Industrial waste, burning excessive Hydro carbon and acid rain is the major source of CO2 in air and fresh water as well. Industrial waste if properly not treated enter and it's Cox dissolve in water and form carbonic acid, which ultimately lowers the pH of water and as a result, endanger marine life . Some time i ponder that what we are doing? we are destroying world environment at the cost of industrialization. so It's a time to give awareness to common people and do all sincere effort what he can do on his own behalf.