Environmental Studies Unit 1/4

Environment

The total external surroundings—living and non-living—that support life and provide natural resources.

Environmental Studies

An applied, multidisciplinary field that examines how humans interact with the environment and seeks practical solutions for sustainability.

Ecosystem

A functional unit of nature where living organisms interact with each other and with the physical environment.

Ecology

The scientific study of organisms and their relationships with one another and their surroundings.

Multidisciplinary Approach

Studying a concept from multiple academic perspectives (e.g., physics, economics, sociology) to gain deeper insight.

Natural Resources

Materials and energy sources provided by nature, essential for human survival and economic activity.

Renewable Resources

Natural resources that can regenerate through natural processes, e.g., forests, solar energy.

Non-renewable Resources

Resources that exist in finite quantities and cannot regenerate on a human time-scale, e.g., coal, petroleum.

Recyclable Resource

A non-renewable resource that can be collected after use and processed for reuse, e.g., aluminium.

Non-recyclable Resource

A resource that cannot be reused or recycled once consumed, e.g., fossil fuels like coal.

Biodegradable Pollutant

Waste that can be broken down naturally by microorganisms, causing minimal long-term harm.

Non-biodegradable Pollutant

Substance that resists natural decomposition and persists in the environment, e.g., plastics.

Atmosphere

The gaseous layer (mainly nitrogen and oxygen) surrounding Earth, protecting life from outer-space hazards.

Hydrosphere

All water bodies on Earth—oceans, rivers, lakes, glaciers—comprising about 97 % saline and 3 % fresh water.

Biosphere

The global sum of all living organisms and their interactions with air, water and land.

Lithosphere

Earth’s solid outer layer, containing rocks, soil and mineral resources above and below the surface.

Sustainability

Meeting present needs without compromising the ability of future generations to meet theirs.

Three Pillars of Sustainability

Interdependent aspects—social, economic and environmental—that must all be satisfied for true sustainability.

Social Aspect (of Sustainability)

Focuses on societal awareness, cultural practices and legislation that encourage conservation of resources.

Economic Aspect (of Sustainability)

Promotes eco-friendly business operations that generate profit while paying the true cost of resource use.

Environmental Aspect (of Sustainability)

Emphasises reuse, recycling and activities that maintain ecological balance.

Sustainable Development

Development that fulfils current human needs while safeguarding environmental resources for the future.

Wind Energy

Electricity or mechanical power generated from moving air using windmills or wind turbines.

Solar Energy

Energy harnessed from sunlight through solar panels for electricity or heat.

Crop Rotation

Sequential planting of different crops on the same land to maintain or improve soil fertility.

Rainwater Harvesting

Collecting and storing precipitation in tanks or reservoirs for later use.

Green Space

Designated areas reserved for vegetation and wildlife to flourish with minimal human interference.

Compressed Natural Gas (CNG)

Cleaner-burning fuel used in vehicles to reduce air pollution compared with petrol or diesel.

Biogas

Methane-rich gas produced from anaerobic decomposition of organic waste, used as a renewable fuel.

Scope of Environmental Studies

Range of topics—resource types, problem solving, eco-technology, R&D—covered to guide decision-making.

Importance of Environmental Studies

Highlights pollution control, resource conservation, ecological balance and informed public decision-making.

Reduce-Reuse-Recycle (3 R’s)

Guiding principle for minimizing waste and conserving resources.

Depletion of Natural Resources

Gradual exhaustion of resources due to overuse, leading to scarcity.

Bio-geochemical Cycle

Natural pathway by which essential elements circulate through the biosphere and abiotic compartments.

Energy Transformation (Ecosystem)

Process where energy flows through food chains and is eventually lost as heat.

Resource Utilisation

Measurement and management of how efficiently natural resources are consumed.

Environmental Protection Act, 1986 (India)

Comprehensive law aimed at safeguarding India’s environment and biodiversity.

Environmental Impact Assessment (EIA)

Procedure to evaluate the potential environmental effects of proposed projects before approval.

Deforestation

Large-scale removal of forests, leading to loss of biodiversity and ecological imbalance.

Water-neutral Methods

Corporate practices (e.g., Coca-Cola India) aimed at balancing water used in operations with water replenished.

Ecology

The study of organisms and their relationships with each other and their physical surroundings.

Ecosystem

A functional unit where living organisms interact with each other and with abiotic factors, linked by energy flow and nutrient cycling.

Abiotic Component

The non-living physical factors of an ecosystem such as temperature, light, water, air, soil, and minerals.

Biotic Component

All living organisms in an ecosystem, including plants, animals, and microorganisms.

Producers (Autotrophs)

Organisms, mainly green plants and algae, that convert solar energy into chemical energy via photosynthesis.

Photoautotroph

A producer that uses light energy to synthesize food, e.g., green plants and cyanobacteria.

Chemoautotroph

An organism (e.g., sulfur-oxidising bacteria) that synthesizes organic compounds using energy released from chemical reactions.

Consumers (Heterotrophs)

Organisms that obtain energy by eating other organisms; include herbivores, carnivores, omnivores, and parasites.

Primary Consumer

A herbivore that feeds directly on producers.

Secondary Consumer

A carnivore that feeds on primary consumers.

Tertiary Consumer

An organism that feeds on primary and secondary consumers; often an apex predator.

Quaternary Consumer

Top carnivore at the highest trophic level, e.g., lion or whale.

Herbivore

An animal that eats plants or plant products.

Carnivore

An animal that feeds exclusively on other animals.

Omnivore

An animal that eats both plant and animal matter.

Detritivore

An organism that feeds on dead organic matter, breaking it into smaller particles.

Decomposer (Saprotroph)

Microorganism such as bacteria or fungi that chemically break down dead matter into inorganic nutrients.

Trophic Level

A step in a food chain representing organisms that share the same function in the food transfer sequence.

Food Chain

A linear sequence showing how energy and nutrients pass from producers to various levels of consumers.

Grazing Food Chain

A food chain that starts with green plants and ends with carnivores.

Detritus Food Chain

A food chain that begins with dead organic matter consumed by detritivores and decomposers.

Food Web

A network of interlinked food chains showing multiple energy pathways within an ecosystem.

Energy Flow

The unidirectional movement of energy through trophic levels, governed by thermodynamic laws.

Energy Pyramid (Food Pyramid)

A graphical representation of energy quantity at each trophic level, widest at producer level and narrowing upward.

First Law of Thermodynamics

Energy cannot be created or destroyed; it only changes form.

Second Law of Thermodynamics

In any energy transfer, entropy increases; energy conversions are never 100 % efficient.

Potential Energy

Stored energy possessed by an object at rest.

Kinetic Energy

Energy of motion.

Nitrogen Cycle

The cyclic movement of nitrogen through atmosphere, soil, organisms, and back, involving fixation, uptake, and decomposition.

Carbon Cycle

The circulation of carbon among the atmosphere, biosphere, oceans, and geosphere via processes like photosynthesis and respiration.

Water Cycle

The continuous movement of water through evaporation, condensation, precipitation, and runoff.

Oxygen Cycle

The movement of oxygen between living organisms and the atmosphere, largely driven by photosynthesis and respiration.

Energy Cycle

Transfer of solar energy into biological forms by producers and its movement through food chains, ending as heat loss.

Ecological Succession

The gradual, orderly replacement of one community by another until a stable climax community is reached.

Hydrosere

A succession sequence that starts in a freshwater body and progresses toward a climax terrestrial forest.

Xerosere

Succession beginning on dry, barren substrates with minimal moisture, leading eventually to forest vegetation.

Sere

Any one of the sequential plant communities in a successional series.

Phytoplankton Stage

The pioneer stage of hydrosere where microscopic photosynthetic organisms first colonize the water body.

Rooted Submerged Stage

The hydrosere phase where rooted underwater plants establish as sediment builds up.

Reed-Swamp Stage

A hydrosere stage dominated by tall, amphibious plants with roots in water and shoots in air.

Crustose-Lichen Stage

Initial xerosere stage where crust-forming lichens weather bare rock surfaces.

Moss Stage

Xerosere stage where mosses colonize thin soil formed by lichens, aiding further soil development.

Climax Community

A stable, mature ecological community that undergoes little succession unless disturbed.

Law of 10 %

Ecological rule stating that roughly 10 % of energy at one trophic level is transferred to the next level.

Sustainable Development

Development that meets present needs without compromising the ability of future generations to meet theirs.

Anthropogenic

Resulting from or produced by human activities.

Biogeochemical Cycle

Natural pathway by which essential elements circulate between living organisms and the physical environment.

Renewable Natural Resource

A resource that can be used repeatedly because it is naturally replenished faster than it is depleted.

Perpetual Resource

A subset of renewable resources (e.g., sunlight, wind) whose quantity is not affected by human consumption.

Biotic Resource

Living natural resource derived from the biosphere such as plants, animals, and marine organisms.

Abiotic Resource

Non-living natural resource such as land, air, water, and mineral ores.

Natural Capital

Another term for natural resources viewed as a form of economic equity.

Photovoltaic Cell

A semiconductor device that converts solar radiation directly into electricity.

Hydropower

Electricity generated by converting the mechanical energy of flowing or falling water into electrical energy.

Wind Energy

Power obtained by converting the kinetic energy of moving air into electricity via wind turbines.

Biomass Energy

Energy produced from organic material originating from plants, animals, or waste.

Geothermal Energy

Heat energy generated and stored in Earth’s interior, tapped for electricity or direct heating.

Tidal Energy

Renewable power obtained from the movement of ocean tides, often via underwater turbines.

Land Resource

All features and processes of land—including soil, water, plants, and human structures—used to satisfy human needs.

Land Degradation

Reduction or loss of land’s biological or economic productivity due to natural processes or human activities.