Biogenic carbon – sheep aren’t an exhaust pipe! Why have we been trying to fit a square peg in a round hole?

Being appointed as an Independent Director of WoolProducers in 2025, I’m delighted to have the opportunity to write about a topic that has been a key focus for me in recent years, the carbon balance of wool producing enterprises. I manage Mount Hesse, one of Australia’s oldest and largest Merino sheep farms, which was acquired by the Suedwolle Group in 2002. Mount Hesse is home to over 25.000 adult ewes, producing up to 135,000 kg of greasy wool annually, with an average micron range of 17.5-18.

Over the last few years, we have worked to calculate our methane emissions using various calculators, and the results were somewhat deflating. We are subscribed to various quality assurance programs that focus on sustainability and regenerating our land, along with also conducting most of the eligible land management activities approved by the Clean Energy Regulator for sequestering carbon under the soil carbon method.

We also have relatively high reproduction rates and turn off weights, and use very few chemicals, employing a conservative synthetic fertiliser program, yet somehow, we were still getting high emissions figures. To put this in perspective a 5% reduction on our farm emissions would save 321 tones which is the equivalent of taking 97 cars off the road.

A recently published peer reviewed study, A biogenic life cycle approach towards estimating the carbon intensity of wool production: Evidence from six Australian case studies, applying ISO 14067:2018 to Australian wool production systems delivers an internationally recognised carbon accounting framework that reflects the biological reality of grazing systems. The findings of the study have major implications for not only how our fibre is assessed, valued, and compared with synthetics, but for agricultural production systems generally.

Current life cycle assessments (LCAs) of wool (and other ruminant based commodities) have taken an overly simplified approach, particularly in relation to enteric methane, which treated wool as if it were part of a one-way fossil carbon system, ignoring the fact that sheep production operates within a short, renewable biogenic carbon cycle.

This new study is the first to map the full on-farm biogenic carbon flows for Australian greasy wool in a way that aligns with international standards.

The result of this study helped to explain why, despite our best efforts to improve our farm sustainability, that we kept getting disappointing results that left us scratching our heads.

By tracing the carbon ingested by grazing sheep, researchers found that most carbon ends up in manure (54.1%), followed by respiration (22.7%), urine (7.5%), and enteric emissions (5.2%). Crucially, when biogenic carbon dynamics were included in the LCA, wool’s emissions intensity dropped dramatically by an average of 102% when two thirds of manure remained within the grazing system. In simple terms, failure to account for biogenic carbon significantly inflates and misrepresents wool’s true carbon footprint.

For growers, this matters. It means the positive environmental profile of wool has been systematically understated for more than a decade. It also means that productivity improvements, grazing management, and soil stewardship have a measurable positive impact on global warming, not just on emissions. Unlike fossil fuel based synthetic fibres, wool is part of a regenerative loop; some carbon absorbed by pasture becomes fibre, while much of it is returned to the soil, supporting long term landscape function.

The study strengthens the case for fairer carbon accounting in international markets. Brands and regulators increasingly rely on LCA data to make sourcing decisions, meaning if wool’s biogenic system is properly recognised, our fibre stands in even stronger contrast to synthetics derived entirely from fossil-fuel.

As an industry, we now have robust ISO aligned evidence showing that wool’s climate impact has been overstated and that our production systems offer genuine pathways to reduced warming. For growers, this is not just a scientific correction; it’s a strategic advantage. It reinforces the value of the work that we already do and positions Australian wool as a natural fibre with a credible, evidence based sustainability story.

Herein lies an opportunity for us to promote our industry by further demonstrating wools eco-credentials to increasingly environmentally conscious global consumers and governments.

Edward Brand

Director WoolProducers Australia