Why in the News?
A recent study by the think-tank Climate Trends has revealed that levels of black carbon in the Himalayas have been rising steadily over the past two decades.
About Black Carbon (BC):
- What is it: Black carbon is a fine particulate pollutant formed from the incomplete combustion of biomass and fossil fuels.
- Impact: It is a short-lived climate pollutant and the second-largest contributor to global warming after carbon dioxide.
- Lifespan: Unlike CO₂, black carbon stays in the atmosphere for short periods and can be quickly reduced if emissions stop.
- Warming Mechanism: As an aerosol, it absorbs sunlight, heats the atmosphere, and reduces albedo when deposited on snow and ice, leading to faster melting.
- Health Effects: Exposure increases the risk of heart disease, birth complications, and premature death.
- Major Sources in India:
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- Residential Biomass Burning: Accounts for 47% of BC emissions, including cow dung and straw burning.
- Industries and Vehicles: Industries contribute 22%, while diesel vehicles add 17%.
- Other Sources: Open burning contributes 12%, and other minor sources 2%.
- High-Emission States: Madhya Pradesh and Maharashtra are major emitters due to agricultural and forest fires.
- Biofuel Usage: Alone contributes nearly 42% of India’s total BC emissions.
Key Findings from the Study (2000–2023):
- Snow Temperature Rise: Himalayan snow surface temperature rose from -11.27°C to -7.13°C over two decades.
- Regional Trends: The Eastern Himalayas were warmest, followed by the Central and Western regions.
- BC Influence: Deposits of black carbon lower snow reflectivity, increase heat absorption, and accelerate glacier melt.
- Population Risk: Glacier loss threatens the freshwater supply for nearly 2 billion people downstream.
- Increase in Snow Depth: Despite warming, average snow depth rose from 0.059 m to 0.117 m.
- Reasons: This is due to more snowfall, changing precipitation, and wind redistribution.
- Regional Comparison: The Western Himalayas showed highest snow depth, linked to elevation and winter storms, while the Eastern and Central Himalayas had less snow due to proximity to BC sources.
| [UPSC 2017] Consider the following statements:
1. Climate and Clean Air Coalition (CCAC) to Reduce Short-Lived Climate Pollutants is a unique initiative of G20 group of countries; 2. The CCAC focuses on methane, black carbon and hydrofluorocarbons. Which of the statements given above is/are correct? Options: (a) 1 only (b) 2 only* (c) Both 1 and 2 (d) Neither 1 nor 2 |
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