What Is the Greenhouse Effect
Greenhouse Effect is a term for the role the atmosphere plays in helping warm the earth’s surface. The atmosphere is largely transparent to incoming short-wave ( or ultrviolet) soalr radiation, which is absorbed by earth’s surface. The earth receives energy from the sun, which warms the earth’s surface. As this energy passes through the atmosphere, a certain percentage gets scattered. Some part of this energy is reflected back into the atmosphere from the land and ocean surface. The rest (70%) actually remains behind to heat the earth. n order to establisha balance, therefore, the earth must radiate some energy back into the atmosphere. As the earth is much cooler than the sun, it does not emit energy as visisble llight. It emitsthrought is frared or thermal radiation. However, certain gases in the atmosphere. Without this blanket effect, the earth would be around 30oC colder than it normally is. These gases like carbon dioxide, methane and nitrous oxide along with water vapour, comprise less than one per cent of the atmosphere.
They are called ‘greenhouse gases” as the working principle is same as that which occurs in a greenhouse. Just as the galss of the greenhouse prevent the radiation of excess energy, this ‘gas blanket’ absorbs some of the energy emitted by the earth and keeps temperaature level intact. This effect was first recognized by a France scientist, Jean-Baptiste Fourier, who pionted out the similarly in what happen in the atmosphere and in a green house. Hence he terms the greenhouse effect. This gas blanket has been in place ever since the creation of the earth.
Since the industrial revolution human activities have been releasing more and more of these greenhouse gases into atmosphere. This leads to the blanket becaming thicker and upsets gses are called ‘sources’ and those that remove them are known as ‘sink’. A balance between ‘source’ and ‘sink’ maintains the level of these greenhouse gases. Humankind upsets this balance when new source that interfere with the natural gas. When we destroy forest, the carbon stored in the treeescapes as carbon dioxide into the atmosphere.
Increasing agricultural activities, changes in land use patterns, and other sources lead to rising level of methane and nitrous oxide. Industrial processes also release artificial and new greenhouse gases like CFCs (chlorofluorocarbons), while automobile exhaust fumes lead to ozone generation. The resulting enchaned greenhouse effect is more commonly referred to as global warming or climate change. Global warming is a result of the increase of thickness of the greenhouse gas layer that is release into the atmosphere through human activity like burning fossil fuel.
Increase greenhouse gas concerntration may be resulting in more heat being trap in the atmosphere and increasing global temperature emitted by the cars we drive, the furnaces we use to heat our homes and the industries that produce oil and gas, create electricity and develop products for the world’s marketplace. These greeghouse are completely human caused. They harm stratospheric ozone and so are not as directly responsible for global warming as carbon dioxideis.
The question of reducing their presence in the stratosphere is being taken care of in another global convention, the Montreal Protocol. These gases are particularly effective in absorbing long wave radiation from the earth’s surface and preventing heat from escaping. Alhtough the views and opinions of people across the world vary on issues relating to the cause of global warming and its possible impacts, there is a common understanding that is is a cause for major global concern and must be adressed immediately.
