Adapting cities to climate change: Remote sensing tools for identification of urban areas exposed to heat waves

Abstract

Heatwaves are increasingly frequent in the Mediterranean basin; in Italy excess deaths in the summer are predicted to increase significantly in the coming decades. The risk is particularly high in urban areas also because of the heat island covering. Artificial covers may, in fact, determine an absorption of 10% more solar energy compared to green areas. Both daytime and night-time air temperatures can be up to 12 degrees higher than those of the surrounding natural areas. The strategic positioning of trees, however, is capable of dropping the mercury by as much as 2-8 Celsius degrees. According to Food and Agricultural Organization (FAO), urban greenery contributes to reducing air conditioning consumption by 30% and, by ensuring better thermal comfort, saving 20 to 50% of the energy needed for heating. Based on these premises, our contribution discusses the development of urban greenery as an essential tool in the sustainable development path of metropolitan regions. We specifically debate on urban greening as facilitating the intrinsic adaptation of local systems to climate warming, mitigating the impact of extreme events such as heat waves, droughts and floods. We also focused on the mitigation of emergency conditions, since urban greening contributes in turn to the absorption of carbon dioxide. Finally, the presence of trees, parks and gardens also slows down land consumption, preventing new structures, buildings and artificial roofs from fueling land degradation.