Reflection on Pollution

From the Great Oxidation to the ‘Great Pollution’

Around 2.4 billion years ago, a profound environmental change occurred on our planet, which had a gigantic impact on the composition of the atmosphere (and therefore on the climate) and which brought with it the mass extinction of a large number of the microorganisms that populated the Earth at that time.

This catastrophe is known as the Great Oxidation or the Oxygen Catastrophe, and it was the product of the appearance and multiplication of the first photosynthetic organisms, that is, of the first microorganisms capable of synthesizing their own food, using sunlight: the ancestors of the first plants.

These new organisms began to flood the atmosphere with oxygen molecules (O2), which were toxic and lethal for other microorganisms, since they obtained their energy from anoxygenic biochemical processes, that is, they were unaccustomed to the presence of oxygen.

Billions of years later, human beings populate the planet and, like other animals, we depend on the presence of that same oxygen to survive. What for those primitive bacteria meant mass extinction, for us it represents life and the possibility of remaining on the planet. And despite this, there is not much we do to preserve it in our atmosphere.

The Great Pollution

The world, like 2.4 billion years ago, was not prepared for the arrival of the human industries. The ability of our species to govern the laws of the world and transform matter has allowed us to prosper and build unique societies but, at the same time, threatens our future as a species.

In fact, by releasing high-carbon gases, such as carbon dioxide (CO2) and methane (CH4), or other compounds of sulfur (S) and nitrogen (N), we are rapidly transforming our atmosphere, making it more like the one that existed before the Great Oxidation.

This means that its percentage of oxygen decreases in relation to other gases, and also that the atmosphere becomes much warmer, since these heavy gases (known as greenhouse gases) capture solar radiation and increase global temperature. Pollution of the atmosphere is thus changing our planet and making it less hospitable to known life.

And just as at the time the Great Oxidation wiped out the species that did not know how to adapt to the new panorama, it is very possible that our Great Pollution will have the same effect in the not too distant future. And nobody can guarantee us that among the species capable of adapting to a world with less oxygen we are, precisely, those who pollute it.

Urgent action must be taken

More than two centuries of continuous pollution of the atmosphere have put us on the edge of a precipice. Climate change scholars warn that we may have less than 30 years to reduce our carbon emissions and radically change our way of life, before the new climate system we have put in place becomes irreversible.

The climatic catastrophe will not only alter the way in which the different ecosystems function, but it will pose a huge economic problem for humanity itself, as the sea levels rise (as a result of the melting of the poles) and spread deserts on dry land. There will be less arable land on the planet, more ferocious climatic cycles (colder winters and hotter summers) and more acidic oceans, with less oxygen, unable to support the same amount of living beings.

The future outlook is not good, and action must be taken urgently. Otherwise, we run the risk that the planet will change and turn its back on us, and it will be our turn, like the old anoxygenic species, to give way to new life forms and become extinct.


  • “Pollution” in Wikipedia.
  • “Great Oxidation” in Wikipedia.
  • “What is environmental pollution?” at the Aquae Foundation.
  • “It’s time for a global agreement against marine plastic pollution” by Manuel Jaramillo in La Nación (Argentina).
  • “Reflections on environmental pollution” by Ricardo Katz in CEP (Chile).

What is a reflection?

A reflection or dissertation is a text in which the author thinks freely about a topic. In other words, in this type of text the author shares his thoughts with the reader, inviting him to assume a point of view or evaluate different arguments, without necessarily having a role for reflection, but the pure pleasure of thinking about the subject. The reflections can deal with any topic and be more or less formal, and can be part of speeches, books, etc.