RBSE Class 12 Biology Notes Chapter 16 Environmental Issues

These comprehensive RBSE Class 12 Biology Notes Chapter 16 Environmental Issues will give a brief overview of all the concepts.

RBSE Class 12 Biology Chapter 16 Notes Environmental Issues

→ As we all observes that human population is increasing day by day. This increasing population putting pressure on the valuable natural resources. To meet the increasing demand humans are over exploiting the nature to fulfill the daily needs causing the unwanted and undesirable changes in the physical, chemical and biological properties of the environment which are called pollution and the agents are called pollutants. The pollution is of different types like air pollution results from burning of fossil fuel, from industries etc. 

→ Water pollution arises from domestic sewage discharge into water bodies like rivers, lakes and ponds. It is rich in nutrients especially nitrogen and phosphorus causes eutrophication and algal blooms. Municipal solid wastes also create many problems like soil pollution, methane generation which is an important green house gases. Soil pollution primarily results from agricultural chemicals like pesticides and fertilizers.

→ Two major environmental issues at global level are greenhouse effect which is the warming of earth and depletion of ozone in stratosphere. 

→ Enhanced greenhouse effect is mainly due to increased emission of carbon dioxide, methane, nitrous oxide and CFCs. It may drastically change the global rainfall patterns, global temperature effecting millions of people across the world in a way or other. So, humans have to develop the sustainable mode of living in order to mitigate the ill effects of pollution, deforestation, ozone hole and global warming, v

→ Pollution: Any undesirable change in physical, chemical and biological characteristics of air, water, land and soil.

→ Pollutants are the agents that causes undesirable changes in the environment.

→ ESP: Electrostatic precipitator, an electric device to remove particulate matter present in the exhaust of power plants.

→ CNG: Compressed Natural Gas.

→ Biological Magnification: Any increase in concentration of toxicants at successive trophic levels in aquatic food chain.

→ Eutrophication: Natural aging of a lake by nutrient enrichment of its water.

→ BOD: Biological oxygen demand, amount of oxygen required for microbial breakdown of biodegradable organic matter.

→ Polyblend: A mixture used to lay down road made up of mix type of plastic.

→ Greenhouse Effect: Natural occuring phenomenon responsible for heating of earth’s surface due to the presence of certain gases in the atmosphere. 

→ GHGs: Greenhouse Gases for example, CO₂, CH₄, N₂O and CFCs.

→Ozone hole: The depletion of ozone over Antarctic region.