India’s first ‘teal carbon’ study bets on wetlands to address the challenges of climate adaptation and resilience

The wetlands at Keoladeo National Park in Bharatpur, where India’s first study on teal carbon was undertaken. Photo: Special Arrangement

India’s first study on ‘teal carbon’, undertaken at Keoladeo National Park (KNP) in Rajasthan’s Bharatpur district, has highlighted the significance of wetland conservation to address the challenges of climate adaptation and resilience. The pilot project sought to develop holistic nature-based solutions to address climate change.

The concept of teal carbon is a recent addition to the environmental science pertaining to organic carbon in inland fresh wetlands. The study, carried out in the form of the KNP’s global review, has depicted the potential of teal carbon as a tool to mitigate climate change if the anthropogenic pollution in the wetlands can be controlled.

Teal carbon refers to carbon stored in non-tidal freshwater wetlands, encompassing carbon sequestered in vegetation, microbial biomass, and dissolved and particulate organic matter. Though these wetlands play a crucial role in regulating greenhouse gases, they are vulnerable to degradation from pollution, land use changes, water extraction, and landscape modifications.

Laxmi Kant Sharma, professor and head of the Department of Environmental Science at the Central University of Rajasthan, who led the review, told The Hindu that wetlands, when degraded, could release methane and carbon dioxide into the atmosphere. “Given the fragility of these ecosystems, we need urgent conservation and management efforts across the country,” Dr. Sharma said.

The wetlands at Keoladeo National Park in Bharatpur, where India’s first study on teal carbon was undertaken. Photo: Special Arrangement

‘Teal carbon’ being a colour-based terminology reflects the classification of the organic carbon based on its functions and location rather than its physical properties. As opposed to teal carbon, black and brown carbon are primarily produced by incomplete combustion of organic matter from sources such as wild fires, fossil fuel combustion, and industrial activities. They contribute to global warming.

The comprehensive review at KNP was conducted by researchers from the Central University of Rajasthan, led by Dr. Sharma, in collaboration with Amanda Nahlik of the U.S. Environmental Protection Agency (EPA) and Siobhan Fennessy from Kenyon College, Ohio, U.S. The review focused on four major teal carbon ecosystems to assess the status and potential role of teal carbon in mitigating climate change.

Preliminary results from the research conducted at KNP revealed elevated levels of methane emissions, necessitating the reduction of these discharges through the use of a specialised type of biochar, which is a form of charcoal. Dr. Sharma said developing this specific biochar – a lightweight black residue comprising carbon and ashes – and its research would require sophisticated instruments, such as the LI-COR device for real-time ground-based greenhouse gas measurements.

Ensuring availability of water and selecting suitable vegetation will ensure effective conservation of wetlands in the national park, which in turn will sustain the teal carbon pools. Dr. Sharma said the teal carbon ecosystem would also contribute to an increase in the ground water level, flood mitigation and heat island reduction, supporting a sustainable urban adaptation.

At the global level, the storage of teal carbon across the ecosystems is estimated to be 500.21 petagrams of carbon (PgC), which is a unit to measure carbon. Peatlands, freshwater swamps, and natural freshwater marshes account for significant amount of this storage.

Dr. Sharma presented the findings of his study recently at the International Union of Forest Research Organisations (IUFRO) World Conference in Stockholm, Sweden. While he laid emphasis on the conservation and restoration strategies to enhance natural carbon storage efficacy and reduce emissions from teal carbon ecosystems, scientists from other countries exchanged ideas on climate change, loss of biodiversity and environmental pollution. (EOM)