UGC NET Environmental Science Unit-X: Contemporary Environmental Issues Syllabus

Why are hydro-power projects in Jammu & Kashmir, Himachal Pradesh, and the North-Eastern states environmentally sensitive?

They lie in the seismically active, fragile young Himalaya. Concerns include landslides and slope instability, deforestation, threats to high biodiversity, glacial-lake outburst flood (GLOF) risk, disruption of river flow and fish, and displacement of tribal/local communities.

What is a watershed, and what does watershed development involve?

A watershed is an area of land that drains all its water to a common outlet (river, stream, or reservoir). Watershed development is the integrated management of its soil, water, and vegetation - through contour bunding, check dams, afforestation, and water harvesting - to conserve resources and improve productivity.

Define rainwater harvesting and name its two broad methods.

Rainwater harvesting is the collection and storage of rainwater for use or recharge instead of letting it run off. Two broad methods: (1) surface/storage harvesting (tanks, ponds, rooftop collection into storage), and (2) recharge of groundwater (recharge pits, trenches, recharge wells, percolation tanks).

What are common artificial groundwater recharge structures?

Recharge pits and shafts, recharge (injection) wells, percolation tanks, check dams/nala bunds, contour trenches, and rooftop-to-borewell recharge systems - all designed to channel rainwater/runoff into aquifers to raise the water table.

What is the National River Conservation Plan (NRCP), and how did it originate?

A centrally sponsored scheme to abate pollution in India's rivers by intercepting, diverting, and treating sewage before it reaches rivers. It grew out of the Ganga Action Plan (launched 1985) and was expanded into the NRCP (1995) covering many rivers across states.

Define eutrophication and identify its main cause.

Eutrophication is the nutrient enrichment of a water body - mainly by nitrogen and phosphorus from sewage, fertilizers, and detergents - that triggers excessive algal/plant growth (algal blooms). Decomposition of this biomass depletes dissolved oxygen, killing fish and degrading water quality.

What techniques are used to restore eutrophic or polluted lakes?

Diversion/treatment of incoming sewage, removal of nutrient-rich bottom sediment (dredging), harvesting of excess weeds/algae, aeration to raise dissolved oxygen, bioremediation/biomanipulation, catchment management, and de-silting - as under India's National Lake Conservation Plan (NLCP).

What is the Ramsar Convention, and what is a Ramsar site?

The Ramsar Convention (1971, signed in Ramsar, Iran) is the international treaty for the conservation and 'wise use' of wetlands. A Ramsar site is a wetland designated as being of international importance under this convention.

Roughly how many Ramsar sites does India have, and name a few notable ones.

India has 80+ Ramsar sites (the most of any Asian country). Notable examples include Chilika Lake (Odisha), Keoladeo National Park (Rajasthan), Loktak Lake (Manipur), Wular Lake (J&K), Sambhar Lake (Rajasthan), and the Sundarbans Wetland (West Bengal).

What are the main types of soil erosion?

By water: sheet erosion, rill erosion, gully erosion, and stream-bank erosion; by wind: deflation, abrasion, and suspension/saltation. Splash erosion (raindrop impact) is the initiating stage of water erosion.

What does reclamation of degraded land involve?

Restoring degraded/waste land to productive use through measures such as afforestation, gypsum application for saline-alkaline (usar) soils, leaching of salts, drainage of waterlogged land, gully plugging, sand-dune stabilization, and addition of organic matter to rebuild soil fertility.

Define desertification and name the international convention that addresses it.

Desertification is land degradation in arid, semi-arid, and dry sub-humid areas caused by climatic variation and human activities (overgrazing, deforestation, poor irrigation). It is addressed by the UNCCD - the United Nations Convention to Combat Desertification (1994).

In climate change response, distinguish mitigation from adaptation.

Mitigation reduces the causes - cutting greenhouse-gas emissions or enhancing carbon sinks (renewables, afforestation). Adaptation adjusts to the impacts - building resilience through drought-resistant crops, sea walls, water harvesting, and early-warning systems.

What is energy security in the climate-change context?

Energy security is the uninterrupted availability of energy at affordable prices. In a climate context it means securing supply while shifting from imported fossil fuels to diversified, low-carbon domestic sources (solar, wind, nuclear, efficiency) to reduce both emissions and import dependence.

What is food security, and what are its four dimensions?

Food security exists when all people, at all times, have physical and economic access to sufficient, safe, and nutritious food. Its four dimensions are: availability, access, utilization, and stability. Climate change threatens it via reduced yields, water stress, and extreme weather.

What is sustainable development, per the Brundtland Commission definition?

Development that 'meets the needs of the present without compromising the ability of future generations to meet their own needs' (Brundtland Report, 'Our Common Future', 1987). It balances economic, social, and environmental goals.

What is the key provision of India's Forest (Conservation) Act, 1980?

It requires prior approval of the central government before any forest land can be diverted to non-forest purposes (e.g., mining, industry, agriculture). It was enacted to check deforestation and regulate de-reservation of forests.

What is Project Tiger - when did it start and what does it manage?

India's flagship wildlife conservation programme launched in 1973 to protect Bengal tigers and their habitat through a network of tiger reserves. It is administered by the National Tiger Conservation Authority (NTCA) and now covers 50+ tiger reserves.

What is Project Elephant and when was it launched?

A centrally sponsored scheme launched in 1992 to protect elephants, their habitats, and corridors; to address human-elephant conflict; and to ensure welfare of captive elephants. It also designates Elephant Reserves across India.

What is carbon sequestration, and what are its two main types?

Carbon sequestration is the long-term capture and storage of atmospheric CO2. Two main types: (1) biological/terrestrial - storage in forests, soils, and oceans via photosynthesis; and (2) geological/engineered - capturing CO2 and injecting it into deep rock formations (CCS).

What is a carbon credit, and which protocol introduced the concept?

A carbon credit is a tradable permit representing the right to emit one tonne of CO2-equivalent. The concept comes from the Kyoto Protocol; under its Clean Development Mechanism, certified emission reductions (CERs) can be earned and traded.

What is the Kyoto Protocol, and name its three flexible market mechanisms.

Adopted in 1997 (in force 2005), it set legally binding GHG-reduction targets for developed (Annex I) countries. Its three flexible mechanisms are: the Clean Development Mechanism (CDM), Joint Implementation (JI), and International Emissions Trading (ET).

What is the Clean Development Mechanism (CDM)?

A Kyoto Protocol mechanism that lets a developed (Annex I) country meet part of its emission-reduction commitment by funding emission-reduction projects in developing countries, earning Certified Emission Reductions (CERs) - one CER equals one tonne CO2-equivalent.

What is the waste-management hierarchy (the '3Rs' and beyond)?

In order of preference: Prevention/Reduce, Reuse, Recycle, Recovery (including composting and energy recovery), and finally Disposal (landfill) as the least preferred option. The classic '3Rs' are Reduce, Reuse, Recycle.

What is the difference between sanitary landfilling and incineration as waste-disposal methods?

Sanitary landfilling is the engineered burial of waste in lined, capped cells with leachate and landfill-gas collection. Incineration is controlled high-temperature combustion that reduces waste volume (up to ~90%) and can recover energy, but requires emission controls for dioxins and ash.

What defines a 'sustainable habitat'?

A human settlement designed to minimize environmental impact: energy-efficient green buildings, renewable energy, efficient public transport, water conservation and recycling, sustainable solid-waste management, green spaces, and compact, climate-resilient urban planning.

What are Bharat Stage emission norms, and what is the current standard in India?

Bharat Stage (BS) norms are India's vehicular-emission standards (based on European Euro norms) limiting pollutants like CO, hydrocarbons, NOx, and particulate matter. India moved directly from BS-IV to BS-VI nationwide on 1 April 2020 (skipping BS-V).

What major emission improvement did BS-VI bring over BS-IV in India?

BS-VI drastically lowered allowed pollutants - notably reducing sulphur in fuel from 50 ppm to 10 ppm, cutting diesel NOx by about 70% and particulate matter by about 80%, and introducing Real Driving Emissions and onboard diagnostics requirements.

What are key environmental epidemiological issues, with examples of pollution-linked diseases?

Study of disease patterns linked to environmental exposures. Examples: fluorosis (excess fluoride in groundwater), arsenicosis (arsenic in groundwater), respiratory illness/asthma from air pollution, lead poisoning, methemoglobinemia ('blue baby' from nitrates), Minamata disease (mercury), and itai-itai (cadmium).

What was the Bhopal Gas Tragedy, and what lesson did it teach for environmental disaster management?

In December 1984, a leak of methyl isocyanate (MIC) gas from the Union Carbide pesticide plant in Bhopal killed thousands - the world's worst industrial disaster. It led to stronger industrial-safety/hazardous-substance regulation in India, including the Environment (Protection) Act, 1986 and the Public Liability Insurance Act, 1991.