Test: Environmental Awareness (Environmental Issues) - Software Development MCQ

Concept-

• 'Rise in Earth's temperature and its associated changes in weather' This increase in Earth's temperature (which is estimated at 10 Fahrenheit over a 100-year average temperature) results in changes in rainfall patterns, and the formation of icebergs and glaciers. Melting, sea level rise, and impacts on flora and fauna can come to the fore.
• Greenhouse gases are the most responsible for climate change caused by global warming.
• Green house gases are those gases that absorb heat or heat from outside.
• Greenhouse gases are commonly used in extremely cold areas to keep plants warm which are damaged in extremely cold weather. In such a situation, these plants are kept in a closed glass house and greenhouse gas is filled in the glass house.
• This gas absorbs the heat of the rays coming from the sun and keeps the plants warm. 

Important Points

• The most important of the greenhouse gases is carbon dioxide, which we living beings emit with our breath.
• Environmental scientists say that in the last few years, the amount of carbon dioxide gas on the earth has increased continuously. Scientists have said a deep relationship between carbon dioxide emissions and temperature rise.

Global environmental major issues:

• One of the primary causes of environmental degradation in a country could be attributed to the rapid growth of population, which adversely affects the natural resources and environment.
• The uprising population and environmental deterioration face the challenge of sustainable development.
• The existence or the absence of favorable natural resources can facilitate or retard the process of socio-economic development.
• The three basic demographic factors of births (natality), deaths (mortality) and human migration (migration) and immigration (population moving into a country produces higher population) produce changes in population size, composition, distribution, and these changes raise a number of important questions of cause and effect.
• Population growth and economic development are contributing to many serious environmental calamities in India. These include heavy pressure on land, land degradation, forests, habitat destruction, and loss of biodiversity.
• Changing consumption pattern has led to a rising demand for energy. The final outcomes of this are air pollution, global warming, climate change, water scarcity, and water pollution.
• Environmental issues in India include various natural hazards, particularly cyclones and annual monsoon floods, population growth, increasing individual consumption, industrialization, infrastructural development, poor agricultural practices, and resource mal-distribution have led to the substantial human transformation of India’s natural environment.
• An estimated 60% of cultivated land suffers from soil erosion, waterlogging, and salinity.
• It is also estimated that between 4.7 and 12 billion tons of topsoil are lost annually from soil erosion.
• From 1947 to 2002, average annual per capita water availability declined by almost 70% to 1,822 cubic meters, and overexploitation of groundwater is problematic in the states of Haryana, Punjab, and Uttar Pradesh.
• Forest area covers 18.34% of India’s geographic area (637000 km²). Nearly half of the country’s forest cover is found in the state of Madhya Pradesh (20.7%) and the seven states of the northeast (25.7%); the latter is experiencing net forest loss.
• Forest cover is declining because of harvesting for fuel wood and the expansion of agricultural land. These trends, combined with increasing industrial and motor vehicle pollution output, have led to atmospheric temperature increases, shifting precipitation patterns, and declining intervals of drought recurrence in many areas.
• The Indian Agricultural Research Institute of Parvati has estimated that a 3°C rise in temperature will result in a 15 to 20% loss in annual wheat yields.

These are substantial problems for a nation with such a large population depending on the productivity of primary resources and whose economic growth relies heavily on industrial growth.

Environmental issues at the global level

• Depletion of natural resources
• Water pollution
• Air pollution
• Groundwater pollution
• Toxic chemicals & soil pollution
• Ozone layer depletion
• Global warming
• Loss of biodiversity
• Extinction of wildlife and loss of natural habitat
• Nuclear wastes and radiation issues

Hence, the Global environmental problem is mainly due to the increasing Population.

The correct answer is increase in sea levels.

Key Points

• Global Warming:
  • Global warming is the phenomenon of a gradual increase in the temperature near the earth’s surface.
  • This phenomenon has been observed over the past one or two centuries.
  • This change has disturbed the climatic pattern of the earth.
  • However, the concept of global warming is quite controversial but the scientists have provided relevant data in support of the fact that the temperature of the earth is rising constantly.
  • There are several causes of global warming, which have a negative effect on humans, plants, and animals.
  • These causes may be natural or might be the outcome of human activities.

Additional Information

• Effects of Global Warming:
• Rise in Temperature:
  • Global warming has led to an incredible increase in the earth’s temperature.
  • Since 1880, the earth’s temperature has increased by ~1ºC.
  • This has resulted in an increase in the melting of glaciers, which has led to an increase in the sea level.
• Threats to the Ecosystem:
  • Global warming has affected the coral reefs that can lead to a loss of plant and animal lives.
  • An increase in global temperatures has made the fragility of coral reefs even worse.
• Climate Change:
  • Global warming has led to a change in climatic conditions.
  • There are droughts at some places and floods at some.
  • This climatic imbalance is the result of global warming.
• Spread of Diseases:
  • Global warming leads to a change in the patterns of heat and humidity.
  • This has led to the movement of mosquitoes that carry and spread diseases.

The correct answer is Option 3, i.e Hydrofluorocarbons.

• Hydrofluorocarbons (HFCs) has the highest global warming potential as compared to other gases. 
• Global Warming Potential (GWP) is used to measure the total energy that a particular gas absorbs over a particular period of time ( normally 100 years), compared to carbon dioxide. 
• Gases with a higher GWP absorb more energy, per pound, than gases with a lower GWP, and thus contribute more to warming Earth.
• The major atmospheric gases responsible for causing global warming are Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide.
• Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6) are less prevalent GHGs but are very powerful.

Key Points

Thus, the correct match is (a) - (iii), (b) - (iv), (c) -(ii), (d) - (i).

• The heat is transferred in form of conduction, convection, and radiation. 
• Radiation is the mode of heat transfer that does not require a medium. It happens through infrared radiation. 
• The infrared radiations are electromagnetic waves having a frequency less than the visible spectrum. 
• The infrared radiation is emitted from every hot body. 
• Earth is heated by infrared radiations of the sun. The radiations are reflected back by the earth which is captured by greenhouse gases. 
• The greenhouse gases absorbers some amount of heat and keeps the earth warm. 

Thus, infrared radiation is trapped on the earth’s surface by the greenhouse effect.

Additional Information

• The major Greenhouse gas is Carbon dioxide followed by methane, water vapor, and nitrous oxide.  
• UV rays have a frequency higher than violet and they help in the formation of Ozone. 
• The wavelength of different electromagnetic waves are given in the below diagram. 

The correct answer is Acid rain.

Key Points

• Taj Mahal is getting damaged due to the effects of Acid rain.
• Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere.
• Crude-oil refineries situated in nearby Mathura, spew out vast quantities of sulphur dioxide into the atmosphere.
  • It is carried by winds and acid rain to Agra.
  • ​Acid rain-induced marble cancer is the progressive degradation (or eating away) of marble monuments.
  • Tajmahal is made of marble (CaCO3) which reacts with sulphuric acid of the acid rain. It causes pitting, decolourization and lusterless.
• CaCO₃ of Taj Mahal combines with Sulphuric acid to give → CaSO₄ + H₂O+ CO₂.
• To constrain the damage to the Taj Mahal caused by the oxides of sulfur and nitrogen, the government of India announced an action plan in 1995.
• There are two types of acidic deposition- wet and dry.
• Wet deposition refers to any type of precipitation that takes acids from the atmosphere and deposits them on the earth’s surface.
• Dry deposition of harmful particles and gases clings to the ground in the absence of precipitation via dust and smoke.

Effects of ozone depletion

• It produces a greenhouse effect and also changes the climate
• It results in low production of crops
• It causes damage to the organs of living things
• Ultraviolet rays harm the plants
• It causes to spread the skin cancer disease
• It raises the possibilities of acid rains in urban areas
• It increases the temperature of the environment
• It affects the mental health of man
• It increases the temperature of the atmosphere which has a bad effect on the vegetation
• The UV rays reaching the earth are harmful to the pregnant women and the infant children also

Thus, the correct match is:

Concept:

• The variety of plant and animal life in the world or in a particular habitat is called biodiversity.
•  Biodiversity is the term popularised by sociobiologist Edward Wilson to describe the combined diversity at all the levels of biological organization. 

Explanation:

• Biodiversity and its conservation are now vital environmental issues of international concern.
• Biodiversity is not only essential for ecosystem health but imperative for the very survival of the human race on this planet.
• The accelerated rates of species extinctions that the world is facing now are largely due to human activities.
• The loss of biodiversity in a region may lead to a decline in plant production, lowered resistance to environmental perturbations such as drought, and increased variability in certain ecosystem processes such as plant productivity, water use, and pest and disease cycles.
• There are four major causes:
  • Habitat loss and fragmentation
  • Alien species invasions
  • Over-exploitation:
  • Co-extinctions

• Habitat loss and fragmentation: This is the most important cause of driving animals and plants to extinction.  
  • When large habitats are broken up into small fragments due to various human activities, mammals and birds requiring large territories, and certain animals with migratory habits are badly affected, leading to population declines.
• Over-exploitation: Humans have always depended on nature for food and shelter, but when ‘need’ turns to ‘greed’, it leads to over-exploitation of natural resources.
• Alien species invasions: When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause the decline or extinction of indigenous species.
• Co-extinctions: When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct.

Thus, lack of rainfall is not the major cause of biodiversity losses in a geographical region.

Additional Information 

• The most dramatic examples of habitat loss come from tropical rainforests.
• Once covering more than 14 percent of the earth’s land surface, these rain forests now cover no more than 6 percent.
• Humans have always depended on nature for food and shelter, but when ‘need’ turns to ‘greed’.
• It leads to the exploitation of natural resources.

The correct answer is All the above.

Key Points

Deforestation:

• Deforestation can be defined as the large-scale removal of trees from forests (or other lands) for the facilitation of human activities.
• It is a serious environmental concern since it can result in the loss of biodiversity, damage to natural habitats, disturbances in the water cycle, and soil erosion.
• Deforestation is also a contributor to climate change and global warming.
• Forests cover approximately 31% of the total land surface of the Earth.
• Tropical forests harbour over half of all land-based animal and plant species in the world.
• Between the years 2000 and 2012, over 568 million acres of forest have been claimed by deforestation.
• Approximately 9 million acres of virgin tropical forest were cut down in the year 2018.
• The Amazon rainforest, which is the source of 20% of the world’s oxygen supply, loses approximately 1.32 acres of its area every minute due to deforestation.

Important Points 

Causes of Deforestation:

• Overpopulation and shifting of cultivation.
• Overgrazing and forest fire.
• Increase in demand for fuel.
• Agriculture – small-scale and large scale farming.
• Logging – cutting of trees for use as raw material.
• Mining and urban expansion – clearing of forest area for the construction of infrastructure.
• Destruction of forests due to hurricanes, floods, and other natural calamities.
• Invasion of the forest ecosystem by parasites that destroy trees.
• Forest fires are sparked by lightning and other natural phenomena.

The correct answer is Species invasion.

Key Points

• Invasive alien species (IAS) are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity.
• It occurs in all taxonomic groups, including animals, plants, fungi and microorganisms, and can affect all types of ecosystems.
• Globalization has resulted in greater trade, transport, travel and tourism, all of which can facilitate the introduction and spread of species that are not native to an area.
• There are also some other causes of Species invasion.
• Deforestation is not a direct cause of Species invasion.
• Deforestation 
  • It is the clearing, destroying, or otherwise removal of trees through deliberate, natural, or accidental means.
  • It is a particular concern in tropical rain forests because these forests are home to much of the world’s biodiversity.
• Forests also play a critical role in mitigating climate change because they act as a carbon sink—soaking up carbon dioxide that would otherwise be free in the atmosphere and contributing to ongoing changes in climate patterns.
• The loss of trees and other vegetation can cause climate change, desertification, soil erosion, fewer crops, flooding, increased greenhouse gases in the atmosphere, and a host of problems for indigenous people. 
• Effects of deforestation include soil erosion and coastal flooding. 
• Trees help the land retain water and topsoil, which provides the rich nutrients to sustain additional forest life. Without forests, the soil erodes and washes away.
• One of the most dangerous and unsettling effects of deforestation is the loss of animal and plant species due to their loss of habitat.

Concept:

Ozone Layer: 

• Ozone (O3) is a molecule formed by three atoms of oxygen. Ozone is a deadly poison.
• Ozone is found in the stratosphere layer of the atmosphere.
• However, at the higher levels of the atmosphere, ozone performs an essential function. It shields the surface of the earth from ultraviolet (UV) radiation from the Sun.
• This radiation is highly damaging to organisms, for example, it is known to cause skin cancer in human beings or can split the DNA.
• It is a pale blue gas with a distinctively pungent smell.
• Ozone is an excellent oxidizing agent as it breaks down into oxygen gas and nascent oxygen. { O3 → O2 + [O] }
• It is an allotrope of oxygen that is much less stable than the diatomic allotrope O2, breaking down in the lower atmosphere to O2 or di-oxygen

Its depletion:

• The amount of ozone in the atmosphere began to drop sharply in the 1980s.
• This decrease has been linked to synthetic chemicals like chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers.
• The government bans those products which contain CFCs.

• Ozone is thermodynamically unstable and decomposes to molecular oxygen. Thus, a dynamic equilibrium exists between the production and decomposition of ozone molecules

Explanation:​

• In recent years, there have been reports of the depletion of this protective ozone layer because of the presence of certain chemicals in the stratosphere.
• The main reason for ozone layer depletion is believed to be the release of chlorofluorocarbon compounds (CFCs), also known as Freons.
• These compounds are non-reactive, non-flammable, non-toxic organic molecules and are therefore used in refrigerators, air conditioners, in the production of plastic foam and by the electronic industry for cleaning computer parts etc.
• Once CFCs are released in the atmosphere, they mix with the normal atmospheric gases and eventually reach the stratosphere
• In the 1980s, for the first time, atmospheric scientists working in Antarctica reported about the depletion of the ozone layer commonly known as ozone hole over the South Pole.

Additional Information

• Greenhouse effect:
  • The greenhouse effect is a natural phenomenon that warms the surface of the Earth.
  •  As the Sun's energy enters the Earth's atmosphere, part of it is reflected back in space and the remainder is absorbed and re-radiated by greenhouse gases.  
  • The radiation consumed warms the atmosphere and the Earth's surface.
• Acid Rain:
  • As the name suggests, acid rain may be said to be the easiest way to precipitate acid in the form of rain.
  • This results in acid rain as air contaminants such as nitrogen oxides and sulphur react with rainwater and come down with the rain.
• Smog:
  • The term smog means a mixture of fog and smoke.
  • ​It is a type of air pollution that occurs in many cities worldwide.

When the quantity of acids in the raining water is more than the average, then such rain is called 'Acid rain'.

We are aware that normally rainwater has a pH of 5.6.  When the pH of the rainwater drops below 5.6, it is called acid rain.

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by the wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition.

∴ The average pH value of the acid rain is 4 to 5 and hence the average value of 4.5.

The bad effects of acid rain

• When acid rain falls and flows as groundwater to reach rivers, lakes etc, it affects plants and animal life in the aquatic ecosystem
• Acid rain is harmful to agriculture, trees and plants as it dissolves and washes away nutrients needed for their growth
• It causes respiratory ailments in human beings and animal
• It may also cause corrosion in many buildings bridges, monuments, fencing etc
• It causes irritation in the eyes and skin of human beings
• This rain reduces the lustre of the metals too
• Acid rain damages buildings and other structures made of stone or metal
• The Taj Mahal in India has been affected by acid rain

When the quantity of acids in the raining water is more than the average, then such rain is called 'Acid rain'.

We are aware that normally rainwater has a pH of 5.6.  When the pH of the rainwater drops below 5.6, it is called acid rain.

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition.

Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere. As mentioned earlier, burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides.

SO₂ and NO₂ after oxidation and reaction with water are major contributors to acid rain because polluted air usually contains particulate matter that catalyses the oxidation.

2SO₂ (g) + O₂ (g) + 2H₂O (l) → 2H₂SO₄ (aq)

4NO₂ (g) + O₂ (g)+ 2H₂O (l) → 4HNO₃ (aq)

The bad effects of acid rain

• When acid rain falls and flows as groundwater to reach rivers, lakes etc, it affects plants and animal life in the aquatic ecosystem
• Acid rain is harmful to agriculture, trees and plants as it dissolves and washes away nutrients needed for their growth
• It causes respiratory ailments in human beings and animal
• It may also cause corrosion in many buildings bridges, monuments, fencing etc
• It causes irritation in the eyes and skin of human beings
• This rain reduces the lustre of the metals too
• Acid rain damages buildings and other structures made of stone or metal
• The Taj Mahal in India has been affected by acid rain

Key Points

Thus, Montreal Protocol is related to ozone depletion.

The correct answer is Chlorine and nitrogen.

• Nitrogen and chlorine molecules reverse the impact of each other on ozone - the more chlorine there is, the less powerful nitrogen becomes at destroying ozone, and vice versa.
• The ozone layer protects Earth from the sun's ultraviolet rays which increase the risk of cancer and endanger crops and aquatic life.
• Human-produced chemicals called chlorofluorocarbons(CFCs) attracted headlines in the 1980s when it was clear that they were chewing a hole in the ozone layer over Earth's polar regions.
• Chemicals, especially produced halocarbon refrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons) are the main cause of ozone depletion and the ozone hole.

Concept:

Greenhouse Effect: The solar energy trapped by the earth atmosphere and radiate it slowly so to cover our earth with a warm blanket. This is the natural process of the greenhouse effect on earth to maintain its temperature and makes the earth perfect for life.

Greenhouse gases are carbon dioxide, other greenhouse gases are methane, water vapour, nitrous oxide, CFCs and ozone. 

Values of radiation absorbed by the greenhouse gases are as follow:

Explanation:

Global Warming

• An increase in the average temperature of the earth surface due to the greenhouse effect is called global warming
• It also refers to the increase in the average temperature of the air and sea at the earth's surface.
• The greenhouse gases combined increased the temperature of planet earth so the correct option is greenhouse gases.

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide (SO₂) and nitrogen oxides (NO₂) are released into the air.

• These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
• SO₂ and NO_X react with water, oxygen and other chemicals to form sulfuric and nitric acids.
• These then mix with water and other materials before falling to the ground.

• The major sources of SO₂ and NO_X in the atmosphere are: burning of fossils, vehicles and heavy equipment, oil refineries, manufacturing, industrial releases.