Our Environment — 50 Q&A

The environment includes all living (biotic) and non-living (abiotic) factors interacting together — such as plants, animals, soil, water, air, temperature and sunlight.

An ecosystem consists of organisms (producers, consumers, decomposers) interacting with each other and with physical environment (soil, water, atmosphere), exchanging energy and cycling nutrients.

Producers (autotrophs): plants that make food by photosynthesis. Consumers: herbivores, carnivores and omnivores that eat others. Decomposers: bacteria and fungi that break down dead matter returning nutrients to soil.

A food chain shows a linear sequence of who eats whom (e.g., grass → grasshopper → frog → snake). Food webs connect multiple chains showing complex feeding relationships in an ecosystem.

Energy flows from producers to consumers; at each trophic level most energy is lost as heat and only a small fraction (~10%) is passed to the next level. This leads to pyramid-shaped energy distributions.

Balance is maintained by interactions among species and physical factors. Disruptions include habitat loss, pollution, over-exploitation, introduction of invasive species and climate change leading to loss of species and ecosystem services.

Biodiversity refers to variety at genetic, species and ecosystem levels. It provides ecosystem services: food, medicines, clean water, pollination and resilience to environmental change.

Habitat loss from deforestation, urbanisation, agriculture and infrastructure leads to species decline, reduced genetic diversity and ecosystem instability. Fragmentation isolates populations and increases extinction risk.

Invasive species are non-native organisms that outcompete locals, altering ecosystems. Example: water hyacinth rapidly covers water bodies blocking sunlight and oxygen, harming aquatic life. Control includes mechanical removal and biological agents.

Air pollution comes from vehicle exhaust, industry, burning fossil fuels and biomass. Major pollutants include SO₂, NOₓ, particulates and ozone at ground level. Effects: respiratory problems, smog, acid rain and climate impacts.

Sources: domestic sewage, industrial effluent, agricultural runoff (fertilisers, pesticides), and oil spills. Effects: eutrophication, loss of aquatic biodiversity, unsafe drinking water and health hazards.

Soil erosion is caused by water runoff, wind, deforestation and poor farming. Control: afforestation, terracing, contour ploughing, maintaining vegetation cover and sustainable agriculture to preserve topsoil.

Types: municipal, industrial, biomedical and e-waste. Disposal methods: reduce, reuse, recycle, composting organic waste; safe landfills, controlled incineration and specialised handling for hazardous and biomedical waste.

Biodegradation is breakdown of organic matter by microbes and decomposers. Composting converts kitchen and garden waste into nutrient-rich manure, reducing waste and returning nutrients to soil.

The ozone layer in the stratosphere absorbs harmful UV radiation protecting life. Depletion by CFCs and halons increases UV reaching Earth causing skin cancer, cataracts and ecological effects.

Greenhouse gases (CO₂, CH₄, N₂O) trap outgoing infrared radiation, warming the planet — known as the greenhouse effect. Increased concentrations lead to global warming and climate change.

Global warming is long-term rise in Earth's average temperature due to increased greenhouse gases. Impacts: melting ice, sea-level rise, altered rainfall patterns, heatwaves, and threats to biodiversity and agriculture.

Acid rain forms when SO₂ and NOₓ react with water in atmosphere forming sulfuric and nitric acids. It harms crops, forests, aquatic life and corrodes buildings and monuments.

Sustainable development meets present needs without compromising future generations' ability to meet theirs — by balancing economic growth, social inclusion and environmental protection.

Methods: protected areas (national parks, wildlife sanctuaries), in-situ and ex-situ conservation (botanical gardens, gene banks), captive breeding, habitat restoration and community-led conservation.

Montreal Protocol phased out many ozone-depleting substances like CFCs; replacement and regulation of such chemicals has led to gradual recovery of the ozone layer.

Rainwater harvesting captures and stores rainwater from roofs or land for reuse or to recharge groundwater. It reduces pressure on freshwater sources and helps mitigate water scarcity.

Afforestation is planting forests on lands that previously had little or no tree cover. It helps control soil erosion, enhances biodiversity, acts as carbon sink and improves local climate and water cycles.

Environmental degradation arises from over-exploitation of resources, pollution, deforestation, habitat destruction, population pressures and unsustainable agricultural/industrial practices.

Practices include crop rotation, organic farming, integrated pest management, conservation tillage, and efficient irrigation — all to maintain soil fertility, reduce chemical use and conserve water.

Mangroves protect shorelines from erosion and storm surges, provide nursery habitats for fish and crustaceans, sequester carbon and support coastal biodiversity — making them vital for coastal resilience.

Coral reefs harbour high marine biodiversity, support fisheries and tourism. Threats: warming-induced bleaching, ocean acidification, pollution, overfishing and destructive fishing methods.

E-waste includes discarded electronics containing hazardous materials (lead, mercury). Proper recycling recovers valuable materials and prevents toxic pollution of soil and water.

Awareness through schools, campaigns and media encourages sustainable behaviour: waste segregation, tree planting, water conservation and responsible consumption — all vital for environmental protection.

Governments set regulations, protected areas, pollution standards and incentives for clean technologies. Effective enforcement and public investment are required to ensure compliance and support conservation.

NGOs and communities run awareness programs, restore habitats, monitor biodiversity, promote sustainable livelihoods and hold authorities accountable — bridging policy and local action.

Wetlands filter pollutants, store floodwaters, support high biodiversity and provide fisheries. Threats include pollution, drainage for agriculture and urbanisation — protection maintains their ecosystem services.

Sustainable transport emphasises public transit, walking, cycling and electric vehicles to reduce emissions, congestion and pollution while improving accessibility.

Recycling conserves raw materials, reduces energy use (often less energy than producing from virgin materials), lowers landfill pressure and reduces pollution. Commonly recycled items: paper, glass, metals and some plastics.

Good urban planning includes green spaces, sustainable drainage, public transport, waste management and building energy standards. It reduces heat islands, improves air quality and enhances residents' wellbeing.

EIA evaluates potential environmental effects of proposed projects (dams, industries) before approval. It recommends mitigation, monitoring and alternatives to minimise environmental harm.

Sustainable management balances use and renewal of resources (forests, water, fisheries) using practices like rotational grazing, catch limits, watershed protection and community stewardship.

Carrying capacity is the maximum population size of a species that an environment can sustain indefinitely without degradation, determined by available resources and ecosystem health.

Biogeochemical cycles (carbon, nitrogen, water, phosphorus) describe movement of elements through living and non-living systems, recycling nutrients essential for life and maintaining ecosystem function.

Pollinators (bees, butterflies, birds) enable reproduction of many crops and wild plants. Threats include pesticides, habitat loss, diseases and climate change, endangering food security and biodiversity.

Community-based conservation involves local people in managing resources (e.g., sacred groves, joint forest management). It aligns livelihoods with conservation, improving outcomes and local stewardship.

Green belts are vegetated zones around urban areas that reduce air and noise pollution, provide recreation, act as wildlife corridors and limit urban sprawl — improving urban environmental quality.

Environmental ethics considers moral responsibilities towards nature and future generations. It stresses conservation, sustainable use and fairness in sharing environmental benefits and burdens.

Monitoring (air, water, soil, biodiversity) tracks environmental health, detects pollution early, evaluates policy effectiveness and guides management and remediation efforts.

Mitigation reduces greenhouse gas emissions (renewables, efficiency). Adaptation prepares communities for impacts (flood defences, drought-resistant crops). Both are needed to manage climate risk.

Sustainable tourism minimizes environmental impact, protects natural and cultural heritage, supports local economies and involves communities in planning to ensure long-term benefits.

Examples: solar PV, LED lighting, efficient motors, electric vehicles, wastewater treatment & reuse, waste-to-energy systems and sustainable building materials — technologies that reduce environmental impact.

Ocean acidification occurs when CO₂ dissolves in seawater forming carbonic acid, lowering pH and impacting organisms that form calcium carbonate shells (e.g., molluscs, corals), threatening marine food webs.

Environmental stewardship means acting responsibly to protect nature: reduce waste, conserve water and energy, plant trees, support local conservation initiatives and make sustainable consumer choices.

• Remember ecosystem structure (producers, consumers, decomposers) and energy flow.
• Understand threats: pollution, habitat loss, invasive species, climate change.
• Know conservation measures: protected areas, sustainable practices, waste management, community action.