Although oxygen accounts for only 21% of the Earth’s atmosphere, it is the most crucial gas for the existence of living organisms on our planet. From this fact, have you ever wondered what we would inherit if the oxygen concentration on Earth were to double?
Where Does Oxygen on Earth Come From?
The Earth was formed 4.6 billion years ago. After the Big Bang, the Earth initially took shape as a “massive fireball” that was continuously burning. After cooling for 1.1 billion years, life gradually began to emerge, and the atmosphere started to form.
When the new atmosphere was formed, it contained no oxygen. The initial atmosphere was filled with gases such as ammonia and methane, and the oxygen present in the atmosphere later primarily originated from two sources: one being plants that engage in photosynthesis and the other being abiotic processes during the photolysis of water.
Today, we know that the oxygen content in the air is about 21%, and this level of oxygen is vital for humans and other living beings. In an oxygen-deficient environment, humans cannot even breathe normally.
So, what would happen if the oxygen level on Earth suddenly doubled—resulting in approximately 40% oxygen in the air?
Below are the most significant impacts that would occur if oxygen levels significantly increased on our planet.
How Would Humans Feel at Different Oxygen Levels?
In an oxygen-deficient environment, humans cannot even breathe normally. (Illustrative image).
- When oxygen levels are between 0% to 10%, individuals will experience difficulty breathing, blood oxygen levels will continuously decrease, leading to diminishing clarity of mind, confusion, and ultimately death due to lack of oxygen.
- When oxygen levels are between 10% to 16%, individuals will also feel breathlessness, chest tightness, and may even experience cardiac arrest.
- When oxygen levels are between 15% to 19%, individuals will feel lightheaded, dizzy, and find it hard to concentrate on work and study.
- When oxygen levels are between 19% to 24%, it falls within the normal oxygen concentration range, allowing individuals to live, study, exercise, and rest comfortably.
- When oxygen levels are between 24% to 31%, the environment is rich in oxygen, which is also the most suitable environment for human habitation. People will feel alert, energetic, and sleep quality will improve.
- When oxygen levels are between 31% to 52%, the high oxygen concentration will accelerate the aging process, shorten life expectancy, and make the body more susceptible to diseases such as pneumonia and oxygen-induced retinopathy.
- When oxygen levels are between 52% to 90%, individuals will feel restless; initially, they will gradually adapt, but ultimately they will suffer from oxygen toxicity and die from respiratory failure.
- When oxygen levels are between 90% to 100%, the oxidation process will occur at the fastest rate, leading to immediate death.
If the oxygen level on Earth were to double, the resulting concentration would correspond to levels between 31% to 52%. Although the human body may adapt slowly, the unpredictable long-term damage will certainly manifest.
Impact on Animals
Spiders, cockroaches, and many other terrifying species of reptiles that always send shivers down our spines would grow larger in size. These small creatures breathe through tiny tubes called tracheae, so as more oxygen passes through these tubes, their bodies would “inflate” and grow larger. Dragonflies could reach the size of hawks, while spiders could grow large enough to swallow a pigeon.
However, you need not worry about your safety from these monsters as you would always have time to escape. With more oxygen available in the lungs, each breath significantly increases your endurance. Oxygen-rich blood would pump through the veins, providing energy to the muscles, and with better circulation, humans would become more agile and focused. Athletic running records would improve “dramatically,” breaking previous world records as new records are set in a future with abundant oxygen.
Breathing double the current amount of oxygen will dramatically improve athletic running records.
Neutrophils, a type of white blood cell, play an important role in the human immune system by utilizing oxygen to combat diseases. These cells would increase their resistance to harmful viruses and bacteria due to the higher oxygen supply, leading to fewer illnesses and fever.
Despite these benefits, excessive oxygen can also negatively affect your health. If the organs in the body overexert themselves due to excessive oxygen absorption, you may easily become exhausted, leading to severe life-threatening consequences. Deaths from exhaustion would become more common than those from severe illness.
Impact on Plant Life
If the oxygen concentration on Earth were to double, the most notable changes would be the acceleration of processes like respiration and combustion. With more oxygen present, wildfires would become larger and more devastating; even moist vegetation would not be able to act as a “shield.” Everything would be at a greater risk of catching fire.
At the same time, processes such as photosynthesis would stagnate due to lower CO2 levels in the atmosphere. The current green vegetation would be replaced by a landscape covered in moss and fungi, reminiscent of prehistoric times.
Impact on Mountain Regions
If oxygen levels double, living at such heights would no longer pose any serious issues.
For backpackers and adventurers dreaming of castles above the clouds or living on the highest peaks, low oxygen levels at high altitudes have always made the journey challenging. However, with a more optimistic view, if oxygen levels were to double in the atmosphere, respiratory issues would be the least of concerns, and living at such heights would no longer pose any serious problems.
This could lead to humans occupying mountainous areas and transforming them into living spaces, ultimately degrading natural formations and soil quality. Glaciers on mountain peaks would significantly melt, while habitats for plants and animals would thrive there.
Impact on Earth’s Atmosphere
Higher oxygen levels help birds fly higher in the sky and stay airborne longer.
As oxygen levels increase, the air density in the atmosphere would also rise. This would allow airplanes, gliders, parachutes, and birds to fly higher in the sky and stay airborne longer. Higher oxygen levels would also create a thicker atmosphere, scattering more sunlight and making the sky appear bluer while reducing air temperature.
Impact on Machinery
Oxygen in fuel improves engine performance by reducing nitrogen entering the engine, causing it to heat up. With less heat, performance improves and fuel consumption decreases. This phenomenon would undoubtedly lead to a more promising future for industries and automated machinery worldwide.
However, burning more fuel would result in machines emitting more pollutants, ultimately crippling the atmosphere.
Conclusion
Looking through history, we often see consequences following seemingly positive scenarios. The benefits of doubling the oxygen levels on Earth may sound enticing, but we would pay the price with shorter lifespans and an unpredictable outlook for the planet.
Today, there exists a complete chain of connections among living organisms. A sudden increase in oxygen concentration would make it impossible for many species to adapt to this environment, leading to biological extinctions. Should a mass extinction occur, it would trigger a chain reaction, ultimately leading to a mass extinction event. This process would continue until a new stable chain is re-established.
Moreover, if the oxygen concentration were to double suddenly, the most severe consequence would be environmental imbalance. Since oxygen accelerates combustion, an increase in oxygen levels would facilitate and intensify the burning process.
During this process, once a wildfire occurs, it will burn more fiercely and be more difficult to extinguish. The end of the era of giant insects 300 million years ago was also closely related to the global fires that occurred at that time.
Due to the oxygen-rich environment, with materials consisting of the forests that covered the planet, the fires burned for hundreds of years. Eventually, this led to a sharp increase in Earth’s temperature and caused a mass extinction event. Subsequently, the oxygen levels also dropped rapidly, ultimately leading to the rise of reptiles and the beginning of the age of dinosaurs on Earth.
We should feel fortunate that our planet perfectly balances these elements. Although oxygen only makes up 21% of the atmosphere, which may seem low considering the billions of people sharing this suffocating air, now you understand how dangerous life would be if the universe altered the air composition on Earth!
