A pair of goshawks and their chicks recently set up home in a tree above a car park in central Singapore. Goshawks are rare in that region, yet no one was particularly surprised by their arrival. Animals are returning to the densely populated city-nation and when you visit, you see pretty quickly why. Walking through the city streets is akin to walking through a continuous botanic garden. Even the busiest footpaths are lined with flowerbeds, often little more than a hand-span wide. Flyovers and skyscrapers are swathed in flowering creepers. Just about every street is lined with large figs and other tropical shrubs and trees.
The story goes that Singapore’s founding father, Lee Kuan Yew, began greening the city’s roadways as a way of impressing potential investors who whizzed into town from the airport. With no natural assets, Singapore has relied on its collective brainpower to get ahead. But now, decades on, the greening of Singapore has become key to its identity – and its future. Singapore has officially rebadged itself from “Garden City” to “A City in a Garden” – an important distinction – and its luxuriant cover of flowers and trees is seen as a critical tool in addressing climate change, curbing power costs, and improving liveability. When you have five-and-a-half million people squeezed into high-rise towers on an island 17 times smaller than Sydney, and when that island snuggles right up to the equator, keeping people cool really matters.
In Australia, we can finally exhale as autumn winds bring some relief to our towns and cities. Nothing beats this past summer. It topped every chart. Climate scientists have dubbed it the Angry Summer and the Climate Council of Australia reports that during a 90-day period, 205 weather records were broken. The awful question is, could next summer actually be worse? Sadly, there’s every chance that answer is “yes”. As the Climate Council’s Will Steffen says, “Even if we could magically reduce emissions to zero tomorrow, we would still have another decade or two where the climate system plays out its built-in momentum.”
So what on earth can we do about it?
Before answering that, let’s turn again to Singapore. Last month, a report was released by the World Economic Forum and the Massachusetts Institute of Technology, which used Google Street View to compare tree cover across 17 leading world cities. Remarkably, given that almost no one has a backyard, Singapore came out on top with 30 per cent of its urban area covered by vegetation. That doesn’t include its 72 hectares of roof gardens, which were out of view of the roving car cameras.
Surprisingly, tying at second place with Vancouver, and thanks to the generous green cover of areas such as the leafy north shore, was Sydney, the only Australian city tested. Try telling that good news to the people in Sydney’s far west, where green cover in some areas is as low as 2.5 per cent. Living far from an ocean breeze and hemmed in by the Blue Mountains, for many people this past summer was unbearable.
By world standards, our Australian cities are vast and sprawling. Variations across their geography can produce quite different climate results. Work conducted by AECOM for the City of Melbourne found that the CBD often experienced more hot days and these were up to 4 degrees hotter than the suburbs. Greening Australia reports that while the number of very hot days (35 degrees and above) in the coastal suburbs of Sydney has risen by about 20 per cent over the past three decades, in Western Sydney this figure is 250 per cent. The Bureau of Meteorology’s Penrith Lakes weather station recorded 24 days over 35 degrees in January and February. In 2007, there were nine days and in 1997 there were six.
With a lack of green cover comes a preponderance of roads, roofs and buildings, all hard surfaces that repel moisture and hold heat. This creates heat islands, where absorbed heat pushes localised temperatures up throughout the day and night. Gases and heat pumped out by cars and airconditioning units only add to the problem. Combine this with global warming and you’ve got heat generation on steroids.
In Australia, more people have died from heat stress than all other natural disasters combined. A report by PwC in the 2013 State of Australian Cities found more people died from heat stress in Melbourne than any other national capital, about 175 a year, not far behind Victoria’s road toll that year of 243. When Melbourne and Adelaide experienced a severe heatwave in early 2009, close to 500 extra deaths were recorded. We don’t yet know the grim results from this summer.
Thermal imaging testing by CSIRO and the University of Technology Sydney during a 2011 heatwave in the Penrith area, in Sydney’s west, showed the profound effect of green cover. Recorded differences of up to 20 degrees were found between the worst hotspots and those that were well vegetated. Scientists in Singapore have found consistent differences of up to 4 degrees during the day and – importantly – the night, when grass and trees are present.
There are piecemeal programs to build vegetation cover across our cities, including the Greater Sydney Commission’s Green Grid program. In 2014, Adelaide completed a decade-long program that had three million new trees planted. Programs such as these can’t come fast enough. Greening must be far more than a few new pocket parks. We need connected corridors that support pedestrian and cycle travel, create a green network and allow wildlife movement. We need appropriate planting along our footpaths, even if they are only a handspan wide.
Climate change, the rising cost of power and rapid urbanisation all threaten our national liveability. Singapore might be a different type of city to those here, but at the heart of it, all are inhabited by living, breathing people seeking a good life. Not long ago, a pair of powerful owls returned to Sydney’s Centennial Park, the first sighting in the park for half a century. When grand birds such as these become commonplace again throughout our skies, we’ll know our cities are becoming better places to live, for humans and animals alike.
This article was first published in the print edition of The Saturday Paper on Mar 25, 2017 as "Botanic explosion". Subscribe here.