SSC CGL
Ecology and Environment
Ecology and Environment is an important topic in SSC CGL General Awareness section. Questions cover ecosystems, biodiversity, national parks, pollution, global warming, ozone layer, and environmental laws. 2 to 5 questions appear every year. This chapter covers all key facts in a clear, exam-focused format.
1. Ecosystem
1.1 What is Ecology?
Ecology is a branch of life science that studies the mutual relationships of living communities with their environment. Every animal or plant lives in a definite environment. The word Ecology was first used by Ernst Haeckel. Ecologist Henry Chandler Cowles is famous for studying plant life in Indiana Dunes in 1896.
1.2 Ecosystem Components
Components of any ecosystem are divided into two groups:
Abiotic Components (non-living): Light, rainfall, temperature, humidity and water, latitude, altitude, terrain variations. All non-living substances in an ecosystem are called Abiotic components.
Biotic Components (living): Plants, animals (humans, animals, parasites, microorganisms), Decomposers.
Plant is NOT an Abiotic component - it is a Biotic component.
1.3 Standing Crop
Standing crop at a particular trophic level is measured as Biomass. At a specific time, the quantity of living matter at each trophic level is called Standing Crop or Standing Harvest.
1.4 Aerobic and Anaerobic
Aerobic refers to an environment where Oxygen is easily available. Anaerobic refers to an environment where Oxygen is not easily available.
1.5 Study of Relationships
The study of relationships of animals and plants with their surrounding environment is called Ecology (Paristhitik Vigyan). Ecology is a branch of life science.
1.6 Ecological Relationships
Commensalism (Sahbhojita): Relationship between two organisms of different species where one benefits and the other is unaffected. The second species is always unaffected.
Parasitism (Parjeevitta): Relationship where one organism benefits and the other is harmed.
Mutualism (Sahjeevita): Both organisms benefit from each other.
Brood Parasitism: A reproductive strategy where parasites take advantage of care by other individuals of the same or different species to raise their young.
2. Environmental Protection
2.1 Indian Gaur
Indian Bison or Gaur (Bos gaurus) is the largest species of wild cattle found in India. Found mainly in Nagarhole National Park and Hills in India. Originally found in South and Southeast Asia.
2.2 Rio Summit
Rio Summit (Earth Summit) was held in Rio de Janeiro, Brazil from 3-14 June 1992. Also known as Earth Summit or Rio Summit. 116 nations' heads of state participated. Three binding agreements were made: (1) Convention on Biodiversity, (2) Framework Convention on Climate Change, (3) United Nations Convention to deal with Desertification.
2.3 Environmental Award
Golden Panda Award is the world's highest Environmental Conservation Award. Also known as the Green Oscar.
2.4 Red Data Book
Red Data Book (IUCN Red List) provides information about threatened plants and animals. IUCN (International Union for Conservation of Nature) is the highest organization monitoring conservation status of various species worldwide. IUCN headquarters is at Gland near Geneva, Switzerland. Red Data List was started in 1964. The list shows status of species in extinct, threatened, critically endangered categories.
2.5 Chipko Movement
Slogan "Ecology is the permanent economy" was coined by Sundarlal Bahuguna. Sundarlal Bahuguna was born on 9 January 1927 in present Uttarakhand. Bahuguna is considered the main leader of the Chipko Movement and anti-big-dam movements. As a result of Bahuguna's efforts, the government banned felling of trees in Uttarakhand for 15 years after the movement. During the Chipko Movement, people hugged trees to prevent them from being cut.
2.6 World Wetland Day
According to the Ramsar Convention, World Wetland Day is celebrated on 2 February. The Ramsar Convention was held in Ramsar, Iran on 2 February 1971. Wetlands are also called the kidney of the Earth.
2.7 Biodiversity Hotspots
A Hotspot is a place where there is abundance of species and local species but existence of these species is constantly threatened - where there is richness of species from local and global perspective but threat of habitat destruction. Hot Spot word was first used by famous British ecologist Norman Myers in 1988. India's Hotspots: Western Ghats, Eastern Himalayas.
2.8 Great Barrier Reef
Great Barrier Reef is located in the Pacific Ocean. It is a coral reef spread over 2300 km along the shores of Queensland Island, Australia. Area: 344,400 sq km (included in UNESCO World Heritage).
2.9 ISO 14001
ISO 14001 certification relates to Environmental Management System. It is a systematic approach that ensures production in all production sectors while keeping environmental impacts in mind from pre-production stage to consumer. Purpose: to reduce use of natural resources during organizational activities.
2.10 Joint Forest Management (JFM)
Joint Forest Management (JFM) is a partnership in forest management between state forest departments and local communities in India. This partnership was established in Indian National Forest Policy of 1988.
2.11 Afforestation
Afforestation (Vanikarana) mainly refers to tree planting. Afforestation can prevent floods and can balance our ecosystem. Forest prevents soil erosion, floods and droughts. Forests help maintain balance of Carbon Dioxide and Oxygen in Earth's atmosphere, water conservation, and climate change control. Therefore forests play a very important role in maintaining balance of the ecosystem.
3. Biodiversity
3.1 Project Tiger
Project Tiger was started on 1 April 1973 during the tenure of India's first female Prime Minister Smt. Indira Gandhi. Purpose: to ensure tiger population in their natural habitats, to save tigers from extinction, and to protect areas of biological importance for tigers as natural heritage. Currently India has 54 Tiger Reserves (54th Tiger Reserve: Dholpur-Karauli Tiger Reserve).
3.2 National Parks and Wildlife Sanctuaries
Jim Corbett National Park - Uttarakhand (Nainital district). India's first National Park (1936). Named Hailey National Park in 1936 by Governor Malcolm Hailey. Renamed Jim Corbett in 1956.
Sariska Tiger Reserve - Rajasthan (Alwar district). Declared Tiger Protected Area in 1973 under Project Tiger.
Ranthambore National Park - Rajasthan (Sawai Madhopur district). Declared National Park in 1980.
Bandhavgarh National Park - Madhya Pradesh. Declared National Park in 1968.
Bandipur National Park - Karnataka. Established as Tiger Reserve in 1974.
Silent Valley National Park - Kerala (Palakkad district). Tropical moist evergreen forest. Nilgiri mountain area.
Namdapha National Park - Arunachal Pradesh (Changlang district). Largest protected area in Eastern Himalayan sub-region. Eastern Himalaya declared as Biodiversity Hot Spot.
Rajgir Zoological Park - Bihar (Nalanda district). Opened for public in February 2022.
3.3 Elephant Reserves in India
Mayurbhanj Elephant Reserve - Odisha. Sambalpur Elephant Reserve - Odisha. Mahanadi Elephant Reserve - Odisha. Sonitepur Elephant Reserve - Assam (NOT Odisha).
3.4 Biosphere Reserves
Nilgiri Biosphere Reserve was the first Biosphere Reserve established in India in 1986. Located in Western Ghats and Nilgiri mountain range in South India. Extends over approximately 5520 sq km across Tamil Nadu, Karnataka and Kerala. Declared UNESCO World Heritage Site in 2012.
Nanda Devi Biosphere Reserve - Uttarakhand. Sundarbans Biosphere Reserve - West Bengal. Gulf of Mannar Biosphere Reserve - Tamil Nadu.
3.5 Brahmagiri Wildlife Sanctuary
Brahmagiri Wildlife Sanctuary is in Kodagu district of Karnataka. Part of Western Ghats. Spread over 181 sq km. Near Kerala's Aralam Wildlife Sanctuary. Animals found: Bear, Elephant, Deer, Cheetah, Wild Cat, Lion-tailed Monkey.
3.6 Lodi Garden
Lodi Garden is located in south central Delhi. During British era, the garden's name was "The Lady Willingdon Park". In between the garden are tombs of the Lodi dynasty. Garden area: approximately 90 acres.
3.7 Cheetah Reintroduction
In September 2022, 8 cheetahs (5 female, 3 male) were released in Kuno National Park in Madhya Pradesh. Under the Action Plan for Introduction of Cheetah in India. Cheetah reintroduction plan has been funded under Project Tiger by Government of India.
3.8 Number of National Parks
As per 2019 data, India had 104 National Parks (at time of question). Currently India has 106 National Parks and 565 Wildlife Sanctuaries.
4. Pollution
4.1 E-Waste Management Rules 2022
Ministry of Environment, Forest and Climate Change notified E-Waste (Management) Rules 2022 under Environment (Protection) Act 1986. E-waste means electrical and electronic equipment - includes solar photo-voltaic modules or panels or cells thrown as waste. These rules came into effect from 1 April 2023.
4.2 Water Pollution Act
Water (Prevention and Control of Pollution) Act was passed by Parliament in 1974.
4.3 Sewage Treatment
The process of treating waste water is generally called Sewage Treatment. It removes polluted substances - mainly includes household waste and some industrial waste water.
4.4 Mitigation
Mitigation means reducing or eliminating the degree or intensity of pollution. Restoration, improvement or betterment of natural resources are examples of mitigation.
4.5 Flipfloppy
Flipfloppy is the world's first sailboat made entirely of plastic waste. Purpose: to raise awareness about plastic pollution in oceans.
4.6 Sludge
Solid substances like fat, grease and oil floating on top of liquid waste water are called Sludge (Keechad). Sludge is also known as Solid Waste. During waste water treatment, thick sludge is collected in a tank and used to make Biogas and Fertilizer.
4.7 Sewage (Apashisht Jal)
Sewage is the waste water that comes from kitchen sinks, toilets, laundries etc. (foam-filled, oil-mixed, black-brown colored water going into drains).
4.8 Carbon Monoxide - Why Pollutant?
Carbon Monoxide (CO) is a colorless, odorless, tasteless gas. When its concentration in air exceeds 35 PPM, it becomes harmful for humans and animals. This gas reacts with Haemoglobin present in blood to form Carboxyhaemoglobin. Due to this, the amount of Oxygen in human blood decreases causing death. CO is a pollutant because it reacts with Haemoglobin.
4.9 Lichen as Bio-indicator
Lichen is used as a bio-indicator of air pollution. Where air pollution is more, Lichen does not grow - therefore Lichen is not found near cities. Lichen is a plant of Thallophyta type, made by combining Fungi and Algae.
4.10 Bioremediation
Bioremediation is a waste management system in which microorganisms are used to neutralize or remove pollutants from a concentrated mass. Microorganisms reduce or completely eliminate toxic substances present in waste.
4.11 Water Hyacinth (Jal Kumbhi)
Water Hyacinth (Eichhornia crassipes) is an aquatic weed found in warm countries. Member of plant family Pontederiaceae. Found all over the world except Europe. Water Hyacinth controls water pollution from industrial effluents. Parthenium is also known as Gajar Grass or Chatak Chandni - it is an extremely destructive annual weed.
4.12 Nitrous Oxide - Not Generally an Air Pollutant
Nitrous Oxide (N2O) is generally known as Laughing Gas. Also known to cause Acid Rain. Used as anesthetic. Also used as oxidizer in rockets. N2O is NOT generally an air pollutant in normal amounts.
4.13 Hydrogen - Cleanest Fuel
Among fuels, Hydrogen causes the least environmental pollution. It is a clean and effective medium of energy widely used as an alternative to fossil fuels. India has formed National Hydrogen Energy Board to prepare Hydrogen Energy Road Map.
4.14 Reverse Osmosis - Water Treatment
Reverse Osmosis is a technique to purify water. Uses semi-permeable membrane to separate dissolved ions and other solid particles from water. Removes bacteria along with dissolved impurities. Reverse Osmosis is a treatment for water pollution.
4.15 Maximum Solid Waste Producer
Manufacturing Industry produces the most solid waste.
4.16 Iron and Manganese in Water
Chlorination cannot remove Iron and Manganese from water as pollutants because Chlorine is used only to kill microorganisms. Iron and Manganese can be removed by: Ion Exchange Process, Oxidation with catalyst, Lime Soda Process, Manganese Zeolite Process.
4.17 Arsenic Problem in India
Arsenic problem in India is mainly due to excessive extraction of groundwater in affected areas. Generally use of chemical pesticides and rat-killing medicines like Lead Arsenate and Copper Arsenate causes arsenic contamination in groundwater.
4.18 CO in Automobiles
Carbon Monoxide content in exhaust gas is maximum during Idle (Nichkriya) running of automobiles.
4.19 Marble Cancer
Marble Cancer is the erosion of marble due to Acid Rain. When pH of rain water falls below 5.6, it is Acid Rain. Main cause: Sulfur Dioxide, Nitrogen Dioxide and Nitrous Oxide mixing in rain water. International Acid Rain Information Centre is in Oslo.
4.20 Non-Biodegradable Waste
Non-Biodegradable waste are substances that cannot be decomposed by bacteria. They remain in their original state for many years - e.g. Plastic, polythene, glass etc.
5. Global Warming and Climate Change
5.1 Global Warming
Global Warming means the long-term warming of Earth's surface observed since the pre-industrial era due to human activities, mainly burning of fossil fuels - which increases greenhouse gases in Earth's atmosphere. Global warming causes climate change which creates serious threats to life on Earth in the form of widespread floods and extreme weather. Due to this, glaciers around the world can melt, raising sea water levels, causing small islands to submerge. Both statements A and B about Global Warming are correct.
5.2 Greenhouse Gases
Greenhouse Gases spread heat in the atmosphere, making Earth warm and causing Global Warming. Among Greenhouse Gases, Chlorofluorocarbon (CFC) has the maximum heat-retaining capacity - 1000 times more harmful than CO2. Carbon Dioxide is the most prominent greenhouse gas. CH4 (Methane) is another Greenhouse Gas besides CO2.
5.3 Greenhouse Effect
Greenhouse Effect is a natural process by which gases present in atmosphere help increase atmospheric temperature. Main greenhouse gases: Carbon Dioxide and Methane. Greenhouse Effect was discovered by Joseph Fourier in 1824. Its application was done by John Tyndall in 1858. Greenhouse Effect means atmospheric gases blocking solar energy.
5.4 Least Impact of Global Warming
Among the effects of global warming, decrease in rate of photosynthesis in plants has the least impact possibility.
5.5 Geothermal Energy
Geothermal Energy is the energy that comes from stored heat in the Earth. Generated from original formation of the planet and radioactive decay of minerals. Geothermal Energy is the source that increases Earth's temperature the least.
6. Ozone Layer
6.1 Key Facts
Ozone (O3) is a gas made of three Oxygen atoms. Ozone Layer is found at approximately 15-35 km altitude in the stratosphere. Maximum concentration is about 30 km above sea level. Formed by the effect of Sun's ultraviolet radiation on Oxygen.
6.2 Ozone Layer Formation
Ozone Layer is formed by the reaction between Oxygen and Ultraviolet Rays. Reaction: O2 + hv → O + O; O + O2 + M → O3 + M (where M = N2 or other atmospheric gases). This layer absorbs ultraviolet rays coming from sunlight and protects living organisms on Earth.
6.3 Ozone Depletion Effects
Due to depletion in Ozone Layer, more ultraviolet rays reach Earth causing Skin Cancer in humans. Also causes damage to eyes and immune system. Refrigerators, fire extinguishers and aerosol sprays use CFC (Chloro-Fluoro-Carbon) which causes ozone layer depletion.
6.4 Substances that Destroy Ozone Layer
Chlorine (CFC - Chlorofluorocarbon) destroys the Ozone Layer. CFC includes halon gases and Carbon Tetrachloride. These chemicals decompose Ozone gas into Oxygen. 1 atom of Chlorine can destroy thousands of Ozone (O3) molecules.
6.5 Montreal Protocol
Montreal Protocol (1987) was an agreement for protection of Ozone Layer. Under it, control on CFC (Chloro-Fluoro Carbon) and halon gases was discussed. First protocol on restricting CFC emission was made at Montreal.
6.6 Important International Environmental Agreements
Stockholm Convention (1972): Establishment of UNEP; 5 June declared World Environment Day.
Rio (Earth) Summit (1992): Adoption of Agenda 21; birth of UNFCCC.
Helsinki Convention (1974): Protection of Marine Environment.
Cancun Convention (2010): Decision to establish Green Climate Fund.
Montreal Protocol (1987): Control of CFC to protect Ozone Layer.
7. Miscellaneous
7.1 UN Sustainable Development Goals (SDGs)
All the given options are included in UN SDGs: Zero Hunger, Climate Action, Life Below Water, Quality Education. SDGs were determined at the 70th UN meeting (Paris) in 2015 for the next 15 years.
7.2 Earth Hour
Earth Hour is the annual initiative of WWF (World Wildlife Fund for Nature). Started in 2007. Organized every year on the last Saturday of March. During this, people around the world turn off unnecessary lights for one hour. It is the world's largest movement for stopping climate change and energy conservation. Theme 2022: Shape Our Future.
7.3 Container-Based Sanitation
Container-Based Sanitation refers to a sanitation system where toilets collect human waste in sealed, removable cartridges which are taken to treatment centers.
7.4 Sikkim - First Fully Organic State
Sikkim became the first Indian state to go fully organic. About 75,000 hectares of agricultural land adopted organic practices. Sikkim became India's first Organic State.
7.5 Solid Waste Disposal
The least preferred technique for disposal of solid waste by municipalities is Briquetting. Usually made from green garbage and other carbon materials. Used as fuel for electricity generation and cooking.
7.6 Biodegradable Waste Conversion
Biodegradable waste can be converted into useful substances with the help of Bacteria. Some bacteria attack dead bodies of plants and animals and convert complex organic compounds into simple substances. Some bacteria convert organic substances like dung, feces and rotted leaves into fertilizer and humus.
8. Important One-Liners for SSC CGL
- Ecology word first used by Ernst Haeckel
- Henry Chandler Cowles famous for Indiana Dunes plant study in 1896
- Plant is a Biotic component - NOT Abiotic
- Standing crop measured as Biomass
- Aerobic = Oxygen easily available; Anaerobic = Oxygen not easily available
- Commensalism = one benefits, other unaffected
- Parasitism = one benefits, other harmed
- Brood Parasitism = using others' care to raise own young
- Indian Gaur = largest wild cattle in India; Nagarhole National Park
- Rio Summit 1992 = Rio de Janeiro, Brazil; 116 nations; 3 binding agreements
- Golden Panda Award = world's highest environmental award; also called Green Oscar
- IUCN Red Data Book = threatened plants and animals; started 1964; HQ Gland near Geneva
- Chipko slogan "Ecology is the permanent economy" = Sundarlal Bahuguna
- World Wetland Day = 2 February; Ramsar Convention 1971
- Hot Spot term first used by Norman Myers in 1988
- India's Hotspots = Western Ghats, Eastern Himalayas
- Great Barrier Reef = Pacific Ocean; 2300 km; Queensland, Australia
- ISO 14001 = Environmental Management System
- JFM = started in National Forest Policy 1988
- Project Tiger started 1 April 1973 by Indira Gandhi; 54 Tiger Reserves currently
- Jim Corbett = India's first National Park, 1936, Uttarakhand
- Sariska = Alwar, Rajasthan; Tiger Reserve 1973
- Ranthambore = Sawai Madhopur, Rajasthan; National Park 1980
- Bandipur = Karnataka; Tiger Reserve 1974
- Silent Valley = Kerala, Palakkad district
- Namdapha = Arunachal Pradesh; largest protected area in Eastern Himalayan sub-region
- Nilgiri Biosphere Reserve = first biosphere reserve of India, 1986; UNESCO World Heritage Site 2012
- Brahmagiri Wildlife Sanctuary = Kodagu district, Karnataka
- Lodi Garden = previously "The Lady Willingdon Park" during British era
- Cheetah reintroduction Sept 2022 = 8 cheetahs in Kuno NP, Madhya Pradesh
- India has 106 National Parks and 565 Wildlife Sanctuaries
- E-Waste Rules 2022 effective from 1 April 2023
- Water Pollution Act 1974
- Sewage Treatment = waste water treatment process
- Flipfloppy = world's first plastic waste sailboat
- Sludge = solid substances on waste water; also called Solid Waste
- CO = pollutant because it reacts with Haemoglobin; forms Carboxyhaemoglobin
- Lichen = bio-indicator of air pollution; not found near polluted cities
- Bioremediation = microorganisms to neutralize pollutants
- Water Hyacinth = controls industrial water pollution
- N2O (Nitrous Oxide) = NOT generally an air pollutant; also called Laughing Gas
- Hydrogen = fuel causing least environmental pollution
- Reverse Osmosis = water pollution treatment technique
- Manufacturing Industry = produces most solid waste
- Chlorination cannot remove Iron and Manganese from water
- Arsenic in India = mainly due to excessive groundwater extraction
- CO in automobiles = maximum during Idle running
- Marble Cancer = marble erosion due to Acid Rain
- Non-biodegradable = Plastic, polythene, glass
- Greenhouse Effect discovered by Joseph Fourier 1824; John Tyndall 1858
- CFC = maximum heat-retaining capacity among greenhouse gases
- CO2 = most prominent greenhouse gas; CH4 = another GHG
- Geothermal Energy = least increase in Earth's temperature
- Ozone (O3) = 3 Oxygen atoms
- Ozone Layer = 15-35 km altitude in stratosphere
- Ozone depletion causes Skin Cancer
- Ozone Layer formed by reaction between Oxygen and Ultraviolet Rays
- CFC destroys Ozone Layer; 1 Chlorine atom destroys thousands of O3 molecules
- Montreal Protocol 1987 = first protocol restricting CFC
- Stockholm Convention 1972 = UNEP established; World Environment Day = 5 June
- UN SDGs determined in 2015 in Paris for next 15 years
- Earth Hour = WWF; started 2007; last Saturday of March
- Sikkim = first fully organic state in India
- Briquetting = least preferred solid waste disposal by municipalities
- Bacteria help convert biodegradable waste into useful substances