June 6 marked the very first World Green Roof Day. For a world just emerging from the isolation of lockdown into social distancing, the presence and importance of nature in our lives has become acutely evident.
Stuck at home, our only contact has been our direct family, our pets and nature. The number of people out walking or running in nature and the plant nurseries bursting with customers are testimony to that.
This is a positive outcome of this awful situation. Living in crowded and polluted concrete cities, and distanced from the farmers who cultivate our food, we had lost touch with nature and the fact that we are an integral part of it. We can’t survive without clean air, soils that can grow our food, insects that pollinate our food, clean water and that contact with wildlife.
It is clear that a growing population requires more living space. However, this must not be to the detriment of our physical and emotional well-being. As the World Health Organisation says, each person needs a minimum of nine metres square of green space to be healthy.
For Malta, with a population of around 450,000 people, nine metres square represents over four million metres square (4,000 square kilometres). The whole of Malta is 316 kilometres square so even if 70 per cent of the islands are still untouched nature, how can we do that?
Well, we literally need to green every horizontal and vertical surface, and live in a Mediterranean-style urban jungle. I don’t know about you but just the idea of being surrounded by living plants makes me feel healthy and peaceful.
Green roofs, when applied following the local ecosystem and building on local biodiversity, have enormous benefits to the economy and productivity.
Taking the economic benefits - a sustainable Mediterranean green-roof ecosystem applied to a whole roof will reduce the energy demand of that building by up to 75 per cent. That means paying up to 75 per cent less for your heating and cooling – every year, because you don’t need it – and having that much more disposable income.
A sustainable Mediterranean green roof ecosystem applied to a whole roof will reduce the energy demand of that building by up to 75 per cent
It means less energy demand so lower carbon dioxide emissions from the power plant, so the government has fewer carbon credits to buy; and it also means fewer power cuts which cause huge loss of earnings every time they happen. The more roofs we green in Malta, the smaller the bill for carbon credits; at last count it was over €2 million per year.
Over and above savings, investing in green roofs at a national level will create sustainable jobs in a new, transformed green economy, for farmers and nurseries in growing indigenous Maltese and endemic Mediterranean plants – which incidentally should also be used to sustainably green roadsides, roundabouts and piazzas in every local authority – jobs in transport, lifting equipment, waste management and of course for installation of the green roofs.
A clean and green environment also attracts a more discerning tourist who will not litter and who will enjoy the beauty of Malta without damaging that beauty.
The sustainability and self-sufficiency of our local food systems depends entirely on rebuilding our soils and our biodiversity. As with any species, pollinators will multiply if they have sufficient food. So, the more flowering plants we can plant from their local environment, the more productive our fruit trees, olive trees and fields will be.
To be truly sustainable, a green roof needs to be free of chemicals.
This is because these chemicals poison the soil, killing its natural biodiversity and ability to sustain the growth of the plants; the pesticides make it impossible for the natural predators of pests to thrive.
An all-natural green roof and green wall is home to lizards, geckos, frogs – all-natural pest control. Farming follows these same principles: the healthier and more chemical-free the soil is, the greater its productivity and the healthier the plants it grows. Of course, this all makes much tastier and healthier produce for us to enjoy!
So, sustainable green roofs as part of an investment drive to support the transformation of Malta’s economy post- COVID-19 into a resilient, sustainable, green economy that embraces new, clean technologies and techniques, has benefits beyond just green roofs.
The learnings can be applied to other sectors including energy-efficient construction, energy supply, waste management, farming, food production and preparation to generate more widespread growth and jobs.
Vanya Veras, expert in environmental affairs and green infrastructure