Green roofs, which are gardens installed on top of building structures, offer insulation that allows energy saving and protection from heat. In addition, these green roofs contribute to pollution reduction. With sufficient quantity of these roofs, the quality of environmental conditions in an area can be improved.
“To mitigate the effects of climate change, we can talk about two types of options: to attack it at its origin, by eliminating or reducing the human factors that contribute to it (such as, reducing emissions, controlling pollution, etc.) or developing strategies that allow for its effects to be reduced, such as, in the case that concerns us, increasing green areas in cities, using, for example, the tops of buildings as green roofs”, says Luis Péùrez Urrestarazu, a researcher from University of Seville.
A study conducted by researchers from the Higher Technical School of Agricultural Engineering of the University of Seville has found that around 207 to 740 hectares of green roofs are needed to effect a reduction in the effects of climate change as suggested by the estimated maximum temperature increase of 1.5 to 6 degrees Celsius by the end of the century. In terms of percentage, this estimate of earth warming necessitates green roofs installation on 11 to 40 percent of the buildings in the city.
The study, which can be read in Building and Environment review, was performed by gathering normalized difference vegetation index (NDVI) and ground temperature through the utilization of Landsat 7 ETM+ and Sentinel-2 satellite images. The additional area of vegetation or green roofs required in order to reduce the temperature by an amount equivalent to the predicted rise in Seville’s various climate change models was possible to determine through the inverse relationship observed between their values.
Perez explains the significance of the study, “To fight against climate change, this is, without doubt, a necessary strategy at a global level. However, local measures can be established that contribute to this global strategy and which can help to reduce the local effects that might be produced in one’s own city.”