be picked up in the future geological record. The end of the Cretaceous some 66m years ago is defined by a spike in iridium in sediments across the world, dispersed by the same meteorite that killed off the dinosaurs. The best candidate for the Anthropocene are the radioactive elements that settled all over the world following nuclear weapons tests.

“The radionuclides are probably the sharpest – they really come on with a bang,” said Zalasiewicz. “But we are spoiled for choice. There are so many signals.”

Other spikes being considered as evidence of the onset of the Anthropocene include the tough, unburned carbon spheres emitted by power stations, plastic pollution, aluminum and concrete particles, or high levels of nitrogen and phosphate in soils derived from artificial fertilizers. As for marker fossils, the domestic chicken is an unlikely but very serious suggestion to define the Anthropocene for future geologists.

Quaking their way to paleontological success.
Image credits skeeze / pixabay.

“Since the mid-20th century, it has become the world’s most common bird. It has been fossilised in thousands of landfill sites and on street corners around the world,” said Zalasiewicz. “It is is also a much bigger bird with a different skeleton than its prewar ancestor.”

Out of the 35 members of the WGA, 30 voted in favour of formally designating the Anthropocene, 3 against and 2 were absent. The group will be spending the next two to three years determining which signal will become the official indicator of the epoch, and the type location for it — geological divisions are not defined by dates but by a specific boundary between layers of rock or, in the case of the Holocene, a boundary between two ice layers in a core taken from Greenland and now stored in Denmark.

They’re focusing on sites with annual layer formation, such as mud sediments off the coast of Santa Barbara in California and the Ernesto cave in northern Italy, where stalactites and stalagmites accrete annual rings. Lake sediments, ice cores from Antarctica, corals, tree rings and even layers of rubbish in landfill sites are also being considered.

Once the data has been assembled, it will be formally submitted to the stratigraphic authorities and the Anthropocene could be officially adopted within a few years.

“If we were very lucky and someone came forward with, say, a core from a classic example of laminated sediments in a deep marine environment, I think three years is possibly viable,” said Zalasiewicz.

But geologists are trained to think in terms of millions of years and despite the WGA’s expert recommendation, the Anthropocene might take just as long to catch on.

“Our stratigraphic colleagues are very protective of the geological time scale. They see it very rightly as the backbone of geology and they do not amend it lightly,” said Zalasiewicz. “But I think we can prepare a pretty good case.”

Rapley also believes that they have a solid case for the Anthropocene.

“It is highly appropriate that geologists should pay formal attention to a change in the signal within sedimentary rock layers that will be clearly apparent to future generations of geologists for as long as they exist. The ‘great acceleration’ constitutes a strong, detectable and incontrovertible signal.”

 

 

Fishing vessels level sea bottom – signs of a new dawning geological era

A while ago, several geologists started wondering if the impact humanity is having on Earth isn’t so big, that despite its relatively short duration, we should consider living in a distinct geological era marked by this impact – the Anthropocene. Of course, aside from supporters, there were those who only gave a condescending smile or were ever ironic, but the arguments are starting to stack up.

Most modern fisheries partially rely on trawling – dragging huge nets across the sea floor in order to capture species of fish and crustaceans. But aside from the massive damage this method is doing to the environment when applied excessively, it’s also having another side effect: it is leveling the sea bottom. The situation has been likened to excessive farming.

“Fishermen are not doing anything different than farmers many decades ago,” explains marine scientist Pere Puig of La Agencia Estatal Consejo Superior de Investigaciones Cientificas (CSIC) in Barcelona, who led the research. “Fishing grounds could be seen as farm fields, but there has to be some limitations to avoid the extension of trawling impacts.”

He and his colleagues analyzed the impact of bottom trawling after noticing in 2002 that the technique was stirring up more sediment than all natural processes together. What they found was that 5,378 metric tons of sediment moved this way over the course of 136 days of monitoring only in an undersea canyon in Spain – and trawling has been going on since the 70s.

The effects this leveling is having on bottom sea creatures is still unknown, though all indications point towards a reduction of biodiversity; basically, you level it and destroy unique habitats, you also destroy unique creatures. More extensive studies will likely be conducted in the nearby future, especially to estimate the amount of damage caused by ocean bottom leveling.

Study source