As Indian cities grow denser and hotter, urban forests are increasingly being promoted as a solution to rising temperatures. But evidence from cities such as Chennai suggests that trees alone are not a universal fix. Urban forests can help cool cities and improve quality of life, but only when planners understand local climate conditions, ecological systems and how people use urban land.
Chennai, a coastal city of 4.5 million people, routinely experiences summer temperatures touching 44 degrees Celsius. Despite its cultural richness, with hundreds of temples and a national park embedded within the city, Chennai has limited shaded public spaces. Trees line some roads, but large green parks are scarce, leaving much of the city exposed to extreme heat.
As urbanisation accelerates across India, urban forests clusters of trees in parks, along roads, along rivers and within neighbourhoods are gaining attention for their ability to cool air, support biodiversity and provide recreational space. Yet these green assets are often sidelined in development plans.
Research shows that Chennai currently has around 26 square miles of tree and vegetation cover, largely concentrated in formal green spaces such as Guindy National Park. Beyond this, nearly nine square miles of unused land on the city’s outskirts could potentially support new urban forests. Similar opportunities exist in fast-growing cities like Coimbatore and Tiruchirapalli.
Global planning standards recommend that at least 30 per cent of urban land should be covered by trees, while the World Health Organization suggests cities should provide nine square metres of green space per person. Most Indian cities fall well short of these benchmarks, constrained by high land prices, weak planning frameworks and limited public participation in greening initiatives.
Government policies have increasingly linked tree planting with climate resilience and urban cooling. However, researchers caution that this approach oversimplifies a complex problem. The effectiveness of urban forests depends on rainfall patterns, water availability, species selection and how trees interact with local ecosystems and communities.
In hot, dry cities such as Chennai, some studies indicate that trees can actually slow cooling when water is scarce. Instead of lowering temperatures through evaporation, stressed trees may contribute to heat retention. This effect is particularly pronounced in mid-sized Indian cities, where urban heat is intensified by concrete surfaces, dense construction and limited airflow.
Ecological impacts also deserve attention. Not all wildlife benefits equally from tree planting. Research from Bengaluru shows that non-native tree species contribute little to bird diversity. Meanwhile, urban grasslands, wetlands and marshes — often labelled as “wastelands” — play a critical role in supporting biodiversity and managing flood risks.
Social impacts are equally important. Many Indian cities retain areas of common land used by poorer communities for grazing livestock or collecting fuelwood. Tree-planting drives that ignore these traditional uses can displace livelihoods and deepen inequality, even when framed as environmental improvement.
Urban planners increasingly argue for a “design with nature” approach, a concept developed by landscape architect Ian McHarg. Rather than planting trees indiscriminately, this method prioritises protecting existing natural systems and carefully assessing where new development or greening should occur. Factors such as soil type, drainage, slope and water availability help determine which areas are suitable for forests and which are better left open.
Advances in satellite imagery and geographic information systems have strengthened this approach, allowing planners to map ecological corridors and connect fragmented green spaces. Tree-lined canals, roads and rivers can act as links between parks and reserves, improving both cooling and biodiversity.
Choosing native tree species adapted to dry and drought-prone conditions is another key factor. Involving local communities in selecting fruit-bearing or culturally valuable trees can also improve acceptance and long-term maintenance.
Urban forests could play a role in reducing India’s growing demand for cooling. By 2030, air conditioning is expected to account for nearly one-third of the country’s electricity consumption. Well-designed green spaces can help moderate urban temperatures and reduce energy use.
India has introduced several national programmes to expand urban greenery, including Smart Cities Mission guidelines and the Nagar Van Yojana launched in 2020. While these initiatives aim to increase tree cover through public participation, evidence of large-scale improvement remains limited. Critics argue that many programmes focus on counting planted saplings rather than building resilient urban ecosystems.
Unplanned urban expansion has already reduced tree cover in many Indian cities. But experts say the future does not have to be equally damaging. Protecting existing green spaces, restoring degraded ecosystems and planning urban forests that balance climate resilience, biodiversity and social equity could make cities healthier and more liveable.
The lesson from India’s experience is clear: urban forests are not just about planting more trees. They are about designing landscapes that work with nature and with people in a warming world.