Cities are considered key battlegrounds in the fight against climate change, with rapid urbanisation presenting possibly the biggest challenge for dealing with climate-induced disasters, pollution and biodiversity loss. At the same time, cities have a major impact on a country’s financial health and are often viewed as engines of economic growth.

Globally, cities are expanding quickly. Half of the global population already lives in cities, and by 2050, two-thirds of the world’s population is expected to live in urban areas.

People move to cities for a variety of reasons, including better access to livelihood opportunities, healthcare, education, and social facilities. For many, cities serve as the hope for upward social mobility. Pakistan too is rapidly urbanising and in the next 20 years, there will likely be a notable increase in the number of urban areas across the country.

This projected urban development, if done in an unsustainable manner, presents a grave danger to the environment and biodiversity, raising concerns about its long-term viability as observed in the context of Islamabad.

The humble origins of Islamabad

Islamabad, established in 1960, is a modern and planned city compared to the other urban centres of Pakistan. After Karachi, it has served as Pakistan’s capital since 1963. It is located at the base of the Margalla Hills on the Potohar Plateau, between 457 and 610 meters above sea level, and is surrounded by thick Himalayan forests. Over the years, Islamabad’s population has ballooned from 0.117 million in 1961 to 2.4 million in 2023.

This exponential growth in the city’s population may be attributed to its favourable climate, abundant green spaces, the presence of protected areas like the Margalla Hills National Park [renowned as a tourist spot], its high expatriate population, easy access to healthcare and educational facilities, and for being a hub for business and trade.

Unfortunately, such massive increases in population trigger rapid urban expansion, causing substantial changes in land use and the local ecology of cities. This leads to the replacement of natural land cover with impermeable urban materials, resulting in deforestation, habitat loss, disrupted ecosystems, and harm to biodiversity. It contributes to changing local climates, increases energy consumption, and affects air and water quantity and quality.

In Islamabad, croplands, grasslands, and forests have been converted into urban structures — housing societies, commercial markets, roads, and parking lots — making it one of the fastest-expanding cities in the country.

From 1990 to 2020

A three-decade land use and land cover change analysis conducted by WWF-Pakistan’s Richard Garstang Conservation GIS Laboratory revealed that Islamabad’s overall built-up area has increased dramatically from 2,693 hectares in 1990 to 18,469 hectares in 2020 — a staggering increase of approximately 585 per cent. During these three decades, Islamabad has expanded at a rate of approximately 525 hectares per year.

This swift urban expansion in Islamabad has mostly taken place at the expense of productive agricultural land and grasslands — key ecosystems that provide important services such as carbon storage, a barrier to erosion, and biodiversity growth.

A large portion of Islamabad’s development has been concentrated along major roads such as the Islamabad Motorway, Lehtrar Road, Srinagar Highway, and Peshawar-Rawalpindi (N5) Road, which has in turn transformed rural areas into urban centres. The results also reveal that there have been significant transformations in the city’s landscape over the span of three decades — Islamabad had 28,060 hectares of tree cover in 1990, which had decreased to 25,243 hectares by 2020.

A number of research papers on urban sprawl in Islamabad have also revealed significant expansion of the city’s built-up areas, resulting in the loss of natural habitats. These changes indicate a growing urban footprint and the effects of this continuous expansion on the ecosystem.

Impact of uncontrolled urbanisation on climate

One of the many consequences of uncontrolled urbanisation is an increase in temperature in urban areas relative to surrounding vegetated areas. Man-made structures absorb heat and then radiate it into the air at night, raising the local temperature — a phenomenon known as urban heat island effect.

According to historical data, the average temperature in Islamabad has increased by 3°C between 1961 and 1990. UN-Habitat predicts that Islamabad’s future climate estimates are far more concerning, with temperatures increasing by 0.7°C until 2039 and 2.2°C until 2069. Additionally, sprawling cities can have several environmental consequences, such as increasing traffic congestion, greenhouse gas emissions, and air pollution.

In 2016, Pakistan’s air quality ranked fifth worst in the world, primarily due to industrial and vehicular emissions as well as crop burning. If the current levels of air pollution were to continue, it would shorten the average Pakistani’s lifespan by 2.7 years.

Rapid urbanisation can have long-term consequences on extreme weather events, influencing both temperature and precipitation patterns. Islamabad is vulnerable to these weather extremes, both in terms of temperature and rainfall. According to the ‘Climate Change Vulnerability Assessment’ on Islamabad, the city received 620 mm of rain in under 10 hours, the highest volume rainfall in 24 hours recorded anywhere in Pakistan in the past century. Extreme temperatures have also been recorded, with the maximum being 46°C in June 2005.

Changes in urban land use, which frequently entail the replacement of natural surfaces with impermeable surfaces, can exacerbate urban floods. This happens when precipitation cannot be absorbed adequately into the ground, resulting in excessive surface runoff and overburdened drainage systems.

The urbanisation of Islamabad has also resulted in the growing challenge of urban flooding — a cloudburst in Islamabad triggered an urban flash flood in the E-11 sector and nearby area, resulting in the deaths of a mother and her child.

Population surge and the increasing water stress

According to the Capital Development Authority, Islamabad’s population is projected to reach 4.443 million by 2050. This increase in population, coupled with urbanisation, rural-to-urban migration, and climate change, will also exert great stress on its water quality and availability.

The groundwater table in the Potohar region has been depleted by 116m in the last 30 years, and water availability per capita has dropped dramatically, from 5,300 m3 in 1951 to 850 m3 in 2013.

Islamabad relies on sources like the Simly, Khanpur, and Rawal dams, tube wells, and tiny water streams, but they are unable to satisfy the demand. The maximum combined water production from these sources is 84 million gallons per day (MGD), while Islamabad’s average water demand is 176 MGD — a shortfall of 106 MGD for most of the year.

Residents mitigate this water shortage by drawing from dug wells. The United Nations predicts that water consumption in cities around the world will double between 2007 and 2050, intensifying resource strain and decreasing freshwater supplies. According to a research paper published in 2020, Islamabad has a severe yearly groundwater depletion rate of 1.7 metres due to urbanisation and population increase.

In 2018, Pakistan developed the National Water Policy, with the aim of prioritising water conservation and the enhancement of groundwater recharge through various approaches. One of them is rainwater harvesting, which can effectively manage urban flooding and groundwater depletion. In Islamabad, with an annual rainfall of approximately 1,300 mm, harvesting just 50pc of this potential could balance the current water supply of 142 MCM provided by the Capital Development Authority.

Moreover, WWF-Pakistan is implementing the “Australia-Pakistan Water Security Initiative” to promote the Water Sensitive Cities (WSCs) Vision for Pakistan in Islamabad and Rawalpindi. WSCs employ a nature-based approach to holistically manage the integrated water cycle, enhancing city liveability, resilience, sustainability, and productivity.

What we need for a resilient and sustainable future

Pakistan currently struggles with severe economic, food security, and climate change related challenges. At the same time, the country’s fertile agricultural land is being transformed into buildings and housing societies, resulting in rapid urbanisation, arguably the greatest obstacle to coping with climate change and economic growth.

On the other hand, Pakistan has started initiatives to convert the degraded areas and deserts into arable land to address food security challenges, which requires significant resources and time. Therefore, it’s crucial to prioritise a national climate resilience agenda with priority for sustainable agricultural practices, fostering resilient urban development, promoting initiatives for clean energy, enhancing human capital, and strategically aligning financing mechanisms to mitigate climate change and food security challenges in Pakistan.

The rapid urbanisation of cities is extremely concerning since it is associated with increasing population pressure, environmental deterioration, and the effects of climate change. A multifaceted strategy incorporating urban development, environmental sustainability, and climate adaptation techniques is the need of the hour to counter the challenges of climate change resulting from rapid urbanisation.

Legislators and urban planners should impose stringent land use regulations to preserve green spaces and agricultural land while promoting the use of green infrastructure. The use of modern technology, such as remote sensing and GIS, is critical for monitoring urban expansion trends and land use changes on a regular basis. These techniques are extremely useful for identifying places at high risk of urbanisation as well as measuring the impact of urbanisation on natural resources.

Header image via Shutterstock