It is a hot afternoon in Islamabad. The cool breeze that once rolled down from the Margalla Hills, long considered part of the capital’s natural identity, no longer feels the same. From Blue Area to the Expressway, traffic stretches across the city. Concrete spreads in every direction. New housing schemes rise where open land and trees once softened the landscape. High-rise buildings replace shade. Roads, parking lots and gated colonies absorb the sun.

The city appears to be losing the very character that once made it stand apart.

A few decades ago, Islamabad was widely admired for its green setting, broad roads and carefully planned urban form. Rawalpindi, older and busier, had its own pressures, but the open land, green belts and natural streams between the twin cities helped maintain an ecological balance that could even be felt in the weather.

That balance is now under strain.

Over the past three decades, dozens of housing societies have expanded around Islamabad and Rawalpindi. Hundreds of thousands of people have moved into the region. Roads, flyovers and commercial corridors have multiplied. Vehicle numbers have surged. On the surface, it is a story of growth. Beneath it, however, a slower environmental crisis has taken shape.

It is not only a crisis of rising heat. It is also a crisis of land, water, trees, rainfall, air and public health.

The planning shift that changed the city

A major turning point came in 1992, when Islamabad’s zoning framework earmarked Zones 2 and 5 of the Islamabad Capital Territory for private housing development.

That decision opened the door for a rapid expansion of private real estate. Bahria Town, Bahria Enclave, Multi Gardens, Cabinet Division Employees Cooperative Housing Society, Gulberg Greens and many other schemes grew across thousands of kanals. Some projects expanded far beyond their original approvals through revised plans and later extensions.

From that point onward, Islamabad began moving steadily beyond the image of a planned garden capital. The city that was once designed around a relationship with nature started to become part of a wider concrete corridor stretching into Rawalpindi and beyond.

The numbers behind the transformation

The scale of this change is stark.

In 1990, Islamabad’s built-up area was about 52 square kilometres. By 2021, it had expanded to 233 square kilometres. In other words, the built-up footprint of the capital grew more than four times in just three decades.

Rawalpindi followed a similar pattern. Its built-up area increased from 60 square kilometres in 1990 to 228 square kilometres in 2021.

This growth was not simply the addition of buildings. It came at the cost of natural cover.

Between 2000 and 2020, natural green cover across the Islamabad city region declined from approximately 428 square kilometres to 316 square kilometres.  while built-up land expanded from  58.09 square kilometres to 256.49 square kilometres. 

The safest conclusion is clear: forest, water, grassland and natural cover have been squeezed as the twin cities have expanded. The exact agricultural loss varies by study boundary and method, but the direction of ecological change is unmistakable.

When cities begin producing their own heat

Trees cool cities by providing shade and releasing moisture into the air. Soil and vegetation allow heat to dissipate more naturally. Concrete, asphalt and cement do the opposite. They absorb heat during the day and release it slowly into the evening and night.

This is what climate scientists call the urban heat island effect.

In Islamabad, research shows that impervious surfaces increased by about 11.9 percentage points between 1993 and 2018. The conversion of forest, water, grassland and agricultural surfaces into impervious cover contributed about 1.52°C to relative land-surface warming.

More recent evidence is also worrying. From 2010 to 2022, Islamabad’s surface urban heat island intensity increased by an average of 0.18°C per year, while the city expanded at about 8.07 square kilometres per year.

In Rawalpindi, land-surface temperature has been reported to rise by about 1.2°C per decade over roughly three decades, alongside major built-up expansion.

These are not abstract scientific figures. They help explain why summer in the twin cities feels harsher, why nights remain warmer, and why heat stress is becoming a growing urban risk.

The quiet collapse of groundwater

One of the least discussed impacts of urban expansion is its effect on groundwater.

In the past, rainwater could soak into open land, recharge underground aquifers and sustain water supplies. Today, roads, paved streets, parking areas and concrete floors send much of that water straight into drains and streams.

The result is a city that receives rain but fails to store it.

Groundwater is estimated to be falling by about one metre per year in Islamabad and 1.5 metres per year in Rawalpindi.

This is especially troubling because the region has not lost its rainfall in the same dramatic way. Both cities receive roughly 1,300 millimetres of average annual rainfall, and around 60 percent of it falls during the monsoon months from July to September.

The problem, then, is not simply a lack of rain. It is the failure to absorb, retain and manage that rain.

Floods and water shortages in the same city

When land can no longer absorb rain, water rushes into drains and nullahs. That increases flood risk.

The most devastating reminder came in 2001, when flooding in Lai Nullah killed 74 people and damaged or destroyed around 3,000 houses.

Yet the same urban region also faces water shortages during hot months.

This contradiction defines the planning crisis of the twin cities: too much water during intense rain, too little stored water when it is needed most.

A city that paves over its natural recharge zones can flood and go thirsty at the same time.

More people, more vehicles, more heat

The pressure is also demographic.

Islamabad’s population grew from about 805,000 in 1998 to more than 2.36 million in 2023. Rawalpindi district’s population has crossed 6.11 million, including more than 4.21 million people in urban areas.

Traffic has increased with the population. By 31 March 2024, Rawalpindi district had more than 1.018 million registered motorcycles and nearly 109,000 registered cars.

These vehicles add to air pollution, greenhouse gas emissions and local heat. Roads built for them add more asphalt and reduce more permeable land. The result is a feedback loop: more expansion creates more traffic, more traffic demands more roads, and more roads produce more heat.

Are housing societies alone to blame?

The answer is not simple.

Global climate change is raising temperatures around the world, and Pakistan is already among the countries most exposed to its impacts. Heatwaves, erratic rainfall and climate extremes are not caused by one city’s planning decisions alone.

But in Islamabad and Rawalpindi, the evidence shows that local urban choices are making the global climate problem worse.

Unplanned expansion, shrinking green cover, rising concrete surfaces, traffic pressure and population growth are intensifying the heat that climate change is already amplifying.

In other words, the problem did not only come from the sky. We also built part of it on the ground.

The choice that remains

Every city needs development. People need homes, roads, services and economic opportunity. But development and ecology do not have to be enemies.

Cities around the world are now adopting climate-sensitive planning tools: sponge-city design, urban forests, green roofs, rainwater harvesting, permeable surfaces, better drainage, public transport and stricter environmental conditions for real-estate approvals.

Islamabad and Rawalpindi still have time to change course.

New housing schemes can be tied to serious environmental impact conditions. Green belts and water recharge systems can be made mandatory, not decorative. Urban forests can be expanded. Natural streams and floodplains can be protected from encroachment. Public transport can be prioritized over endless road expansion. Heat mapping can guide planning decisions before vulnerable communities are pushed into hotter, riskier neighbourhoods.

The question is whether the twin cities will treat nature as infrastructure, or continue treating it as empty land waiting to be built over.

If the current pace continues, future generations may not remember Islamabad as a green capital. They may remember it as a city where development came fast, but nature paid the highest price.