Tag Archives: sustainability

The backyard of Sustainable Cities

Your backyard

HOW BIG IS YOUR backyard? Is it a roof top or patio garden, a patch behind a terrace house, or the proverbial quarter acre in the suburbs. Could your backyard sustain you?

“Are you self-sufficient?” is a question often asked by visitors to Dr Richard Stirzaker’s Canberra backyard at the height of summer. At this time of year his fruit trees are laden and the backyard overflowing with vegetables, leading visitors to wonder about whether he ever visits the shops.

The reality is that Richard’s bountiful backyard falls a long way short of feeding himself for the year, let alone his wife and three kids. In his book, The Scientists Garden Richard calculates that on his 877-square-metre block, the backyard could just grow enough potatoes, fence to fence, to supply enough calories for himself only. Gone would be the fruit trees and vegetables which make the backyard so appealing during summer and provide the necessary variety in our diets.

Sustainable Cities

The notion of sustainable cities requires us to redefine our backyard. For cities are not, and never will be sustainable within their boundaries. Instead the backyard of a sustainable city extends well past what you see from your back door. The challenge is how can we contribute to the stewardship of this extended backyard?

Dome

To understand how big a backyard a sustainable city needs, let’s imagine an air and water-tight dome over our city. Such a dome would be roughly 40 kilometres across to enclose a city the size of Sydney or Melbourne and be home to around four and a half million people.

Our dome needs some farmland to produce our food as even Richards’s bountiful backyard is too small to provide a balanced diet. In fact our current diet requires around 2.8 hectares of farmland per person to grow enough food for the year (pdf). So we need to extend our dome out to 400 kilometres to include this farmland for our 4.5 million people.

But our dome needs to be much bigger to supply the water and fresh air we need. It would balloon to nearly 600 kilometres if we add a catchment area to supply water, and vegetation to absorb the carbon dioxide released by our city and stabilise the atmosphere.

A dome spanning 600 kilometres would be quite an engineering feat. When we tried running one on a small scale in the 1990’s Biosphere 2 project we could not manage it with only eight people in a dome 128 metres across. And our mega dome would become even more unmanageable if we add in space for the treatment of waste, the energy used by the city, resources for commerce, climate regulation, the national parks we like to retreat too, and room for Australia’s diverse plants and animals.

Our imaginary dome highlights the fact that the backyard which sustains you is a lot bigger than what is immediately outside the back door.

Extended backyard

So when you stand in your backyard, be it a roof top or patio garden, a patch behind a terrace house, or the quarter acre in the suburbs, look beyond the boundaries of your own backyard. Look beyond your street, your suburb and your city, for this is where the future of sustainable cities lies.

The need to connect and look after our expanded backyard is not just altruism, but enlightened self-interest: last time I looked there were no new continents to move to, so we better start looking after what we have.

This article first appeared on the ABC website

Soil Biology Masterclass – exploring the new frontier

This week the inaugural Soil Biology Masterclass was run at the Hawkesbury Institute for the Environment – University of Western Sydney. Soil biology is at the core of key processes underpinning agricultural productivity.

Nutrient cycling and availability, carbon storage as soil organic matter, soil water storage and movement, root and soil pests and diseases, are all determined or strongly influenced by soil biology. Our current management of soils, through tillage, fertilisers and pesticides, focus on the chemical and physical aspects, often to the detriment of soil biology.

Future improvements in agricultural productivity will increasingly be driven by soil biology.  We are now entering a period where the scarcity and cost of energy, nutrients and water are limiting productivity growth. However, the demand for food and fibre continues to grow.  New ways of explicitly managing soil biology is required to unlock low energy and nutrient input productivity. 

This is the fifth Masterclass I have been involved in developing and another incredibly challenging, stimulating and enjoyable group to work with. The mix of researchers from three Universities together with the diverse industry participants ( private consultants, farmers, policy-makers, EPA, advisors, commercial suppliers and R&D managers) produced a “hothouse” for the exchange of ideas, testing of assumptions and the collective development of new understandings and insights into the role of soil biology in agriculture and our ecosystems.

But don’t take my word for it have a read of Adrianna’s Soil Biology Masterclass blog

Soil Biology Masterclass August 2013 at Hawkesbury Institute for the Environment at University of Western Sydney

Soil Biology Masterclass August 2013 at Hawkesbury Institute for the Environment at University of Western Sydney

Kader Asmal

Mixing water, human rights and leadership – the Kader Asmal legacy

Chairing a conference can be a lot of hard work with a few minutes of fame at the beginning and end – ask the current IAL2011 Chair, Chris Thompson. But for me one of the highlights of chairing 2010’s One Water: Many Futures conference was hosting our two overseas keynote speakers, Professor Kader Asmal from South Africa and Sandra Postel from USA. Both provided insightful, challenging and positive views from the outside looking in.

Almost a year to the day after the conference I heard of the passing of Kader Asmal. We were indeed most fortunate to have heard from such an eloquent, outspoken and colourful character as Kader.

Kader Asmal became involved in water management through some dramatic events in recent South African history. It was an unusual, but some considered inspired, choice by Nelson Mandela to appoint Kader as his first water minister in 1994.

It was a challenge that he relished: “my relationship with water use and management has been one of the most creative and exciting aspects of a chequered and full life”.

As a human rights lawyer, Kader brought a unique perspective to the redrafting of the South Africa’s Water Act. The act introduced the “Reserve” to meet the basic needs of all people and the ecosystem, and placed this as the most important share of the water resource. It also dramatically changed the way the natural resource was viewed and managed. As he explained, “The fact that the National Water Act placed the Reserve above industry and irrigation does not mean that these sectors are less important, it just emphasises that there are constraints to development set by the environment, and we need to recognise those limitations, a key principle in sustainability”.

One evening last year, Kader was guest of honour at a parliament, this time in NSW rather South Africa. He urged those attending the Water Leaders Dinner to take a greater world leadership role. “The management of our precarious and dwindling water resource is likely to be the barometer for managing the economy in general under conditions of resource constraints. Are we up to this test? I hope so.”

Both our international guests were impressed with Australia’s progress and the level of discussion across the industry. With so many challenges and so much happening on the home front it’s easy for us to get self absorbed. What we are doing is leading the world in many areas of water management. We are being watched!

It would be a fitting tribute to Kader Asmal if we could increase the cooperation between Australia and South Africa to expand our connections beyond rugby and cricket to learn from each other with respect to water management.

I will leave the last words to Kader. “I also propose a trade. Please send back our water sector professionals – we need them at home – and you can take all your eucalypts and wattles back.”

Note. You can view Kader Asmal’s presentation on water management, “Responsible transformation of water management in an era of scarcity: achieving multiple objectives in a complex and dynamic content”.