urban heat islands

Last year I did research into, and gave speeches about, the public health benefits of public open space. [See also, "Kelvin Thomson: Too few trees make high-density Coburg and Glenroy risky during heat waves"] My view about the importance of this is reinforced by recent statements in the Moreland Leader by University of Sydney Associate Professor Tonia Gray that research shows that neighbourhoods with more green spaces are much healthier and socially cohesive. She says, "Nature has a calming effect, it recalibrates your body. Australian kids spend an average of 52 hours a week in front of a screen but an average of 40 minutes outside". (Originally published at http://kelvinthomson.blogspot.com.au/2015/02/melbourne-heat-island-effect.html)

The importance of trees and vegetation cover is also reinforced by research calling for Melbourne suburbs to increase their tree cover to combat rising temperatures. The urban heat island effect occurs when built-up areas with surfaces such as roads, concrete and buildings absorb heat on hot days. It is dangerous to public health. In 2013 and 2014 over 400 Victorians were admitted to hospital for heat related illness. Researchers say "heat islands" are only going to get hotter unless more green spaces are incorporated.

Given this, it is folly to allow dual occupancy, multi-unit and high rise developments to lead to the cutting down of trees and shrubs and the paving over of open spaces which are presently cooling Melbourne down. We need to push back against plans by property developers and council officers to allow more buildings in what are already built up suburbs.

In place of urban sprawl, urban consolidation is supposed to reduce our environmental footprint, by compacting housing for less car usage, more “affordable housing”, and reducing greenhouse gas emissions. On the contrary, it tends to have the opposite effect.

Trees, which provide shade and act as natural air conditioners, play an important role in helping to create cities that are more resilient to extreme temperatures as the climate warms. But, trees are being cleared for the cluttering of cookie-cutter, generic concrete multi-unit blocks, instead of the garden-surrounded an identifiable single houses of a few years ago.

The "heat island effect" results from hard surfaces absorbing and then radiating heat, thus capturing hot city temperatures.    Experts say this phenomenon is expected to become more prevalent with increasing urbanisation and will exacerbate climate change impacts.

ANU research shows that some of Canberra’s inner-city suburbs are the most heat-vulnerable in the territory, despite the benefits of their leafy tree-lined streets. It showed Canberra’s mostly-treeless outer suburbs were likely to be up to seven degrees hotter in summer than those with more established trees - such as those inner suburbs.

In that study of 21 Canberra suburbs, researchers found temperatures could vary by as much as 7.5 degrees between treeless postcodes and those with more trees.

Canberra Times: Canberra's heat vulnerable suburbs revealed

ANU Researcher Dr Liz Hanna said: "If we have planning designs and housing designs where there's insufficient front and backyard to plant a tree, and if street trees are not shade trees, we think that's foolish”. We agree it's “foolish”, but with high rates of population growth and increasing urban density, backyards and traditional housing with gardens and trees, are disappearing.

Power outages

Up to 100,000 Victorian premises were threatened to lose power during the January heatwave as demand crippled the state's electricity grid.

Melbourne is following the lead of Asian cities such as Hong Kong for extreme housing density, with more people living in apartments. The housing affordability squeeze, and the marketing of thousands of tiny apartments to investors, is threatening to undermine Melbourne’s liveability.

Mr Tony Arnel, Victorian Building Commissioner, suggests that buildings above three storeys begin to use more energy due to the need for lighting in common areas, lifts, security and the lifestyle of residents. The Victorian Building Commission has found there is “no conclusive evidence that vertical living was more sustainable than conventional homes.”

A NSW Energy Australia study found that high-rise apartments use 30 per cent more power than a typical detached house. The use of air-conditioners is a mandatory part of the lifestyle.

Climate change is predicted to increase the number and intensity of heatwaves experienced in Melbourne. Along with the densification of our city, and a population that's projected to double by 2060, it means the converging effects of more power being soaked up by a growing number of apartment dwellers, more power outages, higher utility and health costs - and the compounding factor of higher greenhouse gas emissions.

Loss of Vegetation to make way to mobilize more people

To build the East West Link tunnel under Royal Park, the Melbourne City Council estimates that some 5,000 trees, many very old, would be lost. The remnant bushland in West Royal Park, the only area of this kind of vegetation left in Melbourne, would be dug up. By actively cooling the urban landscape, vegetation helps reduce energy use and carbon dioxide emissions, and ultimately lessens the risk of residents suffering heat stress, heatstroke or even death…

Wetlands from storm water, which supplies water for Melbourne's parks and street trees plus the Royal Park Golf course,  will be completely destroyed.

The East West Link/tunnel will increase temperatures in Melbourne, and the nibbling away of Green Wedges for urbanisation will compound the problems of power demands, infrastructure break-downs, anti-social behaviours, and deaths/illness from heat stress.

Privatisation woes

The SEC provided cheap and reliable power to Victoria for 70 years. Selling off Victoria's power supplies and raised some revenue in the short term but in the long term it has resulted in a huge financial burden on the entire population through rapidly increasing prices. Now, unplanned overloads and outages are placing extra stress on the power grid, one that's fine-tuned for profits rather than service.

Privatising state owned assets is a strategy is to reduce employees, and  increase remuneration to share holders and owners. 

Population growth driven by heavy economic reliance on property development

The population of major Australian cities is expected to double in the next four to five decades, thanks to high rates of net overseas immigration.

The government powers-that-be in Canberra view the economic growth meta-statistics and see our economy is “growing”, without considering democracy, the costs of growth, and the human-environmental fallouts. They simply open up the draw-bridge of our borders and allow the new-comers to flow in from oversea! Planned increases in urban density are likely to result in the removal of a significant number of trees from urban areas.

Canberra’s population could increase to 904,000 by 2061 according to new projections released by the Australian Bureau of Statistics. This growth means significant challenges for governments and ACT infrastructure. There's no diplomatic, administrative or public service increases to justify this growth, except general population overflow.

Melbourne’s population is swelling by 2 per cent a year, or at a doubling rate of 35 years.   The power infrastructure must not only be routinely maintained and upgraded or replaced every 50 years, but must keep expanding at 2% each year - and also cope with outages and heat-waves.   

We need a u-turn in our economy from a growth-based, road-dependent, high resource and energy-consuming one that's trapping us in islands of heat - to an alternative model that's bio-centric and human-friendly,  and relevant to an age of extreme weather patterns, and the hostilities of climate change.

#F8E0E6;line-height:120%;">Federal Member for Wills, Kelvin Thomson, today said Monash University research which showed people in Coburg and Glenroy as vulnerable during heatwaves, highlights the need for more trees to be planted, and the risk from constantly adding more buildings.

Fewer trees, more buildings, more sickness

“There is a clear association between areas with few trees, and increased concrete urban density, and increased vulnerability during heatwaves”, Mr Thomson said.

“This has serious health implications and risks for local residents. The research shows
people living in high risk areas make up the large portion of hospital emergency visits and
ambulance callouts on extremely hot days. This raises the risk of sickness and death,
particularly for older residents”.

Monash University’s Cooperative Research Centre for Water Sensitive Cities (CRC), found
Melbourne’s inner northern, western and south-eastern suburbs, are most affected.

The research found low-risk areas included the leafy eastern suburbs such as Toorak, Kew,
Glen Iris, Box Hill, Hampton and Beaumaris.

Tree canopies can mean difference between life and death

“According to Professor Wong, CEO of Monash University CRC, research shows daytime
shading provided by street tree canopies improves human comfort by significantly reducing
radiant temperatures. He says urban street monitoring has shown that during Melbourne’s
heatwaves, a person’s physiological equivalent temperature can be up to 18 degrees lower
near midday in areas with tree canopy shading”, Mr Thomson said."

Call for Moratorium on tree removal; plant more trees; decrease concrete high-density

In light of these findings, Mr Thomson said Moreland Council should put a moratorium on the
removal of any more trees from public open spaces, parks, and nature strips across
Moreland, with the exception of trees that may be considered a threat to public safety.
Mr Thomson says Councils should investigate increased investment and resources to
proactively plant more trees.

“Trees have the ability to cool down our suburb. In light of the recent unprecedented
heatwave over January and February this year, Council should be working to increase the
provision of trees along our nature strips and public open spaces.

“We also need to cut back on the amount of concrete we are pouring into our community
through high density developments, and plant more trees instead.”

This threat to clearfell half of Melbourne's street and park trees because they are supposedly "nearing the end of their lives" is an unprecedented threat to Melbourne's heritage. I regard the threat to Melbourne's trees as one of greatest threats to Melbourne and its livability. Plus the revival of the East West Link tollway-in-a-tunnel through the inner suburbs and parks. Can you imagine what this tree clearance of elms and plane trees will do to tourism? And what about living conditions in the city - the "heat island effect" will be extraordinary if half the city's trees are to be removed. Just as they are looking fantastic with recent good rainfall! - Julianne Bell, Protectors of Public Lands Victoria

Julianne Bell (of Protectors of Public Lands Inc.) writes:

I appeared at the Future Melbourne Committee on Tuesday last and spoke on the agenda item on the Draft Urban Forest Policy. I was the only person to speak and PPL VIC the only group apparently to make a submission.

This threat to clearfell half of Melbourne's street and park trees because they are supposedly "nearing the end of their lives" is an unprecedented threat to Melbourne's heritage. See my submission below. Also the Herald Sun report of 5 November 2011 with comments from the Lord Mayor in case you think I am making this up.

"Stately elms going in city tree change"

I did not make a submission on the Committee of Melbourne's (CoM's) Open Space Strategy which was raised the same night but am following this up. I would not have been allowed to speak anyway as there were hundreds of residents there to hear the result of resolutions regarding a review of the CoM's electoral system and Occupy Melbourne protests.

Note that there are supposed to be "consultations" on the "Draft Urban Forest Policy" and the "Draft Open Space Strategy."

I regard the threat to Melbourne's trees as one of greatest threats to Melbourne and its livability. Plus the revival of the East West Link tollway-in-a-tunnel through the inner suburbs and parks. Can you imagine what this tree clearance of elms and plane trees will do to tourism? And what about living conditions in the city - the "heat island effect" will be extraordinary if half the city's trees are to be removed. Just as they are looking fantastic with recent good rainfall!

Protectors of Public Lands Victoria Inc (PPL VIC)
The Chair
Future Melbourne Committee
Town Hall,
Melbourne 3000

8 November 2011

Dear Chairperson

Submission on Item 5.3 Draft Urban Forest Strategy

I am speaking for Protectors of Public Lands Victoria Inc. (PPL VIC) in commenting on this draft strategy.

I wish to make the following points:

Our organisation applauds the objectives expressed in the document of the Draft Urban Forest policy. The trendy name tends to conceal the fact that we are dealing mostly with street trees.

We recognise that the drought has impacted badly on Melbourne’s trees and that it was the intransigence of the Bracks Government for refusing to assist the City of Melbourne to drought proof the trees by, for instance, building a sewer mining project in Princes Park which would have supplied water to Melbourne’s parks and street trees.

We are alarmed, however about suggestions that there will be a wholesale felling of trees classified as “nearing the end of their lives.” In particular we are concerned over the fate of avenues

Staff of the City of Melbourne appear to have a purist view about removal of avenues of trees and maintain that the entire avenue should be removed rather than attempting removal of failing trees and interstitial planting of the gaps. At a recent hearing on the World Heritage Management Plan of the Royal Exhibition Building and Carlton Gardens held by Heritage Victoria, the spokesperson for the CoM suggested that as the Plane Tree avenue in the Carlton Gardens was nearly the end of its life then the whole avenue should be removed. Our arborist who gave evidence, was of the opinion it was the finest avenue of plane trees in Victoria: that the trees are healthy; and that they have another 20 years or so lifespan.

Several years ago we had the unfortunate example of the avenue of Camperdown elms - 550 elms in the main street – which a Committee of representatives including Heritage Victoria and Friends of the Elms, with I believe the support of the City of Melbourne arborist, recommended the whole avenue be felled. The Corangamite Shire Council accepted the recommendations of our consultant arborist that the few gaps be filled by interstitial plantings. Consequently a moratorium has been placed on the destruction of the elm avenue and elm avenues in side streets. They have adopted a policy of interstitial planting in any gaps. between trees.

We would request that the City of Melbourne identify exactly what trees you are proposing to remove and what species you are proposing to plant in their stead. Additionally with regard to avenues we would like explanations as to why healthy trees cannot be saved and replacement trees of the same species planted in the gaps. (We realise that there may be problems with this approach in St Kilda Road.)

I have heard that Council has a questionnaire on the Draft Urban Forest policy. I can’t locate it on the website.

Signed Julianne Bell Secretary PPL VIC Mobile: 0408022408

Article adapted for candobetter.net from emails and announcements by
Julianne Bell
Secretary
Protectors of Public Lands Victoria Inc.
PO Box 197
Parkville 3052

Mobile: 0408022408