There were 18 Questions from Environment in 2023, of which

• 5 Questions were related to Climate Change
• 6 Questions were related to Environmental Ecology
• 7 Questions were related to Bio-Diversity

The examiner covered areas such as the Basics of Climate Change, Global Climate Issues,, Alternate and Sustainable Fuels, the Basics of the Environment, the basics of Biodiversity, Biodiversity in India, and Global Biodiversity..

The level of the questions was moderate.

Questions were aimed to test the basic and applied sections of Environment, Bio-Diversity and Climate Change. 

Previous Year UPSC Environment Questions With Explanation 2023

1. Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?

(a) Bhitarkanika Mangroves

(b) Marakkanam Salt Pans

(c) Naupada Swamp

(d) Rann of Kutch 

1. Ans: d

Explanation:

Marshland

• A marsh is a type of wetland, an area of land where water covers ground for long periods of time. Unlike swamps, which are dominated by trees, marshes are usually treeless and dominated by grasses and other herbaceous plants.
• There are three types of marshes: tidal salt marshes, tidal freshwater marshes, and inland freshwater marshes.

Mangroves 

• Mangroves are a group of trees and shrubs that live in the coastal intertidal zone. . There are about 80 different species of mangrove trees. All mangrove trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangroves are coastal swamps bordering major deltas of the country. Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperature 
• The largest amount of mangrove coverage can be found in Indonesia.
• Odisha’s Bhitarkanika National Park, the second-largest mangrove forest in India after the Sundarbans, is known for a successful saltwater crocodile conservation programme. 

Salt Pan

• A salt pan is  formed when pools of seawater evaporate more quickly than they can be replenished by rainfall. During this evaporation process, the minerals and salt ions that were dissolved in the water are left behind, creating a mineral-rich landscape.
• Salt is often the most prevalent mineral in this region, forming a hard white crust on the surface as it accumulates over thousands of years..
• Natural salt pans are different from  the man-made salt pans used in solar salt production  
• Marakkanam is the ancient port town, located at about 120 km from Chennai. The Marakkanam salt pans are spread over an area of 4,000 acres and is one of the largest producers of salt in Tamil Nadu. 
• Nationally, some 60,000 acres have been demarcated as salt pan lands, spread across Maharashtra, Andhra Pradesh, Tamil Nadu, Odisha, Gujarat, and Karnataka. Andhra Pradesh (20,716 acres) boasts the largest expanse of such land, followed by Tamil Nadu (17,095 acres) and Maharashtra (12,662 acres).
• Naupada swamps is in Andhra Pradesh. It is a complex of wetlands consisting of swamps, mud and salt meadows and creek. It is a transitional zone between terrestrial and marine ecosystems and many permanent shallow marine waters on the coastal lines.

Rann of Kutch 

Rann comes from a Hindi word meaning desert, and the region is famous for its marshy salt flats which become snow white when the summer monsoon flood waters dry up. These inhospitable lowlands are resource-rich with minerals and natural gas deposits. Rann of Kutch is the best example of repeated falls in sea level. 

Hence option d is correct.

2. Consider the following statements:

Statement-I: Marsupials are not naturally found in India.

Statement-II: Marsupials can thrive only in montane grasslands with no predators.

Which one of the following is correct in respect of the above statements?

(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I

(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-II

(c) Statement-I is correct but Statement-II is incorrect·

(d) Statement-II is incorrect but Statement-II is correct.

2. Ans: c

Explanation:

Marsupials are mammals whose young are born incompletely developed. They develop inside a pouch on the mother’s belly. They give live birth, but they do not have long gestation times like placental mammals. Instead, they give birth very early and the young animal, essentially a helpless embryo. The forelimbs however are developed, and the toes are armed with sharp, curved claws. They use these claws to make the journey to the pouch. 

Population:  

Today, most marsupials are found in Central and South America (around 70 species) and Australasia (around 200 species).

Habitat: Most Australian marsupials live in dry scrub or desert habitat. In South America, marsupials live in forests or tropical rainforests. Marsupials can live in any part of the forest habitat, from the trees to the forest floor where, like the wombat, they burrow underground.

Hence, option c is correct.

3. Invasive Species Specialist (that develops Global Invasive Species Database) belongs to which one of the following organisations?

(a) The International Union for Conservation of Nature

(b) The United Nations Environment Programme

(c) The United Nations World Commission for Environment and Development

(d) The World Wide Fund for Nature

3. Ans: a

Explanation:

Invasive Species Specialist Group (ISSG) 

• The Global Invasive Species Database is managed by the IUCN Species Survival Commission Invasive Species Specialist Group (ISSG) and the Global Register of Introduced and Invasive Species is an ISSG led initiative. The Invasive Species Specialist Group (ISSG) aims to reduce threats to natural ecosystems and the native species. The ISSG promotes and facilitates the exchange of invasive species information and knowledge.
• The IUCN Red List of Threatened Species also holds information on the impacts of invasive alien species (IAS)

Hence, option a is correct.

4. Consider the following fauna:

1. Lion-tailed Macaque

2. Malabar Civet

3. Sambar Deer

How many of the above are generally nocturnal or most active after sunset?

(a) Only one

(b) Only two

(c) All three

(d) None

4. Ans: a

Explanation:

Nocturnal animals become more active at night to hunt, mate, or avoid heat and predators. 

Nocturnal animals have evolved physical traits that let them to be active in the dark . 

• The eyes get bigger and the pupils widen. 
• Animals like owls and large cats have specialized hearing to hunt at night.
• Many nocturnal animals have a good sense of smell and often communicate with scent marking.   

Sambar Deer

• Of the seven species of deer found in South Asia, the sambar is the largest. 
• Only males have antlers, which in adults, have three tines on each side, and are shed annually.
• Males grow spike antlers in their second year, and their second set of antlers usually has small brow tines. Mature stags have six-tine antlers, and irregularities are rare.
• The sambar is distributed from the Philippine Islands in the east, through Indonesia, southern China, Indo-China, Thailand and Myanmar, to India in the west. 
• It is distributed throughout India, except in the arid and desert regions of western India. The sambar has been introduced in several countries outside its geographical range.
• The sambar utilises areas with moderate-to-steep slopes. The sambar subsists on a wider variety of plants than any other ungulate in India and this si largely due to the varied habitats it uses. 
• The diet can be broadly classified into browse (eating leaves) and grass. 
• The basic social unit of the sambar is the maternal family group: adult female, calf and yearling.
• Sambar deer are more active during the night than day, nocturnal movement , this movement varies with seasons and is  greater in  spring, summer and autumn.
•  Crepuscular activity was found to be high in all seasons. Maximum movement occur in the morning between 4 am to 8 am and in the evening between 6pm to 10pm.

Lion-tailed macaque

• Lion-tailed macaque is the the most primitive of all extant Asian macaques. 
• The lion-tailed m macaque is considered direct descendant of Macaca paleoindica, the first macaque to reach Asia, nearly five million years ago. 
• The lion-tailed macaque is endemic to the tropical rainforest (also called wet evergreen forest) of the Western Ghats in peninsular India. 
• They are a diurnal and arboreal species, and active during day time.
• The lion-tailed macaque feeds on fruits, seeds , nectar as well as on invertebrates and small vertebrates so largely it is omnivores. 
• Like other macaques lion-tailed macaque live in social groups. Most of the groups  in undisturbed forests have only one adult male, with 6 or 7 adult females and one subadult male, the remaining being immatures.

Malabar Civet

• It is considered mostly nocturnal.
• It is one of the rarest and most elusive mammals in the world.
• In the Western Ghats alone there are four species of civets, namely the common palm civet, brown palm civet, the small Indian civet and Malabar civet. 

Hence, option a is correct.  

5. Which of the following organisms perform waggle dance for others of their kin to indicate the direction and the distance to a source of their food?

(a) Butterflies

(b) Dragonflies

(c) Honey Bees

(d) Wasps

5. Ans: c

Explanation: 

Astonishingly, honeybees possess one of the most complicated examples of nonhuman communication.

Honey bees use a complex form of spatial referential communication. Their waggle dance communicates to nestmates the direction, distance, and quality of a resource by encoding celestial cues, retinal optic flow, and relative food value into motion and sound within the nest.

Hence, option c is correct. 

6. Consider the following statements:

1. Some mushrooms have medicinal properties.

2. Some mushrooms have psychoactive properties.

3. Some mushrooms have insecticidal properties.

4. Some mushrooms have bioluminescent properties.

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) Only three

(d) All four

6. Ans: d

Explanation:

About Mushroom:

Mushrooms are a lot like plants, but they lack chlorophyll and have to take nutrients from other materials. Mushrooms are neither plants nor animals.

They constitute their own kingdom: the Fungi. These include the familiar mushroom-forming species, as well as yeasts, molds, smuts, and rusts. 

Mushrooms usually don’t last very long. Once they’ve shed their spores, they collapse and deteriorate. 

Oyster mushroom possesses medicinal properties and health-promoting effects. 

Hence Statement 1 is correct.

An active compound known as hericenones that’s found in Lion’s Mane mushroom promote neuron projections, extending and connecting to other neurons. This means these components can stimulate the growth and repair of nerve cells, also known as neurons. They may protect against dementia, relieve mild depression, anxiety and speed up recovery from nervous system injuries. They could further treat and protect against neurodegenerative cognitive disorders such as Alzheimer’s disease. 

Hence Statement 2 is correct.

Cordyceps militaris has several beneficial effects and it is used for multiple medicinal purposes. It acts as an antitumor, antiproliferative, antimetastatic, insecticidal, and antibacterial compound.

Hence Statement 3 is correct.

The new species — named Roridomyces phyllostachydis — first sighted at night near a stream in Meghalaya’s Mawlynnong in East Khasi Hills district. It is one among the 97 known species of bioluminescent fungi in the world. In the case of fungi, the luminescence comes from the enzyme, luciferase. 

Hence Statement 4 is correct.

7. Consider the following statements regarding the Indian squirrels:

1. They build nests by making burrows in the ground.

2. They store their food materials like nuts and seeds in the ground.

3. They are omnivorous. 

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

 7. Ans: b

Explanation:

About Indian Squirrel:

• The squirrel family includes tree squirrels, ground squirrels, chipmunks, marmots (including woodchucks), flying squirrels, and prairie dogs amongst other rodents. 
• Indian squirrel is a very adaptable species. It is active during the day (diurnal animal) and semi-arboreal. 
• Indian palm squirrel is an omnivore. Its diet is mostly based on the fruit and nuts, but it also consumes eggs, small birds, larvae and insects. 
• Indian squirrels build nests in the treetops using the grass and branches. 
• In deciduous forests squirrels scatter-hoard seeds and nuts in shallow pits just below leaf litter.
• In this process squirrels will store hundreds of nuts and fruits per individual, some may germinate in this process. Individual squirrels remember precise location of their stored nuts.

Only Statement 2 and 3 are correct and 1is incorrect.

8. Consider the following statements:

1. Some microorganisms can grow in environments with temperature above the boiling point of water.

2. Some microorganisms can grow in environments with temperature below the freezing point of water.

3. Some microorganisms can grow in a highly acidic environment with a pH below 3.

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

 8. Ans: c

Explanation:

Thermophilic microorganisms have the capacity to grow at elevated temperatures sometimes exceeding the boiling point of water. The record is presently held by a hyperthermophilic Archaea, close to Pyrodictium occultum, known as strain 121 that still grows at 121 °C. 

Hence Statement 1 is correct.

The microorganisms live in every part of the biosphere, and some of them are even capable of growing at low temperatures, including those below the freezing point. Most of the microorganisms are well able to grow down to 0°-2°C. 

Hence Statement 2 is correct.

Acidophiles are microorganisms that show optimal growth in highly acidic environments. These are of two types. The extreme acidophiles dwell in environments with a pH value <3, and moderate acidophiles grow optimally in conditions having pH values ranging between 3 and 5.

Hence Statement 3 is correct.

9. Which one of the following makes a tool with a stick to scrape insects from a hole in a tree or a log of wood?

(a) Fishing cat

(b) Orangutan

(c) Otter

(d) Sloth bear

9. Ans: b

Explanation:

About Orangutans: 

• The name orangutan means “man of the forest” in the Malay language. In the lowland forests in which they reside, orangutans live solitary existences. 
• They feast on wild fruits like lychees, mangosteens, and figs, and slurp water from holes in trees. They make nests in trees of vegetation to sleep at night and rest during the day.
• Orangutans have been observed in the wild using simple tools like sticks to collect insects and leaves to shield them from the elements. They are renowned for having the ability to use tools, a unique trait among non-human animals. 
• Orangutans can make two separate sounds at the same time, just like songbirds and human beatboxers. 
• There are three species of orangutan – the Bornean, Sumatran and Tapanuli – which differ a little in appearance and behavior. The Bornean and Sumatran species have shaggy reddish fur, Sumatran orangutans have longer facial hair.
• All three orangutan species are considered critically endangered.
• Orangutans are the world’s largest tree-climbing mammals. 
• Orangutans are known as gardeners of the forest. They play a vital role in seed dispersal and in maintaining the health of the forest ecosystem, which is important for people and a host of other animals, including tigers, Asian elephants and Sumatran rhinos. 
• Orangutans are found only in the rain forests of the Southeast Asian islands of Borneo and Sumatra. They spend nearly their entire lives in trees—swinging in tree tops and building nests for sleep.
• Fruit makes up about 60% of the orangutan’s diet, including lychees, mangosteens, mangoes, and figs. They also eat young leaves and shoots, insects, soil, tree bark, and occasionally eggs and small vertebrates

About Sloth Bear:

• India has four species of bears : Asiatic Black, Sloth, Sun and Himalayan Brown Bear. Bear belong to the order of Carnivora. They are omnivorous animals who have a varied diet ranging from meat to fruit and are also known to scavenge on dead animals. 
• All Indian Bear species are listed under Appendix I in CITES and Schedule I of the Wildlife (Protection) Act, 1972. This provides complete protection to the species from hunting and trade.
• The Asiatic Black Bear is classed by the IUCN as a vulnerable species. 
• The Sun Bear is mostly distributed in South-East Asia. In India it occurs in the North-eastern region, though it is not common. It is the smallest of the eight bear species found across the globe. IUCN lists the Sun Bear as Vulnerable.
• The Sloth Bear is endemic to the Indian subcontinent and occurs in India, Nepal, Bhutan and Sri Lanka. The Sloth Bear is unique among the bear species in being adapted to ‘myrmecophagy’, i.e to eating ants and termites, which form a large proportion of its diet. This bear species is killed for their gall bladder.
• IUCN lists the Sloth Bear as Vulnerable.
• Himalayan brown bear is “critically endangered”.

About Fishing Cats:

• About twice the size of a typical house cat, the fishing cat is a feline with a powerful build and stocky legs. It is an adept swimmer and enters water frequently to prey on fish as its name suggests. It is known to even dive to catch fish.
• Wetlands are the favorite habitats of the fishing cat. In India, fishing cats are mainly found in the mangrove forests of the Sundarbans, on the foothills of the Himalayas along the Ganga and Brahmaputra river valleys and in the Western Ghats.
• The fishing cat is nocturnal and apart from fish also preys on frogs, crustaceans, snakes, birds, and scavenges on carcasses of larger animals.
• The fishing cat is listed as Endangered on the IUCN Red List, which means that it faces a high threat of extinction in the wild. 
• The Convention on International Trade in Endangered Species (CITES) lists the fishing cat on Appendix II part of Article IV of CITES, which governs international trade in this species. 
• In India, the fishing cat is included in Schedule I of the Indian Wildlife (Protection) Act, 1972 and thereby protected from hunting. 

About Otters:

• Otters are members of the mammalian family called Mustelidae. They are shy and have elusive habits, adapting to a variety of habitats ranging from marine to freshwater environments. 
• Otters are invariably associated with water, with a few exceptions. 
• African clawless Otter found in Central Equatorial Africa, are least adapted aquatically.
• Otters are mainly active around dawn and dusk, being, what is known as, crepuscular.
• Otters are found the world over, except in Australia, New Zealand, Madagascar, and other oceanic islands. 
• India is home to 3 of the 13 species of otters found worldwide. 
• These are – Eurasian Otter; Smooth-coated Otter and Small-clawed otter. The Small-clawed Otter (Aonyx cinereus) is the smallest.
• Fish forms the primary food item, although their diet is supplemented with rodents, snakes, amphibians, small mammals, and even young fledgling birds.
• Otters, as high-order carnivores at the top of their small niche eco-systems, metabolise poison slowly, storing it in their fatty tissues until they need to draw on these energy reserves. There is no evidence that chemical poisons kill otters.
• Sea Otters often keep their favorite rock with them, using it to smash open the hard shell of a clam or mussel that pried out of the waters, and they’ll do it all while still floating on their backs. 
• In India, the nomadic hunting tribes such as Gilhara, Badiya and Jogis are known to regularly kill otters for their skin and flesh.

10. Consider the following:

1. Aerosols

2. Foam agents

3. Fire retardants

4. Lubricants

In the making of how many of the above are Hydrofluorocarbons used?

(a) Only one

(b) Only two

(c) Only three

(d) All four

10. Ans: c

Explanation: 

Only in the making of the first three Hydrofluorocarbons (HFCs) are used.

About Hydrofluorocarbons (HFCs)

These are a group of synthetic gases primarily used for cooling and refrigeration. Many HFCs are very powerful, short-lived climate pollutants with an average atmospheric lifetime of 15 years.

HFCs are entirely human-made. They are primarily produced for use in refrigeration, air-conditioning, insulating foams and aerosol propellants, with minor uses as solvents and for fire protection. (Hence1,2,3 are correct) .

However, while HFCs have an ozone depletion potential of zero, they are potent greenhouse gases, and thus their manufacture and use became increasingly regulated in the 21st century.

As refrigerants, HFCs are used in a wide variety of cooling systems, from refrigerators and freezers to automotive air-conditioning units. HFCs are also used as blowing agents in the production of polymer foams; as firefighting agents (having replaced halons); as solvents in cleaning products for plastics and metals and in plasma etching for semiconductor technology; and as propellants in metred-dose inhalers prescribed for the treatment of asthma.

Lubricating oils are composed of 80–90% petroleum hydrocarbon distillate with 10–20% additives to impart specific properties to the oil. The petroleum hydrocarbon distillate generally consists of paraffinic or naphthenic compounds. They do not involve use of HFCs in their making. They are made from hydrocarbons.(Hence 4 is wrong)

About Hydrocarbons:

• Hydrocarbon is a class of organic chemical compounds composed only of the elements carbon (C) and hydrogen (H). 
• The carbon atoms join together to form the framework of the compound, and the hydrogen atoms attach to them in many different configurations. 
• Hydrocarbons are the principal constituents of petroleum and natural gas. 
• They serve as fuels and lubricants as well as raw materials for the production of plastics, fibres, rubbers, solvents, explosives, and industrial chemicals.

11. Consider the following statements: 

Once the Central Government notifies an area as a ‘Community Reserve’

1. The Chief Wildlife Warden of the State becomes the governing authority of such forest

2. Hunting is not allowed in such area

3. People of such area are allowed to collect non-timber forest produce

4. People of such area are allowed traditional agricultural practices

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) Only three

(d) All four

11. Ans: b

Explanation:

As per section 36C of Wildlife Protection Act 1972 the State Government may declare any private or community land as community reserve where the community or an individual has volunteered to conserve wild life and its habitat for protecting fauna, flora, traditional conservation and cultural conservation values and practices. Such land should not be comprised within a National Park, sanctuary or a conservation reserve.

Section 36Dof the WLP Act says that the State Government shall constitute a Community Reserve management committee, which shall be the authority responsible for conserving, maintaining and managing the community reserve. 

• The committee shall be the competent authority to prepare and implement the management plan for the community reserve and to take steps to ensure the protection of wild life and its habitat in the reserve. 
• The committee shall elect a Chairman who shall also be the Honorary Wild Life Warden on the community reserve. 
• The committee shall regulate its own procedure including the quorum.

Hence Statement 1 is incorrect.

After a forest has been made into a community reserve, people cannot hunt there, not they can use it for agricultural practices, leave alone jhum cultivation. 

Hence Statement 2 is correct and 4 is incorrect.

CR reserves allow for extraction of natural resources, the levels of which are governed by a multi-stakeholder Reserve Management Committee. Therefore, people are allowed to collect non-timber forest produce.

Hence Statement 3 is correct.

12. Consider the following statements regarding mercury pollution:

1. Gold mining activity is a source of mercury pollution in the world.

2. Coal-based thermal power plants cause mercury pollution.

3. There is no known safe level of exposure to mercury.

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

12. Ans: b

Expalanation:

Mercury

Mercury is highly toxic to human health, posing a particular threat to the development of the child in utero and early in life. It occurs naturally and exists in various forms: elemental (or metallic); inorganic (for example, mercuric chloride); and organic (for example, methylmercury and ethylmercury). These forms all have different toxicities, with different implications for health and for measures to prevent exposure.

 Elemental mercury is a liquid that vaporizes readily. It can stay for up to a year in the atmosphere, where it can be transported and deposited globally. It ultimately settles in the sediment of lakes, rivers or bays, where it is transformed into methylmercury, absorbed by phytoplankton, ingested by zooplankton and fish, and accumulates especially in long-lived predatory species, such as sharks and swordfish .

Mercury releases 

• Natural: volcanic activity, weathering of rocks, water movements, biological processes.
• Human activities: mercury-added products; manufacturing processes in which mercury or mercury compounds are used; artisanal and small-scale gold mining; coalfired power plants; coal-fired industrial boilers; smelting and roasting processes used in the production of non-ferrous metals; waste incineration facilities; cement clinker production facilities.
• Remobilization of legacy sources: mercury in soil, sediment, water, landfill, waste 

Hence Statement 1& 2 are correct.

WHO guidance values: provisional tolerable weekly intake

Joint FAO/WHO Expert Committee on Food Additives (JECFA) established a tolerable intake of µg/kg body weight per week for dietary exposure to methylmercury & inorganic mercury.

Hence Statement 3 is incorrect.

The Minamata Convention on Mercury, which entered in to force in 2017, implemented guidelines, which includes banning new mercury mines and phasing-out existing ones; regulating the use of mercury in artisanal and small-scale gold mining, certain industrial processes and the production of everyday items such as certain Compact fluorescent lamps, batteries and teeth fillings; as well as controlling the emissions of mercury as a by-product from a range of industrial sectors including coal burning.

13 .With reference to green hydrogen, consider the following statements:

1. It can be used directly as a fuel for internal combustion.

2. It can be blended with natural gas and used as fuel for heat or power generation.

3. It can be used in the hydrogen fuel cell to run vehicles.

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

13.Ans: c

Expalantion:

Hydrogen-powered engines There are two technologies: hydrogen Fuel Cell Electric Vehicles (FCEVs) and Hydrogen Internal Combustion Engines (H2ICE). 

A hydrogen engine(HCE) is an engine that uses hydrogen (H2) as fuel and burns hydrogen in an internal combustion engine. It is a modified gasoline-powered engine but doesnot emit any carbon based product.

 Since the earliest attempt at developing a hydrogen engine was reported by Reverend W. Cecil in 1820, hydrogen engines are not a recent invention. However adoption was passive due to high hydrogen costs and safet concerns with HCEs.

Hence Statement 1 is correct.

FCEVs generate electricity from hydrogen in a device known as a fuel cell that is used to power the electric motor. Therefore, fuel cell receive energy via electrochemical processes.

Hydrogen has a wide flammability range in comparison with all other fuels. As a result, hydrogen can be blended with a wide range of fuel-air mixtures. Hydrogen can be used in power plants as a fuel by either blending it with natural gas or alone in specialised turbines, or it can be used in fuel cells, (which consume H₂ and O₂), to generate electricity (power), heat and using hydrogen in these sectors reduce their carbon emissions. 

Hence Statement 2 and 3 are correct.

14 . Consider the following statements: 

Statement I: The soil in tropical rainforests is rich in nutrients. 

Statement II: The high temperature and moisture of tropical rainforests cause dead organic matter in the soil to decompose quickly. 

Which one of the following is correct in respect of the above statements? 

(a) Both Statement I and Statement II  are correct and Statement II is the correct explanation for Statement I

(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I

(c) Statement I is correct but Statement II is incorrect 

(d) Statement I is incorrect but Statement II is correct

14. Ans: d

Explanation:

It is a misconception that tropical soils are rich in nutrients. Initially, soil in its untouched state contains a thick mantle of Humus, making the soil fairly fertile due to the heavy leaf fall and decomposition of leaves by bacteria. But once the humus is used and natural vegetative cover is removed, the torrential downpours in these tropical rainforests soon wash out most of the soil nutrients. Thus, the soil deteriorates rapidly with subsequent soil erosion and soil impoverishment. 

Hence, statement 1 is incorrect.

Factors effecting decomposition

Organic matter decomposition is influenced by climatic conditions such as high temperature, sun exposure, soil moisture, aeration and soil type. Warm, humid climates have faster decomposition rates, while cool, dry climates have slower rates.

Temperature:

Decomposition rates increase with higher temperatures because microbial activity is generally more rapid in warmer conditions. Decomposing organisms are less active at colder temperatures, resulting in a low rate of decomposition. This is why food is kept in a fridge. As temperatures, increase, soil microorganisms become more active, leading to faster litter turnover and less organic matter accumulation.

Moisture:

Adequate moisture is necessary for microbial activity. Extremely dry or waterlogged conditions microorganisms’ activity can reduce and decomposition can be hindered. Moisture is crucial in decomposition, as it aids microbial activity and the breakdown of organic matter. Microorganisms, like bacteria and fungi, require water for metabolic processes and to transport nutrients within decomposing materials. Dry conditions can hinder microbial activity, as microorganisms require specific water levels. Maintaining a balanced moisture level is essential for optimizing decomposition processes, ensuring efficient nutrient cycling and soil fertility. 

Soil temperature and moisture content are crucial factors affecting decomposition rates. Warmer temperatures and high moisture levels result in higher rates of decomposition, faster litter turnover, and less organic matter accumulation

The high temperature and moisture of tropical rainforests cause dead organic matter in the soil to decompose more quickly than in other climates, thus releasing and losing its nutrients rapidly.

Hence, statement 2 is correct.

15. Consider the following activities: 

1. Spreading finely ground basalt rock on farmlands extensively 

2. Increasing the alkalinity of oceans by adding lime. 

3. Capturing carbon dioxide released by various industries and pumping it into abandoned subterranean mines in the form of carbonated waters. 

How many of the above activities are often considered and discussed for carbon capture and sequestration? 

(a) Only one 

(b) Only two 

(c) All three 

(d) None

15.Ans: c                                                             

Explanation:

Atmospheric enrichment of GreenHouse Gas can be moderated by either reducing anthropogenic emissions, or sequestering C in plant biomass or the soil or Oceans . Transfer of atmospheric CO2 into other pools with a longer Mean residence time (MRT), in such a manner that it is not re-emitted into the atmosphere in the near future, is called sequestration. Carbon dioxide is the most commonly produced greenhouse gas. 

Depending on the processes and technological innovations, there are three main types of C sequestration : (i) those based on the natural process of photosynthesis and conversion of atmospheric CO2 into biomass, soil organic matter or humus and other components of the terrestrial biosphere; (ii) those involving engineering techniques; and (iii) those involving chemical transformations 

Geologic carbon sequestration is the process of storing carbon dioxide (CO2) in underground geologic formations. The CO2 is usually pressurized until it becomes a liquid, and then it is injected into porous rock formations in geologic basins.

Biologic carbon sequestration refers to storage of atmospheric carbon in vegetation, soils, woody products, and aquatic environments. 

Carbon sequestration techniques

Enhanced rock weathering (ERW) 

Involves spreading finely crushed basalt, a natural volcanic rock, on fields to boost the soil’s ability to extract CO2 from the air.

Crushed basalt is applied to farmland due to its benefits for soil fertility, soil biology, crop yield and health. This mineral-rich volcanic rock also removes carbon dioxide from the atmosphere through a process called enhanced rock weathering.

Enhanced rock weathering (ERW) is a nature-based method of Carbon Dioxide Removal (CDR)  based on a geological process. In the planet’s carbon cycle, this process takes hundreds of thousands of years but

Silicate rock or basalt rock, when crushed into a fine powder, and spread on agricultural land then the rock begins weathering straight away, speed up by the increased reactive surface area. The basalt reacts with carbon dioxide to form stable carbonates, effectively storing carbon.

Hence, statement 1 is correct.

Ocean Alkalinity Enhancement

Ocean alkalinization is an approach to carbon removal that involves adding alkaline substances  with high pH to seawater to enhance the ocean’s natural carbon sink. These substances could include minerals, such as olivine, or artificial substances, such as lime or some industrial byproducts. Adding alkalinity to the ocean removes carbon dioxide (CO2) from the atmosphere through a series of reactions that convert dissolved CO2 into stable bicarbonate and carbonate molecules, which in turn causes the ocean to absorb more CO2 from the air to restore equilibrium. 

Hence, statement 2 is correct. 

Carbon capture and storage (CCS) 

Carbon dioxide emissions from industrial processes are captured and stored underground. Abandoned subterranean mines can serve as suitable storage sites, with the captured carbon dioxide pumped into these locations in the form of carbonated waters.

The process of capturing carbon dioxide (CO2) and storing it can be condensed into three stages: capture, transportation, and underground injection. Once discharged into rock formations, the CO2 is stored long-term.

Hence, statement 3 is correct.

Direct Air Capture 

Direct air capture encompasses land-based processes that directly remove carbon dioxide from the air via filtration. Carbon dioxide is then transported to storage reservoirs in solid or liquid form, where it is durably stored for hundreds to thousands of years. 

Microalgal cultivation

The large-scale farming of seaweed, also known as microalgal cultivation or aquaculture, draws down carbon dioxide from the atmosphere as part of the process of photosynthesis that occurs as the seaweed grows. 

Ocean Fertilization 

Ocean fertilisation is the addition of nutrients such as iron, nitrogen, and phosphorus to the surface of the ocean to stimulate the growth of phytoplankton that naturally absorb carbon dioxide during photosynthesis.

Coastal Blue Carbon 

The process by which coastal blue carbon ecosystems (e.g. seagrass, mangroves, and salt marshes) sequester and store carbon. Coastal blue carbon ecosystems absorb carbon from the atmosphere via photosynthesis.

16. Consider the following statements: 

Statement-I: According to the United Nations ‘World Water Development Report, 2022’, India extracts more than a quarter of the world’s groundwater withdrawal each year. 

Statement-II: India needs to extract more third quarter of the world’s groundwater each year to satisfy the drinking water and sanitation needs of almost 18% of world’s population living in its territory. 

Which one of the following is correct in respect of the above statements? 

(a) Both Statement-I and Statement-II are correct and Statement II is the correct explanation for Statement I 

(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I

(c) Statement I is correct but Statement II is incorrect 

(d) Statement I is incorrect but Statement II is correct

16. Ans: c

Explanation:

The distribution of water on the Earth’s surface is extremely uneven. Only 3% of water on the surface is fresh; the remaining 97% resides in the ocean. Of freshwater, 69% resides in glaciers, 30% underground, and less than 1% is located in lakes, rivers, and swamps. 

The United Nations released the 2022 edition of the UN World Water Development Report (WWDR), which focuses on groundwater, aiming to make “the invisible visible.” According to the report, 99% of the Earth’s running freshwater is groundwater. Among other things, the report highlights the overexploitation of this precious resource and why proper management is the need of the hour.

Country comparison of groundwater-sourced irrigation

Countries with the largest area under irrigation include China (73 Mha), India (70 Mha), the USA (27 Mha) and Pakistan (20 Mha). The proportion of total groundwater abstraction used for irrigation varies significantly in these countries. India, as the largest groundwater user globally, at an estimated 251 km³ per year abstracted, uses 89% of its groundwater abstraction for irrigation. China is relatively less reliant on groundwater, with an estimated 54% of total groundwater abstraction going into irrigation on average

The United Nations ‘World Water Development Report, 2022’, notes that India is the largest groundwater user globally with an estimated withdrawal of 251 km³ per year through an estimated 20 million wells and tube wells. This accounts for almost 26% of the groundwater extracted globally. 

Hence, statement 1 is correct.

About 89% of groundwater is used in India for irrigation. In India, 60% of the electricity used in the water sector is for groundwater abstraction.  

 India’s water crisis can be largely traced to the expansion of groundwater irrigation, a trajectory set on course by India’s food and electricity policy since the late 1970s. 

The food policy guaranteeing cheap food to consumers dictates the need to keep input prices low, including the level of electricity tariffs for pumping groundwater. 

Reduced electricity tariffs or free electricity to agriculture, as exist in many Indian states, coupled with assured state or government procurement of crops, encourage farmers to grow water-intensive crops, such as sugarcane, including in semi-arid regions with low natural recharge. This is responsible for unprecedented groundwater depletion in large parts of India

Groundwater overwithdrawal in India can be traced to a lack of coherence between water, energy and food policies. Hence, solutions to India’s groundwater problems should be positioned within a broader water–energy– food nexus context.

Hence, statement 2 is incorrect.

17. Consider the following statements:

1. In India, the Biodiversity Management Committees are key to the realization of the objectives of the Nagoya Protocol. 

2. The Biodiversity Management Committees have important functions in determining access and benefit sharing, including the power to levy collection fees on the access of biological resources within its jurisdiction. 

Which of the statements given above is/are correct?

 (a) 1 only

 (b) 2 only

 (c) Both 1 and 2

 (d) Neither 1 nor 2

17. Ans: c

Explanation:

The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization to the Convention on Biological Diversity is an international agreement which aims at sharing the benefits arising from the utilization of genetic resources in a fair and equitable way. It entered into force on 12 October 2014

The primary responsibility of BMCs is the preparation of peoples’ biodiversity registers (PBRs) containing comprehensive knowledge on the availability and knowledge of local biological resources, their medicinal, or any other use or associated traditional knowledge.

The BMCs also have important functions in determining access and benefit-sharing (ABS), including the power to levy collection fees on the access of biological resources within its jurisdiction. 

BMCs are, thus, key to the realisation of the objectives of the Nagoya Protocol (2010), negotiated within the CBD.

The enjoining parties have to take measures to ensure that benefits from the utilisation of genetic resources and associated traditional knowledge accrue to indigenous and local communities on mutually agreed terms.

Hence Statement 1 is correct.

Section 41 of  Biological Diversity Act 2002- Constitution of Biodiversity Management Committee-

(1) Every local body shall constitute a Biodiversity Management Committee within its area for the purpose of promoting conservation, sustainable use and documentation of biological diversity including preservation of habitats, conservation of land races, folk varieties and cultivars, domesticated stocks and breeds of animals and microorganisms and chronicling of knowledge relating to biological diversity. 

(2) The National Biodiversity Authority and the State Biodiversity Boards shall consult the Biodiversity Management Committees while taking any decision relating to the use of biological resources and knowledge associated with resources occurring within the territorial jurisdiction of the Biodiversity Management Committee. 

(3) The Biodiversity Management Committees may levy charges by way of collection fees from any person for accessing or collecting any biological resource for commercial purposes from areas falling within its territorial jurisdiction. 

Hence Statement 2 is correct.

18. Consider the following heavy industries: 

1. Fertilizer plants 

2. Oil refineries 

3. Steel plants 

Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries? 

(a) Only one 

(b) Only two 

(c) All three 

(d) None

18. Ans: c

Explanation:

Green hydrogen for decarbonizing steel making

The steel industry contributes 7% of total CO2 emissions worldwide. Hydrogen can be injected into blast furnaces, where steel is made, thus substituting coke oven gas for a clean fuel (green hydrogen). This technology has certain limitations such as the cooling effect of the hydrogen inside the blast furnace and is still being developed.

Green hydrogen for decarbonizing the chemical industry

The chemical industry, with 10% of global energy consumption and 7% of greenhouse gas effect emissions, encompasses many sectors in the modern economy. It represents all activities focused on obtaining and transforming materials and composites by applying chemical processes to them.

Although the industry still largely depends on oil, hydrogen is now increasingly used in the manufacture of chemical and intermediate products. Real sustainable transformation will arrive when this hydrogen is completely green. 

Green hydrogen for decarbonizing refineries Refineries are used to convert crude oil into products that are useful to people. Responsible for 4% of world CO2 emissions, this sector produces the likes of petrol, diesel, asphalt, kerosene, liquid gas, oils and other fuels.

One of the main uses of green hydrogen in this sector is as a substitute for fuels and hydrogen of fossil origin in various processes currently performed in refineries and petrochemical plants.

Another promising application in this sector is the development of sustainable fuels for heavy transportation, as in the aviation and maritime transport sectors.

Hence all statements are correct.