The climate futures of Kolkata and the Sundarbans are deeply intertwined, and experts now warn that failing to address them together could worsen the vulnerabilities of both regions. In a recent meeting held in Kolkata, scientists, activists, and urban planners came together to issue the ‘Kolkata Declaration 2025’, calling for an integrated climate security strategy, particularly highlighting the revival of eco-friendly public transport like trams as part of the solution.
The air and water pollution from Kolkata is degrading the Sundarbans mangroves, which in turn weakens the city’s natural shield against cyclones and extreme weather. Experts said that despite being just 100 km apart, Kolkata and the Sundarbans are often dealt with separately in climate policies a mistake that needs urgent correction.
The citizen assembly, attended by over a hundred people, was organized by environmentalists from Kolkata and Melbourne under the Tramjatra movement, which has been advocating for tram preservation in the city for over three decades.
The declaration outlines five key priorities:
- Developing a joint climate strategy for Kolkata and the Sundarbans
- Promoting low-emission public transport like trams
- Expanding civil society and political participation
- Pushing for legal climate justice for affected communities
- Presenting a white paper to national and international bodies soon
Michael Douglas of RMIT University, activist Roberto D’Andrea, and filmmaker Mahadeb Shee confirmed the team will take this agenda to global platforms. Sanjay Vashist of Climate Action Network South Asia (CANSA) emphasized the need to highlight issues like climate-induced migration from the Sundarbans and loss of livelihoods due to rising salinity and extreme events.
Former bureaucrat Jawahar Sarkar and cardiac surgeon Kunal Sarkar both pointed out that environmental concerns rarely get political priority, a trend that worsened globally after climate-sceptic leaders gained influence.
Scientists presented alarming findings. Abhijeet Chatterjee from Bose Institute explained that a 1% rise in Kolkata’s emissions could reduce photosynthesis in the Sundarbans by 15%, threatening its carbon sink capacity, which currently stores around 270 million tonnes of carbon. Biologist Punyaslok Bhadury from IISER Kolkata warned that toxic metals and microplastics in city water are degrading the Sundarbans’ biodiversity, including fish populations.
Oceanographer Tuhin Ghosh from Jadavpur University stressed that human-planted mangroves funded by carbon credit schemes often fail, while natural regeneration must be encouraged. Botanist Krishna Ray and Sundarbans Development Board member Subhas Acharya both agreed that natural mangroves offer better ecosystem services than artificially planted ones.
Retired forester Pradeep Vyas noted that despite nearly 4,000 sq km of forested area, the Sundarbans remain highly vulnerable to cyclones and rising salinity.
Meanwhile, environmental lawyer Ritwik Datta emphasized the need for climate justice, arguing that people suffering due to environmental changes are often innocent of contributing to the crisis. Though legal pathways are currently limited, he’s hopeful for future reforms.
On the topic of urban infrastructure, Kolkata’s tram system became a major point of focus. With the city facing traffic congestion and worsening air quality, transport experts like Bhargab Maitra of IIT Kharagpur and Anumita Roychoudhury from the Centre for Science and Environment said reviving and modernizing trams is crucial to meeting climate goals.
While the West Bengal government plans to shut down tram operations, keeping only a heritage line, experts warned this would be disastrous. Alok Jain, a transport planner from Hong Kong, said trams must be made user friendly and efficient to regain popularity.
Urban economist Mahalaya Chatterjee blamed past decisions like introducing buses instead of modernizing trams for their decline. Urban planner Tathagata Chatterjee called for a data-driven, inclusive strategy to balance environmental and economic needs.
Cultural icons like filmmakers Gautam Ghosh and Asok Viswanathan also joined the call to protect the environment and preserve Kolkata’s historic tramways not just as relics, but as a functional green transport system.
Ghosh whose next film focuses on climate migration, expressed his intent to make a new project based on ecological refugees from the Sundarbans, further emphasizing how art can amplify climate justice narratives.