Rice paddies on roof tops?
Grow rice on Hong Kong rooftops? Why Not…
GreenRoof Asia has been in a very engaging consultancy with the Canadian International School of Hong Kong to design and develop a green roof space.
GRA started to talk with CDNIS back in 2011 and the project has since grown and morphed, as they often do, and what was going to be a very Canadian roof space is more likely going to be a mix of Chinese formal garden, less formal social and study spaces and probably vegetable growing areas – which started us all thinking…
Why not put some rice paddies up on the rooftop? We are working with rooftop wetland areas right now, which are what rice paddies essentially are, and we have also done a lot of work with water catchments and water recycling.
Rice paddies have featured a lot in the scientific journals in recent years because of the role they are playing in climate change. Emissions from methane — a gas that is found in everything from cows to garbage dumps — are currently much lower than CO2 emissions, but kilo for kilo, methane is a more powerful greenhouse gas than CO2 and the warming effect is possibly as much as 20 times higher. Methane emissions, just like CO2, are on the rise and in the last ten years science has began to focus on two unlikely sources: natural wetlands and rice paddies.
Studies has shown that wetlands currently contribute a surprising 55% of global methane emissions and that rice paddies – that are in many ways are a form of constructed wetland – are responsible for more than a quarter of this output. It’s a complicated subject because wetlands and rice paddies also act as invaluable CO2 stores but there seems to be little doubt that as the crops decay, then they release increasing amount of gases back into the atmosphere.
Early talks with the school have examined the possibility of working with one of the regional rice growing institutes on the rooftop paddy field. As this type of wet-field cultivation is so prevalent to this part of the world, it fits perfectly with our ethos of working with local plant palettes whenever possible. Rice paddies also can look very beautiful however, as methane levels rise, then the widespread study and understanding of this kind of environment becomes all the more important. It’s a project we are really looking forward to.