Global Climate Change
1. Complete the chain.
Answer:
| A | B | C |
| (1) Melting of snow | (1) Methane | (1) Flooding |
| (2) Effects of insolation | (2) Average temperature of the earth | (2) Agriculture |
| (3) Greenhouse gases | (3) Erratic rains | (3) Existence of life on Earth |
| (4) Climate change | (4) Increase in sea level | (4) Increase in frequency on cyclones |
Q. 2) Identify the incorrect factor:
1) The causes of global warming
a) Emission of greenhouse gases
b) Deforestation
c) Apparent movement of the sun
d) Industrialization
Answer: Incorrect factor: c) Apparent movement of the sun
- Explanation: Emission of greenhouse gases, deforestation, and industrialization are human-related activities that contribute to global warming by increasing atmospheric greenhouse gas concentrations. The apparent movement of the sun is a natural astronomical phenomenon and not a cause of global warming.
2) The indicators of climate change
a) Retreat of glaciers
b) Increase in the frequency of floods
c) Increase in the frequency of cyclones
d) Increase in the minimum and maximum temperature
Answer: Incorrect factor: None
- Explanation: All listed factors—retreat of glaciers, increase in the frequency of floods, increase in the frequency of cyclones, and increase in minimum and maximum temperatures—are recognized indicators of climate change, as they reflect changes in climate patterns and environmental conditions.
3) The tools for studying climate change
a) Ice cores b) Coral reef
c) Tree rings d) Ancient forts
Answer: Incorrect factor: d) Ancient forts
- Explanation: Ice cores, coral reefs, and tree rings are proxy data used in paleoclimatology to study past climate conditions. Ancient forts are historical structures and not tools for studying climate change.
4) Measures to combat climate change
a) Banning the use of pesticides and insecticides.
b) Promoting afforestation and banning deforestation
c) Banning public transport
d) Banning fossi
Answer: Incorrect factor: c) Banning public transport
- Explanation: Promoting afforestation, banning deforestation, and banning fossil fuels are measures that reduce greenhouse gas emissions and mitigate climate change. Banning public transport would likely increase reliance on private vehicles, potentially increasing emissions, and is not a recognized measure to combat climate change.
Q. 3) Give geographical reasons:
1) It is important to study climate change.
Answer:
- Climate change affects global ecosystems, weather patterns, and human livelihoods, making it critical to understand its causes and impacts.
- Studying climate change helps predict future environmental changes, such as sea level rise and extreme weather events, enabling better adaptation and mitigation strategies.
- It informs policy decisions, like those in the Paris Agreement, to reduce greenhouse gas emissions and limit global warming to 1.5°C.
2) There is a great possibility that we may not see Maldives on the world map in the future.
Answer:
- The Maldives, a low-lying island nation, is highly vulnerable to sea level rise caused by global warming and melting ice caps.
- Rising sea levels threaten to submerge the islands, with projections indicating significant land loss by 2100.
- Increased flooding and coastal erosion further endanger the habitability of the Maldives, potentially leading to its disappearance from the world map.
3) The snowline is retreating.
Answer:
- Global warming increases average temperatures, causing glaciers and snow at higher altitudes to melt faster than they accumulate.
- This retreat is evident in glaciers like the Gangotri Glacier, which has receded by over 850 meters in 25 years due to higher temperatures.
- Reduced snowfall and increased melting rates contribute to the upward shift of the snowline in mountainous regions.
4) There is an increase in the frequency of droughts and cyclones.
Answer:
- Global warming enhances evaporation, increasing atmospheric water vapor and leading to more intense and frequent rainfall events, which can cause cyclones.
- Simultaneously, warmer temperatures exacerbate drought conditions in some regions by increasing evaporation rates and reducing soil moisture.
- Examples include the doubling of drought-affected land areas since the 1970s and increased cyclone activity in tropical regions.
Q. 4) Write short notes:
1) Bleaching of coral reefs
Answer:
- Coral bleaching occurs when rising ocean temperatures cause corals to expel the symbiotic algae living in their tissues, which provide their color and energy.
- A temperature increase of 1°-2°C for prolonged periods can lead to bleaching, turning corals white, and extended bleaching can cause coral death.
- Over one-fifth of global coral reefs have already been lost due to bleaching, impacting marine ecosystems and biodiversity.
2) Flash floods
Answer:
- Flash floods are sudden, intense floods caused by heavy rainfall in a short period, often in urban areas or regions with altered drainage systems.
- Global warming increases the frequency of extreme precipitation events, contributing to flash floods, as seen in Mumbai (2005) and Kedarnath (2013).
- Urbanization and deforestation exacerbate flash floods by reducing natural water absorption and increasing runoff.
3) Tools to study Paleoclimatolgy
Answer:
- Paleoclimatology uses proxy data like ice cores, tree rings, coral reefs, and ocean sediments to study past climates.
- Ice cores reveal annual climate variations through layers of snow in Greenland and Antarctica. Tree rings indicate environmental conditions via growth patterns.
- Coral reefs show seasonal temperature changes through calcium carbonate density, aiding in reconstructing historical climate patterns.
4) Greenhouse gases
Answer:
- Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (NO2), trap heat in the atmosphere, contributing to global warming.
- CO2, primarily from fossil fuel combustion and deforestation, has increased to over 350 ppm, harming the environment, as per WHO guidelines.
- These gases enhance the atmosphere’s heat-holding capacity, leading to rising global temperatures and climate change impacts.
Q. 5) Answer in detail :
1) Climate change has not always been anthropogenic in nature. Explain.
Answer:
- Natural Causes of Climate Change: Climate change has occurred throughout Earth’s history due to natural factors. Variations in the Sun’s energy output can alter the amount of insolation received, affecting Earth’s temperature. For instance, low solar output can cool the planet. Milankovitch oscillations, which involve changes in Earth’s orbit and axial tilt, modify insolation and can lead to warmer or cooler climates, such as during ice ages. Volcanic eruptions release aerosols like sulfur dioxide, which reflect sunlight and temporarily cool the Earth, as seen after the Pinatubo eruption in 1991. Additionally, the Earth’s position in the Goldilocks Zone has shifted over time as the Sun’s size changes, influencing long-term climate trends.
- Historical Climate Variations: Geological records, such as sediment deposits in glacial lakes and tree rings, show alternating glacial and interglacial periods. The Earth is currently in an interglacial period within an ice age, indicating natural climate fluctuations. Fossil records and proxy data, like coral reefs and ice cores, reveal past warm and cool periods, such as a warmer Earth 500-300 million years ago or a wet Rajasthan 8,000 years ago. These changes occurred without human influence, driven by natural processes.
- Contrast with Anthropogenic Causes: While natural factors have historically driven climate change, the current warming trend since the mid-20th century is largely anthropogenic. Human activities, such as fossil fuel combustion and deforestation, have significantly increased CO2 levels (e.g., from 280 ppm to over 400 ppm), accelerating warming at an unprecedented rate—roughly ten times faster than natural post-glacial warming. Unlike past changes, the rapid rise in greenhouse gases and its correlation with industrialization highlight human responsibility for the current climate crisis.
2) What measures will you suggest to combat climate change in your village/city.
Answer:
- Promote Renewable Energy: Encourage the use of solar panels and wind turbines for households and public buildings to reduce reliance on fossil fuels. Local governments can provide subsidies for solar installations in villages or cities.
- Afforestation and Green Spaces: Initiate tree-planting drives in rural and urban areas to absorb CO2 and mitigate heat island effects. In cities, create green roofs and parks; in villages, protect and expand local forests.
- Sustainable Transport: Promote public transport, cycling, and walking in cities to reduce vehicle emissions. In villages, encourage shared transport systems or electric rickshaws for short distances.
- Waste Management: Implement waste segregation, composting, and recycling programs to reduce methane emissions from landfills. Villages can use organic waste for biogas production, while cities can enforce strict waste disposal regulations.
- Water Conservation: Adopt rainwater harvesting and efficient irrigation techniques (e.g., drip irrigation) in villages to combat drought risks. In cities, repair leaking water systems and promote water-saving appliances.
- Community Awareness: Conduct workshops to educate residents about climate change impacts and lifestyle changes, such as using energy-efficient devices, reducing plastic use, and conserving resources.
- Local Policy Advocacy: Collaborate with local authorities to enforce bans on illegal deforestation, promote clean energy projects, and align with national plans like India’s National Action Plan on Climate Change (NAPCC).
- These measures, tailored to local needs, can reduce emissions, enhance resilience, and contribute to global efforts to limit warming to 1.5°C, as outlined in international agreements like the Paris Agreement.
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