By Dr Zawwar Hussain
In the 21st century, climate change is no longer merely a scientific term; it has become one of the greatest global challenges affecting human life, urban planning, agriculture, economies and public health. Rising heatwaves across the world have pushed urban temperatures to dangerous levels. Modern research now confirms that extreme heat does not disappear after sunset; instead, cities continue to radiate heat throughout the night. This reality is raising serious questions about traditional urban park design and green infrastructure planning. A significant study conducted by researchers at Concordia University in Montreal examined 13 urban parks and revealed new dimensions in the relationship between urban environments and temperature regulation. According to the research, dense tree clusters provide highly effective shade during the daytime and significantly reduce urban heat, but these same clusters release stored heat slowly during the night, resulting in warmer nighttime conditions.
In contrast, open grassy areas become hotter during the day but cool down much faster after sunset. Lead researcher Lingshan Li emphasized that parks designed to meet visitors’ needs throughout both day and night must possess structural diversity. In other words, neither dense tree cover alone nor entirely open spaces are sufficient; instead, a balanced combination of mature trees and open grassy landscapes is more effective for maintaining comfortable temperatures around the clock. This research delivers an important message for cities worldwide that are increasingly experiencing the “urban heat island effect”. Under this phenomenon, concrete buildings, roads, vehicles, industrial activity and shrinking green spaces absorb heat throughout the day and gradually release it at night. As a result, urban areas often remain several degrees hotter than surrounding rural regions.
Pakistan is currently among the countries most vulnerable to climate change. Global climate assessments indicate that during the past two decades, it has ranked among the nations most severely affected by extreme heat, floods, droughts and environmental instability. Major cities such as Karachi, Lahore, Islamabad, Khairpur Mirs and Mirpur Khas are already witnessing the direct consequences of rising temperatures. Karachi, Pakistan’s largest coastal and economic hub, has become increasingly vulnerable due to the combined effects of heat and humidity. During May and June, temperatures frequently rise between 40C and 45C, while high humidity pushes the “feels-like” temperature several degrees higher. During the devastating 2015 heatwave, more than 1,200 people reportedly lost their lives in Karachi alone, exposing severe weaknesses in urban planning and green infrastructure systems.
Uncontrolled urban expansion, declining tree cover, extensive concrete development and insufficient public parks are further intensifying the crisis in Karachi. Although a few large parks and coastal winds provide limited relief, nighttime heat retention is becoming a growing concern. Lahore is also facing severe environmental stress. The city has repeatedly ranked among the world’s most polluted urban centers, where extreme heat and air pollution combine to create what experts describe as “double climate stress”. Rapid population growth, deforestation, expanding housing societies and shrinking green belts are contributing to rising urban temperatures. The increasing heat is not only affecting public health but also placing pressure on electricity systems, water supply and economic productivity.
Islamabad, once regarded as a relatively green and moderate city, has also experienced rising temperatures in recent years. Despite the presence of the Margalla Hills, urban sprawl, road expansion and declining tree cover are affecting local climate conditions. Although Islamabad still maintains better green coverage compared with many other Pakistani cities, environmental pressures are expected to increase in the future. Meanwhile, agricultural regions in Sindh, particularly Khairpur Mirs and Mirpur Khas, are confronting the agricultural consequences of climate change. Khairpur Mirs is internationally recognised for date production, while Mirpur Khas is famous for its mango orchards. However, rising temperatures, water scarcity, irregular rainfall patterns and prolonged heatwaves are threatening these agricultural systems.
Pakistan is among the world’s major date-producing countries, and millions of acres in Khairpur Mirs are dedicated to date palm cultivation. However, extreme heat is increasingly causing sunburn damage to fruit, moisture loss, premature drying and declining crop yields. Similarly, mango production, which holds a major position in Pakistan’s agricultural exports, is being affected by heat stress and unpredictable weather conditions. Agricultural experts warn that even a temperature increase of 1C to 2C could significantly reduce mango productivity. Farmers in Mirpur Khas and surrounding areas report that mangoes are ripening earlier than normal, reducing fruit quality and export value. At the same time, higher temperatures are increasing irrigation demands while underground water reserves continue to decline. These realities demonstrate that urban green infrastructure and agricultural climate planning cannot be treated separately.
Parks, trees, open landscapes, agricultural belts and urban forests are no longer simply aesthetic features; they are becoming essential components of human survival. Many developed countries are now investing in the concept of “climate resilient cities”, where parks are designed not only as recreational spaces but also as natural cooling systems. Modern urban planning increasingly incorporates diverse tree species, airflow corridors, water bodies, grassy landscapes and low heat-absorbing construction materials to regulate temperatures during both day and night. Pakistan must now urgently adapt its urban planning strategies to climate realities. Cities such as Karachi, Lahore and Islamabad require large-scale tree plantation drives, urban forests, green corridors, rainwater harvesting systems and scientifically designed parks.
Similarly, agricultural regions like Khairpur Mirs and Mirpur Khas need heat-resistant crops, advanced irrigation methods, microclimate management and stronger agricultural research systems. Extreme heat is no longer merely a seasonal issue; it has become a critical challenge for human health, food security, economic stability and the future of urban life. If immediate and effective measures are not taken to protect trees, parks, agricultural lands and natural ecosystems, many South Asian cities may become increasingly difficult to inhabit in the coming decades. This is why the modern world no longer considers development to mean only the construction of roads and buildings. True progress is now increasingly defined by the creation of environments where humans, trees, land and climate coexist in sustainable balance.
(The writer is a PhD scholar with a strong research and analytical background and can be reached at editorial@metro-Morning.com)
