Heatwaves, street trees and vertical gardens

Heatwaves, street trees and vertical gardens

Heat waves have killed more Australians than all other natural hazards combined. At
least 4,500 Australians have died from heat waves since 1900 (Dr Karl Great Moments in Science ABC Published 25 November 2014).


Heat waves are the most underrated of the natural disasters. Bushfires that accompany heat waves tend to get all the attention yet in Australia it is heatwaves that have caused the greatest loss of life out of any natural hazard (except disease).


Our Cities and their climate are getting hotter due to rising temperatures. Every day trees and shrubs in our cities and surrounds are being replaced by concrete and asphalt; this is causing what is called the “Heat Island” effect.


Tree filled avenues can reduce the amount of heat, and reflection, reaching the road and heating up the cars and surrounding buildings. The Australian Council of Social Services chief executive Cassandra Goldie comments “Governments must implement measures to ensure that the community sector is well-prepared and resourced, to support those most at risk, so they are better able to deal with heat events as they inevitably occur” (ABC Environment Published 4 SEP 2014).


Climate change,  urbanisation and loss of vegetation is increasing our risk of continued rising temperatures.


Increasing urbanisation is raising air temperatures in built-up areas. Homes are being built with air-conditioning and although air-conditioning certainly assists in combating the impacts of heat waves, it may also increase vulnerability should the power fail.


Despite the removal of traditional trees, and avenues plantings, there has been an increased interest, and recognition of the importance of the role of green walls and roofs. The challenge is to promote the positive environmental impact, rather than just the aesthetically pleasing design factor, when a balance of both can be achieved.


Cooling buildings with green roofs and walls is a measure to reduce the ambient heat of a summer’s day. Energy bills are always rising along with the temperature. With an  increase in apartment and high rise living, green walls and roofs are a viable solution in combating the “Heat Island” effect, and well as counteracting the decrease of vegetation and biodiversity in our cities.


Robbie Renu
Gecko Plantscapes
Horticulturist/ Green Wall and Roof Specialist