Deon Saayman, CEO of Cape Wools SA, explained to Farmer’s Weekly that, for years, incorrect methodologies had been used to determine wool’s carbon footprint. As such, synthetic fibres derived from fossil fuels scored higher than wool in terms of sustainability.
“The study is part of a broader effort to get the EU to change the methodology by which they determine a product’s carbon footprint. For years we have argued that, by not taking the full production cycle into account, wool’s footprint has been skewed. However, we needed a scientific, peer-reviewed study to prove it, and now we have one,” he said.
The study, titled ‘A biogenic lifecycle approach towards estimating the carbon intensity of wool production: evidence from six Australian case studies’, was published this year in the journal Agricultural Systems by Prof James Blignaut, Dr Paul Swan, and Lemuel Blignaut. It shows that, when biogenic carbon flows are properly accounted for, wool production shifts from being a carbon source to a carbon sink.
Where earlier studies went wrong
According to the study, most wool life cycle assessments (LCAs) published between 2010 and 2024 were conducted under ISO 14040 and 14044 standards, which do not explicitly require biogenic carbon to be measured.
As a result, natural fibres such as wool were assessed using accounting approaches better suited to fossil fuel-based products, such as polyester and acrylic, whose carbon originates from non-renewable sources.
This led to systematic bias, as emissions from sheep were counted while carbon removals inherent in the production process, such as plant growth, manure return and soil processes, were largely ignored.
To address this gap, the researchers applied the ISO 14067:2018 standard, which explicitly recognises biogenic carbon, to six representative Australian wool enterprises across three production zones. Using detailed farm data, they tracked where carbon consumed by grazing sheep ended up, rather than simply measuring what was emitted.
On average, the study found that previous LCAs overstated wool’s emissions intensity by more than 100% when biogenic carbon was not included.
The results showed that about 54% of the carbon consumed by sheep was returned to the land in the form of manure, a further 22% was released through respiration, and only about 5% was lost as methane and other gaseous emissions.
When these biogenic flows were incorporated into the carbon footprint calculations, the wool’s emissions intensity declined dramatically. Under scenarios where just one-third of manure carbon was retained in the grazing system, wool’s carbon footprint fell by more than 70%. When two-thirds was retained, several farms became net carbon-negative.
Implications for farmers and consumers
Saayman said the process to correct the image of wool’s sustainability is far from over. “The wool industry as a whole, together with the International Wool Textile Organisation [IWTO], now needs to drive the ‘Make the Label Count’ campaign even harder in EU parliament to ensure the correct methodology is used for carbon footprints and that wool is treated as the sustainable fibre it is.”
He noted that the volume of synthetic fibres far outweighed that of wool, which only made up 1% of global textiles. Thus, he expects pushback on the research findings.
“There are those with vested interests in synthetic fibres who are lobbying parliament, but we must continue to fight for natural fibres and counter the imagined idea that synthetic fibres are better for the planet. We must put the correct facts on the table,” he added.
Dalena White, secretary general of the IWTO, noted in a statement that the implications of the study extended beyond wool.
“All ruminant- and photosynthesis-based industries face similar challenges with current accounting methods. [The study] opens pathways for more accurate environmental assessment across agricultural sectors,” she said.
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