An Essay about Causes of Climate Changes
April 20, 2018 Writing Help
The atmosphere of the Earth periodically changed in the past. Today scientists are very concerned about the fact of global warming and climate shift. Among the main causes of this situation are astronomical, geographic and meteorological.
What Can Provoke Changes of Climate
Main Reasons of Global Warming
Astronomical factors of climate change are the unequal position of the Earth relatively to the Sun, changes in the shape of its orbit and the speed of rotation. They cause an increase or decrease in the amount of solar energy that can change the climate condition. Also, astronomical changes affect the nature of the movement of air masses. Such situation is associated with changes in solar activity.
The geographical causes of climate shift include changes in the ratio of land and sea areas, earthquakes, and the like. Thus, the appearance of new mountain ranges influences the direction of movement of air masses, which, in turn, contributes to the redistribution of heat and moisture. During the onset of the sea on the dry ground, the climate becomes softer and warmer, and the retreat of the sea leads to cold weather and increasing of the continental climate.
Meteorological factors have the impact mainly on the chemical composition and mass of the atmosphere. However, this effect is temporary.
People and the Atmosphere
Human society, especially during the last century, also significantly affects the climatic conditions of the Earth. Increasing household emissions of pollutants, a person changes its gas composition. Using a large number of different types of energy and scattering it in the airspace, people often affect the thermal equilibrium of the atmosphere.
Causes of Acid Rains and Smog
Humans in their activity can change the composition and properties of the atmosphere. In recent years, the air contains a large amount of harmful gases. They get into the atmosphere from the pipes of industrial enterprises.
If such gases accumulate in the air and mix with droplets of fog, smog is formed. Poisonous fog spreads to the ground at the level of the human respiratory organs, which is especially dangerous. Especially often smog occurs in large cities.
Air pollution by sulfur and nitrogen compounds is also very dangerous. When combined with water vapor, they return to the ground in the form of acid rain. Such rains sometimes fall out thousands of kilometers from the place of their formation. They damage people's health, destroy forests, and pollute soils. Some scientists believe that the increasing pollution of the atmosphere by chemicals destroys a thin ozone layer. It creates peculiar "holes". The largest ozone hole was found over Antarctica.
Scientists around the world are trying to figure out "hidden" factors that can affect the future Earth climate changes.
The concentration of carbon dioxide in the air in 2050 can amount from 0.04 to 0.05%, which can lead to the increase in the average temperature of the Earth's surface and lower layers of the atmosphere and the rise of the ocean level due to the melting of polar ice in 1.5 m. A similar phenomenon is associated with the so-called "greenhouse effect," which means the properties of the atmosphere to pass through solar radiation but to delay the Earth's radiation and thus contribute to the accumulation of heat by the planet.
The main contribution to the formation of the greenhouse effect is the introduction of water vapor and carbon dioxide contained in the atmosphere. It is also known that the absorption spectrum of the atmosphere in the windows of transparency is determined not only by the influence of carbon dioxide but also by such gas components as ozone and many others, including aerosols.
Reduction of Forest Area
Another major reason for possible climate change on the Earth is the reduction of forest area. Of particular concern is the decline in forest area in Africa, Asia and especially in South America, where more than 55% of their amount is concentrated. Annually the area of tropical forests in the world decreases by about 1%.
Dust in the Atmosphere
A significant influence on global warming and climate change on the Earth can also be caused by the increase in the amount of dust in the atmosphere, especially the finely dispersed aerosols in the stratosphere, which can be stored there from a few months to 1-2 years. The normal layer of stratospheric aerosol makes up a mass of about 0.2 million tons. With the large volcanic eruptions, tens of millions of tons of dust can be deposited into the stratosphere. Increasing the albedo of the atmosphere, the fine dispersed stratospheric aerosols lead to the effect of its cooling. Many researchers explain cold periods in the past by this fact.
Past and Future
Due to climate change, dinosaurs died out. It is known that about 65 million years ago nearly half of all living beings that lived on the Earth disappeared. Such extinction can be explained by the sudden change in climate. Some scientists believe that the climate was affected by the fall of a large cosmic body on the Earth's surface, from which a significant amount of dust has fallen into the atmosphere. It reduced the transparency of the air, and at the same time the receipt of solar heat. Other scientists claim that the cataclysm and disappearance of living organisms were caused by the volcano, the eruption of which significantly reduced the flow of sunlight and heat.
In the second half of the XX century, the greatest climate change occurred over the past 100-150 years. It was characterized by gradual global warming. The consequences include even the melting of glaciers. The temperature rise is evidenced by the observation of the level of the World Ocean, which increases by an average of 2 mm per year.
Scientists are keen to predict how temperature rises may change the weather and climate in the future. To do this, they create computer models of future climatic conditions. With their help, it is predicted that by 2050 the temperature will rise. However, these temperature changes will not be the same throughout the globe: the greatest warming is expected at the poles. According to scientists, due to the increase in temperature, in many areas, clouds and rainfall may increase. Climate warming can also "provoke" natural weather disturbances.