Coastal Lifelines in Mumbai and Chennai: The Neglected Potential of Blue Carbon Conservation in India’s Coastal Cities

Cities like Mumbai and Chennai need to stop overlooking their mangroves, seagrasses, and tidal marshes. Collectively known as blue carbon ecosystems, these spaces are vital in safeguarding urban coastal areas from climate change.

Think of Mumbai and you’ll probably think of India’s “first city” or Urbs Prima, a financial and commercial hub with towering buildings and bustling streets. Thriving coastal ecosystems are probably not high on your mind when you think of Mumbai. Yet the Mumbai metropolitan area, home to approximately twenty million people, also encompasses extensive estuaries, wetlands, marshlands, and mangroves. These vital coastal (blue-carbon) ecosystems, which absorb and store carbon from the atmosphere, are now being damaged by urban expansion, and illegal encroachments are making it challenging to restore these ecosystems.

Mumbai’s mangroves, once abundant along its sprawling coastline of 149 km, are a critical but overlooked component of the city’s natural infrastructure. These mangroves have suffered significant degradation due to rapid urbanisation and industrial development. Between 1990 and 2001, the city lost over 39% of its mangrove cover. Recently, more mangroves were cleared for development projects, such as the Navi Mumbai International Airport development and the Mumbai-Ahmedabad bullet train project.

The consequences of this destruction are stark. The catastrophic 2005 floods, exacerbated by the loss of mangroves along the Mithi River, underscored the critical protective role these ecosystems play. As climate change intensifies, the city’s vulnerability to flooding and storm surges is set to increase, potentially tripling annual flood-related economic losses by 2080. This alarming scenario highlights the urgent need to conserve and restore Mumbai’s mangroves, which are not only natural barriers against coastal erosion and flooding, but also potent carbon sinks. 

The High Cost of Neglect and the Immense Potential of Blue Carbon Conservation

Mangroves, seagrasses, and tidal marshes—collectively known as blue carbon ecosystems—can store up to five times more carbon per hectare than tropical forests. These ecosystems absorb atmospheric carbon dioxide and provide numerous benefits, including protecting coastlines from erosion, floods, and storm surges, stabilising sediments, filtering pollutants from runoff and improving water quality, providing breeding areas for fish, supporting local fisheries, and guaranteeing food security.

However, upon loss or degradation, these ecosystems release the stored carbon into the atmosphere. This contributes to carbon emissions equivalent to 3–19% of the impact caused by global deforestation. Therefore, blue carbon conservation—protecting coastal ecosystems and the carbon they store—is imperative for India’s net-zero ambitions. 

Despite their immense ecological and economic value, blue carbon ecosystems face significant threats from urbanisation, tourism infrastructure, and industrial development, which cause water pollution, threaten water quality, irrevocably impact marine ecosystems, and exacerbate climate impacts. This effect is magnified in cities, which are hotspots of climate change. Studies predict that if global carbon emissions are not significantly reduced, many parts of Mumbai will likely become submerged within 30 years. The rapid loss of Mumbai’s coastal ecosystems makes the city even more vulnerable to climate impacts.

It’s not just Mumbai! 

Chennai’s coastal area has a history of natural disasters, including storms, cyclones, tsunamis, and sea-level rise. On the one hand, rising sea levels pose threats such as wetland loss, beach erosion, saltwater intrusion, and stalled drainage. On the other hand, coastline gentrification via infrastructure development and real-estate projects is threatening the livelihoods of fishing communities. In 2017, an oil spill along the Chennai coast spread across 34 km, destroying several mangrove ecosystems along Ennore Creek. The result was damaged boats, drastic impacts on fishing-based livelihoods, and physical health effects. Further, the oil seeping into the soil blocked the mangroves’ oxygen supply and hindered tree germination, permanently damaging the ecosystem. Today, thermal power plants and industries along Chennai’s  wetlands continue to degrade marine life and increase the risks of flooding.

Coastal urban areas are more susceptible to human intervention due to their potential for economic development. This leads to complex tradeoffs between blue carbon conservation efforts and development plans. Pallikaranai Marsh, Chennai’s only marshland, once spanned 5,500 hectares. Urban pressures have reduced this to just 600 ha by 2013. The Chennai Corporation operates a landfill on this marshland, resulting in substantial carbon dioxide and methane emissions, which far exceed the marshland’s natural carbon absorption capacity. Authorities have proposed an eco-park to restore the marshland. But a staggering 38% of this land is currently occupied (legally or illegally by various organisations). Further, the official approach to bioremediation involves a reckless trial-and-error method of planting new trees, despite growing knowledge that unsuitable tree species would damage the existing, unique wetland ecosystem.

Can Community Initiatives Lead the Way?

Local community groups have been taking action. The restoration of Lake Sembakkam and its surrounding marshland ecosystem in Chennai provides a prime example of successful community stewardship  for blue carbon conservation. This approach has many positive features, such as a focus on restoring the natural ecosystem and sequestering carbon, the involvement of private organisations, entrusting the community with the maintenance and supervision of the lake after its revival, and emphasis on biophysical suitability. Community engagement has been integral to this campaign’s activities to revive the natural ecosystem and enhance flood mitigation measures while also addressing the community’s concerns about groundwater contamination and sustainable water treatment. 

In Mumbai, local organisations such as the Shree Ekvira Aai Pratishthan (SEAP), which enlists fisherfolk to protect and conserve mangrove wetlands, have played a pivotal role. SEAP’s efforts have included petitioning the Bombay High Court to secure different patches of mangroves threatened by encroachment, untreated sewage inlets, and garbage dumping. This work illustrates the vital role of grassroots action. However, several collaborative initiatives started by local volunteers and activists to clean up coastlines in Mumbai suffer from lack of resources and support from local governments, and may thus fail to make a lasting difference.

Inclusive Blue Carbon Futures

Blue carbon projects offer significant potential for climate action, but their success hinges on inclusivity and equity. As seen in Mumbai and Chennai’s restoration cases, the vested interest and traditional knowledge of local communities make these groups  the ideal custodians of these ecosystems. However, depending solely on community action, especially when confronted with resource limitations and bureaucratic hurdles, puts an undue burden on these groups. Protecting and enhancing community members’ rights, knowledge, and leadership requires concerted policy action and wide community participation. These efforts are essential to ensure fair access to coastal ecosystems, which have traditionally been communal resources.

Several Government of India initiatives, such as the Ramsar Convention, Mangrove Initiatives for Shoreline Habitats and Tangible Incomes (MISHTI), the Coastal Regulation Zone (CRZ) notification 2019, and the National Action Plan on Climate Change (NAPCC), aim to protect coastal ecosystems. However, these initiatives remain fragmented and fail to adequately address the unique blue carbon conservation needs of urban areas. They often overlook issues like rapid development, pollution, and flood risks in cities such as Mumbai and Chennai. For instance, national mandates such as the 2019 Coastal Regulation Zone (CRZ) notification and Guidelines for Coastal Zone Management Plans (CZMP) stress on preserving coastal ecosystems but have loopholes allowing land reclamation and/or development without specific guidance on accounting for impacts of shoreline changes. Cities need a contextual approach to blue carbon conservation with targeted incentives, strong enforcement, and attention to urban coastal areas. A few essential aspects of an equitable and sustainable approach to urban blue carbon conservation  include:

  1. Embedding Blue Carbon into Urban Planning and Land Use Policies: Coastal cities must integrate blue carbon conservation into statutory planning frameworks such as master plans to protect urban coastal ecosystems from unregulated development. Cities can achieve this by mapping and identifying marine ecosystems in land use plans, classifying these ecosystems as designated areas for protection and restoration, and integrating these areas into disaster management and resilience strategies. Further, collaboration for supporting capacity building, and working at the neighbourhood scale with nonprofits and residents, are vital steps for equitable planning and successful implementation.
  2. Community Involvement and Indigenous Practices: For effective blue carbon conservation, local communities must be engaged as stewards of these ecosystems. Incorporating traditional ecological knowledge, like the Paadu system used by fishing communities in Pulicat, Chennai, fosters ownership and promotes sustainable practices. However, urbanisation negatively impacts river flow, water quality, and aquatic life. Cities can counter these effects by creating inclusive platforms for community engagement, allowing residents to share knowledge and lead conservation efforts.
  3. Financial Incentives and Economic Opportunities through Blue Carbon Initiatives: To ensure the success of blue carbon projects, cities should enhance financial mechanisms that offer ecological and economic benefits. Cities can secure vital ongoing funding by utilising climate finance, carbon markets, and public-private partnerships. Allocating a portion of port taxes to blue economy investments and reducing the impact of pollutants, can facilitate this process. Additionally, linking blue-carbon conservation  projects to local economies empowers communities by providing income through carbon credits, ecotourism, and sustainable fishing practices.

By embracing our shared responsibility, fostering community involvement, and reshaping our policies, we can preserve our urban blue carbon ecosystems and forge a resilient, sustainable, equitable future for India’s urban coastlines.

Share this:

Related:

Measuring What Matters

Transitions Research, as the Tracking, Learning and Sharing(TLS) lead of Adaptation Research Alliance(ARA), engaged with ARA’s 250+ community of organisations to gather insights on measuring...