Carbon sequestration by mangrove forest: One approach for managing carbon dioxide emission from coal-based power plant

- Sundarban mangroves were recognized as potential CO2 absorber.
- CO2 was dominated in power plant and metropolis over mangrove.
- CO2 uptake by Sundarban was similar to emission from power plant.
- Mangrove coverage was calculated in the context of biosequestration.

Mangroves are known as natural carbon sinks, taking CO2 out of the atmosphere and store it in their biomass for many years. This study aimed to investigate the capacity of world's largest mangrove, the Sundarbans (Indian part) to sequester anthropogenic CO2 emitted from the proximate coal-based thermal power plant in Kolaghat (∼100 km away from mangrove site). Study also includes Kolkata, one of the largest metropolises of India (∼150 km away from mangrove site) for comparing micrometeorological parameters, biosphere-atmosphere CO2 exchange fluxes and atmospheric pollutants between three distinct environments: mangrove-power plant-metropolis. Hourly sampling of atmospheric CO2 in all three sites (late December 2011 and early January 2012) revealed that CO2 concentrations and emission fluxes were maximum around the power plant (360-621 ppmv, 5.6-56.7 mg m−2s−1 respectively) followed by the metropolis (383-459 ppmv, 3.8-20.4 mg m−2s−1 respectively) and mangroves (277-408 ppmv, −8.9-11.4 mg m−2s−1, respectively). Monthly coal consumption rates (41-57, in 104 ton month−1) were converted to CO2 suggesting that 2.83 Tg C was added to the atmosphere in 2011 for the generation of 7469732 MW energy from the power plant. Indian Sundarbans (4264 km2) sequestered total of 2.79 Tg C which was 0.64% of the annual fossil fuel emission from India in the same time period. Based on these data from 2010 to 2011, it is calculated that about 4328 km2 mangrove forest coverage is needed to sequester all CO2 emitted from the Kolaghat power plant.