Australia planning 'urban canopies'

By Jonathan Pearlman For The Straits Times In Sydney

Australia is planning to promote the spread of "urban canopies" in major cities over the next 35 years following concerns that a lack of tree cover has led to rising temperatures.

The federal government plans to introduce decade-by-decade tree- cover goals as part of a "greenspace" scheme modelled on initiatives in New York and Singapore.

The Minister for the Environment, Mr Greg Hunt, said expanding tree cover in big cities would help to offset the extra carbon emissions and poorer air quality caused by a growing population.

He said high levels of trees, foliage and green spaces could absorb pollutants, reduce soil erosion and minimise water run-off.

"Increasing urban canopy coverage decreases heat, which improves health and quality of life," he said in a speech last month to the Sydney Business Chamber.

"An effective way to reduce the severity of the heat-island effect is to increase the greenery."

The government's Clean Air and Urban Landscapes unit, which uses experts to advise on environmental programmes, will work with cities across Australia this year and next year to develop urban canopy targets for each decade to 2050.

Separately, the government has begun a plan to plant 20 million trees by 2020 and has spent A$36 million (S$36.3 million) on a range of community planting projects.

Australia's population largely lives in sprawling coastal cities, where tree cover tends to give way to housing, commercial and transport requirements.

An extensive mapping analysis in 2014 using Google Earth imaging found that Australian cities have an average 39 per cent tree cover, with some parts of Melbourne recording as low as 3 per cent tree cover.

The analysis, conducted by the University of Technology Sydney, covered 139 local areas across Australia. It found 47 per cent of the land was grass and bare ground, 8 per cent was hard surface, 6 per cent was covered by shrub and the remainder had tree cover.

An expert on urban studies, Dr Peter Fisher, from RMIT University, welcomed the plan to create more green space in Australia, but said it should be accompanied by efforts to allow wildlife to live and thrive in cities.

"Trees on their own won't bring wildlife back into our cities," he wrote on The Conversation website on Jan 20.

"Areas will need to be set aside in parklands and other community spaces where small birds and small animals can congregate, breed and flourish… We need to give attention to the subtle connections between species."

Aside from dwindling tree cover, other factors causing higher temperatures in urban areas in Australia include the heat produced by energy-consuming cars and lights, and the dark-paved surfaces of roads. This has led to the formation of "urban heat islands", areas where urban development has led to temperatures rising beyond global warming increases.

Some councils in western Sydney, which has been heavily affected by urban heat, have adopted specific programmes to reduce temperatures, including planting specific types of trees and using their size and position to provide year-long shade cover.

In the centre of Melbourne, the city council has adopted a plan to increase tree canopy cover to 40 per cent by 2040 - roughly double its level in 2013.

It said additional trees will cool the city and "improve the health, well-being and happiness of urban dwellers".

Pointing to Singapore, Mr Hunt said that Australia will also aim to build rooftops with green cover.

This has become a growing trend in city centres here in recent years, with the corporate world taking to covering office towers in shrubbery and building rooftop gardens.

Companies such as Qantas and Macquarie Bank currently house worm farms, chickens, herb gardens and bee hives atop their corporate headquarters.

Ms Kate ffrench Blake, a manager at Macquarie Bank in Sydney, said she uses the rooftop garden for quiet worktime and also helps with watering the plants and feeding the chickens.

"Having grown up in the country, I miss green spaces and appreciate having access to one at work," she told The Australian.

"I help to look after the plants, and especially enjoy tending to our three adopted chickens."