CO₂ hot water system slashes dairy shed energy costs
A Taupo company says it's the first to bring CO₂-powered water heating technology to New Zealand dairy sheds, helping farmers cut energy costs by up to 85%.
Even more important to a business is the suggestion that at least some consumers are doing what they say they will do: Unilever reports that its sustainably labelled brands are growing 30% more than those without labels indicating ‘sustainable’.
The results of the Unilever research support the company’s commitment to halving the environmental footprint of production, and using only sustainably certified palm oil.
Unilever is the third-largest consumer goods company in the world and estimates that the sustainability market is worth 2.5 trillion euros. However, quite what constitutes ‘sustainable’ in the minds of the consumer is still in question. The main issues are still price paid to the farmer, cost paid by the consumer, impact of production on soil and water, generation of greenhouse gases (GHG) and animal (including human) welfare.
Within at least some of these categories, the unit of measurement is important. For example, what appears to be a reduction in environmental impact per hectare could be an increase per kilogram of energy or protein consumed.
A farm leaching the average nitrate per hectare, but doing twice the average production has increased its N use efficiency. If it has increased GHG per hectare because it has increased animal numbers, but is still producing fewer GHG per unit of production than neighbours, is the farm more or less sustainable? The same applies to nitrogen and any other input.
These are important factors to consider, but are not being asked in a systematic manner. Indeed, at the end of last year soil scientists from overseas indicated concern at the media focus on ‘alternative approaches to food production’ which were presented as ‘better’ – but had not been shown to be more sustainable than conventional methods.
Speaking at the Australasian Soils Conference in Queenstown in December, University of Western Australia’s emeritus professor Bob Gilkes stated that he was dismayed at the emphasis in New Zealand media on ‘alternative production systems, presented with the underlying suggestion that somehow conventional systems weren’t as good’.
‘Good, better and best’ are subjective assessments, and frequently are context-dependent. For instance, ‘free-range’ sounds terrific. But for Europe, concerns about animal welfare and business viability are threatening the free-range egg concept. Bird flu means that hens are being kept inside, but after 12 weeks they are no longer considered to meet the definition of ‘free-range’. What then of premium prices?
Staying with poultry, the move to use slower-growing chickens by the Whole Food Market in the US improves the life of the bird, but increases the ultimate cost of the bird to the consumer and use of resources including water, air, fuel and land. The National Chicken Council calculates that if one third of birds were a slower growing breed, nearly 1.5 billion more birds would be needed annually to produce the same amount of meat now produced – requiring an extra 7.6 million acres of land. An extra 5.1b gallons of water would also be needed just for the chickens to drink during their lifetime, and an extra 28.5b pounds of manure would also be added. The cost to the consumer would increase by US$9b.
In fishing, the University of California Merced has reported the sustainable tuna fishing involving selective fishing techniques reduces catch and increases carbon emissions. The research estimates that catching one tonne of tuna today requires three times the amount of fuel it did 25 years ago.
Many companies, including Unilever, are trying to do what consumers think they want, but unintended consequences are rife. Research in all areas must continue to try to identify the sweet spot between environment, price, cost and welfare by considering all aspects of production.
There are no silver bullets or easy answers and ‘good, better, best’ depends on context.
• Jacqueline Rowarth is chief scientist at the Environmental Protection Authority. Her doctoral research was in soil science and she was a member of the panel discussion on the future of soils science in which Professor Gilkes took part.
