Chennai's Green Space Capita way below WHO indicator prescribed for healthy living

 The summer heat is unbearable in Chennai this month and this could be linked to the depleting green vegetation to make way for building new infrastructure like Chennai metro rail network and expansion of roads. According to the draft City Climate Action Plan prepared by the Greater Chennai Corporation(GCC), the green space per capita, an indicator to assess urban green infrastructure in the city, is 8.75 square metre per person, which is unhealthy when compared with 9.5 square metre per person prescribed for a healthy living as per World Health Organisation.

Urban green infrastructure is considered to be a key element in improving quality of life and creating an appropriate framework for sustainable cities. In Chennai it shows a negative relationship with vegetation and water bodies. Higher temperatures are observed in areas with lower vegetation and waterbody cover. From 1991 to 2021, Chennai has seen a threefold increase in the built-up area (from 102 sq. km to 295 sq. km), while the vegetation cover has reduced from 23 per cent to 17 per cent (from 101.9 sq. km to 74.35 sq. km). Additionally, a significant decrease has also been observed in the area covered by water bodies, from 8 per cent to 4 per cent, the draft report accessed by TNIE stated.

The temperature is observed to be significantly higher in areas where the land surface is covered by materials such as concrete, asphalt, metal, and sand, compared to areas with water bodies and vegetation. Higher temperatures have been recorded in industrial areas such as SIDCO industrial estate and integral coach factory, while parks, gardens, forests, and waterbodies are comparatively cooler, says the report.

The impact of increased heat is higher on urban poor communities, as they live in thermally uncomfortable built environments with higher densities, low vegetation cover, and limited choice of roofing materials, the report states. In Chennai, 27 per cent of the slum houses use asbestos sheets as a roofing material, 65 which heats much faster than cement roofs. Nocturnal urban heat Island effect, which prolongs the time it takes for the city to cool off at night, too, has a higher impact on the urban poor, who have limited access to cooling equipment and electricity.

Limited access to fresh water adds to this dilemma by increasing the risk of dehydration. The report quoting Rajiv Gandhi Government General Hospital states that 30 to 50 patients with heat-related symptoms are reported between April and June each year.

Heat exhaustion also reduces economic productivity. In 2016, construction workers report 18-35 per cent less productivity in peak summer due to extreme heat stress. Since extreme heat also impacts poultry and cattle, dairy-based businesses are affected along with the livelihoods of the communities dependent on them, according to the draft report.

However, to increase the green cover, Chennai Metropolitan Development Authority (CMDA) has partnered with The Nature Conservancy (TNC) India  to implement 'Greenprint for Chennai' under the third masterplan. The focus is to enhance the city’s urban green cover, protect its rivers, waterbodies, and coastal wetlands.The Greenprint will integrate natural infrastructure or blue-green infrastructure such as rivers, wetlands, open previous spaces, green cover to mitigate the effects of climate change and rapid urbanisation and making the city water secure.