Annotation. Into article are examined the global environmental problems that have been unresolved in 21st century. In particular: the problem of the world oceans, destruction and depletion of the gene pool, air pollution, ozone layer disturbances and other problems.

Keywords: the coevolution, biosphere, neosphere, climate change, greenhouse gases. 

Introduction 

Nowadays the mankind rigidly faces problems on exhaustion of resources and violation of natural processes. These problems have drawn attention of the whole world since the end of  60s and beginning of 70s of the last century and many international actions and events had been held for finding solutions (like international conferences devoted to environmental issues and development, for example,  in Stockholm "The zero growth" in 1972 and in Rio de Janeiro "The agenda of the 21st century”, in 1992, the report of  international commission for sustainable environment development, in 1987 - "Our common future" and etc.,   where concern had been expressed on the fact that the mankind is threatened by disaster in case of preservation of the existing rates of economic growth and industrial technologies. Therefore, the concept of sustainable development the essence of which consists in continuation of development  economy for reaching requirements of present necessity and without damage of living circumstances of future generations. For this purpose it is necessary to make a rational metabolism and energy consumption between society and  nature where development of economy should be based on strict regularities of self-reproduction of  nature that should be focused on the coevolution of society and  nature  which would be a transition of  biosphere of our planet to new issue – the neosphere where people will be thinking to reduce negative results of own activities not only for themselves, but also on destructive natural power of negative impact onto biosphere (R. Abesadze, 2017). Despite of some useful efforts of mankind to protect  environment, many unresolved problems have been remained in 21-st century. 

Environmental problems of  XXI century 

One of the main factors of environmental problems in 21st century is population growth which leads to increase  the usage of natural resources and  reduction in natural cover, due to the growth of economic and household areas (like grasslands, buildings, roads, landfills, etc.). Nowadays population of the Earth is growing rapidly. For example, 10000 years ago,  population of the Earth was 5 million people. Population reached its first billion in 1804, 2 billion after 123 years (in 1927), 3 billion after 33 years (in 1960), 4 billion after 14 years (in 1974), 5 billion after 13 years (in 1987), 6 billion after 12 years (1999), 7 billion again after 12 years ( in 2011). According to various forecasts, the world's population will reach 8 billion people again after 12 years, in 2023. As we can see, it took the millennia to reach the first billion, but only 12 years to reach the last one.

With  increasing  population of the Earth, different negative issues of  surrounding environment have been grown: disorder of the ozone layer; radioactive contamination; increase in CO2 emission in the atmosphere; soil contamination with pesticides; problems of world’s oceans, extinction of spices of animals and plants; permanent concealment; huge pollution of the atmosphere, fresh air; appearance in the ozone layer (protecting  people from a deadly cosmic reflection); The world’s oceans regulate the natural processes of the Earth and etc [Актуальные... 2019].

The amount of energy consumed increases with population growth. It is assumed that by 2100 energy production should increase up to 4 times, and in developing countries up to10 times which will lead to a significant increasing of carbon dioxide emissions into  atmosphere.

Destruction of gene pool and impoverishment. It is a huge world environmental problem. Scientists have established that within the last 200 years more than 9 000 species of plants and animals have been lost, the amount of minerals also is gradually reduced .

Decreases in biodiversity are caused by: loss of habitation; overexploitation of biological resources; environmental pollution, and etc. [TOP-8 ... 2013].

Deforestation leads to decreasing of oxygen concentration in atmosphere and a serious reduction of the  water resources.

Problems of the world’s oceans. The world’s oceans cover 2/3 part of the Earth's surface. The chemical pollution of oceans which is a very dangerous process as it can cause strong reduction of water and food resources and highly violating of oxygen balance in the  atmosphere. Pollution of the world’s oceans strongly grows up by producing products of the energetic, chemical and military industries.

Atmospheric pollution. The number of harmful emissions increase and it extends on all processes in atmosphere and nowadays it accepts the global character, the acid rains cause extensive damage to the forests. A very serious global economic problems  also are pollution of surfaces of  natural landscape and its distortion. More than 9 billion tons of fuel (oil, natural gas, coal, methane, etc.) are burned annually [Глобальные... 2020].

Violation of the ozone layer. Violation of the ozone layer is a quite dangerous as it protects people from deadly ultra-violet radiation. The first such hole was founded in 1982. Later it has become clear that the ozone layer is collapsed by jet engines of planes, spacecrafts and satellites.

Climate change. It can cause changes of sunlight, terrestrial orbit and bent of the Earth axis, transparency of the atmosphere, concentration of greenhouse gases, abilities of reflection of the Earth's surface, etc. It can cause the global negative phenomena: reduction of humidity of landscapes; movement of climatic and planting zones; thawing of the ice, glaciers and eternal glaciers; rise of world’s oceans level; violation of circulation of oceanic water and a full hydrological cycle on the Earth; reduction of agricultural production; freshwater shortages (Currently 1 billion people in developing countries live in water scarcity [Глобальные...2019], which also causes the poor sanitary-hygienic conditions and other. For solving these problems the reducing of greenhouse gases has a particular importance as they cause ionic holes and climate change, increase the average temperature of the Earth, and consequently increase the world’s oceans levels.

Release of toxic substances into atmosphere. There are different types of toxic substances. Origin: industrial poisons; poisonous chemicals; fertilizers; medications; household chemicals and toxic substances; planting and animal poisons; for toxic effects: nerve-paralytic; cutaneous; suffocating; lacrimal; psychotic; general toxic, and etc. In the process of production and consumption of such substances there is a very important process of their storage, they are founded in atmosphere, and as well as in the human body.

Waste growth. In 20th century, the amount of production and consumption wastes grew so rapidly that their formation became an important problem.

Wastes differ: by origin: production waste (industrial waste); consumption waste (household); military waste; by composition: waste of biological origin; man-made waste; by state of aggregation: solid; liquid; gaseous and etc. The hazard of waste is determined by their physical and chemical properties as well as by conditions of their storage and/or placement in the environmental areas.

Soil degradation is a set of processes that lead to changes in soil function, quantitative and qualitative deterioration of its properties, gradual deterioration and loss of fertility. The following are the most significant types of soil degradation: technological (as a result of long-term usage); soil erosion; salinization; waterlogging; soil pollution; desertification.

Soil desertification is the process of transformation of cultivated fertile irrigated lands into waterless and lifeless deserts with the loss of soil and vegetation fertility. Reasons for soil desertification: water scarcity; drought; aridity of the climate; deforestation; overgrazing of livestock; biological death; lack of drainage; salt accumulation; decrease in the level of groundwater; termination of irrigation; violation of water balance in the reservoirs; loss of fertility •.

Technogenic disasters a man-made disaster is a major accident at a man-made facility, resulting in massive loss of life and even an ecological disaster. One of the features of man-made disasters is their randomness (this is how they differ from terrorist attacks). Usually man-made are opposed to natural disasters. However, like natural disasters, man-made disasters can cause panic and transport collapse. Dozens of man-made disasters of various scales occur in the world every year. For example, on March 11, 2011, as a result of the strongest earthquake in the history of Japan and the subsequent tsunami, there was a major radiation accident of the maximum, 7th level, by the International Scale of Nuclear Events, at  Fukushima 1 NPP. ... In July 2000, in Brazil, as a result of a disaster at the oil refinery, more than a million gallons of oil (about 3,180 tons) flowed into the Iguazu River. On August 12, 2015, as a result of a safety violation during the storage of explosives in a Chinese port, two huge explosions thundered which led to a large number of victims, hundreds of destroyed houses and thousands of destroyed vehicles. 

Conclusions 

1. Despite of the outstanding efforts from  developed countries as well as the European Union and international organizations, many unsolved problems remaining in 21st century;
2. One of the main factors in the current ecological problems of XXI century is population growth, as it leads to increasing in the usage of natural resources; reduces natural cover due to economic and household growth (grasslands, buildings, roads, landfills, etc.);
3. Among the ecological challenges of XXI century can be having the high priorities: destruction and impoverishment of the gene pool; the problems of the world’s oceans; air pollution; ozone depletion; climate change; release of toxic substances into  atmosphere; waste growth; soil degradation and desertification;
4. For solving the ecological challenges of  XXI century, it is necessary to: strengthen the green and circular economy, identify the limitation of resources for future and reduce their usage;
5. Processes in areas of economy such: energy, transport, agriculture and forestry, waste and water management should be managed scrupulously worldwide. To further reduce emissions, standards, environmental taxes, incentives should be create and actively using the environmentally friendly technologies and tools. 

References 

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