UPSC Essentials | Mains answer practice — GS 3 (Week 17)

QUESTION 2

What are the possible reasons behind the cyclic transformation of the Sahara Desert into savannah and woodland ecosystems?

General points on the structure of the answers

Introduction

— The introduction of the answer is essential and should be restricted to 3-5 lines. Remember, a one-liner is not a standard introduction.

— It may consist of basic information by giving some definitions from the trusted source and authentic facts.

Body

— It is the central part of the answer and one should understand the demand of the question to provide rich content.

— The answer must be preferably written as a mix of points and short paragraphs rather than using long paragraphs or just points.

— Using facts from authentic government sources makes your answer more comprehensive. Analysis is important based on the demand of the question, but do not over analyse.

— Underlining keywords gives you an edge over other candidates and enhances presentation of the answer.

— Using flowcharts/tree-diagram in the answers saves much time and boosts your score. However, it should be used logically and only where it is required.

Way forward/ Conclusion

— The ending of the answer should be on a positive note and it should have a forward-looking approach. However, if you feel that an important problem must be highlighted, you may add it in your conclusion. Try not to repeat any point from body or introduction.

— You may use the findings of reports or surveys conducted at national and international levels, quotes etc. in your answers.

Self Evaluation

— It is the most important part of our Mains answer writing practice. UPSC Essentials will provide some guiding points or ideas as a thought process that will help you to evaluate your answers.

THOUGHT PROCESS

You may enrich your answers by some of the following points

QUESTION 1: The ozone layer is a shield of gas that protects our planet from harmful parts of the Sun’s radiation. Discuss how Montreal Protocol had helped in the reduction of ozone-depleting substances.

Introduction:

A simple introduction to this answer can revolve around a general statement about Ozone.

— Ozone is a molecule that is made up of three oxygen atoms. A layer of this gas sits in our planet’s stratosphere between 15 and 30 kilometres above the surface. It absorbs a portion of the radiation from the Sun, preventing it from reaching the planet.

— Ozone is a molecule that is made up of three oxygen atoms. A layer of this gas sits in our planet’s stratosphere between 15 and 30 kilometres above the surface.

— It absorbs a portion of the radiation from the Sun, preventing it from reaching the planet. It also prevents UV-B radiation from reaching the Earth and harming humans and other living beings.

(Source: Ozone Day 2023: Celebrating the success of the Montreal Protocol)

Body:

You may incorporate some of the following points in the body of your answer:

Montreal Protocol

— The 1989 Montreal Protocol is meant to protect the ozone layer of the upper atmosphere.

— A set of chemicals, mainly the chlorofluorocarbons or CFCs, which were being used in the air-conditioning and refrigeration industry earlier, were found to be damaging the ozone layer of the upper atmosphere.

— The extensive use had led to depletion of the ozone layer, and formation of an “ozone hole” over the Antarctic region.

— Montreal Protocol mandated the complete phase-out of CFCs and other ozone-depleting substances (ODS), which it has successfully managed to do in the last three decades.

— CFCs were gradually phased out, first by HCFCs, or hydrochlorofluorocarbons in some situations, and then by HFCs, which have little ozone-depleting potential.

The Kigali Amendment

— In 2016, countries agreed to include HFCs in the list of controlled substances under Montreal Protocol and decided on a schedule for its phase-down.

— If implemented successfully, the Kigali Amendment is expected to prevent about 0.5°C rise in global warming by the end of this century.

(Source: Use Montreal Protocol-type framework to reduce methane fast, says expert by Amitabh Sinha, Ozone Day 2023: Celebrating the success of the Montreal Protocol)

Conclusion:

Your conclusion should be short. You may include:

— September 16 is celebrated as Ozone Day. This year it was celebrated under the theme “Montreal Protocol: Fixing the ozone layer and reducing climate change.”

— The Montreal Protocol is considered the most successful international environmental regulation, having managed to eliminate almost 90 per cent of the ozone-depleting chemicals like chlorofluorocarbons (CFCs) which were widely used in the furniture and air-conditioning industry. Montreal Protocol has a fairly good track record on ensuring climate benefits as well.

— The UNEP estimates that, with Kigali Amendment, the avoided emissions could touch 420 billion tonnes of carbon dioxide equivalent by the end of the century.

— India had played a key role in negotiating the Kigali Amendment. It had fought hard to get an extended timeline for itself, and some other countries, for the reduction of HFC use.

— The 20-year ‘India Cooling Action Plan’, or ICAP, released in 2019, describes cooling as a “developmental need” and seeks to address the rising demand in cooling, from buildings to transport to cold-chains, through sustainable actions.

(Source: Ozone Day 2023: Celebrating the success of the Montreal Protocol)

Points to Ponder

Methane

Greenhouse Gases

Global Warming

Related Previous Year Question

Discuss global warming and mention its effects on the global climate. Explain the control measures to bring down the level of greenhouse gases which cause global warming, in the light of the Kyoto Protocol, 1997. (2022)

QUESTION 2: What are the possible reasons behind the cyclic transformation of the Sahara Desert into savannah and woodland ecosystems?

Introduction:

A simple introduction to this answer can revolve around a general statement about Sahara Desert.

— The Sahara desert covers an area of around 9,200,000 square kilometres and is one of the largest hot deserts in the world.

— Deserts are defined by low average annual rainfall — usually 100 millimeters (less than 4 inches) of rain per year or less.

— The cyclic transformation of the Sahara Desert into savannah and woodland ecosystems is one of the most remarkable environmental changes on the planet.

— According to the research study that was published in the journal Nature Communications, the periodic wet phases in the Sahara desert were caused by changes in Earth’s orbit around the Sun.

(Source: New study sheds light on when and how the Sahara desert turned green)

Body:

You may incorporate some of the following points in the body of your answer:

Possible Reasons

— Increase in the African Humid period which could have allowed the dispersal of various species.

— There is already a lot of evidence to back up the hypothesis that the Sahara was once vegetation. These “North African humid periods” may have had a significant influence in the establishment of vegetation passageways out of Africa.

— The greenings of the Sahara Desert could have been driven by changes in Earth’s orbital precession.

— The Earth’s spin influences seasonality over an approximately 21,000-year cycle. The changes in precession also decide the amount of energy received by the planet during different seasons.

— These changes caused warmer summers in the Northern hemisphere and thereby increased the strength of the West African monsoon system which has increased rain in the Sahara, causing the spread of savannah-type vegetation through the desert.

(Source: New study sheds light on when and how the Sahara desert turned green)

Points to Ponder

Species living in the Sahara Desert

Countries covered under the Sahara Desert

Rivers flowing through the Sahara Desert

Related Previous Year Questions

The process of desertification does not have climate boundaries. Justify with examples. (2020)

Major hot deserts in northern hemisphere are located between 20-30 deg N latitudes and on the western side of the continents. Why? (2013)

Previous Mains Answer Practice

UPSC Essentials: Mains answer practice — GS 1 (Week 16)

UPSC Essentials: Mains answer practice — GS 1 (Week 15)

UPSC Essentials: Mains answer practice — GS 2 (Week 15)

UPSC Essentials: Mains answer practice — GS 2 (Week 16)

UPSC Essentials: Mains answer practice — GS 3 (Week 15)

UPSC Essentials: Mains answer practice — GS 3 (Week 16)

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