Note4Students
From UPSC perspective, the following things are important :
Prelims level: Greenland
Why in the News?
A new study has revealed that over 7,500 lakes in western Greenland have turned brown, suffered water quality deterioration, and started emitting carbon due to extreme weather events in 2022.
About Greenland and Its Lakes
- Greenland, the world’s largest island, is covered by a massive ice sheet that holds nearly 8% of the world’s freshwater.
- The island is home to thousands of glacial-fed lakes, which are crystal blue due to their pristine water quality and low organic content.
- These lakes play a crucial role in providing drinking water, supporting biodiversity, and storing atmospheric carbon by acting as natural carbon sinks.
What are the reasons?
- Extreme Weather in 2022: Greenland saw record-breaking heatwaves and heavy rainfall instead of the usual snowfall.
- Permafrost Thawing: Rising temperatures melted permafrost, releasing large amounts of organic carbon, iron, and other minerals into the lakes.
- Atmospheric Rivers: These long, narrow streams of water vapor in the sky caused intense precipitation, leading to large-scale runoff of organic material and sediments into the lakes.
- Loss of Light Penetration: Increased sedimentation turned the lakes murky brown, reducing sunlight penetration and affecting phytoplankton, which play a key role in carbon absorption.
Why this Study is important?
- The study found that changes in the lakes occurred within months instead of centuries, signaling an unprecedented climate impact.
- Once natural carbon absorbers, the lakes are now releasing 350% more carbon dioxide, accelerating global warming.
- The lakes, which supply drinking water, now contain higher levels of organic pollutants, affecting both humans and aquatic ecosystems.
- Studies suggest atmospheric rivers will become 50–290% more frequent by the end of the century, leading to widespread changes in other freshwater ecosystems worldwide.
- The study adds to growing evidence that Earth’s natural carbon sinks are failing, posing a major challenge to climate mitigation efforts.
PYQ:[2011] The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason? (a) Ice is a bad conductor of heat (b) Since the surface of the lake is at the same temperature as the air, no heat is lost (c) The density of water is maximum at 4 °C (d) None of the statements A, B and C given above is correct. |
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