Question 3: Discuss the causes and effects of global warming. What measures need to be taken to control global warming?
Class 12 - Biology - Environmental Issues Page 286
Answers
Causes of global warming: Global warming occurs as a result of the increased concentration of greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapour. These gases trap solar radiations released back by the Earth. This helps in keeping our planet warm and thus, helps in human survival. However, an increase in the amount of greenhouse gases can lead to an excessive increase in the Earth’s temperature, leading to global warming. Global warming is a result of industrialization, burning of fossil fuels, and deforestation.
Effects of global warming: Global warming is defined as an increase in the average temperature of the Earth’s surface. It has been observed that in the past three decades, the average temperature of the Earth has increased by 0.6ºC. As a result, the natural water cycle has been disturbed resulting in changes in the pattern of rainfall. It also changes the amount of rain water. Also, it results in the melting of Polar ice caps and mountain glaciers, which has caused a rise in the sea level, leading to the inundation of coastal regions.
Control measures for preventing global warming:
(i) Reducing the use of fossil fuels
(ii) Use of bio-fuels
(iii) Improving energy efficiency
(iv) Use of renewable source of energy such as CNG etc.
(v) Reforestation.
(vi) Recycling of materials
Answer:
An increase in the average temperature of the surface of earth is termed as Global warming. It can be caused due to the following reasons:
Increased concentration of the greenhouse gases in the atmosphere of the earth causes the phenomena of global warming. These gases are methane, carbon dioxide and water vapor which trap solar rays that are given out by the Earth helping to keep the planet warm, thus aiding human survival. Rise in the level of these greenhouse gases can cause a huge increase in the temperature of the Earth resulting in Global warming
Global warming can also be caused due to burning of fossil fuels, industrialization and the act of deforestation
Impact of Global warming:
It has been observed over the past few decades that global warming has led the average temperature of the Earth to increase by 0.6 ˚C, causing a disturbance in the natural water cycle, hence fluctuations in the pattern of rainfall. These changes also have an impact on the rainfall.
Global warming has also caused the polar ice caps and mountain glaciers to melt, leading to an increase in the sea level, hence the inundation of coastal areas.
Preventive measures:
Use of fossil fuels must be reduced
Increase the usage of bio-fuels
Switch to renewable source of energy such as CNG
Promote reforestation
Encourage and carry out recycling of materials
Energy must be efficiently used