It made world news last week when a small lake in Canada was chosen as the “Golden Spike” – the location where the emergence of the Anthropocene is most evident. The Anthropocene is the proposed new geological epoch defined by human impact on the planet.
It took 14 years of searching the world before the geoscientists of the Anthropocene Working Group chose Lake Crawford—the calm, deep body of water that is so good at preserving history in the form of layers of sediment. The core samples from the lake give us a remarkably good record of geological change, including, some scientists believe, the moment we started to change everything. For this group, that date was around 1950.
But what went unreported was the resignation of a key member, global ecosystem expert Professor Erle Ellis, who left the working group and published an open letter about his concerns. In short, Ellis believes that the beginning of our great impact on the planet until 1950 is a mistake, because we have already changed the face of the planet.
Some working groups of scientists argue that 1950 was well chosen, because it was the time when people began to make their presence felt through population growth, use of fossil fuels and deforestation, etc. things. This phenomenon is called the Great Acceleration.
Disagreement speaks to something important in science—the ability to accommodate disagreement through debate.
What is the debate?
Will the public accept the idea that our actions are making the world almost unnatural? The answer, of course, depends on the quality of the science. Since most people are not scientists, we rely on the scientific community to open the debate and present the best explanations for the data.
That’s why Ellis’ departure is so interesting. His resignation letter was explosive:
“This […] [im]it is possible to avoid the reality that narrowly defines the Anthropocene […] became more than a scholarly concern. The AWG’s choice to systematically ignore the overwhelming evidence of long-term anthropogenic change on Earth is not just bad science, it’s bad for public understanding and action on global change.”
Not that Ellis thinks the way we live is without problems. The central issue, in his view, is that there is powerful evidence of earlier global-scale effects caused by pre- and proto-capitalist societies.
For example, as shown by Earth system experts Simon Lewis and Mark Maslin, the brutal Portuguese and Spanish colonization of Central and South America indirectly lowered atmospheric carbon dioxide levels. How? By killing millions of natives and destroying local empires. In the absence of people, the trees grew again during the 17th century and covered villages and cities, expanding the Amazon rainforest.
Why we should accept honest disagreement in science
Scientists have debated in recent years whether the Anthropocene should be considered an “epoch” with a specific start date, or rather an extended “event” in history due to various human behavior in different areas, such as early agriculture, European colonization and the spread of capitalism in Europe and North America around the world.
Ellis’ resignation stemmed from this debate. He’s not alone — other team members and experts are also working to debunk the weather idea.
As the philosopher of science Karl Popper and others have argued, fruitful scientific debate can only occur if there is room for dissent and alternative views. Ellis clearly believes that the Anthropocene group has moved from debate to group thinking, which, if true, would challenge free exchange at the center of science.
In the longer term, a compromise can be reached. If the Anthropocene team were to switch gears and label the beginning of the era as a multi-century event (a “long Anthropocene”), we would still benefit from having labels for eras like our current one. where the human impact intensified. significance.
One issue with such tensions is what happens when they hit the media. Consider Climategate, the 2009 incident in which an attacker stole emails from a key climate research center in the United Kingdom. Bad faith actors have seized on imagined issues in emails and used them to claim that anthropogenic climate change is being created. The scientists at the center of the controversy have been cleared of wrongdoing, but the whole affair has helped to seed doubt and slow our transition away from fossil fuels.
The risk here is that if the public only gets a single, simplified view of these debates, they may question the overwhelming evidence of our impact on Earth. It falls to journalists and science communicators to express it accurately.
Regarding our trust in science, the case of declaring the Anthropocene will be subject to close scrutiny and may not be approved by the International Commission on Stratigraphy, the body responsible for separating deep time into specific periods.
Stratigraphers such as Lucy Edwards argue that an emerging epoch is not an appropriate subject for stratigraphy because all evidence cannot, by definition, be contained.
What does this tension mean for the Anthropocene?
The epoch versus event debate does not mean we are off the hook in terms of our impact on the planet. It is very clear that we became the first species in the long history of the Earth to change the functioning of the atmosphere, cryosphere, hydrosphere, biosphere and pedosphere (the soil layer) all at once and very quickly. Species such as cyanobacteria or blue-green algae have a great effect by increasing oxygen in the atmosphere, but they do not affect all the spheres of speed and severity that we have.
Although we do not plan to change the planet, the implications of this are huge. Humans are not only changing the climate but the entirety of the irreplaceable envelope that sustains life on the only planet known to have life. This is a complex story and we should not expect science to simplify it for political or other reasons.
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Citation: Did the Anthropocene begin in 1950—or earlier? Here’s why the debate about our global changing impact matters (2023, July 19) retrieved on 19 July 2023 from https://phys.org/news/2023-07-anthropocene-1950or- earlier-debate-world-changing.html
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