- A latest research measured the carbon sequestration potential of 5 wetlands in Assam and located they retailer between 12,650 and 76,950 kg of carbon per hectare of their soils.
- The wetlands with the very best carbon inventory had better aquatic plant protection and species range than different wetlands, suggesting that these are key elements influencing sequestration.
- As rising temperatures threaten wetlands’ skill to retailer carbon, integrating wetlands into carbon credit score methods might probably assist in their conservation.
Wetlands have lengthy performed a significant function in India’s ecosystems. As of 2025, the nation has 91 wetlands designated as Ramsar websites — internationally acknowledged essential wetlands — which span an space of 1.3 million hectares. These areas help wealthy biodiversity, maintain native livelihoods, and function essential neighborhood commons. In the present day, wetlands are gaining consideration for one more essential function, specifically, carbon sequestration.
A latest research assessed the carbon sequestration potential of 5 wetlands in Assam — 47-Morakolong, Jaliguti, Charan, Chatla, and Urmal — from the Morigaon and Kamrup districts. The researchers discovered that the highest 30 cm of soil in these 5 wetlands saved between 12,650 and 76,950 kg of carbon per hectare, with Chatla having the very best carbon inventory and 47-Morakolong the bottom.
“Wetlands have many alternative ecological companies, and carbon accumulation is one in all them,” explains Subir Nag, a principal scientist on the Central Inland Fisheries Analysis Institute, West Bengal, and one of many research’s authors. “With local weather change analysis gaining extra impetus, the Inland Fisheries Institute is concerned with understanding how our wetland assets can be utilized to handle local weather change.”
When evaluating the carbon sequestration potential of various ecosystems, the strengths and weaknesses of wetland carbon sequestration emerges. “When it comes to carbon sequestration price, forests are undoubtedly excessive. Nonetheless, when it comes to carbon collected in soil, wetlands retailer rather more carbon of their soils than every other ecosystem,” feedback Nag.
The carbon saved by soils on terrestrial methods, far exceeds the quantity of carbon saved in plant matter and the ambiance. Wetlands cowl solely about 5-8% of the Earth’s land floor, however retailer almost 30% of worldwide soil carbon, with as much as 40% of the soil mass being composed of carbon; in distinction, most agricultural soils maintain solely 0.5-2% carbon. Within the research, the researchers discovered that the soil in Chatla and Urmal contained 6.1% and 5.24% carbon respectively, within the first 15 cm of depth. In distinction, upland reference websites had solely about 1% carbon.
When evaluating the outcomes with earlier research in West Bengal, Nag famous that the wetlands in Assam had been poorer in carbon. “We now have carried out detailed research in each West Bengal and Assam,” he stated. “Though wetlands in Assam are accumulating carbon, their total content material is lower than these in West Bengal.”
This could possibly be resulting from quite a lot of elements. Carbon sequestration in wetlands will depend on the wetland sort, aquatic plant range, sediment depth, temperature, water move, salinity, land use patterns, and internet major productiveness (the stability between carbon absorbed by way of photosynthesis and carbon launched by way of respiration).
This research checked out elements resembling water and soil high quality, macrophyte protection, macrophyte species range, phytoplankton and the whole inorganic and natural carbon within the water to evaluate the carbon sequestration of wetlands in Assam.
Position of aquatic vegetation in wetland carbon sequestration
The research signifies that macrophytes, that are massive aquatic vegetation, performed a significant function in figuring out the carbon sequestration potential of a wetland. Macrophytes, which use photosynthesis to soak up atmospheric carbon, saved between 21 to 88 kg of carbon per hectare per 12 months throughout the websites.
Chatla, with the very best macrophyte protection (80%), and species range, had the very best quantity of carbon per unit space amongst the 5 wetlands that had been investigated. 47-Morakolong, with the bottom carbon sequestration potential additionally had the bottom protection of macrophytes.
The authors additionally assessed the affect of plankton productiveness on carbon sequestration and located that they absorbed between 3,400 to 23,900 kg of carbon per hectare per 12 months. The very best internet major productiveness was seen in 47-Morakolong and the bottom in Chatla.
Regardless of Chatla having a plankton productiveness as excessive as 300 milligrams of carbon per cubic metre per hour, the carbon seize contribution by algae in Chatla was the bottom amongst the 5 websites resulting from different elements resembling the realm of the wetland and the common depth of the water. The opposite websites confirmed charges starting from 100-150 mgC/m3/hr.
The authors, nonetheless, warning towards counting on plankton productiveness as a measure for long-term carbon seize, as this carbon is commonly shortly cycled by way of aquatic meals webs.
One other main issue affecting carbon sequestration in wetlands is temperature. The rising temperatures related to local weather change now threaten the carbon-sequestering capability of wetlands, “As temperatures rise and we face hotter summer time durations, many wetlands get dried. On this case, the cardio layer will increase and extra carbon dioxide might be launched into the ambiance,” explains Nag.
A possible carbon credit score system
Nag says that wetlands will be a part of the answer to mitigating local weather change as nicely. Due to their skill to seize and retailer carbon, he sees potential in together with them in carbon credit score methods. “If a wetland is accumulating carbon, and a farmer or fisherman is managing the wetland, they’ll get that carbon credit score and earn cash,” he says.
Nandan Nawn, a professor within the Division of Economics at Jamia Millia Islamia, New Delhi, factors to 2 main obstacles to this concept. “The primary query an economist, or a public coverage particular person would ask is: who owns this carbon inventory? If carbon inventory is to be bought, and due to this fact earn credit score, the property rights of the products to be bought should be clear,” he explains.
Property rights to widespread areas in India stay advanced. Round 66% of civil circumstances within the nation contain land disputes. Even in circumstances the place possession is obvious — resembling forest lands owned by the state — land use rights typically develop into contentious as many native communities have lengthy managed these lands. The Forest Rights Act 2006, grants these communities sure rights to land use and possession of assets, which complicates benefit-sharing in a proper carbon market.
The second problem is defining the bodily boundaries of wetlands. “Forests are nonetheless one thing for which you may make a boundary. For wetlands, it turns into almost unimaginable,” says Nawn. “Wetlands carry on shifting. So how would one determine a boundary for that specific space? Usually, wetlands aren’t clearly outlined throughout the nation — and even globally,” he provides.
This dynamic nature provides to the issue of integrating wetlands into carbon credit score methods. Some wetlands on this research, for example, had been seasonal — altering with river ranges, temperature and rainfall. Defining secure boundaries below such shifting situations could be a big problem.
Nawn additionally questions the practicality of such a system. “Certification companies aren’t concerned with an ecosystem’s carbon sequestration potential, however the precise carbon sequestration that’s occurring,” he says. “Not solely is the measurement of carbon inventory a problem on this case, but it surely additionally comes with an infinite monitoring and transaction price,” he provides.
Regardless of these obstacles, integrating wetlands into the carbon credit score system is probably not unimaginable. Voluntary carbon markets in locations like California have already begun together with them, with the intention of finally integrating wetland carbon credit in a compliance market system.
Nag stays hopeful that India will observe swimsuit. “By incomes carbon credit for safeguarding wetlands, we will concurrently enhance their carbon inventory and defend them. On this approach, to some extent, we might handle greenhouse gasoline emissions and local weather change. Governments ought to give attention to such insurance policies, identical to in different fields of local weather change coverage,” he says.
Learn extra: Majuli’s shrinking wetlands and their combat for survival
Banner picture: Deepor Beel in Kamrup is Assam’s solely Ramsar website, regardless of the state having over 1,000 wetlands, a lot of which face threats from human pressures. Picture by Hirakjyoti Bayan by way of Wikimedia Commons (CC BY-SA 4.0).
