Context:
Black carbon (BC) concentration in Antarctica is considerably higher around research stations and popular tourist destinations than other parts of the continent, according to a new report published in Nature Communications.
Relevance:
GS III- Environment and Ecology
Dimensions of the Article:
- What is Black Carbon?
- Adverse Effects of Black Carbon
- Brown Carbon
What is Black Carbon?
- Black carbon is a potent climate-warming component of particulate matter formed by the incomplete combustion of fossil fuels, wood and other fuels.
- Complete combustion would turn all carbon in the fuel into carbon dioxide (CO2), but combustion is never complete and CO2, carbon monoxide, volatile organic compounds, and organic carbon and black carbon particles are all formed in the process.
- The complex mixture of particulate matter resulting from incomplete combustion is often referred to as soot.
- It reduces the surface albedo and can lead to earlier and more rapid snow melt.
Adverse Effects of Black Carbon
- Black carbon is a short-lived climate pollutant with a lifetime of only days to weeks after release in the atmosphere.
- During this short period of time, black carbon can have significant direct and indirect impacts on the climate, glacial regions, agriculture and human health.
- Several studies have demonstrated that measures to prevent black carbon emissions can reduce near-term warming of the climate, increase crop yields and prevent premature deaths.
- Black carbon absorbs solar energy and warms the atmosphere.
- When it falls to earth with precipitation, it darkens the surface of snow and ice, reducing their albedo (the reflecting power of a surface), warming the snow, and hastening melting.
Brown Carbon:
- Brown carbon is a carbonaceous aerosol which absorbs solar radiation over a broad range of wavelengths which is beginning to be seen as an important contributor to global warming.
- Brown Carbon absorbs both inorganic and organic pollutants, leading to serious effects on human health. Hence, Brown carbon (light-absorbing organic carbon) has attracted interest as a possible cause of climate change.
- Brown Carbon is a class of organic carbon, known for its light brownish colour, absorbs strongly in the ultraviolet wavelengths and less significantly going into the visible.
- Types of brown carbon include tar materials from smouldering fires or coal combustion, breakdown products from biomass burning, a mixture of organic compounds emitted from soil, and volatile organic compounds given off by vegetation.
| Brown Carbon | Black Carbon |
| Brown Carbon is brown in colour and its absorption is limited to UV and lower visible wavelengths. Aerosol absorption depends on the mass, mixing state, chemical composition and the refractive index of the species present in the atmosphere. | The ratio of Black Carbon to organic mass determines the colour of the particles which is in turn influenced by the burning conditions. Black carbon is dark in color and shows strong light absorbing capacity throughout the spectra. |
-Source: Down to Earth
