Greenhouse gases are all those gases which thanks to their physical and chemical qualities , have the ability to absorb solar energy within the confines of the atmosphere. Some of them are natural constituents of the atmosphere and are present in it from millions of years. They made life possible to develop. Some of greenhouse gases occur in nature (water vapour, carbon dioxide, methane, and nitrous oxide), while others are exclusively human-made (like gases used for aerosols). These gases allow sunlight to enter the atmosphere freely. When sunlight strikes the Earth's surface, some of it is reflected back towards space as infrared radiation. Greenhouse gases absorb this infrared radiation and trap the heat in the atmosphere. This warms the Earth - we can observe the increase in temperature in the lowest layers of the atmosphere.
The major part in the greenhouse effect has water vapour, (it causes about 36-70% of the greenhouse effect on Earth).Water vapour levels fluctuate regionally, but in general humans do not produce a direct forcing of water vapour levels. In climate models an increase in atmospheric temperature caused by the greenhouse effect will in turn lead to an increase in the water vapour content of the troposphere, with approximately constant relative humidity. This in turn leads to an increase in the greenhouse effect and thus a further increase in temperature, and thus an increase in water vapour, until equilibrium is reached. Thus water vapour acts as a positive feedback to the forcing provided by human-released greenhouse gases such as CO2 (but has never, so far, acted on Earth as part of a runaway feedback). Changes in the water vapour may also have indirect effects via cloud formation.
The second important/ fundamental for the greenhouse effect, component of the atmosphere is carbon dioxide (CO2.) It causes between 9-26% of the greenhouse effect. Average concentrations of atmospheric carbon dioxide in the year 2005 were about 380 parts per million ). Prior to 1700, levels of carbon dioxide were about 280 parts per million. This increase in carbon dioxide in the atmosphere is primarily due to the human activity. Beginning in 1700, societal changes brought about by the Industrial Revolution increased the amount of carbon dioxide entering the atmosphere It is supposed that in 2100 there will be 2 times more carbon dioxide in the air than nowadays.
Other greenhouse gases which cause the greenhouse effect are: methane, nitrous oxide and chlorofluorocarbons. Those gases are released into the atmosphere through different industrial processes.
About thirty gases are known which destroy ozone in the stratosphere and cause holes to appear in the ozone layer.
The concentrations of several greenhouse gases have increased due to human activities, such as: burning of fossil fuels and deforestation. Gas contamination/ pollution cause trapping some of energy in the atmosphere and heating of the Earth.
The greenhouse effect is very important for life on the Earth. Without the greenhouse effect life on our planet would probably not exist as the average temperature of the Earth would be a chilly -18° C. It would not be warm enough for humans to live. So we need the greenhouse effect like we need a jumper in winter. If the jumper is too warm, we begin to perspire. Human activity caused the intensifying of this natural effect and the global warming. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals. We are afraid of the global warming and we think of the greenhouse effect as something negative. But the natural greenhouse effect is nothing harmful.
The radiation of the ground by sunlight is mostly visible. The largest part of dangerous ultraviolet radiation is absorbed by the ozone layer in the stratosphere. The visible light passes to the troposphere and is reflected in the atmosphere by bright objects on the earth for example ice, snow or clouds. Some of the radiation is absorbed by the earth's surface and changed into warmth. The infrared radiation, which is invisible for our eyes, is emitted by the Earth. Greenhouse gases in the atmosphere absorb the infrared radiation and pass it back into the Earth and space.
The greenhouse effect is a naturally occurring process that aids in heating the Earth's surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, water vapour, and methane, are able to change the energy balance of the planet by absorbing longwave radiation emitted from the Earth's surface. The concentrations of many of the greenhouse gases have increased since the beginning of the Industrial Revolution for example carbon dioxide methane and ozone. . Chlorofluorocarbons (CFCs)are not natural greenhouse gases. The anthropogenic sources of chlorofluorocarbons are refrigerators, aerosol spray propellants and some plastic products. .They are really harmful/dangerous gases because of their long permanence. Scientists have discovered holes in the ozone layer, caused by chlorofluorocarbons.
Another greenhouse gas - nitrous oxide represents only 6 percent of total emissions. It comes from burning fossil fuels and through the use of certain fertilizers.
Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and sub-surface ocean temperatures to rise. Temperatures are, in fact, rising and this may cause floods in some parts of the world as the polar ice cap begins to melt The scientists suppose that seas might flood many European countries for example: Holland, Denmark, some parts of Belgium and Poland. Many people will die in natural disasters. Others may suffer from famine and new illnesses. What we can do to save our planet and environment. There are many solutions to the problem of greenhouse effect and global warming. We should use bio- degradable and recycled products, sort litter. Another solution would be to travel by public transport or bicycles in order to reduce air pollution and emission of greenhouse gases. We should also stop cutting down or burning the trees and rainforests because they absorb carbon dioxide. More trees should be planted.. all things considered, there are many solutions to the problem of global warming. We can all do something to improve our planet and to save our environment.