India’s Sundarbans National Park is among five sites that have the highest blue carbon stocks globally, according to a new assessment of greenhouse gas volumes emitted from and absorbed by forests in UNESCO World Heritage sites.
GS-III: Environment and Ecology (Conservation of Environment and Ecology)
Dimensions of the Article:
- About Sunderbans
- Flora and Fauna of the Sunderbans
- Risks faced by the Sunderbans
- What is Blue Carbon?
- About Sundarbans and Blue Carbon
- The colors of carbon
- Sunderbans, formerly Sunderbunds, is a vast tract of forest and saltwater swamp forming the lower part of the Ganga (Padma)-Brahmaputra River delta in southeastern West Bengal state, northeastern India, and southern Bangladesh.
- The tract extends approximately more than 250 kms west-east along the Bay of Bengal from the Hugli River estuary in India to the western segment of the Meghna River estuary in Bangladesh.
- A network of estuaries, tidal rivers, and creeks intersected by numerous channels, it encloses flat, densely forested, marshy islands.
- Three-fifths of the Sunderbans area is in Bangladesh, out of the approximate 10 thousand square kilometers of area it covers.
- Much of the area has long had the status of a forest reserve, but conservation efforts in India were stepped up with the creation of the Sunderbans Tiger Reserve in 1973.
- Sunderbans National Park, established in 1984, constitutes a core region within the tiger reserve; it was designated a UNESCO World Heritage site in 1987.
Flora and Fauna of the Sunderbans
- The forestland transitions into a low-lying mangrove swamp approaching the coast, which itself consists of sand dunes and mud flats.
- Mangrove forests constitute about two-fifths of the Sunderbans region’s overall surface area, with water covering roughly half of that area.
- Mangrove forests perform multiple ecological functions such as production of woody trees, provision of habitat, food and spawning grounds for fin-fish and shellfish, provision of habitat for birds and other valuable fauna; protection of coastlines and accretion of sediment to form new land.
- Notably, it is one of the last preserves of Bengal tigers (Panthera tigris tigris), which are found in relative abundance there. The Sunderbans Delta is the only mangrove forest in the world inhabited by tigers. s
- Other mammals include spotted deer, wild boars, otters, wildcats, and Ganges river dolphins (Platanista gangetica), but several species that once inhabited the region—including Javan rhinoceroses, guar, water buffalo, and spotted deer—are now believed to be extinct there.
- Several dozen reptile and amphibian species are found in the Sunderbans, notably crocodiles, Indian pythons, cobras, and marine turtles.
- The region is home to more than 250 bird species—both seasonal migrants and permanent residents—including hornbills, storks and other waders, kingfishers, white ibis, and raptors such as sea eagles.
Risks faced by the Sunderbans
- The landscape is constantly being transformed by the erosional forces of the sea and wind along the coast and by the enormous loads of silt and other sediments that are deposited along the myriad estuaries.
- Human activity has also altered the landscape, notably through forest removal, which accelerates erosion.
- In addition, because considerable amounts of river water have been diverted upstream for irrigation and other uses, salinity in the mangrove swamps has moved farther inland, especially in the Indian sector of the territory.
- During each monsoon season almost all the Bengal Delta is submerged, much of it for half a year. The shore currents vary greatly along with the monsoon and they are also affected by cyclonic action. Erosion and accretion through these forces maintains varying levels of physiographic change.
- In a study conducted in 2012, the Zoological Society of London (ZSL) found out that the Sunderban coast was retreating up to 200 metres (660 ft) in a year.
- Agricultural activities had destroyed more than 40 thousand acres of mangroves from 1975 to 2010. Shrimp cultivation had destroyed more than 18 thousand acres during that time.
- The mangrove vegetation itself provides a remarkable stability to the entire system, and loss of the mangrove forest will result in the loss of the protective biological shield against cyclones and tsunamis.
What is Blue Carbon?
- Blue carbon is simply the term for carbon captured by the world’s ocean and coastal ecosystems.
- Our ocean and coasts provide a natural way of reducing the impact of greenhouse gases on our atmosphere, through sequestration (or taking in) of this carbon.
- Sea grasses, mangroves, and salt marshes along our coast “capture and hold” carbon, acting as something called a carbon sink.
- These coastal systems, though much smaller in size than the planet’s forests, sequester this carbon at a much faster rate, and can continue to do so for millions of years.
- Most of the carbon taken up by these ecosystems is stored below ground where we can’t see it, but it is still there. The carbon found in coastal soil is often thousands of years old.
- When these coastal systems are damaged, an enormous amount of carbon is emitted back into the atmosphere, where it can then contribute to climate change.
About Sundarbans and Blue Carbon
- India’s Sundarbans National Park is among five sites that have the highest blue carbon stocks globally – however, such ‘World Heritage forests’ are now releasing more carbon than they are absorbing, primarily due to human activity and climate change.
- Researchers estimated the gross and net carbon absorbed and emitted by UNESCO World Heritage forests between 2001 and 2020 to be comparable to roughly half the United Kingdom’s annual CO2 emissions from fossil fuels.
- The study added that World Heritage forests also stored substantial amounts of carbon in addition to absorbing CO2 from the atmosphere.
- The total carbon stored till now by these forests is approximately 13 billion tonnes of carbon. If all this stored carbon were to be released into the atmosphere as CO2, it would be akin to emitting 1.3 times the world’s total annual CO2 emissions from fossil fuels.
- UNESCO lists 50 sites across the globe for their unique marine values. These represent just one per cent of the global ocean area. But they comprise at least 15 per cent of global blue carbon assests.
The colors of carbon
- Green Carbon – The Carbon incorporated into plant biomass and the soils below is called Green Carbon. Green Carbon is Carbon removed by photosynthesis and stored in the plants and soil of natural ecosystems and is a vital part of the global carbon cycle.
- 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.
- Brown Carbon – Brown carbon is brown smoke released by the combustion of organic matter (and coexisting with black carbon when released in the atmosphere). The way light reflects off brown carbon causes the material to appear brown or yellow. Light absorbing aerosols have become an interest of study because of its effects on atmospheric warming.
- Red carbon – In its broadest context, Red carbon includes all living biological particles on snow and ice that reduce albedo to survive. Red carbon is the newest colour in the carbon spectrum. Red expresses a common pigment produced by snow microorganisms, but the term also encompasses pigments spanning yellow through to purple. These colours absorb abundant green and blue wavelengths of light, melting the snow and ice, and “producing liquid water necessary for life, and freeing up nutrients (such as nitrogen and phosphorous) that are bound within ice crystals”.
Related Prelims Question in 2021:
|What is blue carbon? |
(a) Carbon captured by oceans and coastal ecosystems
(b) Carbon sequestered in forest biomass and agricultural soils
(c) Carbon contained in petroleum and natural gas
(d) Carbon present in the atmosphere
-Source: The Hindu