(a) Reason for these global ecological changes is faulty recycling of carbon dioxide. More of carbon dioxide is being produce than its conumption in photosynthesis due to following curses of urbanisations (i) Excess combustion of fossil fuels in industries, power houses, automobiles, homes and other place. (ii) Reduced in take of `CO_(2)` by plants due to deforestation (Forests serves as sinks of carbon dioxide utilization) (iii) Higher amounts of `CO_(2)`entering the atmosphere not only increases its atmospheric concentratiion but also the concentration of dissolved `CO_(2)` in water especialy in colder seas. The acidity tends to do thinning of hte shells of many marine animals. (iv). `CO_(2)` is a green house gas which is causing global warming. Rise in global temperature is melting snow over poles. This is raising the level of sea water slowly. It has already submerged some low lying islands.
(b) Suggestions for checking global warming.
(i) Large scale tree plantation in all vacant area.
(ii) Reduced felling of forest trees. (iii) Reducing consumption of fossil fuels by reducing dependence on thermal power plants, increasing efficiency of automobiles and switching over to alternate technologies that do not consume fossil fuels (e.g., Solar power systems, small hydroelectric power plants, windmills, etc).
