Research and development reports


Copyright Geoff Wilson, February 22, 2009.

Green roofs and walls will also
greatly reduce our "carbon footprints"
By Geoff Wilson.


If you've been reading about climate change you will know that our production of harmful greenhouse gases has been increasing alarmingly over the last few years.

Our so-called "carbon footprint" on Mother Earth has become unsustainable. It might even wipe us out and change, irrevocably, our planet's stable climate.

Yet simple new green roofs and green walls and allied technologies, applied widely in our built environments, could fairly easily have us greatly reducing our climate-change impacts. At the very least they can well postpone the "tipping point" now feared most sincerely by believers in climate change.

Importantly, they could also save us a great deal of our cost of living and greatly improve our environmental health – so why not adopt them for these reasons too?

Some expert commentators say that private action by educated people could quickly lead to about a 30% reduction in greenhouse gas emissions in Australia. That compares with the 5% to 15% mooted over time by the Commonwealth Government. But the 30% estimate did not take into account the good effects of green roof and green wall technology (see side story on Brisbane's GreenSpeed breakfast conference).

Revision of planning of the world’s cities -- with greenery on roofs and walls and over heat-producing bitumen and concrete -- is a simple and very effective individual and company or community organization answer to our current problems. It gets all of us in full support of governments taking action with carbon tax and ETS issues.

Indeed, strong views by key experts about our future as a species well shows we must now accept the sensible discipline of increasing urban greenery of all kinds.

The world recently passed the point where more than 50% of our population of more than six billion now lives in cities. The next milestone is 60% of the world’s people living in much wider cities and producing much bigger volumes of greenhouse gases that further add to climate change outlooks.

The general debate, however, is about what governments can do, rather than what individuals, companies and community groups may do with greater speed. I think we at the grass roots level must also become well involved at home and in offices or industrial buildings.

Built environment greenery can greatly reduce greenhouse gas emissions, greatly extend built-environment life, provide extremely beneficial human psychological advantages and significantly reduce our climate change impact.

But each of our greened cities will require its own plant species, designs and technology variations. This will mean that our local scientific and technology resources in technical colleges and universities, municipal government and built-environment businesses, will need to enter into local partnerships with ordinary people owning or renting homes, plus owners of offices and industrial plants.

We also need to discipline ourselves in Australia to quickly accept the logic of a sensible carbon tax system in 2010 – as a most effective partner to more city greenery, not as the almost go-it-alone action that currently seems to be the consideration.

A solid new “Carbon Tax and Greenery” partnership will penalize our bad practices and amply reward us for good practices. Also important is that we, as a world-leading nation, must accept the idea of bearing the burden of being leaders. But it is a burden only if we do not capitalize on obvious business opportunities.

If we do not take such action the consequences are likely to be dire. That is fully understood by the current Commonwealth Government as it accelerates Australia’s support of sound Kyoto Treaty developments – especially in India and China.

These two countries have a crucial role to play in making our world’s future secure, and we need to develop our Australian expertise to offer them practical support from individuals, companies and small local groups.

I have chosen a greenery leadership path as a member of Rotary International. When I was a working journalist I spent about 30 years studying and reporting the emerging certainty of climate change and its accentuation by global human blindness about fossil energy over-use.

I know full well that what my leadership in Brisbane might do. It could well be followed by 1.2 million Rotarians globally, if they see good sense in my green infrastructure education for home-owners and office workers. This is what I hope to be starting in Brisbane.

I suggest we can all make our lives much easier and more productive if we quickly adopt green-plant technologies that have multiple benefits in urban areas – meshing the big benefits of growing more urban plants against climate change factors, with the equally big benefits for business, for more employment, for an assured local food supply without fossil fuel transport costs, and for a much healthier urban environment for people.

The urban greenery benefits I foresee are likely to be huge – and not just focused on the carbon tax issue. Here’s my current figuring on how much good urban greenery effects in cities will benefit us:

1. Green roofs and walls can save significant fossil-fuel energy use through better insulation of buildings (reduced energy use in cooling and heating) and the cooling evapo-transpiration effect by plants. Overseas this can mean from 7% to 8% energy saving on industrial sites to more than 25% in homes and offices. We have yet to test what we can do in Australia’s hotter, dryer climate.

2. Lower-priced solar energy development is greatly aided by the cooling effects of green roofs and walls set below them. Cooler solar collection equipment has caused 2% to 12% extra electrical energy collected in Germany when green roofs cooled solar panels. Up to 20% to 25% estimated benefit is expected for such cooling in Australia. Green roofs can cool solar panels by 10 degrees to 30 degrees Celsius to make them work better. The big advantage will come when the world adopts the new Australian National University solar panel designs, and the CSIRO solar energy discoveries, ANU’s sliver cell invention is said to yield five to 10 times the energy collection capacity of existing solar panels – and are better still when cooled by a green roof. Expect solar energy production costs to drop right down when solar energy equipment and green roofs are combined. Germany has found this – and currently has about 50% of the world’s solar panels in use collecting electricity. The low-cost solar energy future is predicted to be significant in faster adoption of solar power in cities with good sunlight.

3. Greatly reduced storm-water management costs are forecast as a most important financial advantage of green roofs and green walls, especially via reducing peak storm-water loads. Green roofs can slow rainwater run-off from 50% to 90%, depending on design. They eliminate costly municipal storm-water system upgrades for expected climate change peak flows. Both roof and wall plants can have built-in water storage that slows water from immediate release when rains fall. A big advantage is that rain-water and recycled “grey water” takes big pressures off municipal water supplies.

4. Greatly iIncreased water use efficiency through in-house collection and storage for rain-water, and recycling of grey water. Savings possible using roof or wall plants are still being calculated, with some costs being static, but others being reduced significantly. The expectation is that much future water use in city food production (using aquaponics) will have little or no water waste, because of in-house recycling through air-moisture harvesting using solar energy.

5. Reduced cost of safer food - via "food from the roof", especially using aquaponics technology for healthy, fresh food production of combined fish and plants in cities. The cost reduction possible is estimated to be 50% of current costs – through complete elimination of rising transport cost (which is especially important to encourage because of necessary reduction of cancer-causing and asthma-causing diesel particulates in our air, and reduction of costly imports of petroleum).

6. Reduced air pollution. This is through both the uptake of harmful airborne chemicals by roof and wall plants, and in great reduction of transport energy use, and coal energy use in electricity generation. Corrie Clark, a PhD researcher in the United States, estimated in 2008 that this benefit is worth from US$640 to US$2,436 a year for a 2,000 square metre green roof.

7. Improved human health via both reduced transport pollution and via psychological effects. One United States scientist has shown that intensive care wards overlooking roof or wall greenery (that is visible to patients), have half a day to a full two days earlier recovery of patients. Another of his experiments showed that commuter-driving down restful greenery on highways, compared with no greenery in city streets, greatly reduces work stress levels all through the day.

8. Greatly reduced "heat island" problems in cities (where currently 50% of the world’s population resides, and where 60% of the world’s 2050 population is expected to live). All of us will need to better cool our city buildings and surrounds in summers not too far ahead. We can expect higher temperatures from climate change factors – to accelerate our urban heat problems. In 2003 an urban heat rise in Europe was said to be caused by climate change factors. It was credited with killing some 30,000 elderly and very young people in poorly designed urban buildings in France.

9. Re-cycling of clean organic wastes in cities – to reduce harmful methane pollution, to reduce nitrous oxide pollution and to have organic nutrients recycled for healthier urban food supply from greenery on roofs or walls. Currently most organic wastes go to land-fill or to the sea. Unwanted methane air pollution results – and methane is more than 20 times worse a greenhouse gas than carbon dioxide..

10. Reduced noise penetration from outside sources. This makes noise-reducing green roofs and walls particularly valuable near airports, or close to transport corridors and noisy industry. We all know what a sleepless night can do to our efficiency at work or our relations with family, neighbors and colleagues.

11. Reduced building penetration of electro-magnetic pollution. Up to 93% reduction of external radiation has been advised by green roof researchers in Europe and North America. The importance of this factor is not yet known, but it will be a strong motivation towards green roofs and green walls by some people.

My view is that within four or five years, green roofs and green walls and closely-associated technologies, should be a major urban, built-environment response in Australia against significant global problems foreseen from predicted climate change.

Whether or not you believe in climate change does not really matter.

The significant advantages of well-designed urban greenery will save much in the way of urban costs and render significant lifestyle advantages for all of us at a grim time of severe, global financial stress.

A most important central thought to me, however, is that reduction of our global “carbon footprint” in diverse ways has much more certainty for the future lives of my children and grandchildren – and theirs too.

At 72 years of age this retired agribusiness journalist believes that his concern and consequent Rotary Club action at the Brisbane suburb of Carindale, is going to become the essence of a grass-roots action by fellow oldies who think the same way.

We were of the generation that accentuated the accelerated release of greenhouse gases from the start of World War 2; we should also choose to be leading the crucial fight to reduce these gas emissions.

Geoff Wilson, retired agribusiness journalist and now a green infrastructure volunteer.

Jim Chisholm, Ergon Energy’s executive general manager, corporate sustainability and innovation, based in Brisbane.

Robert Cawthorne, managing director, Carbon Reduction Institute, Sydney.



30% energy saving is possible – quickly !

Two speakers at the GreenSpeed event in Brisbane on February 24, 2009 forecast that a 30% saving of electrical energy use was possible if Australians were well educated about how to make simple savings in homes and offices.

This compares with the 5% to 15% savings of greenhouse gas emissions slated for the Australian Government’s massively funded programs of carbon tax and emissions trading. While not exactly comparable, energy saving reduces fossil-fuel coal use, and consequent emissions of huge amounts of carbon dioxide.

Two Brisbane speakers were Jim Chisholm, executive general manager, corporate sustainability and innovation, Ergon Energy (absed in Brisbane), and Robert Cawthorne, managing director of the Carbon Reduction Institute (based in Sydney).

Both emphasized that the cost of an Australian greenhouse gas reduction education program could be relatively low, when compared with carbon tax and emission trading measures currently being discussed for 2010 implementation and beyond..

But neither speaker mentioned the additional carbon saving possible with green roofs and green walls, and the allied technologies now possible with them. The promise is that combination of a wide range of education points could greatly increase the public’s ability to cut greenhouse gas emissions to minimize future problems with climate change.

The GreenSpeed event comprised four speakers and discussion at a breakfast function from 7am to 10.30am, organized by the Australian Green Development Forum. The other two speakers were Rebecca Hoare, partner in Brisbane Deacons, who outlined the Federal Government’s carbon pollution reduction scheme, and Warwick Temby, Queensland exective director of the Housing industry Association. He discussed the effects of the carbon pollution reduction scheme on the building industry.

Mr Chisholm said: “We can reduce by 30% the amount of energy we use merely by changing our life-styles via an acceptable education process. … I believe that public education can deliver a far better result than the Australian Federal Government’s 5% to 15% objectives.”

Mr Chisholm said the money saved by individual and companies would be significant.

He said Californian home-owners had proved this in recent years, developing a flat energy use pattern compared with rising national energy use (see graph).

Mr Cawthorne agreed “I see the best option as being in education, bringing in existing educational institutions,” he said.

Ms Hoare said it was sometimes difficult to educate adults “unless a subject in their faces, or hitting their hip pockets.”

Mr Tenby agreed, and said: “Whatever model of education is chosen, we should get into it as quickly as possible – otherwise new technology will be taken up in dubious investment.”

The important questions the GreenSpeed breakfast event raised was whether the carbon tax and the emissions trading schemes being discussed in Federal Parliament are (a) too costly by far and (b) would be better replaced by “grass roots” education programs with similar aims.

A “grass roots” education program might not, however, have the same ability to pay out declining industries in electrical power using fossil fuels, or companies of the petroleum or aluminium industries.

But “grass roots” education is going to be the really big, easily-foreseeable need for green roofs, green walls and allied technologies to work well in Australia.

The author of these reports is retired agribusiness journalist, Geoff Wilson. He founded Green Roofs Australia Inc. in 2007. He is currently communications director of the newly-established World Green Roof Infrastructure Network (based in Toronto, Canada). Geoff also founded Aquaponics Network Australia, which now focuses on urban agriculture development. Websites: www.greenroofs, (plus three more).


Geoff Wilson,

Member, Rotary Club of Carindale,

Rotary District 9630 Water Resource Co-ordinator,

Founder, Green Roofs Australia and Aquaponics Network Australia,

Communications Director (hon.), World Green Roof Infrastructure Network (Based in Toronto, Canada).

32 David Road,

Holland Park 4121,

Queensland. Phones: 0412 622 779 or 07 3411 4524,

Email: Website:


Green Roof research increases world wide:

In the last decades the number of research groups working with green roofs had been increased. In Germany as an example, there will exists about 12 Institution doing more or less complete research activities. In the US -States and Canada about the same number is now acting.

In many more Countries academic institution starts research activities. Outcomes of these are in the academic publication systems. Nearly 100 peer reviewed articles about the ecological benefits of gren roofs exists today. The bigger number of thes are focussed on modelling, only a few are working to get hard data from real roof research fields.

These groups works partly together. To understand the green roof as an urban ecosystem is a real challenging question.

Quite more easier is it to explain a real good construction.

The green roof topic is real interdisciplinary. There is enough stuff for more academic generation. WGRIN try to support Green roof researcher. It is a real fruitful field of doing.

Beside the large Research nations, a lot of single institution starts, as examples in Uganda, Thailand, Bolivia and Chile ...

Under construction.
Manfred Köhler, Dec. 2008