It's no secret how beneficial phytoplankton is for the environment. It also plays an important role in the atmosphere. After all, it is to him that we owe the release of oxygen into the air. In addition, it is at the base of the food pyramid, and, in fact, feeds the entire sea.
Scientists have calculated that in 80 years oxygen will completely disappear. University staff in Michigan have calculated that in 2100, phytoplankton, the main source of oxygen, will finally cease to exist. The reason for this is global warming.
As a result of numerous analyzes of 130 species of phytoplankton, it was found that in the waters of the polar region and the seas of temperate zones, phytoplankton reproduces better. Since the temperature there is higher than the annual average, which is typical for its habitat.
Tropical plankton, on the contrary, reproduce well at average annual temperatures or even lower ones. It turns out that it is tropical phytoplankton that will be more sensitive to global warming.
Until now, scientists around the world are not fully aware of how phytoplankton is distributed throughout the world’s waters and how it will behave during global warming.
As a result, in about 80 years, according to experts, tropical phytoplankton, which makes up a significant part of the World Ocean, will be pushed to the poles or die out altogether. In both outcomes, the death of phytoplankton would be a major blow to marine ecosystems. However, there is still hope that phytoplankton will somehow manage to adapt to new conditions.
Scientists find it difficult to say why some species of plankton did not have ways to adapt to the new temperature regime, especially since northern species of phytoplankton should adapt well to harsh conditions. In addition, the researchers do not exclude the possibility that seaweed may have had such an opportunity, but over time it was used up. This still allows us to hope that plankton will still be able to adapt to changing climatic conditions. The task for the near future is precisely to find out at what speed phytoplankton will adapt to changes in nature.
The Earth's atmosphere has no clear limitations. The outer layers extend up to several thousand kilometers. but 90% of its mass is concentrated in the 16-kilometer surface layer.
Although there is no precise geometric boundary between atmosphere and space, it can be defined in physical terms. The physical boundary of the atmosphere is the height at which the air is still quite dense. to register the order of physical phenomena related to the earth and its space.
The physical properties of the atmosphere are heterogeneous - not only vertical; but also horizontal. With increasing altitude, the composition and quantity of its other properties and parameters change. There are several divisions in the atmosphere, such as separation temperature.
As a basis, it is customary to take the average change in air temperature with altitude in ascent (r = - dT 1 dg). According to their different signs (temperature changes with altitude, atmospheric composition and the presence of charged particles) the atmosphere is divided into five main layers called fields. Between each transition there is a thin layer called breaks. Their names are based on their location; how is the troposphere above the tropopause, etc.
The air that forms the earth's atmosphere is a mixture of various gases. Gases that do not react chemically with each other are called a mechanical mixture. The composition of the air at the surface of the earth is established with greater accuracy. In addition to the main gases - nitrogen, oxygen and argon mixtures, there are also mechanical and other gaseous impurities with much lower concentrations. The composition of the air is not the same at different altitudes.
Up to an altitude of about 800 km, the atmosphere is dominated by nitrogen and oxygen. More than 400 km began to increase the content of light gases - helium at the beginning: and then hydrogen. 800 km above the main content of the atmosphere is mainly hydrogen.
A clean plan can be assumed to be up to approximately 200 km of air; surrounding is a thin and uniform coating of their physical characteristics. As the surface density increases, the unevenness of the density decreases, leading to an uneven distribution of atmospheric mass. About half the table is in layers up to 5 km above the Earth's surface; at an altitude of 30 km is about 99 percent contained. Above 35 km the atmospheric mass is less than 1%l. Nevertheless; There are a number of processes and phenomena. which arise as a result of direct exposure to solar radiation. In fact, it is a 1°/l intermediate that is responsive to solar radiation and transmits it to the lower atmosphere.
However, to call the pace frightening would be an exaggeration.
After studying air bubbles trapped in the glaciers of Granland for hundreds of thousands of years, scientists found that during this time there was less oxygen in the Earth's atmosphere. At the same time, a group of specialists led by Daniel Stolper from Princeton University cannot yet confidently name the reason why over 800 thousand years the atmosphere has lost more oxygen than it acquired.
Researchers emphasize that the concentration of oxygen in the air is decreasing at a very moderate pace - over hundreds of millennia since the Pleistocene, it has decreased by only 0.7 percent. According to experts, they themselves carried out the measurements, primarily out of curiosity, and could not predict in advance whether the oxygen content in the air had changed during this time and, if so, in what direction. The measurement showed not the brightest, but absolutely clear trend towards its decrease, the researchers note.
As experts remind, in the distant past, fluctuations in oxygen levels on our planet were very significant. A couple of billion years ago, it is assumed that this material was not present in the atmosphere at all, but then cyanobacteria began to release it, thereby forever setting the direction of evolution on the planet. Subsequently, oxygen began to be produced by a wide variety of plants, and even later it turned out to be necessary to support the life of complex animals. Oxygen is not only consumed by living beings, but is also “wasted” during the weathering of silicate rocks. Also, according to scientists, approximately every millennium, all O atoms in the atmosphere manage to be in water molecules and become oxygen again.
Scientists assured that, whatever the true causes of the phenomenon they discovered, oxygen on Earth will definitely not run out in the very near future. Nevertheless, experts tend to consider the results obtained as another reason to think about how exactly the planet is affected by human actions - today people consume a thousand times more oxygen than before, thereby accelerating the process of reducing its amount already observed in nature.
Oxygen is most often associated with the atmosphere. The atmosphere is the spacesuit of planet Earth. If we compare what is more important for a person to live on Earth, then we can try to compare without what and how long a person cannot live. So, a person can live without food for about a month; a person can live without water for a week; but without air a person cannot last even an hour. However, one should not be mistaken on this score, since all the components of our monastery are vital for us and without them not only our development, but also life itself is impossible.
Where do we get oxygen from?
The word atmosphere itself is of Greek origin and consists of “atmos” - steam and “sphaira” - ball; it is a spacesuit for the planet and is a reservoir of oxygen. This chemical element is a necessary component for redox reactions to occur in the body and, in addition, performs a number of protective functions.
The atmosphere extends over a thousand kilometers; yes, even at such a height traces of gases entering the atmosphere are detected. This is not surprising since the action of the Earth’s gravitational field extends to 10 Earth radii, which is about 60,000 km.
Let us recall that the atmosphere consists of five main spheres:
- Troposphere (0-10 km).
- Stratosphere (10-50 km).
- Mesosphere (50-100 km).
- Thermosphere (100-800 km).
- Exosphere (800-1100 km).
However, this division of the atmosphere does not accurately reflect its contents. For example, the name ionosphere is given to the layer of the atmosphere that is irradiated at approximately 80 km altitude and exhibits a large number of ions and free electrons.
Throughout its entire length, the atmosphere is more or less stable because it consists of gaseous products that do not react under normal conditions. This mixture is called air. Air mainly consists of nitrogen (78%), oxygen (21%) and argon (1%). Scientists also estimated that the mass of our planet’s atmosphere is 5 * 1015 tons and, of course, that the main part of it is “at the bottom” of the air fifth ocean.
However, the atmosphere is not the only source of air and oxygen in particular. For example, huge water reserves, which produce a lot of evaporation every second, cause fluctuations in the composition of the air and, as a result, oxygen. Forests, which are often called the “lungs” of the planet, provide a significant massive increase in the oxygen component of the atmosphere. Human activity plays an important role in shaping the composition of air and the oxygen content in it. The fact that oxygen is present in a number of substances in solid and liquid states does not have much influence on the oxygen content in the atmosphere.
An important fact is also that oxygen was not always present in the Earth’s atmosphere - it appeared there approximately 2 billion years ago with the appearance of the first chlorophyll organisms. But only over the last 20 million years has the oxygen concentration in the atmosphere become approximately the same as it is now.
Could we run out of oxygen?
Is there a real possibility of complete depletion of oxygen on Earth? Theoretically, such a possibility exists, but there is no reason to panic.
The main “consumers” of oxygen are now widely known:
- A car traveling a distance of 500 km “eats” a person’s annual respiratory rate;
- An airplane flying 10 thousand km burns 30-50 tons of oxygen, which is the daily production norm of a forest area of 15-20 thousand hectares
The level of oxygen consumption on Earth is enormous, but experimental measurements show that the amount of atmospheric oxygen has not decreased over the past 100 years. The loss of oxygen in the atmosphere is compensated by the vegetation of the land and oceans, which are so far capable of producing about 320 billion tons of free oxygen. However, it should be remembered that oxygen consumption by people is growing, and the plant population on earth is rapidly declining. These processes are not yet controlled by anyone.
Still, the increase in oxygen consumption does not pose such a significant threat as the annual emissions into the atmosphere of about a billion tons of chemical compounds, as well as several billion tons of particulate matter and various aerosols. In other words, it is not the lack of oxygen, but the excess of other substances constantly emitted into the atmosphere that poses the main threat to the breathability of atmospheric air.
What is ozone
As already mentioned, the gas composition changes from one layer of the atmosphere to another. Oxygen near the earth's surface exists in the form of diatomic molecules, but in rarefied layers of the atmosphere it undergoes dissociation into atoms under the influence of solar radiation. Thus, somewhere at an altitude of 40 km the content of atomic oxygen is already significant, and at altitudes of 120-150 km there are practically no O2 molecules.
At a relatively short distance from the earth's surface - about 20-35 km, atomic oxygen, being quite active, forms triatomic ozone molecules O3 with molecular oxygen. This is the height of the Earth's ozone layer. Its importance is that it protects the Earth's surface by blocking ultraviolet rays. Ozone molecules themselves are opaque to ultraviolet radiation from the Sun and almost completely absorb it. On the other hand, the ozone layer retains about a fifth of infrared thermal radiation from the Earth's surface, thus providing a stable thermal regime for all living things.
It is noteworthy that the ozone layer appeared approximately 500-400 million years ago and since then the natural balance of life on Earth has been maintained thanks to it. Ozone makes up parts per million of all the air on the planet, but it is enough to maintain conditions suitable for life.
The main “enemies,” or destroyers, of the ozone layer are freons, gaseous pollutants from the refrigeration industry, perfume production, and a number of other sectors of human activity. The main producers of freons are:
- Europe – 40%.
- USA – 35%
- Japan – 10%
- CIS – 12%.
The influence of freon near the surface is practically absent; here it is an inert gas. When it evaporates and reaches the ozone layer, it becomes an atomic gas under the influence of solar radiation in the form of ultraviolet radiation, and then reacts with ozone. The chlorine monoxide and molecular oxygen obtained during this reaction do not act as absorbers of ultraviolet rays and they reach the Earth.
People have long known about the existence of “ozone holes” and it is still difficult to say anything definite about their origin; however, it is reliably known that, for example, in Antarctica, not only is there half as much ozone in the atmosphere, but the concentration of chlorine monoxide there is hundreds of times higher than normal.
What is being done
The debate on oxygen and, in particular, ozone continues. To date, the achievements of mankind include the signing of a number of protocols: from the 1985 Vienna Convention on the protection of the ozone layer by freon producing countries to the recent Kyoto Agreement of 2009. This latest international agreement has been signed by 181 countries, which account for over 61% of all global emissions.
With regard to steps to preserve the atmosphere and its ozone layer in particular, it can be said that quite active work is being carried out to reduce freon emissions into the atmosphere (recycling of used freon, replacing freon with compressed air in aerosol packages, etc.). On the other hand, numerous campaigns are being carried out to save forests and prevent pollution of the world's oceans, which have already acquired international status.
Scientists of the last century expanded their views on the problem associated with oxygen. According to calculations, it turned out that if we do not reduce the rate of pollution of our environment, the oxygen we breathe will run out in about three centuries, and people and animals will simply suffocate. This end of the world may turn out to be true, since this problem is quite well substantiated by both mathematical calculations and logic. Three tons of oxygen are needed to burn just one ton of fuel. There are 6.75 kilograms of air per square inch; in total, Earth's oxygen weighs 1,020,000,000,000 tons. It is enough to burn fuel weighing 340,000,000,000 tons. Humanity burns approximately 600,000,000 tons of coal every year, forests are burned, oil products and other combustible minerals are used and burned. If you add it all up, it comes out to about 1,000,000,000 tons. Even by eye, one can estimate that oxygen at this rate will run out quite soon, in about 340 years. Lord Kelvin, the famous American and scientist, predicted that man would cease to be independent of the air. The time will come when oxygen will be stored for future use by pumping it into large reservoirs, and each family will be allocated an air ration just enough so that only vital functions can be supported by the body. Pearl fishermen - this is how such a society could be characterized. Take a breath of air - and don’t breathe until the cells of your organs have used up every last drop, take another breath of air - and again go under water. In the morgues, during the autopsy, they will conclude in the future society: death occurred from oxygen starvation. If there is no money, then there is no air for you. It's a sad end of the world. But it is worth noting that at the beginning of the last century, the knowledge of scientists was limited; they did not yet know that the Earth itself also had oxygen reserves, so the problem was somewhat exaggerated. Our technology has reached the point where it can start generating oxygen if necessary.from water using electrolysis. The urgent need for this will not come for a long time, but on one condition, if our algae, plants, forests produce the gas we need in abundance. An adult, if he is not engaged in heavy physical labor, consumes approximately 300 kilograms of oxygen over the years. Even if we use the old calculations and take as a basis the sum of the weight of the air of those scientists, it turns out that the available oxygen without its generation will be enough to provide life for 3,400,000,000,000 people, while in the present there are approximately 6 billion of us.
