Modern civilisation thrives in cities. In India, with around 20 people migrating to urban areas every minute, this trend is particularly pronounced. Every April, the urban “concrete jungle” begins to simmer, causing widespread discomfort. In the following months, rising heat dominates headlines, with consequences such as heat strokes, power outages, depleted water tables, and general distress.
By 2050, urban India is projected to house 850–900 million people, significantly amplifying the urban heat island (UHI) effect and severely impacting quality of life. Addressing this requires integrating urban green spaces (UGS)—often referred to as “green oases”—into urban planning.
Research from Europe reveals that cities can be up to 12°C hotter than rural areas during summer, with a 1°C rise in temperature increasing death risks by 1–3%. Heat exposure exacerbates cardiovascular and respiratory illnesses. Urban materials like concrete and asphalt, with their high thermal capacity and low albedo, absorb solar radiation during the day and release it at night. This process raises nighttime temperatures, elevates cooling demands, and worsens air pollution and smog, leading to significant stress on public health systems and governance.
Tamil Nadu recently declared heatwaves a state emergency and has consistently championed sustainable development models centred on resource conservation. Other states must follow this lead, planning urban and peri-urban green spaces thoughtfully to combat UHI effects.
While tier II and tier III cities are advancing in public amenities, limited job and education opportunities continue to drive the migration to larger urban centres. UGSs are vital in such scenarios, offering ecosystem services like temperature regulation, carbon sequestration, stormwater retention, groundwater recharge, and recreational opportunities.
Global standards for UGSs underscore a glaring shortfall in Indian cities. The US Public Health Bureau recommends a minimum of 18 sqm per capita, while World Health Organization (WHO) suggests 9 sqm. India’s Urban and Regional Development Plans Formulation and Implementation (URDPFI) guidelines prescribe 10 sqm per capita, a standard met only by Jammu and Noida. Cities like Jaipur, Chandigarh, and Lucknow have seen a significant decline in green space availability over recent years.
Historically, ancient Greek, Roman, and Mughal urban planning emphasised dedicated green spaces, recognising their ecological and social benefits. Today, the UHI effect presents pressing challenges, adversely affecting air quality, thermal comfort, energy use, and public well-being, particularly among vulnerable populations like children and the elderly.
India’s URDPFI guidelines remain the most followed document for city planning but primarily focus on recreational spaces. However, the geographic diversity of Indian cities necessitates tailored approaches to quantifying greenspace needs. Objective planning is crucial to mitigate land surface temperature (LST) and reduce the temperature disparity between urban and nearby rural areas.
Urban greening initiatives—ranging from green roofs to large parks and city forests—can create porous surfaces, facilitate airflow, and support evapotranspiration, thus reducing UHI effects and regulating the microclimate. According to Onishi et al. (2010), tree rows and green patches in parking lots can reduce temperatures by up to 7.26°C. Among cooling measures, trees are the most effective, followed by shrubs and grasslands. Moreover, with global warming extending summer seasons, accessible parks for physical activities like yoga and meditation can significantly alleviate rising public health expenditures.
Recent studies have modelled UGS requirements for various cities, accounting for geographic and anthropogenic factors such as population density, building structures, roads, and water bodies. Research by the department of architecture and planning at MNIT Jaipur (Akanksha, 2019) highlighted specific UGS needs for Rajasthan’s cities: 15.7 ha for Sikar, 8.4 ha for Churu, and 18.23 ha for Sri Ganganagar. The study also identified areas suitable for developing green spaces to address UHI impacts effectively.
While land availability is a primary factor in planning UGS, water availability and quality are equally critical. These determine the most suitable vegetation types for a given area, ensuring ecological sustainability at minimal cost. Developing a well-planned UGS is essential for mitigating UHI effects, promoting ecological balance, and ensuring a higher quality of life in India’s growing urban centres.
Savita Dahiya, IFS is deputy conservator of forests and member secretary, District Environment Committee, Barmer-Balotra, Rajasthan. The views expressed are personal
