As Europe battles scorching temperatures this summer and wildfires blaze across the continent from the Mediterranean to Spain, the role of climate change in making heatwaves hotter and more frequent has come into focus. At a broader level, greenhouse gas emissions from human activities have heated the planet by about 1.2 degrees Celsius since pre-industrial times. Temperatures will only stop rising if humans stop adding greenhouse gases to the atmosphere, and until then heatwaves will continue to worsen, according to a Reuters report. These grim predictions have brought attention to a range of mitigation measures. One such initiative to bring greenery back to urban spaces in Spain involves installing vegetated awnings or canopies. What are vegetated canopies? Introduced in Santa Maria Street in Valladolid, Spain, the awnings are tensioned sail-like structures that have been anchored to the facades of surrounding buildings. They mimic natural canopies found in forests and various plant species. The lightness and ease of installation of the 'Greenshades' allow for shade and the presence of greenery in commercial streets and public spaces, where trees or other vegetation are often absent. Here is how they work: The sails with anchors and supports are prepared by laying down the specific geotextile substrate or material. An irrigation system is installed at the highest side, from where the water falls by gravity, soaking the entire substrate. In addition to water, fertilizer keeps the vegetation in perfect condition. The excess water is collected at the lowest point and into a connected drainage system. The seed mixture is then projected onto the geotextile. After four months, the shade is expected to be completely covered with vegetation. The awnings can be placed in streets, where planting trees may not be feasible owing to the lack of space. The plants grow hydroponically, with a water supply point and water outlet for draining purposes. What are their advantages? As per Singular Green, the company that created the awnings, the tensile spaces are designed to reduce the temperature both in their surroundings and under the cover. Behind this is the phenomenon of evapotranspiration, which is the transfer of water to the atmosphere by plants. The plants chosen for these awnings belong to species that are optimised for the absorption of gases such as carbon monoxide and nitrogen oxide. The substrate also absorbs sound waves, reducing noise pollution. A square metre of a vegetated canopy generates the oxygen required by a person for the whole year, apart from filtering harmful gases, according to the company. The hanging planter also allows for the centralisation of water and light installations. This is meant to induce savings as the lights are equipped with movement sensors that illuminate the street according to its need. The adoption of such canopies could eventually contribute to urban biodiversity, creating a healthier ecosystem that supports a variety of wildlife.
