Coming to a rooftop near you...

Long before most of us in Durban knew much about COP, last month's climate conference, Clive Greenstone was creating living green roofs.

These are fully functioning ecosystems with indigenous local plants that attract birds, bees, butterflies, geckos and other garden dwellers.

Greenstone's green fingers were behind ethekwini's "green roof pilot project" which, since 2008, has been reintroducing biodiversity to the city centre through experimental planting on rooftops at the city engineer's office, in K E Masinga Road.

The project is adequately irrigated - Greenstone's philosophy is "you plant, you watch, you leave, you neglect" - applying an inventive system he came up with that involves collecting water from the building's airconditioning units. "You don't want to plant things that need water," he says, "unless it can be collected, harvested and recycled back."

Greenstone did his masters on green rooftops at the University of Kwazulu-natal, through the School of Architecture, Planning and Housing. For that, he created a temporary green roof at the Howard College campus.

Now researching for his PHD, which he will do through the same department, Greenstone this time has much bigger plans. These include rooftop agriculture, chickens and goats on roofs, and medicinal plant cultivation. If they work out as he hopes they will, the plans could create huge opportunities for interdepartmental collaboration on the campus and provide a blueprint for other campuses.

They could be a food source and provide jobs for students, offer viable options for traditional healers, and, taken into the wider community, result in more resilient cities.

We meet outside the Cape Town pavilion judged best overall stand in the COP17 climate response expo. It is a steamy day. I am melting in the humidity.

"Imagine if you were a lettuce," he says as I mop my brow yet again. The thought makes me wilt. But few of the 3 600 salad seedlings he planted at the request of Cape Town Pavilion project manager Stephen Lamb are wilting. Growing in two-litre milk bottles packed into milk crates, they are well hydrated with recycled water - all part of the winning design.

Normally, Greenstone - who collaborates on many of his projects, including the city engineer's project, with fellow green roof expert Mike Hickman, aka Ecoman - would not plant lettuces.

The pair (Hickman spent several years working on green roofs in Germany and New Zealand and Greenstone describes him as "my mentor") have written a green roof guidelines manual, available through ethekwini's environmental planning and climate protection department, which has its headquarters at the city engineer's building.

Lettuces, Greenstone points out, are not indigenous. They need a lot of water. And if you're considering food sources, lettuces are not filling. He has had some success with spinach, chillies, peppers, madumbis, traditional cow peas and mfino (wild spinach).

While he sees a future for food production on rooftops and it is something he'll be researching for his PHD, biodiversity and other benefits are his current focus.

For example, roof temperatures at the ethekwini pilot project are 30 percent lower in planted areas compared with where the roof is left bare.

And in Limpopo where he did a successful green roof system for Oprah's Angel Network (a joint project with the Limpopo department of education) using all plants grown within an 80km radius, pupils studying science and biology monitor the roof and report back, so the project is educational.

The many projects he has done through Green Roof Designs, the company he founded, are all collaborations.

Progressive architecture is involved, which includes design features such as rainwater harvesting.

Structural engineers determine load, which needs to be measured for when all intended plants are fully grown and saturated.

The water membrane on the roof must be sound. What is to be planted must be researched, keeping in mind drainage and the potential for chemical leeching.

Given all this, Greenstone sees huge potential for rooftop cultivation and farming, including interdisciplinary collaborations at university level by architects, engineers, soil scientists, climatologists and others.

"Do you know that people who live in tree-lined streets are less prone to violent behaviour?" he asks. "And people who work in an environmentally friendly environment take off fewer sick days?"

Maybe there's also a place for psychologists in the collaboration.

And philosophy and politics? "How does rooftop agriculture mend the metabolic rift - when people lose contact with the soil - is that what Karl Marx was talking about?" he asks.

Greenstone can't help but get passionate when he talks about what he's done and what he's seen as a consequence.

On his green roof at his Berea home, for example, he's had visiting paradise flycatchers and sunbirds and blackeyed bulbuls and three hammerkop mating. "Well, two were mating and one was watching," he says.

There's more. Greenstone is in the process of expanding from horizontal systems - those created on roofs - to vertical gardens, or living walls.

Have a cappuccino at the Corner Cafe on the corner of Cromwell and Brand streets in Glenwood in a few weeks' time to see Greenstone's first major project of this nature.

And since climate conferences keep happening, keep a lookout for a tangible response to climate change in the form of Greenstone's greening projects, which you won't have to travel the world to see. They will be coming to a rooftop or a wall close to your home.

Sunday Tribune

Posted at 07:45AM Jan 09, 2012 by Editor in Industry  |