Curtin University researchers have found the removal of tree canopy as part of urban infill may worsen health problems associated with climate change.
Ms Helen Brown, from Curtin University’s School of Public Health, said the impacts of climate change were already being experienced around the world, affecting food, water, air, and, ultimately health.
The research aimed to address the dual challenge of climate challenge and increasing urbanisation in Perth and provide recommendations to create a healthier, more climate-resilient city, to benefit future generations.
“The way societies react to these risks today will influence the extent to which current and future generations are affected. While climate change is a global phenomenon, adaptation is a local affair.
“Our research established that increases in extreme heat in Perth, would pose the greatest risk to human health associated with climate change.”
The effects of extreme heat range from heat-related illnesses (such as heat rash and heat cramps) to heat exhaustion and heat stroke which can lead to death.
The elderly, the very young and people with existing heart, respiratory, kidney and mental health conditions, will be particularly vulnerable and significant reductions in productivity, particularly for outdoor workers, are also likely.
People who live in urban environments are particularly susceptible to heat-related stresses as Urban Heat Islands (UHIs) – caused by reductions in vegetation and increases in man-made surfaces –can be created in built-up areas.
“We know that loss of tree canopy is a significant contributor to the creation of UHIs and that the effects of UHIs can be reduced by green spaces and vegetation,” said Ms Brown.
“Trees have been shown to provide multiple benefits to people and the environment, and international and national support for the retention and planting of urban trees is strong.
“Unfortunately, some areas of Perth are currently experiencing significant reductions in tree canopy due to a lack of adequate policy, regulation and awareness of the issue.
“Without appropriate intervention, we may find ourselves in a situation where the expected increases in extreme temperatures from climate change are made worse by planning decisions taken today.
“Other benefits provided by trees, such as shade, improvements in air and water quality, reductions in energy use and links to improved physical and mental health, will also be affected.”
Recommendations that emerged from this research included developing a tree canopy target and policies to counter the loss of tree canopy associated with urban infill, and developing an urban heat island mitigation plan. These recommendations provide an opportunity to move towards a more climate-resilient city. Whether or not these recommendations are implemented will influence the health and wellbeing of Perth’s residents for many years to come.
The research is part of Project 7 of the Urbanism, Climate Adaptation and Health Cluster funded by the CSIRO Climate Adaptation Flagship. Project 7 is focused on improving our understanding of interactions between climate and health in urban areas.