Environment and Global Warming
Global warming is a gradual increase in the average temperature of the earth’s lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. Much of the recent observed and projected global warming is human-induced. It is caused by man-made increases in carbon dioxide and other greenhouse gases through the burning of fossil fuels and deforestation. Adding carbon dioxide, methane and such other gases (that have the potential to absorb heat) to the atmosphere with no other changes will make our planet’s surface warmer. The atmospheric concentrations of carbon dioxide and CH4 have increased by 31 per cent and 149 per cent respectively above pre-industrial levels since 1750. During the past century, the atmospheric temperature has risen by 1.1°F (0.6°C) and sea level has risen several inches. Some of the longer-term results of global warming are melting of polar ice with a resulting rise in sea level and coastal flooding; disruption of drinking water supplies dependent on snow melts; extinction of species as ecological niches disappear; more frequent tropical storms; and an increased incidence of tropical diseases. A UN Conference on Climate Change, held in Kyoto, Japan, in 1997, resulted in an international agreement to fight global warming which called for reductions in emissions of greenhouse gases by industrialised nations.
The lower atmospheric temperature of the earth is rising because of greenhouse gas emissions. Which of the following problem is associated with the given statement?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Global warming
Gases such as carbon dioxide and methane absorb the heat the earth gives off. Since the Industrial Revolution, burning fossil fuels and cutting forests have added more of them to the air, so the earth’s lower atmosphere holds more heat and its average temperature rises gradually. This rise is global warming, the problem with which the passage opens.
Why the other options are incorrect
Option (1) Deforestation — Incorrect. Deforestation is one of the causes of global warming, because it leaves more carbon dioxide in the air; it is not the name of the rise in temperature.
Option (2) Urbanisation. — Incorrect. Urbanisation is the growth of towns and cities; it is not the warming of the atmosphere.
Option (3) Globalization. — Incorrect. Globalisation is the integration of a country’s economy with the world economy, through trade and investment; it has nothing to do with the temperature of the atmosphere.