Environment

4.1 Definition of Environment 20732070

Environment: The surroundings of all living and non-living things constitute an environment. It is defined as "the surroundings in which an organization operates including air, water, land and natural resources, flora, fauna, humans and their inter-relations" (ISO Definition). The word is derived from the French word "environ" meaning "encompass" or "encircle." It was introduced by German biologist Jacob Von Uexkull in the early 1900s.

Ecosystem: An ecosystem is a grouping of organisms that interact with each other and their environment in such a way as to preserve the grouping. It includes both biotic (living) and abiotic (non-living) components functioning together as a unit.

Components of Environment:

1. Hydrosphere — Water
2. Atmosphere — Air
3. Lithosphere — Land
4. Biosphere — Flora, Fauna, Microbes
5. Anthrosphere — Man-made things

Components can also be classified as:

• Biotic Components (living): Producers (autotrophs — plants), Consumers (heterotrophs — animals), Decomposers (detritivores — fungi, bacteria)
• Abiotic Components (non-living): Climatic (temperature, light, moisture, air currents) and Edaphic (soil-related factors)

4.2 Importance, Ecology & Ecosystem 20742072207120702069

4.2.1 Ecology and Ecosystem 20712069

Ecology: Ecology is the branch of biology concerned with the relations between organisms and their environment. It is the scientific study of interactions between different organisms and between organisms and their surroundings.

Ecosystem: An ecosystem is a grouping of organisms that interact with each other and their environment in such a way as to preserve the grouping. It operates through three major principles: nutrient cycling, energy flow, and structure.

Characteristics of Ecosystem:

• Structure: Comprises biotic components (producers, consumers, decomposers) and abiotic components (sunlight, water, soil, temperature, minerals).
• Energy Flow: Energy flows unidirectionally from the sun through producers to consumers — following the food chain and food web.
• Nutrient Cycling: Nutrients (C, N, P, S) cycle repeatedly between living organisms and the physical environment through biogeochemical cycles.
• Dynamic Nature: Ecosystems are not static — they undergo constant change through ecological succession and seasonal variations.
• Self-Regulating: Ecosystems maintain homeostasis through feedback mechanisms (e.g., predator-prey balance).
• Interdependence: All components are interconnected — a change in one component affects the entire system (holocoenotic nature).

4.2.2 Population Disturbance to Ecosystem 2070

• Excessive use of fossil fuels leading to greenhouse gas emissions and global warming
• Deforestation for agricultural land and settlements — destroying carbon sinks and habitats
• Overfishing and overgrazing depleting natural resources
• Industrial waste contaminating water, air, and soil
• Loss of biodiversity — extinction of species due to habitat destruction
• Excessive use of agrochemicals (fertilizers, pesticides) damaging soil and water

4.2.3 Minimizing the Disturbance 2070

• Conservation of natural resources through sustainable management
• Use of renewable energy sources (solar, hydro, wind, geothermal)
• Awareness programs about environmental conservation
• Enacting and enforcing environmental protection policies
• Reducing, reusing, and recycling (3 R's)
• Forestation and protection of biodiversity

4.2.4 Human Interventions in the Ecosystem 20742072

Human interventions in the ecosystem are driven by the following primary reasons:

1. Population Growth: Increasing population demands more food, shelter, and resources, leading to exploitation of natural ecosystems — deforestation, overfishing, and land conversion for agriculture.
2. Economic Development: Industrialization, urbanization, and infrastructure development require clearing of forests, mining of minerals, and damming of rivers, all of which disrupt ecosystems.
3. Energy Needs: Dependence on fossil fuels (coal, petroleum, natural gas) for energy leads to resource depletion, air pollution, and greenhouse gas emissions causing global warming.
4. Agricultural Expansion: Intensive agriculture uses chemical fertilizers, pesticides, and insecticides that degrade soil quality and contaminate water bodies, disrupting nutrient cycling.
5. Resource Extraction: Mining of minerals and fossil fuels, logging, and sand extraction cause habitat destruction, soil erosion, and water pollution.
6. Urbanization: Expansion of cities leads to land degradation, displacement of flora and fauna, increased waste generation, and air/water pollution.
7. Technological Advancement: While technology improves living standards, industrial emissions, electronic waste, and chemical pollutants disrupt natural processes.
8. Consumption Patterns: Unsustainable consumption and waste generation — particularly plastics — create pollution that harms marine and terrestrial ecosystems.

Impact on Ecosystem: These interventions disrupt nutrient cycling, energy flow, and structural relationships within ecosystems, leading to pollution, global warming, biodiversity loss, ocean acidification, ozone depletion, and climate change.

4.2.5 Conversion of Natural Resources into Wealth 2072

1. Agriculture: Soil, water, and sunlight used to grow crops and raise livestock — the backbone of national economies, especially in developing countries like Nepal.
2. Energy Generation: Fossil fuels (coal, petroleum, natural gas) and renewable sources (hydropower, solar, wind) converted into electricity and fuel for industrial production and transportation.
3. Mining & Extraction: Minerals, metals, and building materials (sand, stone) extracted and processed into construction materials, machinery, and consumer products.
4. Forestry: Timber used for construction, furniture, and paper. Non-timber forest products (medicinal plants, herbs) collected and traded.
5. Water Resources: Used for irrigation, hydropower generation, fisheries, and domestic/industrial consumption.
6. Tourism: Natural landscapes, national parks, and biodiversity attract tourism revenue.

Key principle: Natural resources are the backbone of national economy. However, the current depletion rate risks the needs of future generations. The goal should be optimum utilization — satisfying human needs at minimum cost on a sustainable basis.

4.3 Conservation of Environment

Definition: Conservation is an ethic of resource use, allocation, and protection. Its primary focus is upon maintaining the health of the natural world: its fisheries, habitats, and biological diversity. Secondary focus includes materials conservation and energy conservation. Environment conservation is the wise management and utilization of natural resources in a sustainable manner to ensure the maintenance of biodiversity.

Types of Environmental Conservation:

1. Energy Conservation: Efforts to reduce energy consumption and preserve it for future generations. Achieved through increased efficient energy use, decreased consumption, and use of alternative energy sources (renewable resources).
2. Water Conservation: Reducing the usage of water and recycling wastewater for different purposes (cleaning, manufacturing, agriculture). Goals include sustainability (ensuring availability for future generations) and energy conservation (reducing energy for water pumping and treatment).
3. Soil Conservation: Management strategies for prevention of soil erosion from the earth's surface or becoming chemically altered by overuse, acidification, salinization, or other chemical contamination.
4. Plant Conservation: Study of plant decline and its causes, and techniques to conserve rare and endangered plants. Subfields include: forest conservation, wild plant conservation, invasive species study and control, medicinal plant conservation.

Why Conservation?

• Limited resources available on earth
• Resources are expensive
• Demand is continuously increasing
• Countries face power shortages
• Non-renewable resources may be exhausted — need to switch to alternative energy
• For healthy environment and survival of living beings

How to Conserve:

• Cleaner Transport: Use environment-friendly transportation; walk/cycle for short distances; check vehicles regularly.
• Energy-Saving Features: Install energy-saving lamps; choose energy-efficient appliances; use biodegradable cleaning products.
• Energy-Saving Habits: Turn off unused electrical appliances; use both sides of paper.
• Water Conservation: Turn off taps while brushing/shaving; shorten showering; run full loads in washing machines; fix dripping taps.
• Minimize Environmental Footprint: Reduce ecological, carbon, and water footprints.
• The 3 R's: Reduce, Reuse, Recycle.
• Other: Throw trash in bins; plant trees; use green power; close doors while using A/C; awareness programs; enact environmental policies.

4.4 Optimum Utilization of Natural Resources 20812079

Concept: Natural resources are the backbone of national economy. The current depletion rate of natural resources risks the needs of future generations. Optimum utilization means the allocation of natural resources so as to make the best use of the environment in satisfying human needs at minimum cost, on a sustainable basis.

4.4.1 Objectives of Optimum Utilization 20812079

1. Conservation, development, and sustainable management of natural resources and their utilization techniques.
2. Restoration of ecological balance in degraded and fragile ecosystems by trees and grasses.
3. Creation of sustained employment opportunities for rural communities.
4. Reduction in the global use of non-renewable resources by developing different alternatives.
5. Pollution control through policy formulation and implementation.

4.4.2 Types of Resources 2079

• Perpetual resources: Virtually inexhaustible for human consumption (e.g., solar energy, wind).
• Renewable resources: Available over a period of time; can be produced by human involvement (e.g., forests, fisheries).
• Non-renewable resources: Present in fixed amounts; get exhausted after certain time. Some can be recycled or reused. More focus must be given to proper use of renewable and non-renewable resources.

4.4.3 Examples of Optimum Utilization 2081

• Community Forestry (Nepal): Local communities manage forest resources sustainably — harvesting timber and firewood within regeneration capacity, recovering forest cover from 29% (1994) to 40.36% (2015).
• Micro-Hydro Power: Utilizing river flow for small-scale electricity generation without depleting water resources — over 3,000 micro-hydro plants serve rural Nepal.
• Solar Energy Adoption: Replacing diesel generators with solar panels in off-grid areas — reduces fossil fuel dependence while meeting energy needs.
• Sustainable Agriculture: Crop rotation, organic farming, and integrated pest management optimize soil and water use while maintaining long-term fertility.
• Rainwater Harvesting: Collecting and storing monsoon rainfall for dry-season use — optimizes available water without depleting groundwater.

Note: For the concept of “Conflict of Resources” (also asked in the 2081 exam question), see Section 4.6.

4.5 Renewable and Non-Renewable Resources 20792071

Renewable Resources: A natural resource that is not depleted upon consumption or can be reproduced in a short period of time. Examples:

1. Bio-fuel: Fuel made from living things (plants, algae). Plants like corn and switch grass are used to produce bio-ethanol. Bio-diesel is made from vegetable oils and animal fat. Burns cleaner and pollutes less.
2. Geothermal Energy: Uses temperature of the ground to generate power or heat/cool buildings. Water pumped through pipes absorbs ground heat (~55°F). Large plants extract hot water and convert it to steam for electricity.
3. Solar Energy: Photoelectric (PV) panels absorb sunlight, exciting electrons to create electric flow. Can be stored in batteries. Becoming more affordable.
4. Hydro Energy: Flow of water spins turbines connected to generators. Typically requires a dam to create pressure. Water is directed through a pen-stock.

Non-Renewable Resources: Natural resources that exist in finite quantities and cannot be reproduced at a scale comparable to consumption. Higher risk of exhaustion. Less environmentally friendly.

1. Coal: Rock primarily of carbon; formed by compressing plant matter over thousands of years. Leading fuel source but produces about double the pollution of natural gas.
2. Petroleum Oil: Refined into gasoline and jet fuel. Used for heating, asphalt, and plastics. World consumes ~90 million barrels per day.
3. Natural Gas: Found deep underground in rocky areas or where organic matter has been buried. Used for cooking, heating, and power generation. Takes thousands of years to form.

4.6 Conflict of Resources 20812078

Conflict of Resources is the situation where the allocation, management, or use of natural resources results in violence, human rights abuses, or denial of access to resources that significantly diminishes human welfare.

Key Facts:

• Natural resources are the centre of development for any country and a reason for conflicts among and within countries.
• About 40% of conflicts among countries are due to conflict over ownership of resources.

4.6.1 Causes of Resource Conflicts 2078

1. Rapid population growth resulting in environmental degradation and resource scarcity
2. Social inequality resulting in skewed access to natural resources and services
3. Failure of governing bodies to address the issue
4. Unsustainable consumption
5. Economic globalization

Examples:

• Minerals: Diamonds in western Africa, amber in Russia, gold in Indonesia. Africa has been plagued by diamond-related conflicts. All minerals generate revenue and power for governments or rebel groups.
• In Nepal: Conflicts over land, water, and forests are dominant:
  • Land conflicts: Boundary/demarcation disputes, change in ownership rights, tenant eviction, development on particular sites, obstruction of paths.
  • Forest conflicts: Ownership disputes, identification of users, access to forest products, illegal collection, hunting and poaching of wild animals, collection of medicinal plants by commercial traders.
  • Water conflicts: Source disputes, sharing of drinking water and irrigation water, compensation for damage from water-related projects.

4.7 Global Environmental Issues 20792077

4.7.1 Regional and Global Environmental Issues 20792077

Regional Environmental Issues: Environmental problems that affect a specific region or area. Examples: air/water pollution in Kathmandu Valley, deforestation in Terai, illegal sand mining in Nepal.

Global Environmental Issues: Environmental problems that affect the entire planet. Major issues include:

• Pollution (air, water, soil)
• Global Warming
• Overpopulation
• Natural Resource Depletion
• Climate Change
• Loss of Biodiversity
• Ocean Acidification
• Genetic Engineering

4.7.2 Factors Contributing to Global Warming 2079

1. Greenhouse Gas Emissions: CO2, methane, N2O from burning fossil fuels, industrial processes, and agriculture.
2. Deforestation: Reduces carbon sinks; trees that absorb CO2 are destroyed.
3. Industrial Activity: Factories emit large quantities of GHGs and pollutants.
4. Transportation: Vehicles burning petroleum contribute significantly to CO2 emissions.
5. Agriculture: Methane from livestock, fertilizer use producing N2O.

Effects: Rise in ocean and land temperature, melting of polar ice, uneven precipitation patterns, sea-level rise.

Major global environmental issues and their driving forces:

Remedies: Carbon sinks, use of renewable resources, conservation of biodiversity, human awareness, cleaner technology.

4.8 Environmental Issues of Nepal 20802074207220702069

4.8.1 Major Environmental Issues 2074207220702069

Nepal faces several major environmental issues:

1. Climate Change & Global Warming: Melting of snow and glaciers, rise in sea level, change in seasonal and rainfall patterns, affects agricultural production, heavy rainfall and drought.
2. Air & Water Pollution: Untreated sewage, industrial waste, and agrochemicals polluting water bodies. Biological contamination of water in rural areas. Arsenic, high iron, manganese, coliform bacteria in Terai. Vehicular and industrial emissions in city areas.
3. Deforestation & Land Degradation: Overgrazing and land fragmentation. Improper use of agrochemicals and fertilizers. Flood and soil erosion. Habitat degradation. Agro-biodiversity under threat.
4. Illegal Mining: Sand and stone mining causing soil instability, land caving, lowered river levels, soil erosion, degradation of productive land, and lowering water table.
5. Poaching: Illegal hunting/capturing of wild animals. Ecosystem heavily affected. Extinction of endangered animals and plants.
6. Water-borne Diseases: Cholera, diarrhea, typhoid, dysentery, jaundice. Diarrheal deaths reached 7,882 (4.83% of total deaths in Nepal per WHO 2017 data).

4.8.2 Environmental Issues of Kathmandu Valley 2080

• Air pollution (vehicular and industrial emissions)
• Water pollution (untreated sewage, industrial waste in Bagmati and other rivers)
• Haphazard urbanization
• Solid waste management crisis

Pressing Factors:

1. Vehicular Emissions: Rapid increase in vehicles; old and poorly maintained vehicles emitting excessive pollutants; traffic congestion increasing idling emissions.
2. Industrial Emissions: Brick kilns and industries operating with minimal pollution controls.
3. Untreated Sewage: Sewage directly discharged into Bagmati and other rivers without treatment, causing severe water contamination.
4. Haphazard Urbanization: Unplanned growth leading to loss of green areas, increased waste, drainage problems, and land degradation.
5. Population Pressure: Migration from rural areas increasing demand on limited resources and infrastructure.

4.8.3 Causes and Mitigation Measures 2074

1. Environment Impact Assessment (EIA) for all projects
2. Financing sustainable development
3. Formation and implementation of sustainable development policies
4. Protecting and conserving biodiversity
5. Changing human behavior through awareness
6. Environment monitoring systems
7. Proper disposal of chemical toxins
8. Alternative energy sources
9. Emission rate standards for industries
10. Clean development mechanism principle
11. Women empowerment for sustainable development
12. Low carbon economic development strategy

4.8.4 Causes of Acid Rain 2072

Acid rain is caused when sulphur dioxide (SO2) and nitrogen oxides (NO2) are emitted into the atmosphere and mix with water molecules to form sulphuric acid and nitric acid. Sources include:

• Burning of fossil fuels: Coal and petroleum combustion in power plants and factories releases SO2 and NO2.
• Vehicular emissions: Internal combustion engines release nitrogen oxides.
• Industrial processes: Metal smelting, oil refining, and chemical manufacturing.
• Natural sources: Volcanic eruptions and lightning (minor contribution).

Effects of Acid Rain:

• Serious effects on human health, wildlife, and aquatic species
• Causes slow growth, injury, or death of forests
• Washes away soil nutrients and releases aluminium, making water absorption difficult for plants
• Damages buildings, monuments, and infrastructure

Quick-Revision Summary

Chapter 4 — Environment & Ecology — 21 past exam questions

Key Points to Remember

1. Environment = totality of external conditions affecting life (physical + chemical + biological)
2. Ecosystem: nutrient cycling + energy flow + structure; self-regulating, dynamic
3. Optimum utilization: use resources at minimum cost on a sustainable basis
4. Renewable (forests, fisheries) vs Non-renewable (coal, oil, gas, minerals)
5. Nepal: forest cover 29% (1994) → 40.36% (2015); community forestry success
6. Acid rain: SO₂ + NOₓ → H₂SO₄ + HNO₃; pH < 5.0; damages aquatic life, forests, buildings