Where does oxygen on Earth come from?
Earth was born in 4.6 billion years. After the Big Bang, the Earth was initially formed into a “big fireball” that was continuously burned, after 1.1 billion years of cooling, life on Earth began to gradually be born, gas. book was also initially formed.
When the new atmosphere was formed, its composition was devoid of oxygen, the atmosphere was initially filled with gases such as ammonia and methane, the oxygen in the atmosphere that was produced then mainly came from two aspects, one was the plants involved. photosynthesis and the second is the participation of abiotic in the photolysis of water.
Now, we all know that the oxygen content in the air is about 21%, and the oxygen content is very important for humans or other living things. In an oxygen-deficient environment, humans can’t even breathe normally.
So what if the amount of oxygen on Earth suddenly doubled – about 40% of the oxygen in the air?
How will people feel with different levels of oxygen in the air?
When the oxygen content is from 0% to 10%, people will feel short of breath, the amount of oxygen in the blood continuously decreases, gradually lose their sanity, confusion and finally death due to lack of oxygen.
When the oxygen content is from 10% to 16%, people will also feel shortness of breath, chest tightness, even cardiac arrest.
When the oxygen content is at 15% to 19%, people will feel dizzy, dizzy, difficult to concentrate, work and study.
When the oxygen content is between 19% and 24%, it belongs to the normal atmospheric oxygen concentration, and humans can live, study, exercise and rest normally.
When the oxygen content is from 24% to 31%, the environment is rich in oxygen, which is also the most suitable environment for humans to live. People will feel the mind is alert, full of energy and sleep will be improved.
When the oxygen content is from 31% to 52%, at this time the environment with high oxygen concentration will cause the aging process to happen faster, the lifespan is shortened, the body is susceptible to diseases such as pneumonia, retinopathy. oxygenated membranes.
When the oxygen content is from 52% to 90%, people will feel restless, in a short time will gradually adapt, but eventually will have oxygen poisoning and die of respiratory failure.
When the oxygen content is from 90% to 100%, the oxidation rate reaches the fastest and people will lose their lives immediately.
If the oxygen content on Earth only doubled, then in the environment the oxygen concentration would correspond to an oxygen content of 31% to 52%, although the human body may be slow to adapt but the damage is unpredictable. will definitely appear over time.
Earth once experienced a high oxygen environment
In fact, the Earth used to have a super-oxygen environment with a super-oxygen content of 40%.
More than 300 million years ago, at the end of the Carboniferous period, the Earth’s environment at that time was very different from the Earth’s environment today, 5 continents were basically linked together to form a giant continent. scientists called Pangea.
The appearance of lignin gave birth to a large number of towering vascular plants, and the real giant tree was born, conifers also covered the ground, due to photosynthesis, plants absorbed carbon dioxide and give off oxygen, resulting in the air on Earth being filled with oxygen – the oxygen content was as high as 45% at the time, twice as much as it is today.
The high oxygen concentration gave birth to giant insects and amphibians
The land “lords” of the Late Carboniferous were not dinosaurs, but rather giant insects and amphibians, whose oxygen content was very high during the Carboniferous period, which also spurred the evolution of insect.
Although the eggs of amphibians are not covered by a hard shell and they have to return to the water occasionally to soak their skin, amphibians have also evolved to be large because they have no competitors.
The body length of dragonflies that we can see today was only 5 or 6 cm, while the body length of dragonflies at that time could reach 20 cm and their wingspan could reach about one meters, dozens of times larger than modern dragonflies.
The giant dragonfly also possesses superhuman flight skills, can move quickly and sensitively between the trees, the flight speed can reach nearly 65 km / h, it can be said that it is the real lord. in the forest.
Disaster comes from too high oxygen volume
Lush coniferous forests have gradually formed layers of coal up to tens of meters thick through the process of sediment accumulation over time, this layer of coal is found almost everywhere in the world and causes surface fires and underground coal fires. .
The high oxygen environment has properties that support combustion, which also accelerates the spread of the fire, within a few months the fire has spread 2,000 km and no animal can escape from the burning forest. on fire.
More than half a century later, the fire is still burning, and half of the Earth’s area has been consumed by the raging fire, under which many creatures have become extinct. At the same time, the combustion process also produced a large amount of toxic gas, increasing the average temperature at that time to nearly 6 degrees Celsius, the eggs of many amphibians and reptiles failed to hatch, leading to extinction. of them.
Toxic gases have further increased global temperatures. More than a century after the fire broke out, the average temperature has reached 32 degrees Celsius. Even after more than 1,500 years, the toxic gases produced by the fire are still evaporating.
Dense smog blocks the sun, almost half of the earth can’t see sunlight, this also causes a large number of photosynthetic plants and organisms with poor respiratory function to die.
Therefore, if the oxygen content on Earth suddenly doubles, our planet may again enter the “giant age” of insects and amphibians, but humans will suffer from diseases caused by continued Long-term exposure to environments with high oxygen content, plants will grow rapidly, which will eventually still lead to global fires and cause the extinction of many species.