Discuss the causes and effects of global warming. What measures need to be taken to control global warming?

Global warming is defined as an increase in the average temperature of the Earth’s surface.
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:

•  Reducing the use of fossil fuels
•  Use of bio-fuels
•  Improving energy efficiency
•  Use of renewable source of energy such as CNG etc.
•  Reforestation.
• Recycling of materials

• Global warming is rise in mean temperature of lower atmosphere and earth’s surface.
• Causes – increase in quantity of radioactively active green house gases CO₂, CH₄, N₂O, CFCs. They allow heat waves to reach surface and prevents their escape. 
• They are produced by combustion of fossil fuels, biomass [CO₂]; burning of nitrogen rich fuels [N₂O]; paddy fields, fermentation in cattle and wet lands [CH₄]; refrigerators, aerosols, drying, cleaning [CFCs].
• Effects: Heating of earth surface [mean temperature is increased] Climatic changes e.g.: El Nino effect.
• Increased melting of polar ice caps and Himalayan snow caps. Increased sea levels and coastal areas will submerge.
• Measures – Decreased use of fossil fuels, improve efficiency of energy usage, Reduce deforestation, plant trees Control of man made sources of green house gases like vehicles, aerosol sprays.

1. Phase down or ban the use of CFCs (CFC free refrigerants). 

2. Minimizing the use of chemicals such as halons and halocarbons. 

3. Creating awareness about ozone depleting agents. UV rays may penetrate deep into the skin and can lead to premature skin aging and wrinkling of skin; suppression of the immune system, skin cancer (melanoma) and chronic effects leading to eye damage. DNA damage can result from free radicals and reactive oxygen and. photons can damage the DNA itself.