Causes of global warming:
(i) Deforestation
(ii) Rise in the concentration of greenhouse gases (CO2 , CH4 , CFCs, N2O).
(iii) Burning of fossil fuels
(iv) Rise in industrial wastes and pollutants.
Global warming is a warning to mankind because:
(i) Rise in temperature is leading to increased melting of polar ice-caps as well as of other places like the Himalayan snow caps. This will result in a rise in sea level that can submerge many coastal areas.
(ii) Deleterious changes in the environment results in odd weather and climate changes, e.g., El Nino effect.
