Proper urban green space placing could save lives

Five cities from India were part of a recent study — Bengaluru, Chennai, Delhi, Kolkata, and Mumbai. Part of a group called the C40 cities, these were among 96 C40 cities, spread across 48 countries and six continents, and home to 291 million residents, as highlighted by Mongabay India (MI) in an analysis.

The MI analysis reports that in July 2021, mayors of 31 cities belonging to the C40 Cities Climate Leadership Group committed to increasing green (e.g., parks and trees) and blue (e.g., rivers and lakes) spaces to tackle the climate crisis. Signatories of the C40 Urban Nature Accelerator committed to two crucial goals for 2030 – quality total cover, specifically for the green or permeable spaces to occupy 30-40% of the total built-up city area, and equitable spatial distribution which includes blue or green space access for 70% of the population.

Four years since the declaration, at about the halfway mark to the 2030 deadline, the MI analysis says a research paper published in the Lancet Planet Health journal has assessed the health impacts of the progress towards the Urban Nature Accelerator targets in C40 cities.

For the five Indian cities, experts cited in the MI analysis said that increasing green area by 1% could reduce the number of annual premature deaths by 875-2439, depending on where you add green spaces. As South Asian cities tend to be densely populated, making it difficult to add more green spaces, it helps to think small-scale. The immediate goals for urban planners and city councils should be to preserve existing spaces. Apart from long-term targets for green space expansion, experts propose that India experiment with vertical and terrace gardening to help cool buildings and clamp down on energy spending.

Harnessing satellite data and global health databases, the researchers calculated annual avoided deaths based on increments in urban green cover under the Urban Nature Accelerator targets of quality total cover (QTC) and equitable spatial distribution (ESD).

The study modelled three different ways to add green spaces. In the uniform scenario (even distribution of new green spaces), every 1% increase in green space (QTC) yielded an annual city median of 53 fewer premature deaths, and every 1% increase in population with nature nearby (ESD) yielded an annual city median of 15 fewer premature deaths. In the nature-deprived scenario (distribution of new green spaces in low-nature areas), every 1% increase in green space (QTC) yielded an annual city median of 76 fewer premature deaths, and every 1% increase in population with nature nearby (ESD) yielded an annual city median of 27 fewer premature deaths.

In the population-centred scenario (distribution of new green spaces in densely populated areas), every 1% increase in green space (QTC) yielded an annual city median of 158 fewer premature deaths, and every 1% increase in population with nature nearby (ESD) yielded an annual city median of 50 fewer premature deaths. According to the C40 website, mayors of C40 cities are committed to using an inclusive, science-based and collaborative approach to cut their fair share of emissions in half by 2030, help the world limit global heating in line with the Paris Agreement, and build healthy, equitable and resilient communities. C40 supports mayors to do this by:

• raising climate ambition through 1.5°C climate action plan support, high-impact accelerators and fostering innovation,

• building equitable and thriving communities via global and regional programmes,

• building a global movement through robust international advocacy and diplomacy,

• scaling up climate action and sharing best practices across high-impact sectors, and

• facilitating access to finance for investment in green jobs and projects that improve resilience in cities.

C40 Leadership Standards 2025 — 2030 reinforce two actions. First to Implement and second to Lead. Cities are implementing ambitious climate actions to deliver their city-wide GHG emissions targets by 2030 (or earlier), reduce the use of and end support for fossil fuels and address emissions from urban consumption, address priority risks, enhance resilience and deliver city-wide adaptation goals and targets, and deliver stronger and more equitable outcomes for all

To lead, cities need to ensure that by 2030 they have established comprehensive governance structures that ensure climate targets and considerations are integrated across decision-making, including introducing climate budgeting.