UN Official Advocates for Nature-Based Solutions at Mumbai Climate Action Week
As Mumbai prepares for its inaugural Mumbai Climate Action Week (MCW), a senior United Nations environment official has emphasized the critical need to expand "nature-based cooling" and climate-smart construction practices. These measures are essential to shield urban centers from escalating heat, flooding, and other climate-related impacts.
Urgent Adaptation for a Coastal Megacity
Martin Krause, Director of the Climate Change Division at the United Nations Environment Programme (UNEP), highlighted Mumbai's vulnerability due to its low-lying geography and rapidly rising temperatures. He stated that adaptation is now an immediate priority for the city.
"Mumbai is a coastal megacity where sea-level rise, flooding, and extreme heat are no longer distant risks — they are already affecting people's lives," Krause explained. "Fortunately, there are practical, affordable solutions — many of which work with nature rather than just machines."
Practical Nature-Based Interventions
Krause pointed to several effective nature-based solutions that can be implemented in urban environments like Mumbai. These include:
- Restoring wetlands to enhance natural water absorption
- Reconnecting rivers to parks to manage rainwater effectively
- Expanding urban tree cover to provide shade and cooling
- Introducing rooftop gardens to reduce heat absorption
These approaches form part of what experts term nature-based solutions — cost-effective interventions that leverage natural processes to reduce ambient temperatures. "Tree cover, shaded streets, reflective roofs, and green spaces can lower temperatures by several degrees," Krause noted. "These measures help not just the environment but human health and comfort, especially for vulnerable populations."
Integrating Passive Cooling with Building Design
While nature-based strategies can significantly mitigate outdoor heat, Krause acknowledged that indoor cooling often still requires mechanical systems. He advocated for a combined approach that pairs nature-based solutions with passive cooling techniques in buildings.
This includes energy-efficient air conditioning and district cooling systems that minimize electricity demand and avoid peak load spikes. "We are working with cities across Africa, Asia, and Latin America to support these measures," he said, noting that passive cooling has gained global traction with over 230 cities now exploring it as part of climate adaptation planning.
Krause cited European examples like Paris, which operates district cooling networks that circulate chilled water to buildings — a model that could benefit Indian megacities as well.
From Pilots to Mandatory Practice
Regarding the Memorandum of Understanding between UNEP and the Maharashtra government under the global "BeCool" program, Krause emphasized that a key focus is integrating passive cooling into building regulations. This represents a shift from experimental pilots to mandatory practice.
"It's always cheaper to build climate-smart from the outset than retrofit later," he stressed. "We are working with developers and builders to integrate shading, insulation, roof orientation, and better materials into designs."
While retrofit efforts in older buildings, schools, and hospitals remain important, they are often more costly to implement effectively.
Addressing Implementation Barriers
When asked why green building practices often remain as pilots rather than becoming mainstream norms, Krause identified several barriers including awareness gaps, capacity limitations, and financial constraints.
"Pilots demonstrate what's possible, but the market needs incentives," he explained. "Architects, engineers, and builders need training — and buyers need access to affordable finance."
He pointed to international examples where buildings with energy-efficient design or "green labels" qualify for lower interest loans — an approach UNEP is exploring with Indian financial institutions.
Cooling as a Health and Dignity Issue
Krause highlighted that extreme heat disproportionately affects poor and vulnerable populations, arguing that cooling should be reframed as a matter of health and dignity rather than luxury.
"In many Indian cities, people already experience 40–45°C heat for weeks at a time," he noted. "Cooling is not a luxury — it is essential for well-being."
Several Maharashtra cities have signed up for the Beat the Heat program, which aims to raise awareness and catalyze action focused specifically on vulnerable populations.
Data-Driven Tracking for Measurable Outcomes
To ensure climate pledges translate into tangible results, Krause stressed the importance of data-driven tracking mechanisms. UNEP is supporting heat-mapping initiatives using satellite and ground-based tools to identify urban heat islands and prioritize interventions accordingly.
"Setting baselines and clear targets — such as retrofitting a certain percentage of public buildings — allows progress to be tracked and verified," he emphasized.
Connecting Local Realities with Global Experience
Krause described the Mumbai Climate Action Week as "significant" for its potential to link local challenges with global expertise. "Climate impacts are felt most strongly at the local level," he observed. "Bringing municipal leaders, policymakers, and international experts together accelerates learning and action."
The inaugural event represents a crucial step in Mumbai's climate resilience journey, combining nature-based solutions with innovative building practices to create a more sustainable urban future.
