Climate changes

What is a climate change? The source of various atmospheric phenomena which happen on the earth is the energy from sun. The energy which the earth received from the sun is exchanged mutually in all parts, and, eventually is returned to space as infrared radiation. Therefore, the energy income and outgo of the mostly stable earth are maintained. All the systems of the earth which participates in the flow of such energy are called a climate system, and an atmospheric average state is called climate. Climate is changed with various factors and various time scales. A natural factor and an artificial factor are one of the factors of a climate change. Natural factors include change of what is inherent in the atmosphere itself, or the ocean, the increase in the aerosol (particulates in the atmosphere) by volcanic eruption, change of a solar activity, etc. Especially the ocean that occupies 70 percent of earth surface is exchanging heat and vapor through a sea surface between the atmospheres, and change of an ocean current or sea surface temperature has big influence on atmospheric movement. On the other hand, there are an increase in greenhouse effect gas, such as carbon dioxide accompanying human activities, an increase in an aerosol, deforestation, etc. in an artificial factor. The increase in greenhouse effect gas, such as carbon dioxide, raises ground temperature, and change of vegetation, such as deforestation, affects the amount of reflection of the solar radiation on the surface of the earth or circulation of water. The concern over global warming by the increase in the carbon dioxide levels in atmospheric air by consumption of fossil fuels, such as a lot of petroleum and coal, has become strong in recent years. And the concern about the climate change by an artificial factor has become strong.

The example of a climate change is given.

1.    Global warming

Since the last report described global warming, it omits this time.

2.    Desertification

 【Meaning】An arid region becomes a desert by fault pasturage, a deforestation, farmland of a prairie, saline, etc. around a desert. Land should dry and growth of plants other than succulent plants, such as a cactus, should become impossible.

・The main structure of desertification

 Although the process of desertification differs from areas where desertification is advancing, respectively, there are mainly erosion, saline, and blown sand.

・・erosion

 The soil into which agricultural products can grow up including nourishment, such as an organic matter, should flow out by rain, a flood, etc. The base which weathering is not following is exposed and a water holding property is also lost. It sees in India, the Middle East, Ocher Plateau, etc.

・・saline

 The salts concentration in soil rises and it becomes impossible to raise a plant. It generates, when there are more amounts of transpiration than the quantity in which the cold water containing salts flows out of soil into the exterior. Salts will stagnate in a soil surface (salt accumulation). Because the ground where salt accumulation advanced has the character near concrete, difficulty is also caused to agricultural work. Therefore, cultivation, pasturage, and the land use itself may often be abandoned. It sees around the Aral Sea etc.

・・blown sand

 Sand should flow into the area which is not a desert from the sand hill which existed on the outskirts, cover topsoil, and keep as a part of desert. In this case, by removing surface sand, since reproduction is comparatively easy, defending sand serves as the main measures. Research is also advanced although it is remarkable in Australia.

 3.    Deforestation

【Meaning】Deforestation refers to the situation where a forest stops decreasing in number or existing by felling of the trees exceeding natural recuperative strength.

・Problem

 As a result of losing the water retention ability of a forest,　the　flood and a landslide may be caused (fall of a head cultivation function). Moreover, water quality and air cleaning ability are reduced. Furthermore, it is indicated that it leads to global warming as a result of the fall of the fixed function of carbon dioxide. When it sees from an ecological viewpoint, dwellings of the animals and plants which reduce the stability of the ecosystem itself by losing the forest used as the base of terrestrial ecosystems, and are useful in a forest, or an insect will be taken.

As mentioned above, in recent years, the climate change by man poses a problem.