The twentieth century was the century of a huge scientific- technical revolution and progress in whole spaces of industry and life. It was the century that created the nuclear and hydrogen bombs, pushed planes and spaceships, and computerized all developed civilization. It was the century when life was improved, elaborated, and made more and more modern. In spite of so much progress and as a result of people’s actions, new problems were born. Scientists considered global warming, or the greenhouse effect, to be one of the most serious problems in the modern world. Global warming means there is gradually increasing temperature on the earth, and consequently climate changing. These changes happened so fast that governments and their citizens were warmed about the dangers of the greenhouse effect. If they don’t take the necessary steps to prevent the climate from worsening, who knows what life would be like in the year 2050 under these conditions?
The earth is covered by a gaseous blanket, the atmosphere. The atmosphere lets the sun’s warming rays through and blocks the heat trying to get out. This heat is absorbed by the earth and atmosphere. This act causes the greenhouse or heat effect. As a result of the greenhouse effect, the temperature will gradually increase 2 to 6 C (4 to 11 F) over the next 100 years. The coldest years in the 1980s were warmer then warmest years of 1880s.
As a result of global warming the ozone depletion continues. Three main gases, carbon dioxide, methane and ozone cause the heating, or greenhouse effect. Their concentration and interaction is in a stable balance in the atmosphere. The atmosphere contains the Ozone layer, which is like an umbrella of the Earth. Ozone is a form of oxygen, created when ultraviolet radiation from the sun meets oxygen in the atmosphere. The Ozone layer absorbs the most of the dangerous ultraviolet radiation that comes from the sun.
Global warming is the result of human actions. The atmosphere is changing, and the ozone layer is under the threat from chemicals that people use on the earth. The amount of using fossil fuels, such as oil, gas, coal, and deforestation produces carbon dioxide. Carbon dioxide is also produced from car and airplane emissions and from using computers and cell phones. Chlorofluorocarbons are guilty chemicals contained in aerosol cans, refrigerators, air-condition systems, some packaging materials. 98% of gases are caused naturally animals and plants letting out methane.
Unfortunately, pollutants and chemicals can destroy ozone and break the balance in the atmosphere. These pollutants and chemicals, as a result of people’s action are divided into three main gases: carbon dioxide, methane and ozone. All of them contain dangerous chlorine chemicals, which are released after man- made pollution. These chemicals reach the ozone layer, where they interact with ultraviolet radiation. Chlorine is a result of this interaction. It is a dangerous chemical, which destroys ozone. Chlorine goes up to the atmosphere, reaches the Ozone layer and starts to react with the molecules of ozone. Chlorine destroys Ozone, but by itself remains unchanged, and it continues to destroy ozone over and over, and destroys the balance in the atmosphere. When it happens, the ozone layer is depleted. The amount of dangerous ultraviolet radiation reaching the earth may increase. This causes an increase in diseases, such as skin cancer, eye disease.
Ultraviolet radiation also damages plants, crops, and trees, which are the basis of the food chain supply on the land. Also, ultraviolet radiation is dangerous for plankton, which are the basic food for the marine creatures.
The global warming increases temperature on the earth and causes the glaciers to melt, consequently, increasing water levels in the sea, flooding costal cities. Furthermore, if the seas overflow, they may contaminate fresh drinking water, and we may lack enough supply of drinking water for the future. The global warming also causes sea temperature to rise, killing sea creatures, on one hand, and bringing drought and massive fires, on the other hand. It causes starvation of people and animals. The disappearance of plants and forests causes increasing coastal erosion and massive tropical storms. Salt intrusion into soil has affected our traditional food crops. This increasing temperature may send the planet back into an ice age. It becomes possible, when the water from the melting glaciers dilute the salt of the sea, causing more snowfall. Snowfall deflects the sun’s heat back into space, causing the planet to cool substantially.
The threat of global warming has the potential to damage the web of life more than anything, except nuclear war. Large agreements have been sign by developed countries during the last century. They called for countries to reduce, phase out, transition air and water pollution, which produce greenhouse gases and lead to the destruction of the ozone layer. T