Greening our rooftops

Each year more than 35 billion tons of carbon dioxide are released into the atmosphere, which stays there warming the world. Its disruptive consequences for us are baked in and costly: more flooding along the Indus in summer and drought-like conditions in winter, as now.

While we are still awash in green hype from the recent conference on climate change in Islamabad, it is a good time to discuss steps to mitigate its consequences and adjust. There were of course several discussed at the conference. But the idea I give here is simple: roof gardens, which though trivial by conference standards have been around since Biblical times, and may be one useful way to achieve climate resilience at the rooftop level.

So, here is the story of roof gardens from ancient times to current practices that we and our civic authorities could learn from to green Islamabad’s rooftops.

Our story begins with the mother of all rooftop gardens: the ancient Hanging Gardens of Babylon, one of the seven wonders of the ancient world. Though their physical traces are undiscovered, Will Durant gives us this vivid description of them: The Hanging Gardens were supported on a succession of superimposed circular colonnades. The topmost terrace was covered with rich soil to the depth of many feet, providing space and nourishment for varied flowers and plants, and deep-rooted trees, seventy-five feet above the ground!

It is said that the King (Nebuchadnezzar d 1104 BC) built them for one of his wives, a Persian princess who ‘longed for the meadows of her homeland, roses with hundred petals of Shiraz and Firuzabad’, and rose festivals, such as the Kashan Rosewater festival that persists even today and far exceeds the extravagance of Holland’s Keukenhof in mid-March.

The Persian princess and Nebuchadnezzar’s other myriad wives walked the Hanging Gardens surrounded by shrubs and fragrant flowers. While ‘in the streets below, the common man and woman ploughed, wove, built, carried burdens, and reproduced their kind’.

Even in its Biblical beginnings, our story of roof gardens – as with all gardens – is also about exclusiveness and about casting out people who toil to build them. But that is another more important story.

Our present story meanwhile, has reached modern times and Frank Lloyd Wright who called his hanging gardens ‘organic architecture’; and Le Corbusier who saw them as an important ‘component of a properly executed living space, restoring the footprint of green space lost in construction’. He wrote: that the roof garden could be an elevated space with vegetation within the heart of the building, a terraced garden, and a solarium, at the top.

They set the modern standards of climate-resilient design used worldwide.

In New York, at the turn of the last century rooftop theaters – landscaped with flowers, vines, and trees – provided respite in the long hot summers. Its High Line is the longest green roof worldwide (1.45 miles) built on an elevated former rail line. And like the Promenade Plantee in Paris, inspired Sydney’s Goods Line, the Seoullo in Seoul, and London’s Camden Highline (to open in 2027).

Chicago has over five million square feet of green roofs. Munich requires a green roof on a newly constructed rooftop over 1,086 square feet. There are now 63 million green rooftops in Germany.

So, with this history and current practices in mind, how can we regreen the places our roofs cover? Mimic what was on the ground before, and bring back indigenous flora? As well as build ourselves an escape hatch into an exclusive paradise? Briefly, how do we make a hanging garden in Islamabad?

There are two designs I can think of for this purpose to use in miniature, and/or in combination based on experience with my rooftop garden, which includes a grass meadow, flowery bushes, palms, a fountain pool, and Bougainville rising from the ground 20 feet below and making a colourful barrier of white, red and orange flowers along its borders.

One design is Cyrus’ (d 530 BC) Persian paradise garden, the Char-bagh: four gardens with a pool in the middle, separated by rills and trees and bushes arranged in geometric patterns. Babur’s (d 1530) version of this was his Char-chamans in Kabul and elsewhere, and he is buried in one of them, in the Bagh-e-Babur in Kabul; his successors made Char-chamans in Delhi, Agra, Lahore, and Kashmir.

Cyrus’ gardens called paradeisos in Greek (or paradise) appear also in the Old Testament referring to heaven and the garden of Eden. So, his garden came first, and heaven trailed in its wake – making his design heavenly ordained!

The other design follows modern landscape architects striving to balance conscious decisions and wild happenstance. They say a garden loses its charm if it is manicured, and you don’t feel shut out of the made-over world. Let nature take its course. But too much ‘happenstance’ can result in an unweeded and neglected garden, and may upset you as does a ‘newly damaged and contaminated world.’

So, using either of these designs or a combination, let’s drape our roofs in a tapestry of flowers, plants, and trees; build enclosed and enchanted gardens on our roofs, our exclusive paradeisos of idleness and luxury. And gently coerce recalcitrant citizens by tweaking the city’s building rules to make green roofs mandatory (as in Munich).

Greening our rooftops is a fine way to turn self-interest into a social good reducing the ‘urban heat island effect’ and carbon footprint by 85 Kg/Hectare annually – a tremendous bonus for climate resilience.

The writer is a freelancecontributor. He can be reached at: Khwaja.Sarmad@gmail.com