Use nature to tackle floods, not concrete: Scientist on Mumbai’s urban resilience | Mumbai News
MUMBAI: In cities like Mumbai which face regular floods on extreme rain days during the monsoon months, marine ecologist Mat Vanderklift, whose research primarily focuses on coastal ecosystems, said that urban resilience could be improved by integrating natural wetlands into flood management.“Instead of channeling all runoff through concrete drains, we can create multifunctional wetlands that store excess water, filter pollutants, and serve as community spaces. These could be open spaces like parks,” he said.“It’s not a quick fix, but economically, the return on investment in mangrove restoration is around ten to one — the benefits far outweigh the costs.” As climate extremes intensify, Vanderklift stressed the need for both mitigation and adaptation. “For low-lying nations and coastal cities, it’s no longer just about preventing change—it’s about surviving it.”An analysis by the BMC on rainfall recordings in the last one decade from 2014-2024 which was done last year flagged this worrying rise in intense rain days in the city. According to it on an average, Mumbai records 16 days a year with rainfall exceeding 100 mm. However, the past three years have shown a noticeable uptick, with 13 such days in the year 2022, 14 in 2023, and a steep rise to 21 days in 2024. This analysis also highlights that between 2014 and 2024, the city experienced 28 high-intensity rain events—defined as receiving between 120 mm and 267 mm of rainfall within a span of just four hours.Beyond their climate benefits Vanderklift said that coastal ecosystems provide crucial protection and livelihood support. Referring to the 2004 Indian Ocean tsunami, Vanderklift also director of the IORA Indian Ocean Blue Carbon Hub leads research projects in the Indian Ocean and Australia that seek to provide the science to support development of policies for “blue carbon” pointed out how villages shielded by mangroves suffered less damage and loss of life compared to those where mangroves had been cleared. “Natural barriers such as mangroves and coral reefs act as frictional buffers against storm surges and waves,” he said. “They perform better than even cement embankments in many cases.”Further speaking about the differences between land and ocean carbon cycles, Vanderklift explained that decomposition occurs much more slowly underwater because oxygen moves sluggishly through water compared to air. “The carbon that gets locked into plants in these ecosystems tends to stay there, buried in the sediment, rather than being rapidly released,” he said. Moreover, salinity in coastal systems suppresses methane-producing bacteria—making them more climate-friendly than freshwater systems such as rivers and lakes.“These systems are natural climate solutions,” said Vanderklift. “Globally, they could account for about three percent of climate abatement. It’s not enough to solve climate change, but it’s a meaningful contribution, especially for sectors where reducing emissions is hard—like aviation and shipping.”Australia, he added, has begun recognising these benefits through projects that restore degraded coastal wetlands and issue Australian Carbon Credit Units (ACCUs) for blue carbon restoration. Similar large-scale mangrove restoration projects exist in Indonesia, Vietnam, and India, though Vanderklift said he hopes to study India’s MISHTI mangrove initiative more closely. MISHTI stands for Mangrove Initiative for Shoreline Habitats & Tangible Incomes. It was announced in the Union Budget 2023-24 and formally launched on 5 June 2023 (World Environment Day) by the Ministry of Environment, Forest & Climate Change (MoEFCC).The scheme is aimed at restoring and conserving mangrove ecosystems (and by implication their associated coastal habitats) across India’s shoreline.He cautioned, however, that ocean-based mitigation cannot compensate for unchecked emissions. “Most of the energy from global warming is already being absorbed by the ocean. It’s buffering us now, but it’s also warming and bleaching coral reefs faster than expected,” he warned.
