- Ozone (O₃) in the upper atmosphere forms a protective layer that blocks harmful UV-B rays from the sun.
- Chlorofluorocarbons (CFCs) from refrigerators, aerosol sprays, and styrofoam break down ozone into oxygen, thinning this layer.
- Ozone depletion allows more UV-B rays to reach Earth, causing sunburn, skin cancer, genetic damage, and reduced ecosystem productivity.
Definitions [20]
Define Hotspots.
Hotspot is a biodegradable region that is both a significant reservoir of biodiversity and is threatened with destruction.
Definition: Biodiversity
The diversity of life forms present on Earth, including plants, animals, and microorganisms, is called biodiversity.
Define Ramsar Sites.
Ramsar Sites: It is a wetland site designed of international importance under the Ramsar convention. It is an inter-governmental environmental treaty established in 1971 by UNESCO and coming into force in 1975.
Define Eutrophication.
Eutrophication: The process by which a body of water enriched in dissolved nutrients (such as phosphates) that stimulates the growth of aquatic algae usually resulting in the depletion of dissolved oxygen.
Define Biodiversity.
Biodiversity is defined as the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable
The sum total of species richness, i.e., the number of species of plants, animals and micro-organisms inhabiting in a given habitat, is known as biodiversity.
Define dichotomous key.
It is a tool used to classify organisms based on their similarities and differences.
Give definitions of Extinct species.
Species that completely disappear from the planet are referred to as extinct.
Give definitions of Endangered species.
When a species possesses a very high risk of extinction as a result of rapid population decline of 50 to more than 70 per cent over the previous 10 years, it is said to be an endangered species.
Give definitions of Invasive species.
Species that are not native to a region or locality but are unintentionally or purposefully introduced and cause harm to the native species already present are referred to as invasive species.
Define cryopreservation.
Cryopreservation is a technique in which organisms, tissue, and cells are preserved and stored at the very low temperature of liquid nitrogen (−196°C) for years. They remain viable in the frozen state for future use.
Definition: Air Pollution
Air pollution means degradation of the air quality which harmfully affects the living organisms as well as certain objects.
or
Contamination of air by harmful substances like poisonous gases, smoke, particulate matter, microbes, etc., is called air pollution.
Definition: Noise Pollution
Noise is defined as any unpleasant/loud undesired sound interfering with one's hearing and concentration and the pollution caused due to noise is termed as noise pollution.
Define the following term:
Noise
Noise is defined as any unpleasant, loud, undesired sound that interferes with one’s hearing and concentration, and the pollution caused by noise is termed noise pollution.
Define the following term:
Oil spills
Oil spills are the accidental discharges of petroleum into oceans or estuaries. The sources of spills are overturned oil tankers, offshore oil mining, and oil refineries.
Definition: Water pollution
Water pollution means any change in the water quality which makes it unsuitable for use by humans and by other living organisms.
Define 'Greenhouse effect'.
The heating-up of the earth’s atmosphere due to trapped infrared rays reflected from the earth's surface by atmospheric gases is called the greenhouse effect.
Define global warming.
The gradual increase in Earth’s average surface temperature due to rising concentrations of greenhouse gases in the atmosphere is called global warming.
Definition: Global Warming
The gradual increase in the average surface temperature of the Earth due to rising concentrations of greenhouse gases in the atmosphere is called global warming.
Define the following
Greenhouse effect
The warming up of the atmosphere due to trapping of the solar radiation reflected by the earth by gases like carbon dioxide is called Greenhouse effect.
Definition: Deforestation
Deforestation is the conversion of forested areas into non-forested areas for agricultural, industrial, urban or other human uses.
Key Points
Key Points: Loss of Biodiversity
- Habitat loss and fragmentation due to agriculture, deforestation, urbanisation, and industrialisation is the major cause of biodiversity loss.
- Over-exploitation of plants and animals for food, trade, medicine, and luxury items leads to rapid decline and extinction of species.
- Alien species invasion disturbs native ecosystems by competition, predation, and disease (e.g., water hyacinth, Nile perch).
- Pet trade and illegal wildlife trade result in large-scale removal and death of species from their natural habitats.
- Co-extinctions occur when the extinction of one species leads to the loss of other dependent species.
Key Points: Prevention and Control of Air Pollution
- Control at Source
Air pollution can be reduced by proper planning and siting of industries, improved design of equipment, correct fuel–air mixture, use of fuel additives, and efficient engine design in vehicles. - Vehicular Pollution Control
Installation of catalytic converters, use of unleaded petrol, adoption of CNG/LPG, and enforcement of Bharat Stage (Euro) emission norms significantly reduce harmful exhaust emissions. - Industrial Pollution Control Devices
Emissions from industries and power plants are controlled using cyclone collectors, scrubbers, and electrostatic precipitators, which remove particulate matter and harmful gases before release into the atmosphere. - Legislative and Policy Measures
Laws such as the Air (Prevention and Control of Pollution) Act, 1981 and Environment (Protection) Act, 1986, along with emission standards and fuel regulations, play a crucial role in controlling air pollution. - Afforestation and Public Awareness
Planting pollution-tolerant trees around urban and industrial areas, along with environmental education and public awareness programmes, helps improve air quality and reduce pollution impacts.
Key Points: Ozone Layer Depletion
Concepts [20]
- Biodiversity
- Levels of Biodiversity
- Patterns of Biodiversity
- Importance of Species Diversity to the Ecosystem
- Biodiversity Current Scenario
- Loss of Biodiversity
- Conservation of Biodiversity
- Biodiversity Conservation Methods
- Biological Diversity Act, 2002
- Environmental Issues
- Air Pollution
- Noise Pollution
- Water Pollution
- Prevention and Control of Air Pollution
- Solid Waste Management
- Green House Effect
- Global Warming
- Ozone Layer Depletion
- Deforestation and Its Causes
- Mission Harit Maharashtra
