Climate change is the most important problem in the environmental field in the last century. It can cause a variety of phenomena such as raising the sea level and changing the local climatic conditions, which can affect the socio-economic development of many countries. There is no doubt, that global warming may cause unexpected processes in the environment. Even a slight change in radiation balance can provoke difference in wind direction and direction of ocean currents. This can greatly affect the existing climatic conditions and lead to unintended consequences. As a result, the world's population and most of its ecosystems can suffer from irreparable damage (Haugen, David, 2010).
There are several reasons for the global warming. Firstly, it is using fossil fuels. Today`s industry is the main enemy for the environment. The greenhouse gases such as carbon dioxide, methane and nitrogen dioxide (the main factories emissions) that are evolved during the combustion of coal, natural gas and oil, are the main reasons of heating of the Earth's atmosphere. Carbon dioxide (CO2) is the most significant one, because it is responsible for 80% of thermal pollution. Today the level of CO2 in the atmosphere has the highest level since the last 420.000 years (Miller, Debra, 2011). Secondly, it is cutting the forests. The well known fact is that oceans and forests absorb carbon dioxide. The less forests will be able to absorb it, the more emissions will be in the atmosphere. Over the past 10 thousand years, man has destroyed about two-thirds of all forests on the planet. Thus, in the 20-s of XX century much forest was destroyed in England - 95%, France and Spain - from 80% to 90%, Finland and Sweden - 50% (Miller, Debra A, 2011). Thirdly, it is the emissions of the gases of all electrical appliances. Even the modest refrigerator in the house produces gases, which contribute to the greenhouse effect. These gases are known as Chlorofluorocarbons (CFCs). They are used in aerosol cans, refrigerators, , a fire extinguisher chemicals and cleaning products used in the electronics industry, some foaming agents in the packaging industry,. Some processes of the cement manufacturing industry also act as one of the reasons for the greenhouse effect (Lomborg, Bjorn, 2010).
In order to slow down the global warming process the following things should be done. First of all, the usage of alternative sources of energy is not the new invention today. The major polluters of the environment are the thermal power plants. They provide people with the warmth; however, they are the main constructors of CO2. The usage of solar, wind and water plants will reduce amount of CO2. Today wind power of Denmark covers about 2% of the country's electricity needs. In the U.S. there are about 17,000 wind aggregators, which have the total capacity to 1,500 MW. Wind energy devices are produced not only in the U.S. and of Denmark, but also in Great Britain, Canada, Japan and certain countries (Miller, Debra A, 2011). Using solar energy can be useful in several respects: decreasing of the air and water pollution, reduction of fuel imports, replacing nuclear fuel. Secondly, the recycling can solve the problem of the cutting the trees. According to the scientists, one hectare of forest absorbs from 120-280 kg of carbon dioxide and provides 180-200 kg of oxygen. One tree of average size produces enough oxygen for three men. Hectare pine forest holds 40 tons of dust and 100 tons of deciduous (Miller, Debra A, 2011). However, each year more and more trees are cut. The solution is the recycling system that can save much forest. The importance of recycling can be judged from the statistics. If the U.S. recycles only 10% of the wasted paper, greenhouse gas emissions will be reduced by 1.6 million tons (Spencer, Roy, 2010). Thus, there are two main solutions: the usage of alternative sources of energy and the recycling system.