Marine Solutions to Address Climate Change Impacts

Climate change risks are acknowledged in global conventions such as the United Nations Framework Convention on Climate Change (UNFCCC). However, the UNFCCC’s Paris Agreement aim of limiting global warming below 2°C and the CBD biodiversity targets are on track to be missed. Quick and far-reaching action to restrict greenhouse gas emissions and remove CO2 from the atmosphere is critical to avoiding the worst effects of climate change. According to the 2020 Emissions Gap Report [1], countries must increase their mitigation targets “threefold to achieve the 2°C goal, and more than fivefold to achieve the 1.5°C goal”.

Nature-based solutions (NbS) are defined as “actions to protect, sustainably manage, and restore natural or modified ecosystems that efficiently and adaptively tackle societal concerns while simultaneously providing benefits to human wellbeing and biodiversity” [2]. While boosting natural CO2 sequestration, the NbS has the potential to reduce greenhouse gas emissions caused by ecosystem loss, degradation, and mismanagement. Climate change mitigation and adaptation, natural disasters, human health, food and water security, and biodiversity loss are all challenges that well-designed Nature-based solutions may address simultaneously. By reducing greenhouse gas emissions caused by ecosystem loss, degradation, and mismanagement, the NbS can both reduce greenhouse gas emissions and enhance natural CO2 sequestration. The Earth’s marine and terrestrial ecosystems absorb roughly 56% of anthropogenic CO2 [3].
 

Tropical forests, peatlands, and mangroves have the largest carbon stocks per hectare, followed by all other natural terrestrial/coastal ecosystems. Much of the carbon is stored as soil organic carbon in the latter two habitats with peatlands worldwide average of 1375 tonnes per hectare [4] and mangroves at 361 tonnes per hectare [5].

Coastal ecosystems are among the most productive natural systems in the world, providing habitat for a wide diversity of species. Coral reefs, mangroves, seagrass meadows, tidal marshes, sand dune systems, and salt marshes are all important habitats in coastal and marine ecosystems. They are among the world’s greatest carbon storehouses, with CO2 burial rates 20 times higher than any other terrestrial ecosystem, including boreal and tropical forests [6]. Globally, policymakers are becoming more aware of their role in sequestering and storing ‘blue’ carbon from the atmosphere and oceans. Blue carbon ecosystems, which include mangroves, seagrasses, and tidal salt marshes, provide a wide range of mitigation, adaptation, and resilience benefits, including storm surge and sea-level rise protection, erosion prevention, coastal water quality regulation, nutrient recycling, sediment trapping, habitat establishment for numerous commercially important and endangered marine flora and fauna [8].

India has a mangrove cover of about 6,749 km2 [9], and with a total expected mangrove cover of 4,95,842 ha in 2020 and a carbon stock value of 386 tonnes/ ha, the mangrove’s total carbon sequestration potential is estimated to be 702.42 million tonnes of CO2. By 2030, the potential for carbon sequestration will be 748.17 million tonnes of CO2e. Conserving and safeguarding mangrove cover could increase CO2e sequestration by 207.91 million tonnes. The overall carbon sequestration capacity of seagrass has been determined to be 10.2 million tonnes of CO2e [10], based on a carbon stock of 108 tonnes/ha and a total mapped area of 25,378.4 ha. More research is needed to determine the size of tidal salt marshes and estimate their carbon sequestration potential.

The total mitigation potential to safeguard natural ecosystems from conversion ranges from 3.4 GtCO2e in 2030 to 4.6 GtCO2e in 2050. Coastal wetlands (mangrove, salt marshes, and seagrass) contribute to around 4% (3-4%) of overall mitigation potential by 2050 [11], given their limited area. Despite their small size in comparison to other ecosystems, they sequester and store significant amounts of carbon in their soil, as well as provide a variety of ecosystem benefits and services essential for climate change mitigation and adaptation, such as coastal protection and food security for many communities.
 

Several initiatives and reforestation programmes have been publicly recognised to maintain carbon stored in the world’s forests on land. Unfortunately, equivalent solutions in the marine ecosystem are often overlooked. The use of the UNFCCC to incentivize improved management action, as well as the protection of coastal ecosystems as a potential climate mitigation option, is now a topic of debate and is not fully reflected in most coastal countries’ NDC plans, including India’s. As a requirement for more carbon finance for coastal environment conservation, the Indian government should enact a Carbon Neutrality Policy. Marine bonds, blue bonds, and blue finance should be used in industries such as shipping, oil refineries, cement factories, seafood processing facilities, power plants, port infrastructure, and other manufacturing plants.

Furthermore, research must be revamped to develop approaches for measuring the carbon stocks of various coastal ecosystems, particularly soil organic carbon (SOC) and below-ground biomass [12]. Although nature-based solutions offer significant decarbonization potential, they must be combined with quick, broad-based emission reductions in the energy, industry, and transportation sectors. Total mitigation will be insufficient to avoid climate-related risks without this combined strategy and it limits the ability of nature-based solutions to contribute to climate change mitigation.

- Manish Dabkara, CMD & CEO, EKI Energy Services Ltd
- Arun Kumar, Senior Manager (Nature based Solutions), EKI Energy Services Ltd