Question

Explain the greenhouse effect with reference to gases responsible for it and their sources.

Hint:

Reducing greenhouse gas emissions through renewable energy and conservation can mitigate global warming.

Answer 1

The greenhouse effect is the warming of Earth's atmosphere due to the trapping of heat by greenhouse gases. 
(i) The sun emits shortwave radiation that reaches Earth's surface. 
(ii) Earth absorbs this energy and emits it as longwave infrared radiation. 
(iii) Greenhouse gases trap this infrared radiation, preventing it from escaping into space. 
(iv) This leads to an increase in Earth's temperature, contributing to global warming. 
Major Greenhouse Gases and Their Sources: 
(i) Carbon dioxide (CO$_2$) – Released from burning fossil fuels, deforestation, and industrial processes. 
(ii) Methane (CH$_4$) – Emitted by cattle digestion (enteric fermentation), rice paddies, and landfills. 
(iii) Nitrous Oxide (N$_2$O) – Originates from excessive use of nitrogen fertilizers and combustion engines. 
(iv) Chlorofluorocarbons (CFCs) – Released from refrigerants, aerosol sprays, and foam-blowing agents. 
Effects of the Greenhouse Effect: 
(i) Rise in global temperatures, leading to climate change. 
(ii) Melting of polar ice caps and rising sea levels. 
(iii) Increased frequency of extreme weather events (hurricanes, droughts).