Class 7 Science Chapter 6 – Climate Change And Its Impact – All Textual Solutions | ASSEB Assam (English Medium)

Class 7 Science Chapter 6 Climate Change And Its Impact Solutions | ASSEB Assam | English Medium

Class 7 Science (Amar Bijan) Chapter 6 – Climate Change And Its Impact Complete Textual Question Answers and Solutions (ASSEB Assam – English Medium)

The sixth chapter of the Class 7 Science (English Medium) syllabus, ‘Climate Change And Its Impact,’ is a highly relevant and critical topic for environmental awareness. Based on the new ASSEB (Assam State School Education Board) guidelines and the latest National Education Policy (NEP) framework according to the current syllabus, we have prepared comprehensive textual question answers for this chapter. This special guide includes very short answers (VSA), short questions, long descriptive answers, multiple-choice questions (MCQs), and additional questions. Brought to you by Ospin Academy, these solutions are accurate, easy to understand, and highly exam-oriented.

In ‘Climate Change And Its Impact’, students learn about the crucial differences between weather and climate, the causes of global warming, the greenhouse effect, and how these factors severely impact our planet’s ecosystems. The chapter also explores how various animals adapt to extreme climates to survive. Understanding these environmental changes is vital for both academic success and global awareness. Our textual solutions not only cover the textbook exercises but also provide extra important questions and MCQs to ensure students have a thorough grasp of the topic.

What you will learn and get from these textual solutions:

• Clear explanations of weather, climate, and the factors causing climate change.
• 1-mark objective questions (VSA), MCQs, and detailed 2-3 mark short questions tailored for exams.
• Step-by-step explanations for 4-5 mark long questions, discussing the greenhouse effect, global warming, and mitigation strategies.
• A wide range of additional questions and MCQs specifically designed according to the new syllabus pattern.
• Comprehensive insights into animal adaptations in polar and tropical regions, explained in simple English.

Special Features of Ospin Academy’s Notes:

• Prepared strictly according to the new ASSEB syllabus and current educational guidelines.
• 100% accurate and written in simple, easy-to-memorize English (Class 7 Science Notes).
• Includes quick revision summaries on environmental issues, highly beneficial for last-minute exam preparation.
• Exclusive compilation of extra important questions and MCQs to maximize your scores.

Aiming for academic excellence, Ospin Academy provides these comprehensive textual solutions to aid students in their studies. Start your preparation today and secure the highest marks in Class 7 Science.

 SCERT Assam, Class 7: Science

Lesson-6                                                                 Ospin Academy

Climate Change and Its Impact

 

EXERCISE 

1. Darken the circle for correct answer 

(i) Which gas is the main cause of global warming?
(a) Oxygen
(b) Carbon dioxide
(c) Hydrogen
(d) Nitrogen
Answer: (b)

(ii) Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Methane
(c) Nitrous oxide
(d) Oxygen
Answer: (d)

(iii) Climate change mainly refers to
(a) Daily weather changes
(b) Weekly weather changes
(c) Long-term changes in temperature and rainfall
(d) Change of climate with seasons
Answer: (c)

(iv) Planting more trees helps in-
(a) Increasing global warming
(b) Reducing oxygen
(c) Increasing ozone hole
(d) Reducing carbon dioxide
Answer: (d)

(v) Melting of glaciers due to climate change causes
(a) Earthquake
(b) Volcano
(c) Floods and sea level rise
(d) Landslide
Answer: (c)

2. Fill in the blanks
(a) The gradual increase in Earth’s average temperature is called ______
Answer: global warming 

(b) ______ is the main greenhouse gas released from vehicles.
Answer: carbon dioxide (c) The process of cutting down forests is called ______
Answer: deforestation 

(d) Planting trees increases ______ in the atmosphere.
Answer: oxygen 

(e) Deforestation increases the amount of ______ in the atmosphere.
Answer: carbon dioxide

3. True or False
(a) Climate change only affects humans, not animals. (True/False)
Answer: False 

(b) Burning fossil fuels adds greenhouse gases to the atmosphere.
(True/False)
Answer: True 

(c) Deforestation helps in reducing global warming. (True/False)
Answer: False 

(d) Global warming has no connection with sea level rise. (True/False)
Answer: False 

(e) Planting trees is one solution to reduce climate change. (True/
False)
Answer: True 

4. Match the following:

Column A	Column B
(a) Methane	(i) Released by burning fossil fuels
(b) Sea level rise	(ii) Rise in Earth’s temperature
(c) Global warming	(iii) Melting of glaciers
(d) Carbon dioxide	(iv) Green house gas from cattle.

Answer: 

Column A	Column B
(a) Methane	(iv) Green house gas from cattle.
(b) Sea level rise	(iii) Melting of glaciers
(c) Global warming	(ii) Rise in Earth’s temperature
(d) Carbon dioxide	(i) Released by burning fossil fuels

5. Name and describe briefly the different climatic zones of India.
Answer: India exhibits diverse climatic conditions, broadly categorized into several distinct zones:
(i) Tropical Wet: Characterized by persistent heavy rainfall nearly year-round. These regions maintain high humidity, featuring extended monsoons and very brief dry periods, leading to the growth of dense, lush evergreen forests.
(ii) Tropical Wet and Dry: These areas experience significant rainfall specifically during the monsoon season. However, they endure long, arid dry seasons and intensely hot summers, which supports the growth of deciduous forests.
(iii) Sub-tropical Humid: This zone sees moderate to heavy summer monsoons. The summers are typically sweltering and humid, contrasting sharply with winters that are notably frigid and dry, also fostering deciduous vegetation.
(iv) Semi-arid: Defined by relatively sparse rainfall. The summers are scorching while winters remain mild. The landscape here is dominated by hardy grasses and thorny scrub vegetation.
(v) Arid or Dry Desert: These regions suffer from extreme scarcity of rain, resulting in very arid air. They experience extreme temperature fluctuations with blistering hot days and freezing nights, making vegetation extremely scarce.
(vi) Montane (Alpines): Found at high elevations, this zone has a cold climate year-round. Winters bring heavy snowfall, and summers remain cool, providing an ideal environment for coniferous pine forests.

 6. What is climate change? Explain with suitable examples.
Answer: Climate change represents substantial, long-lasting alterations in the Earth’s average weather patterns and overall climatic conditions over extended periods. Rather than day-to-day weather fluctuations, it signifies persistent shifts in global systems. Concrete examples include the continuous upward trend in global temperatures, the accelerated melting of ancient polar ice caps and glaciers, the consequential rising of global sea levels, and the increasing frequency of extreme weather events like severe droughts, intense heatwaves, and catastrophic flooding.

7. Why is climate change considered one of the biggest challenges facing the world today?
Answer: Climate change is a monumental global challenge because its destructive impacts penetrate every facet of planetary existence. It dangerously elevates global temperatures and triggers deadly heatwaves. The resulting glacial melt raises sea levels, directly threatening coastal cities with submersion. Furthermore, it disrupts predictable weather cycles, unleashing abnormal rainfall, devastating floods, and severe droughts. These disruptions severely cripple agricultural food production, destroy natural ecosystems, and pose grave, escalating threats to human health and survival worldwide.
8. What is global warming? Explain it with reference to the greenhouse effect.
Answer: Global warming is the sustained, gradual increase in the overall temperature of the Earth’s atmosphere and oceAnswer: This phenomenon is intricately linked to the “greenhouse effect.” Certain gases in the atmosphere, like carbon dioxide, methane, and nitrous oxide, act much like the glass walls of a greenhouse. They permit the sun’s incoming light to reach the Earth but trap the outgoing heat radiating back from the surface, preventing it from escaping into space. While a natural greenhouse effect is necessary to keep Earth warm enough for life, the excessive accumulation of these gases—primarily due to human actions—has intensified this heat-trapping process, leading to the dangerous overarching warming of the globe.

9. How do human activities cause global warming, and why is it
considered a serious environment problem?
Answer: Human activities are the primary drivers of modern global warming through the massive emission of greenhouse gases. Industrial processes, the combustion of fossil fuels (coal, oil, gas) for electricity and transportation, and unchecked deforestation severely increase carbon dioxide levels. Additionally, poor waste management, agricultural practices, and the widespread use of appliances like refrigerators and air conditioners release potent gases like methane and CFCs into the atmosphere.
It is classified as a severe environmental crisis because it destabilizes the planet’s ecological balance. The trapped heat causes extreme climatic shifts: escalating global temperatures trigger lethal heatwaves and massive wildfires. The melting of polar ice caps and glaciers causes sea levels to surge, endangering low-lying regions. It also provokes erratic, extreme weather patterns—ranging from catastrophic floods to prolonged droughts—threatening global food security and biodiversity.
10. As a class 7 student, what steps can you take at the individual level to help reduce global warming?
Answer: As a conscientious 7th-grade student, I can make meaningful contributions to combat global warming through several individual actions:
(i) I will minimize reliance on fossil-fuel-driven transport by choosing to walk or ride a bicycle for shorter distances, thereby reducing my personal carbon footprint.
(ii) I will practice energy conservation diligently by always turning off lights, ceiling fans, televisions, and other electrical appliances immediately when they are not in use.
(iii) I will actively participate in environmental greening by planting more trees in my surroundings and ensuring their proper care, as trees naturally absorb harmful carbon dioxide.

 

Multiple Choice Questions (MCQs)

1. Which of the following is NOT a consequence of global warming?
(A) Melting of glaciers
(B) Rise in sea levels
(C) Increase in earthquake frequency
(D) Extreme weather events
Answer: (C)

2. What is the primary source of the greenhouse gas methane?
(A) Deforestation
(B) Agricultural practices and cattle digestion
(C) Burning of coal
(D) Vehicular exhaust
Answer: (B)

3. The trapping of the sun’s heat in the Earth’s lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface is known as:
(A) Solar radiation
(B) Ozone depletion
(C) The Greenhouse Effect
(D) Global dimming
Answer: (C)

4. Which human activity contributes most significantly to the increase of carbon dioxide in the atmosphere?
(A) Planting trees
(B) Using bicycles
(C) Burning fossil fuels
(D) Solar power generation
Answer: (C)

5. How does deforestation directly contribute to global warming?
(A) It increases the oxygen level
(B) It reduces the number of trees available to absorb carbon dioxide
(C) It cools the Earth’s surface
(D) It stops rainfall
Answer: (B)

6. Which of these is a simple individual action to mitigate climate change?
(A) Leaving lights on when leaving a room
(B) Using public transport or carpooling
(C) Cutting down backyard trees
(D) Burning plastic waste
Answer: (B)

7. In which climatic zone of India are dense evergreen forests primarily found?
(A) Arid or dry desert
(B) Semi-arid
(C) Montane
(D) Tropical wet
Answer: (D)

8. What type of vegetation is characteristic of the ‘Semi-arid’ climatic zone?
(A) Tall pine trees
(B) Dense evergreen forests
(C) Thorny shrubs and grasses
(D) Mangroves
Answer: (C)

9. The slow, gradual rise in the average temperature of the Earth’s atmosphere and its oceans is termed:
(A) Weather fluctuation
(B) Climate cycle
(C) Global warming
(D) Thermal inversion
Answer: (C)

10. Which of the following releases Chlorofluorocarbons (CFCs), a potent greenhouse gas?
(A) Traditional wood stoves
(B) Air conditioners and refrigerators
(C) Wind turbines
(D) Bicycles
Answer: (B)

11. What is the impact of rising global temperatures on polar regions?
(A) Ice caps grow thicker
(B) More snowfall occurs
(C) Accelerated melting of glaciers and ice sheets
(D) No visible change
Answer: (C)

12. What distinguishes ‘climate’ from ‘weather’?
(A) Climate is short-term; weather is long-term
(B) Climate refers to long-term average conditions; weather is the day-to-day condition
(C) They mean exactly the same thing
(D) Climate only applies to deserts
Answer: (B)

13. How does climate change typically affect agricultural production?
(A) It guarantees higher crop yields globally
(B) It causes erratic rainfall and droughts, negatively impacting crop yields
(C) It eliminates all agricultural pests
(D) It has zero effect on farming
Answer: (B)

14. Which regions are most immediately threatened by sea-level rise caused by global warming?
(A) High mountain ranges
(B) Inland deserts
(C) Low-lying coastal areas and islands
(D) Deep forest interiors
Answer: (C)

15. The ‘Arid or dry desert’ climatic zone in India is characterized by:
(A) Very hot days, cold nights, and very little rainfall
(B) Heavy rainfall year-round
(C) Humid summers and snowy winters
(D) Dense forests
Answer: (A)

Long Questions with Answers

1. Explain the mechanism of the greenhouse effect and distinguish it from global warming.
Answer: The greenhouse effect is a natural process where specific gases in the Earth’s atmosphere (like carbon dioxide and methane) trap thermal energy radiated from the planet’s surface, preventing it from escaping into space. This process naturally keeps the Earth warm enough to sustain life. Global warming, however, is the abnormal, rapid, and continuous increase in the Earth’s average temperature. It is caused by the amplification or intensification of the natural greenhouse effect, primarily due to excessive human emissions of these heat-trapping gases.

2. Discuss the main human activities that are exacerbating climate change.
Answer: Human industrial and developmental activities are the root cause of the current accelerated climate change. The foremost activity is the relentless burning of fossil fuels—coal, oil, and natural gas—for electricity generation, industrial manufacturing, and transportation, which releases colossal amounts of carbon dioxide. Secondly, widespread deforestation permanently removes trees that naturally absorb this carbon dioxide. Additionally, modern agricultural practices, livestock rearing, and poor solid waste management release immense quantities of methane, a highly potent greenhouse gas.
3. Detail the catastrophic effects of global warming on the world’s oceans and coastal areas.
Answer: Global warming inflicts devastating consequences on oceans and coasts. As global temperatures rise, vast ice sheets in Antarctica and Greenland, along with mountain glaciers, are melting at an unprecedented rate, pouring massive volumes of freshwater into the oceAnswer: Furthermore, water expands as it warms (thermal expansion). These combined factors cause a dramatic rise in global sea levels. This rising water threatens to completely submerge low-lying coastal cities and island nations, causing severe coastal erosion, destroying marine habitats, and displacing millions of people.
4. Analyze how climate change impacts the agricultural sector and food security.
Answer: The agricultural sector is highly sensitive to climatic shifts. Climate change alters traditional, predictable weather patterns, leading to erratic rainfall distribution. This unpredictability results in devastating prolonged droughts in some regions and destructive, unexpected floods in others, both of which obliterate crop yields. Furthermore, extreme heatwaves stress crops and livestock, while changing climates allow agricultural pests and diseases to spread to new areas. Ultimately, these disruptions severely reduce global agricultural productivity, directly threatening global food security and causing severe economic hardship for farmers.
5. Why is planting trees strongly advocated as a primary strategy to combat global warming?
Answer: Planting trees is a highly effective, natural strategy to mitigate global warming because trees act as crucial “carbon sinks.” During the biological process of photosynthesis, trees naturally absorb carbon dioxide—the most prevalent greenhouse gas—from the atmosphere to produce their food, storing the carbon within their wood, leaves, and roots, while simultaneously releasing life-sustaining oxygen back into the air. Therefore, large-scale afforestation directly reduces the concentration of heat-trapping gases in the atmosphere, actively helping to cool the planet and restore ecological balance.