The paper is dedicated to the study of ecological balance and possible reasons that could lead to the consequent change of the world climate. In particular, two groups of hypotheses are analyzed. The first group deals with reasons that are conditioned by the changes in the energy received by the Earth from the Sun. The possible changes in the Sun itself and in the dust clouds that can affect the way the energy is taken by the planet are considered. The second group of hypotheses is dedicated to the changes in CO2 level and possible consequences it can lead to. As a result of the research, it is possible to draw a conclusion that it is always better not to interfere with the natural processes maintaining ecological balance, and to reduce the influence which is inevitably exerted on them. In this way it is possible to reach minimal level of damage to the Earth and harmonious living of people on it in comfortable conditions.
Keywords: ecological balance, climate change, greenhouse effect, solar energy.
Ecological Balance and Changing Patterns of Climate Worldwide
Ecological balance is a balance between the use and restoration of natural resources, the processes of violation and restoration of normal environmental conditions (Trenberth & Josey, 2007). Today there are major concerns as to the violation of the ecological balance due to the anthropogenic influence on the planet, which leads to certain changes in the world climate. Still, it is a very complex issue.
It is extremely difficult to answer the question why climate is changing worldwide, as there are many different factors influencing such changes, which is why there exist many hypotheses, considering the various possible reasons for this change. All hypotheses about the causes of the onset of glaciation epochs can be divided into two groups. Some of them try to explain this event by causes that are beyond the Earth, as the main source of energy, heat, on which the climate of the Earth depends, is the Sun (Smith et al., 2009). These hypotheses are based on the fact that the flow of solar energy could somehow drastically change. Thus, the amount of heat that the Earth receives from the Sun also changed.
But why can the Sun change energy? First, we cannot exclude the fact that the processes inside the Sun take place at regular intervals, the duration of which is hundreds of millions of years. Solar activity is changing within the periods of 11, 22, 33, 90, 200, 600, 2000 years (Hulme, 2010). The level of solar activity defines the amount of energy that the Sun sends in the space in the form of solar charged particles. Why cannot there be such a periodicity (but with a longer period) in the change of energy that the Sun sends in the space in the form of microwave radiation - visible light, X-ray and ultraviolet radiation? It is not reasonable to exclude this possibility.
Still, it is possible to find the reason for reducing the energy that goes to the Earth from the Sun, beyond the actual Sun. It radiates in the same way all the time, but occasionally falls into a kind of black (dusty) band, and as a result, the energy is dissipated and does not reach the Earth. It is possible, but it is less likely and less justified than the assumption of batch processes inside the Sun, especially since such processes with shorter periods are evident. But they are related to the variability of solar energy that is transferred by solar charged particles. Experts believe that within the Earth existence, which is 4.6 billion years, the Sun's luminosity has been gradually increasing without showing oscillatory changes. Within all this time, this increase was approximately 25-30% of the initial value (Trenberth & Josey, 2007). This significant (one-third) increase in the energy level that Earth receives from the Sun, cannot remain without consequences – the Earth must have been heated more and more over time. It is easy to calculate that, if the energy coming from the Sun to the Earth is increased by 1%, this should cause an increase in the average temperature of Earth's surface at 1° C. This means that if the luminosity of the Sun rose in the history of the Earth by 30%, its average temperature was increased to 30° C within this time. But it did not happen.
As for the cosmic dust, through the cloud of which the Earth goes and is shielded from solar energy, this dust could be the result of the passage of a comet on a very short distance from the Earth. From the tail of a comet dust should spatter. A sufficient number of comets run at various distances from the Earth. Each year, five of them run at such a distance from the Earth that is equal to the distance between the Sun and the Earth. This distance is taken as the unit of length and is called the astronomical unit (Parmesan, 2006). Applying the laws of probability theory, it is possible to understand that among this great quantity of comets running around the Earth for millions of years, once in a hundred million years a comet can run past the Earth so close that it will make it very dusty, especially its atmosphere. If this dust leaves is in the weather layer of the atmosphere – under the clouds, rain and snow will wash it away from the atmosphere very quickly and will set on the Earth's surface, after which it will no longer affect the flow of energy coming to the Earth from the Sun.
The second group of hypotheses is seeking the cause of ice ages not in the changes in the flux of solar energy that reaches Earth, but in the varying degrees of absorption of this energy by the Earth. The idea is that for some reason from time to time in the atmosphere such an environment is created, in which solar energy is utilized much worse and the temperature drops considerably. The reason for this change in digestibility of energy can be sought only in the atmosphere, where sorting of the solar energy takes place: a part of the energy is sent back into space by the atmosphere, a part of it reaches the Earth's surface, and the rest is consumed by the atmosphere itself for self-heating purposes (Smith et al., 2009). But this ability of the atmosphere depends on its composition, and atmospheric composition of Earth has been changing quite radically within the history of its existence. Not all the constituents of the atmosphere play the same role in the redistribution of solar energy. Important role in this regard is played by carbon dioxide, CO2, although its absolute amount in the atmosphere is negligible – only 0.03% of the total volume (Solomon et al., 2009).
Carbon dioxide in the atmosphere acts as a foil in the greenhouse by the principle of admitting, but not releasing. As a result, about 30% of the incoming solar radiation is reflected from the upper atmosphere and goes back into space, but most part passes through the atmosphere and warms the Earth's surface (Hulme, 2010). The heated surface emits infrared radiation. Some of the gases that make up the atmosphere in relatively small amounts (0.1%) are able to keep the infrared radiation. They are called greenhouse gases, and such a phenomenon is the greenhouse effect.
Greenhouse gases have been present in the atmosphere throughout almost the whole Earth's history, and their balance has been maintained at the expense of the natural cycle. In the absence of greenhouse gas temperatures at the surface of the Earth would be about 30-33° C lower than today. Prior to the era of industrial development, the concentration of carbon dioxide in the atmosphere was equal to 280ppm (parts per million), and now it has increased by 30% to 368ppm.
If the natural greenhouse effect supported the Earth's atmosphere in a state of thermal balance, favorable to the existence of animals and plants, the increase in anthropogenic greenhouse gas concentrations in the atmosphere, on the contrary, interfered with the natural heat balance of the planet due to the enhanced greenhouse effect, and as a consequence, caused global warming.
Sun rays reaching the surface of the Earth pass the atmosphere without any obstacles, which we see as the light. Of course, a part of it is scattered by the atmospheric turbidity. The light energy is partially absorbed and heats the Earth. Part of the solar energy is reflected from the Earth's surface (land and water surface) back into the atmosphere and further into space. The heated earth, like any hot body, begins to radiate (Parmesan, 2006). But having received light energy, it radiates heat. This is infrared or ultraviolet radiation. This radiation, outgoing from the earth, keeps carbon dioxide CO2. If the CO2 in the atmosphere was not available, the average surface temperature would be reduced significantly. Consequently, the earth would enter the age of glaciation.
References
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Parmesan, C. (2006). Ecological and Evolutionary Responses to Recent Climate Change. Annual Review of Ecology, Evolution, and Systematics, 37, 637-669.
Smith, J.B. et al. (2009). Assessing dangerous climate change through an update of the Intergovernmental Panel on Climate Change (IPCC) “reasons for concern”. Proceedings of the National Academy of Sciences, 106(11), 4133-4137.
Solomon, S., Plattner, G.-K., Knutti, R., & Friedlingstein, P. (2009). Irreversible climate change due to carbon dioxide emissions. Proceedings of the National Academy of Sciences, 106(6), 1704-1709.
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