2019 UPSC Main GS 1 Examination Answers to Questions on Environment and Ecology

General Studies Paper 1

Q.No.4. Assess the impact of global warming on coral life system with examples. (150 words; 10 Marks).                    

Coral reefs, mostly found in the shallow coastal zones, are hard, intricate, and colourful three-dimensional structures. They are the nurseries and habitats for thousands of species of marine animals. Corals are built by very large colonies of tiny organisms called polyps.

Coral reefs protect marine biodiversity, provide many ecosystem services, and protect the coast against tsunamis and cyclones. Coral reefs are very vulnerable to damage because they grow very slowly, get disrupted easily, and are very sensitive to variations in temperature and salinity.

Global warming has led to the following negative impacts on corals:

·      Coral bleaching: When global warming increases the ocean temperature, coral reefs become stressed, eject the zooxanthellae, and thus lose their food and die. This is called bleaching, because they turn white.

·      Sea-level rise: Global warming leads to sea-level rise and the vertical growth rate of coral is likely to be slower than the rate of sea-level rise. Consequently, corals will be deeper, receive less sunlight, and grow more slowly.

·      Ocean acidification: The ocean absorbs about 25% of the carbon we deposit in the atmosphere through our emissions. Since we have been rapidly increasing our emissions, more carbon enters the ocean, making it more acidic. This in turn makes it difficult for polyps to create their reefs. With greater acidification, corals may also form weaker reefs, making them more vulnerable to storm damage, careless tourists, and destructive fishing practices.

·      Storms: More frequent storms that are expected due to climate change may also damage reef structure more significantly, and the corals’ regrowth may not be able to keep pace. Healthy reefs also reduce the impact of storms.

(While the topic of coral reefs is discussed in Chapter 6 of my book, global warming is covered in Chapter 15.)

Q.No.5. Discuss the causes of depletion of mangroves and explain their importance in maintaining coastal ecology. (150 words; 10 Marks)

Mangroves are salt-tolerant trees that grow in the coastal intertidal zone. Like coral reefs, mangroves are also among the most productive and biologically complex ecosystems on earth.

Mangroves are vital for coastal ecology due to the following reasons:

·      Mangroves offer protection against the rising seas and cyclones. They are buffers between the land and the sea.

·      Mangroves help in reclaiming land from seas.

• Mangroves provide nutrients to other ecosystems such as coral reefs and sea grass beds.

·      Mangrove forests are the nurseries and habitats for a large number of marine organisms including shrimps, crabs, and fish species.

·      Mangrove trees are used as timber for house building, furniture, boat building, etc. 

·      Poor people use mangroves as fuelwood and also as a substitute for fodder.

·      Tannin from the bark of some mangrove species is used by fishermen to dye their fishing nets.

·      Honey is collected from some mangrove species.

• Mangroves absorb carbon from the atmosphere.

Mangroves are depleted due to the following reasons:

·      As the coastal zone faces population and developmental pressures, mangroves are cut down to make way for salt pans, aquaculture ponds, human settlements, roads, port facilities, resorts, golf courses, and farms.

·      Mangroves also die from oil spills, chemical pollution, sediment overload, and disruption of their sensitive water and salinity balance.

(The topic of mangroves is discussed in Chapter 6 of my book.)

Q.No.14. What is water stress? How and why does it differ regionally in India? (250 words; 15 Marks)

The minimum per capita requirement of water is about 1700 cu. m per year. This includes the amounts required for home, agriculture, and industry (including energy production). Once the water availability drops below this level, the country becomes water-stressed.

According to a 2019 Report from the World Resources Institute, among the 17 extremely highly water-stressed countries, India ranks 13th. At the same time, India has more than three times the combined population of the other 16 highly stressed countries.

In addition to rivers, lakes and streams, India’s groundwater resources are severely overdrawn, largely to provide water for irrigation. Groundwater tables in some northern aquifers declined at a rate of more than 8 cm per year between 1990 and 2014.

The Union Territory of Chandigarh has the highest water stress, followed by Haryana, Rajasthan, Uttar Pradesh, Punjab, Gujarat, Uttarakhand, Madhya Pradesh, and Jammu and Kashmir. The states of Punjab and Haryana alone produce 50% of the national government’s rice supply and 85% of its wheat stocks. Both crops are highly water intensive.

NITI Aayog has developed a Composite Water Management Index (CWMI) for every state based on groundwater restoration, irrigation management, on-farm water use, rural and urban drinking water supply, water policy frameworks, etc. CWMI is expressed as a score out of 100.

CWMI scores for 2016-17 show that Gujarat is the highest performer, closely followed by Madhya Pradesh and Andhra Pradesh. Meghalaya is the worst performer. Of the 24 states assessed, 14 are low performers, concentrated across the populous agricultural belts of North and East India, and among the North-Eastern and Himalayan states.

The high water-stress in the North is due to:

·      Water- and chemical-intensive agriculture requiring heavy withdrawal of ground water.

·      Availability of free power leading to excessive pumping of water.

Other factors include pollution of water sources and arsenic contamination of tubewells.

(The topic of water resources is discussed in Chapter 7 of my book.)

Q.No.15. How can the mountain ecosystem be restored from the negative impact of development initiatives and tourism? (250 words; 15 Marks)

Mountain ecosystems perform many ecological services for us. The majority of the world’s forests are in the mountains. Apart from being home to endemic species of plants and animals, they are also sanctuaries for animals driven away from the lowland by human activities.

Mountains also play a vital role in the water cycle. They absorb precipitation in the soil and vegetation and slowly release the water through small streams. These streams often join together and become rivers. Thus the mountains act as reservoirs, storing water in the monsoon and releasing it slowly during the dry season.

Human beings have interfered in many mountain ecosystems: We have cleared the forests, laid roads, dammed rivers, mined minerals, built towns, and so on. Tourism has increased the floating population to unsustainable levels. Tourists also dump large quantities of waste on mountain ranges.

Due to deforestation the mountains cannot hold the soil and the water. The slopes become barren there are floods during monsoon and drought during the summer. The biodiversity is also lost.

The following measures should be taken to restore the ecology of mountain ranges:

• Forests should be protected by setting up reserves, national parks or biosphere reserves, as appropriate.
• The existing laws such as the Indian Forest Act 1927, Wildlife (Protection) Act 1972, Forest Conservation Act 1980, and the Environment (Protection) Act 1986 should be strictly enforced.
• Instead of planning big dams, sustainable alternatives such as micro-hydel systems and other alternative energy sources should be examined.
• Strict regulations should be enforced on mountaineering and trekking expeditions.
• Practical steps should include the banning of plastic, conservation of lakes, better town planning, regulation of tourism, rejuvenation of springs and catchments, promoting alternative cooking fuels, involvement of communities, creation of environmental awareness, empowerment of women, etc.

(The topic of mountain ecosystem is discussed in Chapter 2 of my book.)