Notes Natural Resources - Science & Pedagogy Paper 2 for CTET & TET Exams - CTET

Introduction

Natural resources are materials and components that are obtained from the environment and are useful to humans and other living organisms. These resources are essential for survival, economic development and cultural practices. Human activities have increased the rate of use and depletion of many natural resources, while waste generation and pollution have created additional pressures on the Earth's systems.

Natural resources are broadly classified into two main categories:

• Abiotic resources - non-living physical and chemical components of the environment.
• Biotic resources - living components such as plants, animals and microorganisms.

Abiotic Resources

Abiotic resources are the physical or chemical non-living resources of our nature. For example land, water, Energy, Metals and Petroleum and Natural gas.

• Water: Water occurs as oceans, seas, rivers, lakes, ponds and groundwater. Only about 3% of Earth’s water is freshwater, much of which is locked in glaciers and ice caps. The primary source of water on land is precipitation (rainfall). Water is vital for drinking, agriculture, industry, sanitation and many ecological processes. The hydrological cycle (evaporation → condensation → precipitation → runoff/infiltration) continually renews water, though local availability varies and may be affected by pollution and overuse. Conservation measures include rainwater harvesting, efficient irrigation (drip irrigation), reduction of industrial discharge, and protecting watersheds.
• Energy: The prime external source of energy for Earth is solar radiation. Energy resources include fossil fuels (coal, petroleum, natural gas), nuclear fuels (uranium), and renewable sources such as solar, wind, hydro (water), tidal and bioenergy (biogas). Fossil fuels are concentrated stores of ancient biological material converted to coal, oil and gas over geological time under heat and pressure; they are non‐renewable on human timescales. Renewable sources are replenished naturally and are essential for sustainable energy planning.
• Petroleum and natural gas: These are fossil fuels formed from the remains of ancient marine organisms and organic matter that were buried and transformed by geological processes. They are extracted from underground reservoirs and refined into fuels and chemical feedstocks. Petroleum products power transport (petrol, diesel, aviation turbine fuel), heat, and are the raw materials for plastics, fertilisers and many industrial chemicals. Overuse and spills can cause serious environmental contamination.
• Metal ores and minerals: Metal ores are naturally occurring rocks or sediments that contain economically recoverable concentrations of metals such as aluminium, iron, copper, lead, zinc and manganese. These ores are mined, processed and refined to obtain metals for construction, vehicles, machinery, electrical wiring and electronic devices. Mining and mineral extraction can cause land degradation, habitat loss and pollution unless managed sustainably. Recycling of metals reduces pressure on ore deposits and energy consumption.
• Land and soil: Land covers roughly 29% of the Earth's surface and includes mountains, plains, deserts, forests, swamps and grasslands. Soil is the upper layer of the land essential for plant growth; it forms by weathering of rocks and the action of organisms. Soil provides nutrients and water-holding capacity for crops. Soil is a renewable resource but forms very slowly, making its conservation essential. Threats to land and soil include erosion, desertification, salinisation, compaction and pollution. Conservation practices include contour farming, terracing, afforestation, crop rotation and maintaining ground cover.

Biotic Resources

Biotic resources are the living components of the environment that provide food, fibre, medicines and many other materials. These resources are renewable but can be depleted by overexploitation, habitat destruction and pollution.

• Plants: Plants supply many of the foods humans consume - cereals (wheat, rice, maize), pulses (lentils, peas), vegetables, fruits, sugar and oil seeds. Fibre-yielding plants such as cotton, jute and flax provide raw material for textiles. Other important plant products include timber, rubber, resins and medicinal plants. Conservation of plant genetic resources (seed banks, in situ and ex situ conservation) is important for food security and maintaining biodiversity.
• Animals: Animals are sources of food (meat, fish, eggs, milk), clothing materials (wool, leather), transport and agricultural labour (bullocks, camels, horses) and by-products (honey, silk). Domestic animals such as cattle, goats, sheep and poultry are reared for multiple uses. Overfishing, habitat loss and unregulated hunting can reduce animal populations and affect ecosystems.
• Microorganisms: Microbes (bacteria, fungi, protozoa, and algae) perform essential roles: decomposing dead organic matter, recycling nutrients, aiding digestion in animals, producing fermented foods and beverages, and manufacturing antibiotics and industrial enzymes. Microorganisms are used in sewage treatment, composting and biotechnology. Many microbes are beneficial, but some cause disease; microbiological knowledge is important for public health and environmental management.

Classification by Renewability and Origin

• Renewable resources: Resources that can be replenished naturally within a short time (e.g., solar energy, wind, biomass, groundwater with sustainable use, many biotic resources if managed properly).
• Non‐renewable resources: Resources that form over geological timescales and cannot be replaced within human lifetimes (e.g., coal, petroleum, natural gas, many mineral ores).
• Inexhaustible resources: Resources are available in unlimited quantities at human scales (e.g., sunlight, tidal energy, planetary-scale winds).

Human Impact and Conservation

Human activities - agriculture, industry, urbanisation, mining and transport - affect the availability and quality of natural resources. Key issues include pollution, deforestation, overexploitation, soil erosion and loss of biodiversity. Sustainable management aims to use resources to meet present needs without compromising the ability of future generations to meet theirs.

• Conservation practices: afforestation and reforestation, watershed management, soil conservation (contour ploughing, terracing), crop rotation and mixed cropping, protected areas and wildlife sanctuaries, sustainable fishing limits and habitat restoration.
• Resource efficiency: Use of renewable energy sources (solar panels, wind turbines), energy-efficient appliances, reduced consumption, recycling and reuse of materials, waste minimisation and treatment.
• Policy and community actions: Laws regulating pollution and mining, community participation in resource management, education about conservation and sustainable livelihoods for communities dependent on natural resources.

Examples and Applications

• Agriculture: Depends on soil, water, sunlight and plant genetic resources; sustainable irrigation and soil fertility management increase productivity while conserving resources.
• Industry: Requires mineral ores, water and energy; recycling metals and water treatment reduce environmental impacts and resource demand.
• Energy sector: Transitioning from fossil fuels to solar, wind, hydro and bioenergy reduces greenhouse gas emissions and conserves non‐renewable fuels.
• Healthcare and biotechnology: Use of microorganisms for antibiotics, vaccines and fermentation processes; medicinal plants for traditional and modern medicines.

Summary

Natural resources include abiotic and biotic components that sustain life and human activities. Understanding their origin, classification, uses and limitations is essential for prudent management. Conservation, efficient use, adoption of renewable alternatives and community engagement are central to ensuring these resources remain available and healthy for future generations.