Urbanisation is coming at the cost of natural blue and green spaces leading to a surge in surface temperatures and exacerbating the Urban Heat Island (UHI) effect. Researchers warn that without sustainable urban planning or urban centres especially in developing nations like India will face hazardous heat stress, threatening both human health and local ecosystems.
Urbanisation and Rising Temperatures
The C(UN) estimates that by 2050, 68% of the global population will live in urban areas, with 90% of this growth concentrated in Asia and Africa. As a result, the rate of urban land expansion is already twice as fast as population growth, leading to a dramatic transformation of landscapes.
Studies project that by the end of the 21st century, the Land Surface Temperature (LST) could rise by 1.4-5.8°C, intensifying extreme weather events such as heatwaves, wildfires, glacier melts, heavy rainfall, and droughts. In cities, where built-up areas retain more heat, the UHI effect can push surface temperatures beyond 50°C, adding over 10°C to already high urban temperatures.
Recent records from Assam have already shown lethal heat stress levels, where high humidity and temperatures exceeding 35°C pose severe risks to human survival. If left unchecked, this phenomenon will worsen across India’s urban areas.
How Cities are Transforming Local Climates
The expansion of urban land use and land cover (LULC) is depleting air quality and raising temperatures, further amplifying UHI effects. As impervious surfaces like concrete and asphalt replace natural ecosystems, urban regions store heat during the day and release it slowly at night, keeping cities warmer than surrounding rural areas.
Scientists emphasise that LST is a critical indicator of urban health, as higher temperatures disrupt local microclimates, affecting both the environment and human populations. Research shows that small towns and cities in India are also experiencing temperature spikes, proving that heat extremes are no longer limited to metros and large urban centres.
The Role of ‘Blue-Green’ Spaces in Cooling Cities
One of the most effective solutions to combat rising urban temperatures is Urban Blue-Green Spaces (UBGS) which include parks, wetlands, rivers, lakes, and green rooftops. These natural elements act as heat sinks, absorbing excess warmth and regulating local climate conditions.
However, urbanisation is rapidly encroaching on these essential cooling spaces, worsening temperature fluctuations and increasing vulnerability to climate disasters. With India’s urbanisation rate growing by 27.8% from 2001 to 2011, the decline in UBGS has already modified the microclimate of several regions.
The Path Forward: Sustainable Urban Planning
While urban expansion is inevitable, experts stress that proper planning and policy interventions can mitigate its negative impacts. Strategies such as:
- Preserving and expanding urban blue-green spaces
- Using reflective and heat-resistant materials in infrastructure
- Adopting sustainable urban design
- Enforcing strict environmental regulations on land use
can help counteract the UHI effect and maintain urban health. Planners and policymakers must acknowledge that unchecked urbanisation will only worsen climate challenges, putting both cities and their residents at risk.