Environmental Issues

Ocean acidification occurs when the ocean absorbs excess CO₂ from the atmosphere, forming carbonic acid (H₂CO₃) which dissociates to lower ocean pH. The ocean has become approximately 30% more acidic since the Industrial Revolution. This is distinct from global warming, though both are caused by increased CO₂.

The Indian Himalayan Region (IHR) occupies a strategic position along the entire northern and north-eastern boundary of India. It covers 10 states in entirety (Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya) and two states partially (hill districts of Assam and West Bengal). The IHR has wide-ranging ecological and socio-economic significance but faces severe environmental challenges from anthropogenic pressure.

The **greenhouse effect** is a naturally occurring phenomenon responsible for heating of Earth's surface and atmosphere. Without the greenhouse effect, the average temperature at Earth's surface would be −18°C rather than the present average of 15°C. **Mechanism:** Almost half of incoming solar radiation reaches Earth's surface and heats it, while a small proportion is reflected back. Earth's surface re-emits heat in the form of infrared radiation. Atmospheric greenhouse gases (CO₂, methane, etc.) absorb a major fraction of this infrared radiation. The molecules of these gases radiate heat energy, a major part of which again comes to Earth's surface, heating it once more. This cycle is repeated many times. **Greenhouse gases:** Carbon dioxide, methane, nitrous oxide, CFCs, and water vapour. Among these, CO₂ is the most discussed because of its direct link to human combustion activities. **Global warming:** Increase in the level of greenhouse gases has led to considerable heating of Earth. During the past century, the temperature of Earth has increased by 0.6°C, mostly during the last three decades. This rise in temperature is leading to: - Odd climatic changes (e.g., El Niño effect) - Increased melting of polar ice caps and Himalayan snow caps - Rise in sea level that can submerge many coastal areas - Disruption of rainfall patterns **Measures to control global warming:** - Cutting down use of fossil fuels - Improving efficiency of energy usage - Reducing deforestation - Planting trees (reforestation) - Slowing down the growth of human population - International initiatives to reduce emission of greenhouse gases **Deforestation link:** Rapid deforestation and massive burning of fossil fuels have significantly increased the rate of release of CO₂. Trees that hold large amounts of carbon in their biomass are lost with deforestation, releasing CO₂. Deforestation also causes loss of biodiversity, disturbs the hydrological cycle, causes soil erosion, and may lead to desertification. **Reforestation** is the process of restoring a forest that once existed but was removed. It may occur naturally but can be accelerated by planting trees with due consideration to original biodiversity. **Ozone depletion — related but distinct issue:** Ozone in the stratosphere acts as a shield absorbing ultraviolet radiation. CFCs discharged in the lower atmosphere move upward and reach the stratosphere, where UV rays release Cl atoms. Cl degrades ozone releasing molecular oxygen, with Cl atoms acting merely as catalysts (not consumed). Hence CFCs have permanent and continuing effects on ozone levels. - Ozone depletion is particularly marked over Antarctica, forming the **ozone hole** - Ozone thickness is measured in **Dobson units (DU)** - UV-B causes: ageing of skin, damage to skin cells, various types of skin cancers, inflammation of cornea, cataracts - **Montreal Protocol** signed at Montreal, Canada, in 1987 (effective 1989) to control emission of ozone-depleting substances - CFCs find wide use as refrigerants

**Deforestation** is the conversion of forested areas to non-forested ones. According to an estimate, almost 40 per cent of forests have been lost in the tropics, compared to only 1 per cent in the temperate region. **India's deforestation profile:** At the beginning of the twentieth century, forests covered about 30 per cent of the land of India. By the end of the century, it shrunk to **19.4 per cent**, whereas the **National Forest Policy (1988)** of India has recommended **33 per cent forest cover for the plains and 67 per cent for the hills**. --- ### Causes of Deforestation - Conversion of forest to agricultural land to feed growing human population - Trees felled for timber, firewood, cattle ranching - **Jhum cultivation (slash and burn agriculture):** Common in north-eastern states of India. Farmers cut down trees of the forest and burn the plant remains; ash is used as fertiliser and land is used for farming or cattle grazing. After cultivation, the area is left for several years to recover before moving on. In earlier days, enough time-gap was given for recovery. With increasing population and repeated cultivation, this recovery phase is eliminated, resulting in deforestation. --- ### Consequences of Deforestation - **Enhanced CO₂ concentration:** Trees that hold large amounts of carbon in their biomass are lost with deforestation — CO₂ released into atmosphere - **Loss of biodiversity** due to habitat destruction - **Disturbed hydrological cycle** - **Soil erosion** - **Desertification** in extreme cases — when fertile land gradually loses vegetation in patches that expand and meet over time - **Waterlogging and soil salinity:** Irrigation without proper drainage leads to waterlogging; draws salt to the surface creating a thin crust; increased salt content is inimical to crops (a problem in the wake of the Green Revolution) **Reforestation:** The process of restoring a forest that once existed but was removed. May occur naturally but can be accelerated by planting trees with due consideration to biodiversity that earlier existed in that area. --- ### People's Participation in Forest Conservation **Bishnoi community (1731):** The king of Jodhpur in Rajasthan asked a minister to arrange wood for constructing a new palace. Workers went to a forest near a village inhabited by Bishnois. The Bishnoi woman **Amrita Devi** showed exemplary courage by hugging a tree and daring the king's men to cut her first before cutting the tree. She and her three daughters and hundreds of other Bishnois lost their lives saving trees. The Government of India has recently instituted the **Amrita Devi Bishnoi Wildlife Protection Award** for individuals or communities from rural areas that show extraordinary courage and dedication in protecting wildlife. **Chipko Movement (1974):** In 1974, local women of Garhwal Himalayas showed enormous bravery in protecting trees from felling by contractors by hugging them. The Chipko Movement has been acclaimed worldwide. **Joint Forest Management (JFM):** The Government of India in the 1980s introduced the concept of Joint Forest Management to work closely with local communities for protecting and managing forests. In return for their service to the forest, the communities get benefit of various forest products (fruits, gum, rubber, medicine, etc.) and thus the forest can be conserved in a sustainable manner. ---

**Pollution** is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. Agents that bring about such change are called **pollutants**. The Government of India passed the **Environment (Protection) Act, 1986** to protect and improve the quality of our environment (air, water and soil). --- ### Air Pollution Air pollutants cause injury to all living organisms — they reduce growth and yield of crops, cause premature death of plants, and detrimentally affect the respiratory system of humans and animals. **Sources:** Smokestacks of thermal power plants, smelters, industries, and automobiles release particulate and gaseous pollutants. **Particulate matter control:** - **Electrostatic precipitator** — most widely used; removes over 99 per cent of particulate matter from exhaust of thermal power plants. Electrode wires at several thousand volts produce a corona that releases electrons; electrons attach to dust particles giving them a net negative charge; grounded collecting plates attract the charged particles - **Scrubber** — can remove gases like sulphur dioxide; exhaust is passed through a spray of water or lime - **PM 2.5** — particulate matter of 2.5 micrometres or less in diameter (CPCB definition) causes greatest harm; inhaled deep into lungs causing breathing symptoms, inflammation and premature deaths **Automobile pollution:** - Catalytic converters (with platinum-palladium and rhodium) convert unburnt hydrocarbons to CO₂ and water, and CO and nitric oxide to CO₂ and nitrogen. Vehicles with catalytic converters must use unleaded petrol — lead inactivates the catalyst - **Case Study — Delhi:** In the 1990s, Delhi ranked 4th among the 41 most polluted cities in the world. A PIL in the Supreme Court resulted in converting Delhi's entire public transport fleet (buses) from diesel to CNG by end of 2002. CNG burns most efficiently, very little is left unburnt, and it is cheaper than diesel. Simultaneously, Delhi phased out old vehicles, mandated unleaded petrol, low-sulphur petrol/diesel, catalytic converters, and stringent pollution norms. Air quality in Delhi significantly improved — substantial fall in CO and SO₂ levels between 1997 and 2006 - **Air (Prevention and Control of Pollution) Act** came into force in 1981, amended in 1987 to include noise as an air pollutant **Noise pollution:** Brief exposure to 150 dB or more (jet plane, rocket) may permanently damage ear drums. Chronic exposure to lower city noise levels also permanently damages hearing. Noise also causes sleeplessness, increased heart beating, altered breathing pattern — stressing humans. --- ### Water Pollution The **Water (Prevention and Control of Pollution) Act, 1974** was passed to safeguard water resources. **Domestic sewage:** A mere 0.1 per cent impurities make domestic sewage unfit for human use. Sewage primarily contains biodegradable organic matter. Key water quality parameter: **Biochemical Oxygen Demand (BOD)** — the amount of oxygen that would be consumed if all organic matter in one litre of water were oxidised by bacteria. Greater BOD = more polluting potential. **Effects of sewage discharge into a river:** - Micro-organisms involved in biodegradation consume a lot of oxygen → sharp decline in dissolved oxygen downstream → mortality of fish and other aquatic creatures - Large amounts of nutrients cause excessive growth of planktonic algae → **algal bloom** → deterioration of water quality and fish mortality; some bloom-forming algae are extremely toxic to humans and animals **Eutrophication:** Natural aging of a lake by biological enrichment of its water. Cultural or Accelerated Eutrophication occurs when human pollutants (effluents from industries and homes) radically accelerate this process. Prime contaminants: nitrates and phosphates (plant nutrients). They overstimulate algae growth, rob water of dissolved oxygen, and a lake can literally choke to death. **Water hyacinth (Eichhornia crassipes):** World's most problematic aquatic weed; also called "Terror of Bengal." Grows abundantly in eutrophic water bodies and leads to imbalance in ecosystem dynamics. **Biomagnification:** Increase in concentration of a toxicant at successive trophic levels. Happens because a toxic substance accumulated by an organism cannot be metabolised or excreted and is passed to the next trophic level. Well-known for mercury and DDT. Example: DDT concentration starting at 0.003 ppb in water can reach 25 ppm in fish-eating birds through biomagnification. High DDT concentrations disturb calcium metabolism in birds → thinning of eggshells → premature breaking → decline in bird populations. **Industrial effluents:** Contain toxic substances notably heavy metals (elements with density > 5 g/cm³ — mercury, cadmium, copper, lead) and organic compounds. Thermal (heated) wastewater from electricity-generating units eliminates or reduces organisms sensitive to high temperature. **Case Study — Integrated Wastewater Treatment, Arcata (California):** Town of Arcata collaborated with Humboldt State University biologists to create integrated wastewater treatment within a natural system. Conventional sedimentation, filtering and chlorine treatment followed by a series of six connected marshes over 60 hectares where appropriate plants, algae, fungi and bacteria neutralise, absorb and assimilate remaining pollutants. The marshes also constitute a sanctuary with high biodiversity. **Ganga Action Plan and Yamuna Action Plan:** Initiated by the Ministry of Environment and Forests to save major rivers from pollution; propose to build a large number of sewage treatment plants so that only treated sewage is discharged into rivers. --- ### Solid Wastes and Other Pollution - Municipal solid waste: paper, food wastes, plastics, glass, metals, rubber, leather, textile, etc. - Sanitary landfills are the substitute for open-burning dumps - E-wastes (defunct computers, electronic goods) — buried in landfills or incinerated; over half of e-wastes from developed world exported to developing countries (China, India, Pakistan) for recycling; workers exposed to toxic substances in developing country recycling

Environmental Impact Assessment (EIA) is a planning tool that integrates environmental concerns into developmental activities from the feasibility stage. It is accepted as an integral component of sound decision-making. The objective is to foresee potential environmental problems before a project begins and address them in planning and design. **EIA history in India:** - Started 1976–77 when Planning Commission asked Department of Science and Technology to examine river-valley projects from environmental angle - Extended to projects needing Public Investment Board approval - These were administrative (not legislative) decisions - Environment (Protection) Act 1986 made EIA statutory - EIA Notification 1994 under EPA 1986 made environmental clearance mandatory for specified categories

Microbeads are minute, manufactured solid plastic particles, typically less than one millimeter in their largest dimension. They are most frequently composed of polyethylene but can also be made from other petrochemical plastics like polypropylene and polystyrene. These particles are widely incorporated into exfoliating personal care products, toothpastes, and also find application in biomedical and health-science research. For UPSC Prelims, microbeads are a critical environmental issue falling under plastic pollution. Their minuscule size allows them to bypass conventional sewage treatment, leading to widespread water pollution in rivers and oceans. This poses a significant hazard to aquatic ecosystems, as marine life often mistakes them for food, leading to ingestion of plastic and associated harmful chemicals, which can then transfer up the food chain. Understanding their origin, impact, and global policy responses is essential for environmental questions.

Greenwashing, also known as green sheen, is a deceptive marketing and public relations tactic where an organization falsely or misleadingly presents its products, goals, or policies as environmentally friendly. Modeled on "whitewashing," it aims to persuade the public of an exaggerated or untrue commitment to environmental sustainability. Understanding greenwashing is crucial for UPSC as it relates directly to environmental governance, consumer protection, corporate social responsibility, and the integrity of sustainable development efforts. It highlights the challenges in verifying environmental claims, the need for robust regulatory frameworks, and is important for evaluating genuine progress towards environmental goals and preventing misleading practices.

Bioremediation is an environmental management technique that employs biological systems, typically microorganisms like bacteria, microalgae, fungi (in mycoremediation), and plants (in phytoremediation), to remove environmental pollutants. These organisms leverage their natural ability to adsorb, accumulate, and degrade a wide range of contaminants from air, water, and soil in both natural and controlled environments. This concept is crucial for UPSC Prelims as it represents a sustainable, eco-friendly, and often more cost-effective alternative to conventional physicochemical treatment methods. Its focus on natural processes for pollution control and waste management aligns with current environmental policies and initiatives, making it a frequently tested topic concerning environmental issues and conservation.