Climate change and heatwaves in Melbourne - a Review

Abstract: The impacts of Climate change are now being felt at a regional level in cities like Melbourne. The impact of rising temperatures and increasing frequency, duration and intensity of hotspells and heatwaves on Melbourne and its urban heat island poses challenges in how to respond and adapt. There are multiple risks to human health, maintaining urban infrastructure and urban biodiversity. Countering heatwaves and climate change is a major social and political challenge and will require both rapid mitigation of carbon emissions for the long term and widespread adoption of urban climate adaptation strategies and behaviour at personal, business and government levels.

John Englart 10 February 2015.
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DOI: 10.13140/RG.2.1.3050.7688

This article started during my single subject study in Academic Research at NMIT (now Melbourne Polytechnic) during Semester 1 of 2014. The focus was selected in negotiation with my lecturer. A slightly abbreviated version was handed in as my major assessment for the subject. The other two assessments of the subject were an annotated bibliography and a formal classroom presentation, which was also published at slideshare. I received a high distinction for the subject overall.

This literature review is structured in two parts: the first on Melbourne temperature and heatwave impacts from climate change, and the second on risk management, mitigation and adaptation to rising temperatures, heatwaves, and the urban heat island effect in Melbourne.

I thought limiting my focus to one climate impact - temperature and heatwaves - and one location - Melbourne - would narrow the field substantially, but as I dug deeper and read more widely I found a wealth of relevant literature either relevant to heatwave impact or directly to my regional focus. The bulk of the references are peer reviewed academic studies, but some are academic working papers and presentations, reports to Government, and news articles including several by myself published on this blog, Sustainable Fawkner or Climate Action Moreland.

Contents

• 1. Rising temperatures Heatwaves and their impact
• Urban Heat Island effect and heatwaves
• Heatwave impact on Human Health
• Rising summer night temperatures increasing risk
• Heart disease and heatwaves
• Lower socio-economic groups more vulnerable
• Those suffering Mental Health at greater risk
• Childhood Asthma made worse
• Increase in Foodborne disease
• Association with Urban Suicide
• Cost estimates of Victorian bushfire and heatwave mortality
• Heatwave impact on Infrastructure
• Heatwave impact on biodiversity and ecosystems
• 2. Countering the threat of Heatwaves and climate change in Melbourne
• Heatwave Management
• Mitigation
• Adaptation
• Personal measures
• Increase Urban surface albedo (reflectivity)
• Air-conditioning
• Urban Forests
• Water Sensitive Urban Design
• Urban Food Security and building community resilience
• Mode shift to Public Transport, walking and cycling
• 3. Conclusion
• References

Moreland increasing tree canopy to combat Urban Heat island Effect

Article originally published at Climate Action Moreland.

Moreland Council at it's September 2014 Council meeting adopted a report on increasing vegetation tree canopy and resolved "to support and fund current initiatives aligned with the management of climate change and the Urban Heat Island Effect."

The Council report - DCI70/14 REVIEW OF TREE COVER IN MORELAND AND HEAT ISLAND EFFECT (D14/225415) (full text below) - was prepared for the Director of City Infrastructure as a result of a motion by Cr Davidson (full text below) at the July council meeting. It outlines that Council will plant 5,000 trees annually as part of the Moreland Street Landscape Strategy (see Street Trees on Council Website) with the biggest tree suited to an area to be planted to increase canopy coverage. The goal is to plant 30,000 trees across the municipality by 2020.

Australia's 2014 summer breaks more records

Reading the climate Council latest report on the Angry Summer 2013/2014 (PDF) I was struck by the extent and rapidity of the changes in temperature we are seeing now.

The angry summer we have just experienced comes on top of 2013 being the hottest year on record for Australia, with temperatures off the charts setting new temperature records. A risk attribution study found that 2013 record temperatures could be clearly attributed to climate change with 2013 temperatures not found in 13,000 model years of simulations under a natural only scenario.

Urbanization amplifies global warming temperatures for Sydney

A new scientific study finds that Sydney faces hotter temperatures due to the interaction of expanding urbanization, climate change and the urban heat island effect

The study - Temperature response to future urbanization and climate change (abstract) - highlights the combined impact of both new urbanization and climate change on near-surface temperatures for greater Sydney, with positive feedbacks between urban expansion and global warming at the local scales. While Maximum daytime temperatures (Tmax) for Sydney are projected to only increase slightly and mostly in the winter, most of the change will be seen in substantial increases in nigt-time temperatures (Tmin), particularly in Spring and Summer months.

Urban expansion in Western Sydney is creating a multitude of new estates on Sydney's fringes expected to house more than 100,000 residents. These new urban areas are likely to experience the largest rises in temperature of up to 3.7 degrees Celsius by 2050 due to the interaction of land use change, global warming and the urban heat island effect.

The Urban Heat Island effect (UHI) is a well known and studied phenomenon which says that the built urban environment increases local temperatures, while reducing the opportunity for evapo-transpiration for cooling.

Cities to get much hotter as heatwaves amplify Urban Heat Island Effect

A new study just published looked at the way Urban Heat Island effect interacts with heatwaves. It is not a simple addition of the heatwave increase in temperature added to the urban heat island temperature: heatwaves exacerbate and amplify the Urban Heat Island Effect so that the impact is magnified. This is a major energy use and health concern for people living in cities, particularly the poor and vulnerable.

"Not only do heat waves increase the ambient temperatures, but they also intensify the difference between urban and rural temperatures. As a result, the added heat stress in cities will be even higher than the sum of the background urban heat island effect and the heat wave effect." say the researchers, Dan Li and Elie Bou-Zeid, both from the Department of Civil and Environmental Engineering, Princeton University

Temperature Study funded by climate sceptics confirms rate of Global Warming

'Global Warming is real' declares new scientific work from an independent group of researchers called the Berkeley Earth Surface Temperature Study. The research team is at least partially funded by the Koch Brothers who fund several climate denial groups. The team was setup to identify flaws in the climate science of global average temperature trends, but has confirmed the analysis undertaken by NASA, NOAA and the Hadley Centre that about 1 degree Celsius of global warming has occurred since 1950.

The study confirmed that "We are seeing substantial global warming" and subtantially eliminated arguments that heat island effects, temperature station quality, and the risk of data selection bias had more than a very modest or marginal impact on the trend for increasing global average temperatures.

Related Commentary: Nature Different method, same result: global warming is real | Climate Progress Hot Dog Bites Skeptical Man: Koch-Funded Berkeley Temperature Study Does “Confirm the Reality of Global Warming”