We rely too heavily on our beloved parklands to do the heavy lifting for a greener Adelaide.
If we are going to achieve the carbon-neutral city foreshadowed in the Governor’s speech in January, we will have to turn our attention inside the CBD for solutions.
The parklands provide 770 hectares of green space surrounding the CBD. But let us not forget that while they were identified as an integral part of Colonel Light’s plan for the City of Adelaide – as “the lungs of the city” – they were effectively clear-felled, with parts used as a rubbish dump and others quarried, from the beginning of European settlement.
They were not managed well until much later in the 20th century.
Today, the actual area of remnant bushland ecology is estimated at less than 4 per cent.
Our parklands perform a critical role in air-conditioning the CBD by default, and their role can increase dramatically through small-step changes, such as planting more trees and encouraging the many creek ecosystems to regenerate.
But our city streets should be performing a far greater role than they currently do – environmentally, economically and socially – to shape a greener future.
And we need a design-led approach, considering different measures than we currently do, to make that happen.
Currently, more than 40 per cent of Adelaide’s CBD carbon emissions are from transport – both public and private. This is one of the more difficult problems to address, as people need to get around and into the city for many reasons: to live, work and play.
But with a change in approach, our city streets could be habitat-rich, species-rich environments, with a more productive biosphere, to offset those emissions.
The way we view open city spaces – within the laudable but limited lenses of heritage, availability, and the fact someone it planned it that way – needs to be widened.
We must change our mindset to consider environmental qualitative and performance measures as important.
– Total number of shade hours in summer
– Percentage heat reduction to pavements and buildings in summer
– Heating benefits in winter
– Connected shade (length) on our streets
– Reduced runoff into our creeks and rivers (especially the River Torrens)
– Percentage of rubbish collected at the source
– Improved air quality
– Reduced reliance on air conditioning
– Number of operable windows
– Improved economic outcomes (increased trade or retail opportunities)
– Improved walkability/cyclability
– Improved property values
– Improved amenity (the happiness factor); and
– The “hip” factor, and “desirability”, measured through engagement with people.
Green infrastructure in our cities – aimed at climate adaptation on a city-wide scale and led by design – can help us achieve these goals. It’s one of the more constructive and outcome-driven strategies to combat climate change and carbon reduction.
It offers integrated storm-water management, increased biodiversity, reduced urban heat island effects, cleaner water and soils, opportunities for renewable energy production, and increased habitat production.
It also comes with human benefits, such as better-quality open spaces, improved recreation, improved health outcomes, and connected shade and amenity.
The current paradigm, however, enforces the supply of utilities – gas, power, water, sewerage, internet cabline, drainage, telecommunications and other “services” – over the current greening of our streets, simply by demand, cost and availability of space, and traditional municipal management approaches.
Consider the poor old street tree.
Prior to anything being planted, especially in city streets, a long process has been navigated, often involving a plethora of actions, strategies and compromises.
Current risk-management approaches are even more acute for tight city streets: Pirie Street is without trees largely as a result of this.
There simply isn’t any “viable” room for living things in the ground.
Our streets of the future should consider green infrastructure like any other piece of essential infrastructure.
They will provide shade, pleasure, interest and something to sit under; they will collect seeds, leaves and mulch; provide habitat; cleanse our water and air; provide edible food, drainage, soil biota; enhance property values; reduce the need for expensive pipes and infrastructure, and make happier people.
Trees and do add significantly more value than their installation costs or asset value.
But this does not just apply to trees – the same and more can be measured for green roof and green wall initiatives, not to mention other carbon-abatement schemes.
Many residents have west-facing walls, for example. A simple vine planted to climb the wall can reduce the internal temperature by up to 10 degrees on a hot day, and conversely in winter can assist in passively heating the house if the vine is deciduous.
From individuals to governments, there are pragmatic, achievable, workable, negotiable goals we can agree on to green our city, and with measurable outcomes. We can do most of these now. We can measure them now.
It need not require significant additional investment; it requires some adjustments on current expenditure to ensure taxpayers’ money is spent wisely and with real, measurable (including environmental) outcomes beyond just assessing elements such as “asset class”, “depreciation” and “insurance value”.
This is not a question of environmental values over economic and social values. It is one of addressing an imbalance, and asking ourselves how we can best adapt now to reflect the inevitable changes affecting Adelaide. This includes projections in the Government’s 30-year plan for an extra 50,000 residents in the CBD.
It is real, it is here, and we can do something about it. It needs to start now. We can all do our bit without too much fanfare, and when we do, we can all reap the benefits. And we can preserve our parklands the way they are and enjoy them for what we like, while the city can perform the role of a climate-adapted and carbon-neutral city. The choice is before us.
Daniel Bennett is a registered landscape architect. He is currently the city design and transport strategy manager for Adelaide City Council and is a national board member and vice-president of the Australian Institute of Landscape Architects.
This article was originally published in Adelaide’s Indaily, 9 April, 2015 http://indaily.com.au/design/2015/04/09/a-greener-adelaide-needs-more-than-parklands/