question_answer

  List any three human activities which would lead to an increase in the carbon dioxide content of air.         

Answer:

                  An increase in global temperatures can cause: (i) change in the amount and pattern of precipitation, i.e., rain, snow, etc. (ii) melting of polar ice and rise of sea level, (iii) extreme weather conditions like floods, droughts, heat wave, hurricanes and tornadoes, etc.                 As water flows through rivers, it dissolves small amounts of mineral salts from the rocks and soil of the river beds. This very salty water flows into the oceans and seas. Continuous evaporation of water from the oceans and seas (and freezing of polar ice) results in the increased concentration of minerals in sea water. Thus, the remaining water gets rather saltier as time passes.