The shocking images of flooding in Karachi can make an investor run away. On the other hand, the same situation can also help attract private sector investment and transform Karachi into a climate resilient city. The key question is: do we really want to make Karachi a ‘sponge city’ that can absorb all storm water, even if the quantities are several times higher than the present ones?

Before envisioning an alternative future, we need to recognize the fact that Karachi flooding has exposed our collective failure in managing climate risks — any risks, and not just urban flooding. We need to accept that climate vulnerabilities and urban growth are an intrinsically linked challenge. The rapidly increasing urban population also increases the exposure to climate-induced disasters.

In Pakistan, more than half of our urban population lives close to the poverty line, if not actually below it. Since most of them live on marginal lands, and in unplanned and overly congested neighbourhoods, they are often least prepared to manage flooding and other multi-tiered climate challenges. Climate change serves as a threat multiplier. Like poor governance, it spares no one. The poor are the first and the hardest hit. It is therefore imperative that we understand the linkages between them, their physical environment andclimate change.

As the climate crisis deepens, most human settlements are facing a chain of extreme events, oftentimes one after the other. Urban settlements in Pakistan are no exception to this. Climate change has pushed developing countries further behind on their development agendas and their poor populations further into the poverty trap, more so because the slowly creeping onset of climate change is degrading their environment, weakening their ecosystems, and eroding their resilience and coping mechanisms. It often adds to their debt, displacement, and outward migration to cities to face another vulnerability trap.

Cities in Pakistan are growing at a rate that is faster than the national population growth rate. Yet, cities have not grown vertically. Their per-square-metre density levels are far less than in many other Asian cities. The unplanned urban sprawl has left more than half the urban population outside the delivery mechanism of basic municipal services such as drinking water, sewerage, and waste management. Add to this list —schools, hospitals, planned roads and streets, parks and parking spaces, and the public transportation system. All this, together with congestion and air pollution, deteriorates their quality of life. Studies have shown that climate change is lowering (the already low) standard of living that in turn further slows the rate of economic growth.

Karachi’s two rivers, some 64 big nullahs and thousands of their tributaries feeding into the big ones, some as wide as 200 feet but narrowed down to maybe 30 feet or less, have been the victim of Karachi’s growth. With waterways choked, urban flooding has become an inescapable fact. Most of these encroachments are illegal and in violation of the municipal laws. They were weak and required strengthening. Instead, they became victim of multiple governing bodies, some of these managed from Islamabad or overseas. In some cases the new infrastructure, particularly the prestigious oceanfront housing societies and commercial buildings and their supporting infrastructure — roads, bypasses, and underpasses — have created obstructions that have choked the entire city. Boat Basin is a stunning example in this regard.

In theory, citizens have the right to reclaim their rivers and streams as many other cities around the world have done. In Pakistan’s context it will be a politically inconvenient and economically expensive undertaking.

In the meanwhile, the demographic trends can help policymakers determine their responses to urban flooding and mitigate flooding and other climate risks. The level or types of climate vulnerabilities can inform interventions based on the size of human settlement, its locale, demographic and physical environment characteristics. A detailed demographic picture that covers gender, age groups, and income levels when juxtaposed against the physical environment and climate risk can help define the contours of vulnerability assessments for various extreme events and long-term climate exposures. While the physical environment is critical for defining the scale of interventions particularly geared towards infrastructural development, ecosystem-based approaches and solutions will help define the long-term responses aimed at enhancing adaptive capacity of communities and strengthening their resilience. Therefore, only a combination of three fundamental factors — demographic dynamics, physical environment and ecosystem — will complete the triangle for determining local level investment needs, policies and strategies.

It has often been argued that urban population growth represents the relationship between climate change and fertility, mortality, urbanisation and migration. This information allows planners to base their decisions on population dynamics and project changes into future and the impacts these changes will have, not only on the traditional priority areas, but also for climate risk mitigation interventions in transportation andother infrastructures.

With almost half of Pakistan’s population now living close to the poverty line and the majority population residing in urban areas, it is expected that both poverty and population will grow in urban centres faster than in rural settings. Studies have shown that the GHG emissions also grow as urban population grows, particularly if the growth is in the form of an unplanned sprawl driven by land mafia and real estate tycoons. Karachi has the option to continue with business as usual, and allow the unplanned city to further expand with random growth in low lying and marginalized lands or in fertile peri-urban areas and exacerbate climate risks. Even if the federal government and others can provide some immediate relief, how can we make the city resilient?

It is important for Pakistan to understand that well-planned urban centres that plan density and mixed land-use in vertical and horizontal growth — supported by low-carbon mass transit system — will become important hubs of climate mitigation and climate risk management. Urbanisation and migration are, therefore, key components of a country’s population dynamics central to discussing climate risks, especially in regard to movements from rural to urban and peri-urban areas.

A long-term solution rests in finding how to integrate stormwater and groundwater management and what role wetlands play in this regard. Sindh is a province dotted with wetlands that clean and purify water. How can the run-off water in Karachi be used to recharge groundwater and wetlands? Many other cities in the world have worked with the private sector to use aquifer storage and recovery for managing excess water. Properly designed storage purifies and makes storm water fit for open surfaces such as irrigation and city horticulture. With chlorination it can be used, at least initially in some areas, for recycling. Finally, with the help of microfiltration and disinfection with UV and chlorination, it can even be fit for human consumption.

This can be envisioned only if three policy decisions are made: a) as a water insecure country, we will not allow wastage of our storm-water; b) as a climate vulnerable country, we will not abandon the urban poor and free up or reclaim our waterways from chokepoints; and c) as a resource deficit country, we will engage private sector to commercially harvest storm-water for industrial, ecosystem and irrigation (but non-potable) use.

The author is an independent expert on climate change and development. He can be reached at atauqeersheikh@gmail.com