- Question: Cryosphere
- Introduction: Define Cryosphere
- Body: How Cryosphere affects climate?
- Conclusion: cryoSPHERE is imp4 bioSPHERE
Q8. How does the cryosphere affect global climate? (150 words, 10m)
हिमांक-मंडल (क्रायोस्फेयर) वैश्विक जलवायु को किस प्रकार से प्रभावित करता है?
This question was asked in UPSC Civil services IAS/IPS Mains Exam-2017, in General Studies Paper-1 (GSM1)
Introduction: Define Cryosphere
- (Define) Cryosphere is the portion of earth’s surface, where water is found in solid form. This includes Antarctica, Greenland, icebergs, sea ice and most of the high mountain ranges. They affect global climate in following manner:
- (Origin) You could start by saying, “The growth of the ice sheets began about 120,000 years…Glaciers are the remnants from the last Ice Age, and today they’re confined to xyz area which is collectively known as cryosphere”…but it’s a cumbersome way to begin.
- (Data) Irrelevant. You could provide data related to melting of glaciers and polar ice and begin from there, but we are not asked about ‘global warming’. So, this is also a poor way to begin an answer.
Body: How Cryosphere affects climate?
- Albedo: Snow and ice have high albedo. They reflect much of the insolation, which helps in cooling of the earth. Thus, presence or absence of snow and ice affects the heating and cooling of Earth’s surface. This influences the entire planet’s energy balance. [In Hindi NCERTs, Albedo is written as “एल्बिडो” only. So no need for translation.]
- Feedback Loop: Melting ice reduces the reflective surface. And, the ocean and land are darker in color, they absorb more solar radiation, and then release the heat to the atmosphere. This causes more warming and so more ice melts. This is known as a feedback loop.
- Storage of Carbon: The permafrost of the polar region has trapped tonnes of carbon inside its soil. If ‘feedback loop’ aggravates, this carbon will be released in form of methane- a powerful greenhouse gas- which will catalyze the global warming.
- At polar regions, sea-water is converted into sea ice. As a result, surrounding water gets saltier. Saltier water has higher density, it sinks and initiates thermohaline circulation patterns across the oceans of the world. These Ocean currents act like a conveyer belt, transporting warm water from the equator toward the poles and cold water from the poles back to the tropics. Thus, currents regulate global climate. Some of these currents affect rain and drought situation via El-Nino La-Nina effect.
- Melting of cryosphere affects the volume of water in oceans. Any changes in the water cycle, affects global energy / heat budget, and thereby global climate.
Conclusion: cryoSPHERE is imp4 bioSPHERE
- Thus, cryosphere has direct and indirect bearing on the global climate.
- Therefore, to protect the biosphere, we must protect the cryosphere
- As such we’ve to wind up business within 150 words, so, even if you skip conclusion, the examiner will not take it very negatively.
- “How ice affects climate” meaning we were asked to ‘enumerate’ the process points. Therefore, a thought provoking conclusion is unnecessary. But if you devote more time, you can come up with some expression like “how cryosphere is a natural thermometer and thermostat of the earth…blah blah blah”. So, “cryosphere imp4 biosphere” is a good enough conclusion. Perfectionist Amir khans have no place in UPSC’s time limit.
- Common mistakes: spending words on irrelevant filler points such as “70% of Earth’s freshwater stored in glaciers and ice caps, more than a billion people around the world rely on the cryosphere as a source of drinking water. In Arctic regions, sea ice provides a home for animals like seals and polar bears, feeding and breeding areas for a variety of migrating species, and hunting grounds for local communities.” These are correct statements no doubt, but we are asked about the relation between ice and climate; not the relation between ice and drinking water or ice and biodiversity.