Environmental Pollution & Greenhouse Gases
Environmental degradation stems from industrial emissions, particulate matter, chemical effluents, and heat-trapping greenhouse gases. The primary greenhouse gases driving anthropogenic global warming include carbon dioxide ($CO_2$), methane ($CH_4$), nitrous oxide ($N_2O$), and fluorinated gases (HFCs, PFCs, $SF_6$), evaluated by their Global Warming Potential (GWP) relative to $CO_2$. Particulate pollutants $PM_{2.5}$ and $PM_{10}$ penetrate deep into respiratory pathways, monitored in India via the National Air Quality Index (AQI) under the Central Pollution Control Board (CPCB). Stratospheric ozone depletion, caused by chlorofluorocarbons (CFCs) releasing catalytic chlorine radicals, prompted the 1987 Montreal Protocol, one of the most successful international environmental treaties.
Key Concepts & Examination Highlights
- The Montreal Protocol on Substances that Deplete the Ozone Layer was signed on September 16, 1987, recognized globally as World Ozone Day.
- Methane ($CH_4$) possesses a Global Warming Potential over 28 times greater than carbon dioxide ($CO_2$) over a 100-year timescale.
- The National Air Quality Index (AQI) in India tracks eight key pollutants: $PM_{10}$, $PM_{2.5}$, $NO_2$, $SO_2$, $CO$, $O_3$, $NH_3$, and $Pb$.