All that carbon cycle stuff which we learnt, regurgitated in exams, then forgot about in our school years, has now started to regain some importance, as the debate over global warming grows.
At the Landscaping New Zealand conference held in August last year, Landscape Architect Craig Pocock delivered a frighteningly clear picture of how the landscape industry is impacting on the environment. "Over the course of a career most landscape architects will be responsible for generating thousands of tons of carbon through specifying vast material consumption,” says Craig.
Most of us are only now beginning to develop an opinion as to whether global warming actually exists. At the current rate of forest depletion and fossil fuel consumption, it is obvious that sooner or later, the quality of life on our planet will be affected. Add to that the fact that, if every human on earth today was to enjoy the same standard of living we currently enjoy in New Zealand, there would need to be three 'earths' to provide enough food, water, and energy, it is impossible to ignore the fact that we do have a problem.
So what actually is all this talk of carbon footprints? What part do we play in the dreaded 'global warming’? And what should we think about as we go about the practice of modifying and creating our living spaces?
The Carbon Footprint
Design, engineering, construction and manufacturing industries worldwide are moving towards measuring their activities in terms of 'carbon costs', and are adopting sustainable practices with the view to minimising environmental damage. The landscape industry is not immune from this, in fact, landscape construction in particular is extremely unbalanced when it comes to carbon.
The work Craig was engaged in on the shores of the Dead Sea in Jordan - an estimated 16,000 times the amount of carbon was being emitted, in relation to that which was likely be absorbed in the gardens being created. This equates to a massive carbon footprint.
What can we do?
The fact is we need to become conscious of the energy consumed in the process of constructing landscapes. Many of the suggested practices involve what would seem to be totally unrealistic goals, but, nonetheless, they should be explored when planning any landscape project.
Be conscious of the extent of the use of cement and cement based products. A huge amount of energy is required to produce cement, and anything constructed or manufactured with cement, is seen as having ‘high energy embodied content’.
Design any project with efficient 'cut and fill' practices to avoid exporting or importing large quantities of fill when creating desired levels. This keeps energy use, as well as the overall cost, down.
Use plantation grown timber wherever possible - timber should always come from a sustainable source.
Adopt a 'local materials for local jobs' philosophy. This has two main benefits. Firstly, it keeps the cost of transportation to a minimum, and secondly, it encourages the development of a local style of landscape. If both hard and soft components are sourced locally, an honest 'sense of place' can be engendered in the work. In this day and age it can be seen as more trendy to display imaginative use of local materials, rather than showing off by using exotic products from afar. Money is often better spent on good craftsmanship than on fancy imported materials.
Consider water tanks for collecting water for irrigation. Ideally these should be incorporated into the roof and guttering design of the house design. Less dependence on city's water supply for garden maintenance is best.
Consider maximum use of permeable paved surfaces and runoff into gardens and lawns. Landscape in ways which encourage soakage within the property rather than adding to the city's storm water system.
A vegetable garden should be an integral part of any residential landscape plan. It is becoming very popular to grow our own food.
More and more people are thinking green and becoming conscious of playing a responsible part with their residential landscaping. Though the actual impact of incorporating 'greener' practices when creating gardens may seem miniscule in relation to the big picture, there is a sense of contribution for the owners with the knowledge that every little bit may well be helping.
And as for landscape professionals - the recognition of such trends will do no harm when planning marketing strategies and when working at meeting the needs of the client.