The amount of oxygen in the Earth's atmosphere has lost 0.7% without knowing why

Our atmosphere is "leaking" oxygen, oxygen levels have decreased by 0.7% in the past 800 thousand years and although we still don't understand the cause of the problem, scientists are still quite happy because there! Why? Because identifying the trend of changing atmospheric oxygen levels and its causes will help them better understand the aspects of life sustaining of a planet, extremely useful information during the research process. extraterrestrial planets in the universe.

Daniel Stolper, a professor of geology at Princeton University, said: " We have analyzed more interesting things than any previous predictions. In the past, we still do not know whether oxygen will increase, "It will turn out to have a very clear trend: oxygen will decrease !"

In fact, the amount of oxygen in the Earth's atmosphere has changed dramatically in the history of the Earth, but finding data to prove this hypothesis is extremely difficult. We all know that in the first 1 billion years, our atmosphere has no oxygen. Then a green algae called cyanobacteria with photosynthesis has grown and spread everywhere, triggering mass destruction of anaerobic bacteria that consider oxygen as a poison.

Cyanobacteria algae - a source of oxygen to the ancient Earth.

As plants grow and spread, oxygen continues to accumulate in our atmosphere and eventually the amount of oxygen is so high enough to provide the life of complex organisms, including humans. . In the past few million years, everything has been quite stable, so has the oxygen and thus the life of animals on this planet has conditions to thrive.

However, when the analysis deepened, the scientists confirmed that the amount of oxygen also fluctuated. Humans consume oxygen every minute, while plants produce oxygen as part of photosynthesis. In the long run, the amount of oxygen will gradually be dissipated into the weathering process of silicate rock.

Professor Stolper said: " For thousands of years, all the oxygen in the atmosphere will be converted into water and then back to oxygen. But there is still a slight leak according to the time and amount of loss. can be in by-products or consumed ". In a given time period large enough, this leaked oxygen also has a small amount and even this fluctuation can change life on a planet.

Therefore, Professor Stolper and colleagues at Princeton University sought to measure this leaked oxygen. To do that, they focused on analyzing one of the most reliable "oxygen records" that people have. It is the ice core in Greenland and Antarctica, which has preserved numerous villages of air bubbles representing the "image" of the Earth's atmosphere for millions of years. By analyzing the oxygen ratio of the nitrogen isotope in these ice cores, they have determined the trend: oxygen levels have decreased by 0.7% in the past 800 thousand years.

Over thousands of years, all the oxygen in the atmosphere will be converted into water and then back to oxygen.

In the recently published report, the researchers gave some possible explanations for this. First, the speed of erosion has been accelerated in recent geological history, causing more fresh sediment to be exposed and oxidized by increased air, thereby increasing oxygen consumption. up. This is followed by a slight decrease in global average temperatures over the past few million years, making the ocean cooler and dissolving oxygen thus increasing. Professor Stolper explains: "That means you oxidize more organic carbon in the ocean and you have less oxygen to return to the atmosphere."

He added that there are other causes, but identifying evidence is extremely difficult. Studying what is controlling our planet has been a great effort and it helps us better understand aspects of life on a planet, which scientists are extremely interested in. the process of finding the Earth's "twin brothers" .

Interestingly, in Professor Stolper's analysis also includes the last 200 years of the industrialization process in human society, the period he considers very unusual."We are consuming oxygen at a rate 1,000 times faster than before. Humans have completely accelerated the process by burning tons of carbon," he said. Even so, the professor said we still have plenty of breathing and this research is just to determine what happens to the Earth.