The use of various forms of transport made the construction of roads important. As new roads were built each day cities began emerging. Trends changed and people started moving away from small villages and towns to big metropolitan cities to attain better education and get good jobs. The move from small towns and villages changed the traditional values that people had been adhering to for years. With the new and improved automobiles available people were more willing to travel longer distances to benefit from better opportunities.
The ease of transportation allowed people to pursue their thirst for knowledge and to cross continents if needed to attain what they want. Although the construction of high rises and highways is progressive in the sense that human beings have become more civilized and refined the disadvantage is that trees and forests had to be cut down to construct those big cities, demolishing one of the world’s major natural resources. Cutting down trees and forests from hilly areas affected the environment badly. In the summers when the glaciers melted and water flowed down the mountains these forests protected flooding of the surrounding areas by consuming this water.
Now as these trees are no longer there more flooding results in casualties as the areas around and about the mountains are flooded away by the rise in water levels. As the greenhouse gases in the air increase, the atmospheric temperature also increases which melts the glaciers and as the water from these glaciers moves into the sea the sea levels rise which also has an adverse effect on the ecosystem. Parts of glaciers also fall off sometimes blocking roads and pathways becoming a health hazard. In these big cities cars, motorcycles and buses result in one of the major environmental hazards, namely pollution. Pollution of any kind is dangerous to human health, plants, and animals.
All these automobile engines emit gases that are injurious to health. This emission of gases changes temperatures globally. When hydrocarbons and nitrogen oxides react under the sunlight, result in ground-level ozone and acid rains, which aggravate the eyes and respiratory systems and can cause cancer too. Some catalytic converters split nitrogen gases to form a nitrous oxide which can be much more harmful than carbon dioxide that is one of the major catalysts of global warming.
All the gases emitted by these various vehicles are the major cause of global warming and the greenhouse effect. Global warming is the term that was originally used to describe the increase in the surface area temperature of the earth but now it describes an increase in the surface area temperature that is unnaturally fast and which affects climate conditions at the same rate that it occurs.
The greenhouse effect is named after the heat effect in a glass-enclosed space had been observed. Earth receives heat from the sun, some of this heat if is reflected back into the atmosphere by the surface of the earth, some of this reflected heat is consumed by the atmospheric gases while some is reflected back to the earth. This is the greenhouse effect. When this happens on the earth it is harmful to the environment and the presence of these gases emitted by automobiles results in this greenhouse effect thus changing not only the weather but the climate also.