There have been numerous studies lately trying to find out if green or white roofs can really help save cities from climate change. The results are indicating that green and white roofs can indeed offset global warming, but it’s all about the location.
We have been talking about green roofs before, but with focus on the design rather then their environmental importance. Today we are going to see rooftop gardens in a new light – as a forceful way to fight global warming. Who could have thought that roof gardens and white or bright color painted roofs can help save cities from climate change?
It is predicted that the amount of urban land in the US will increase to 261,000 square kilometers by 2100 which is an alarming fact. Building are replacing forests and grasslands, cities are growing and becoming hotter and hotter.
There are numerous studies trying to measure the effect that green or ‘cool’ roofs have on protecting cities from over growth and climate change and most of them agree that while they are surely effective, proper planning is necessary.
A study led by Matei Georgescu, a senior sustainability scientist at Arizona State University, uses climate models to get a better look at the benefits of green and white roofs in the ever growing big cities. Georgescu says that “Each can completely offset the warming due to urban expansion and can even offset the warming due to greenhouse gas emissions,” but what is interesting is the importance of their location. Namely, the research has shown that geography matters as green and white roofs have more benefits in the Northern than in the Southern areas. Why is this so? The reason is as simple as it can be – it is due to the much greater heating requirements in winter in the Northern areas. As the authors of the research say “Judicious planning and design choices can not only counteract rising temperatures due to increasing urban sprawl but also offset a significant portion of anticipated greenhouse gas-driven warming, at scales that extend beyond individual cities to large swaths of the country.”
So we can conclude that although green and white roofs can have a positive effect on global warning but careful planning is essential. Each city is different and the location must play a big part in the planning.
What is your opinion on the subject? Would you consider a roof garden if you had the opportunity to build one? Do you think roof gardens are expensive to build and maintain? Tell us in the comments…