Global warming refers to the continuous rise in the temperature of the earth’s surface. If unchecked the effects of global warming will be devastating like inundation of coastal areas by rising sea levels and turning fertile areas into barren lands because of climatic changes. Hence it is imperative to stop global warming. However before solutions to global warming can be formulated it is essential to understand the causes of global warming.
Global warming is caused by a number of gases, known as greenhouse gases, which are accumulating in the earth’s atmosphere and trapping the solar radiation reflected from the earth. Predominant among these gases is carbon dioxide, but there are others like methane and nitrous oxide. These are released into the atmosphere as a result of human activity. The article will now explore some of the significant activities that are contributing to the increase in greenhouse gases and therefore global warming.
The principal source of carbon dioxide in the atmosphere is the burning of fossil fuels to generate electricity. In the United States of America about 40% of the carbon dioxide emissions can be traced to this source. Of the fossil fuels coal is the largest culprit because it generates by far the greatest amount of carbon dioxide per unit of energy produced.
Next in line is carbon dioxide from automobiles. In the United States this accounts for 20% of the carbon dioxide emissions. The biggest culprits are the older cars because they are less fuel-efficient. Hence better fuel efficiency not only means savings in terms of fuel consumed but also the benefit of lesser global warming. Idling in traffic also contributes to the release of carbon dioxide. It has been estimated that7.5 million tons are released every year in New York and Los Angeles alone.
Two other sources of carbon dioxide that cause global warming are emission from airplanes and building structures. With increased air travel emissions from airplanes are fast becoming a significant contributor to global warming.
The second most significant greenhouse gas is methane. Though methane is 20 times as effective as carbon dioxide in trapping the reflected solar radiation, the quantities of methane in the atmosphere are much lower. Methane is emitted mainly from paddy fields. When the fields are flooded the organic matter in the soil decomposes and releases methane through the rice plants. Other sources of methane are bovine flatulence, bacteria in marshes and fossil fuel production.
Another gas responsible for global warming is nitrous oxide. Oceans and rain forests produce most of the nitrous oxide, so human activity is not responsible. However some human activity produces small quantities of this gas, which include nylon and nitric acid production, the use of fertilizers, cars with catalytic converters and the burning of organic matter.
There are several indirect sources of release of greenhouse gases. A major source of carbon dioxide is deforestation. Trees absorb carbon dioxide and hence deforestation results in the carbon dioxide remaining in the atmosphere. About 34 million acres of forests are destroyed each year and this greatly contributes to global warming. The permafrost and tundra regions of the arctic have over the centuries absorbed huge amounts of carbon dioxide. Lesser quantities of methane have also been absorbed. Now global warming has started to melt the ice thereby releasing the gases. This is how global warming accelerates global warming.
