We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Origin of Air?

Michael Anissimov
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The origin of air as we know it begins with the Oxygen Catastrophe, also known as the Great Oxidation, which occurred about 2.7 billion years ago. Prior to this, the level of oxygen in the air was approximately 1/50th of a percent. This is similar to the level of oxygen present in the atmosphere of Mars, about 1/5th of a percent. Like modern-day Mars, the atmosphere of early Earth was primarily carbon dioxide. Today, the atmosphere contains 20% oxygen, and only 0.038% carbon dioxide, making the air thoroughly breathable for oxygen-dependent organisms such as ourselves.

With the advent of oxyphotosynthesis in microorganisms, this carbon dioxide was progressively consumed, creating the "waste product" of elemental oxygen. The Oxygen Catastrophe is clearly demarcated in the geological record by the introduction of large amounts of oxygenated iron (rust). These relics are called banded iron formations. The event is called a "catastrophe" because oxygen is toxic to anaerobic organisms, which the event wiped out in large numbers. There was a time lag of about 300 million years before the evolution of the first oxygen-producing organisms and the full-fledged Oxygen Catastrophe.

In the subsequent billions of years, oxyphotosynthesizing organisms flourished, producing more and more elemental oxygen. The history of air, from practically zero oxygen to 20% oxygen, stretches over more than two billion years. During the Carboniferous period, approximately 250 million years ago, when plants thrived, oxygen levels were even higher than they are today. This permitted the existence of very large insects, including a dragonfly, Meganeura, with a two-foot wingspan. Today's air would be unbreathable to Meganeura, due to its relative lack of oxygen.

The search is ongoing for extraterrestrial planets with air similar to that of Earth, with no luck thus far. By examining the spectrum of a planetary body closely, astronomers can determine its chemical composition, even if that body is extremely distant. This is the same technique used to determine the chemical makeup of far-away stars.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology, astronomy, chemistry, and futurism to his articles. An avid blogger, Michael is deeply passionate about stem cell research, regenerative medicine, and life extension therapies. His professional experience includes work with the Methuselah Foundation, Singularity Institute for Artificial Intelligence, and Lifeboat Foundation, further showcasing his commitment to scientific advancement.
Discussion Comments
By pleonasm — On Jul 25, 2014

It would have been so amazing to see the world as it was when the oxygen levels were even higher. The giant insects in particular must have been incredible.

I mean, it wouldn't have been ideal for human life, but I'd love to see it as a tourist. Someone needs to hurry up and make a time machine already.

By umbra21 — On Jul 24, 2014

@browncoat - There are already creatures on our planet who don't breath oxygen and live well outside the norms of what we would consider typical life.

I think they even recently discovered organisms that live by using electricity as fuel. I mean, conceivably, you could have creatures who manage to survive in a vacuum if they can do that (with many other adaptions of course).

And the thing is, we are the source of the pollution in our air at the moment. And it's not biological. So if it gets to the point where we ourselves go extinct, the atmosphere probably won't stay the same.

Life evolves though. I don't doubt it will survive. I just think we need to consider how we want it to survive. I wish more people would look at environmentalism as a selfish endeavor. It's basically about preserving good things in the world.

By browncoat — On Jul 23, 2014

It is so weird that life as we know it on Earth was basically made possible by a huge extinction event. We are living in air that was poisonous to almost everything that came before us.

It makes you wonder if we're going to end up doing basically the same thing for another species down the line. We're changing the climate and atmosphere so drastically that we're already seeing a lot of extinctions result from it. Maybe eventually another form of life will develop from the ones that remain and will take over the Earth.

I've never thought that it was entirely necessary for life to need oxygen. That's just how it turned out here for the most part. We could end up creating a world where the inhabitants breath in a different mix.

Michael Anissimov
Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology...
Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.