With heat waves becoming the norm, discussions are sprouting on ways to keep cities cool. Investment in small green spaces seems to be a step further to tackle high temperatures in urban areas.
1. Natural hazard
In a recent report by the World Meteorological Organization, heat waves have been described the “deadliest meteorological hazard” from 2015 to 2019, affecting people living on all continents and setting new national heat records in several regions. Heat waves usually hit harder in urban areas affecting millions of people worldwide. Urbanization is almost always associated with an increase in paved, impervious areas with concrete and asphalt roads and other built materials readily absorbing, storing and releasing heat thus raising city temperatures.
2. “Green roofs”
A recent study by NASA published in the journal Sustainable Cities and Society has shown that due to an effect called the “urban heat island,” temperatures are often ten degrees higher in cities than in surrounding areas due to the heat absorption and retention of materials like asphalt and concrete. In the study, climate scientists stress the importance of greening rooftops — “green roofs” — noting that such actions can alleviate some of the extreme city heat.
Heat waves are becoming increasingly common, exacerbating existing health issues, namely cardiovascular and respiratory diseases. During heat waves, chronic patients are more likely to need medical assistance often contributing to increased hospital admissions, adding an extra strain to already fable healthcare systems.
2. Urban planning
Trying to address the problematic that makes an appearance each year and often causes great social and economic damage, many studies urge local governments to invest in greening cities. “Simply increasing ‘green coverage’ without considering the relative location of green spaces cannot effectively reduce the problem of urban warming,“ Wan-Yu Shih, Associate Professor in the Department of Urban Planning and Disaster Management at Ming-Chuan University, Taiwan told Arch Daily.
For example, when managing small green spaces, city planners and foresters can select tree species based on their ability to cool the environment. Small green spaces, such as yards, rooftops and small parcels of undeveloped land, can make impressive contributions to lowering urban heat.
A recent study in Adelaide, Australia, found that tree canopy cover and, to a lesser extent, grass cover decreased local daytime surface temperatures by up to 6C° during extreme summer heat conditions. Recently, France announced its goal to become one of Europe’s greenest cities by the end of the decade, laying down plans to implement “green roofs”.
Overall, cities can take a leading role in the response to climate change, mitigating and preparing future heat waves. While an effective response to climate change impacts undoubtably requires large-scale, coordinated efforts at an international level, local actions do have an impact and developing green places across urban areas can affect real change at the local level.
