Anna Maria Alonso Zarza: “The Earth will remain, but our world will not remain” | Science
The Anthropocene, the geological age marked by the global influence of human activities, does not exist as such for scientists, although the evidence appears to be clear. The Geological Society of London has already provided data to support it: erosion and sedimentation caused by human action doubles by 24 generated by all rivers of the world; Sea level, which has remained stable for the past seven thousand years, is now rising 0.3 meters per century and this number will double in eight decades; Its waters, after thousands of years without change, have recorded unprecedented levels of acidity for a century. The concentration of carbon dioxide is the highest in the past four million years, more than 100 million times that of all the volcanoes in the world; The species’ extinction rate has doubled by 10,000. Anna Maria Alonso Zarza, who was born 58 years ago in Venera de Morena (Avila), Director of the Institute of Geological Mining of Spain (IGME-CSIC), is accustomed to looking at the planet by an hour where every second measures thousands of years, The Impact of Human Activity on the Planet and its Possible Sixth Extinction.
Question. Why did the Anthropocene not yet exist to geology?
Answer. Anthropocene does not exist as an official term. I like comparing it to the Spanish Royal Academy. There are many words that are used on a daily basis, and until the Academy decides to include it in the dictionary, we use them informally. The same thing happens with the Anthropocene in geology. It is a term used, but the equivalent of the Royal Academy of Geology has not yet included the term in its dictionary. But it does exist, because humanity’s influence on nature suggests its existence. All data indicate that human activity is modifying the Earth system, and in fact, we are in a period when its influence is an important geological factor.
s. What defines the Anthropocene?
R. There are several characteristics: increase in greenhouse gases, temperature, sea level, and rate of species disappearance, which is a colossal proportion. There is also species mobility thanks to communication systems. Many species that were restricted to small areas managed to reach the whole world.
The clearest indication is when nuclear explosions began in the middle of the last century and when chemical ingredients such as pesticides began to be used systematically
s. When did it start?
R. It is a sensitive topic and varies according to researchers. Human influence on Earth began with cultivation about 11,000 years ago. But at that time, it was not yet universal, but registered in some specific areas where agriculture is found. There is a critical moment which is the collision between the old and the new world. There, yes, there is a huge impact and it also leads to animals and plants moving across the continents. Another potential major era for the Anthropocene is the Industrial Revolution, with the systematic use of fossil fuels. This also has an effect that, although initially local, especially in Europe, has gradually become global. This is recorded at the geological level in the sediments. But the clearest hint appeared to be when nuclear explosions began in the middle of the last century and when chemical ingredients such as pesticides began to be used systematically. In this way, it now appears the likely date to be considered will be 1950.
s. Why is the Anthropocene still an informal category then?
R. Everything is up for debate, although the use of the term Anthropocene is accepted by many disciplines. But science has to be foolproof, and when using a new concept, which would be a new geological era in this case, it should be very clear that references from that era will persist in the geological record. It’s hard to explain this because in geology you always look at what really happened, and what was actually recorded. It is a new paradigm in science because it is not something to be looked back at, but rather has to do with what we do and whether it will survive millions of years. If the beginning of the Anthropocene is considered the year 1950, then there must be clear sediments and rocks from that time that differ from previous times, which will be the Holocene era, and all this must be preserved for 100 million years. We cannot guarantee that this will be preserved, and here is the model in which geology is. The International Commission on Stratigraphy has to validate the Anthropocene, and it stands to reason that it still does not see it clearly because it advances science towards the future, rather than direction beyond. It is a paradigm shift.
s. Is plastic the defining ingredient in the Anthropocene?
R. It is very likely that the plastic will not be preserved because it will degrade. But the remains of concrete, cement, bricks, tiles, glass … all those synthetic materials that we have generated that have greater durability and greater potential for preservation in the geological record than plastic will be preserved.
We may be close to what is called the Sixth Extinction, in which one of the organisms that could be involved in it is us
s. Why is the concept of the Anthropocene important?
R. There is a scientific connotation and you have to let the science decide. It’s like the Medicines Agency, which has to assess that vaccines are adequate. Well here’s the same thing, we’re going to let the ICGS Working Group make the decision. But I think that thinking that what we are doing on the planet will leave its mark on the future should make us think that we are harming the Earth, and that we are changing some of its conditions. The planet has millions of years to stabilize and bury what we did and move forward. Even though we are changing it, the planet will seek another equilibrium and it will persist. But what we have to take into account is that what we are doing, who is really affected, is us, humanity, because we need so many resources that at some point will be depleted and then what will we do? Estamos en un momento en el que hay seres supuestamente inteligentes sobre la Tierra que se dan cuenta de que estamos haciendo daño al planeta y que podemos estar cerca de la llamada sexta extinción, en la que uno serisce in somes que puedu en la que uno serisce in somes que puedu we. We have to cast it because we don’t want to be the champions of the Sixth Extinction. We have to do something to avoid it. This is the important thing and it should make us think about our lives on this planet and our world. Earth will survive, but our world will not survive. We are only acting in the most superficial part of our planet and Earth will follow its rhythm. The most understandable case of all is the extinction of the dinosaurs when a massive meteorite fell 66 million years ago and produced a polluted dust cloud that caused the disappearance of about 80% of the species, including dinosaurs. That had a huge impact, moreover, in a short time. what happened? Well, dinosaurs left their place in mammals and thanks to that we are here. This means that each major extinction event, and there were five, and our event is said to be the sixth, causing that there are some species that disappear and others evolve and occupy their place. The earth goes through a different equilibrium, but it continues. When it is said that our planet is in danger, it is not so: our current way of life on this planet is in danger.
When it is said that our planet is in danger, it is not so: our current way of life on this planet is in danger
s. Does a change in lifestyle prevent that?
R. Certainly! If we consume fewer resources and burn less fossil fuels, we will reduce greenhouse gases and slow the rise in sea levels. This is why the geological perspective is important and characterizes this moment. Now we are in danger.