The research shifts the sustainability debate from simply choosing a fibre to understanding how cotton, wool, leather and other raw materials are actually produced.
Fashion’s raw-material sourcing could influence about 1.45 billion hectares, or 30.15% of global agricultural land, when livestock land associated with leather and wool is counted alongside textile crops, according to new research involving the University of Oxford’s Smith School and DIRT Charity.
The estimate is deliberately broader than land directly occupied by textile crops. The authors calculate approximately 876 million hectares associated with leather, 528.4 million with wool, 34.7 million with cotton, 5.9 million with flax and hemp, and 2.3 million with silk. The report describes this as land the fashion industry can potentially influence through purchasing, rather than land attributable exclusively to fashion.
Production system matters as much as fibre
A central finding is that environmental impacts can vary dramatically within the same material category. Reviewed life-cycle studies put leather emissions between 8.5 and 151.9 kg CO₂e/m², while viscose ranged from 0.20 to 8.30 tonnes CO₂e per tonne depending partly on processing and energy sources.
That challenges procurement strategies built mainly around labels such as cotton, viscose or alternative leather. Farm management, electricity mix, chemistry, yields and processing methods can materially alter the footprint.
Cotton sourcing moves upstream
The report cites studies linking organic and biodynamic systems with greater species richness and improved soil indicators. It also references Egyptian research where biodynamic pest management sharply reduced pesticide use while raising cotton yields, and long-term Indian cotton trials showing soil-quality improvements.
For brands and mills, this strengthens the case for farm-level traceability, verified production data and sourcing specifications based on measurable outcomes, rather than fibre identity alone.
Claims face greater scrutiny
The timing is significant. EU Directive 2024/825 applies from September 27, 2026, restricting unsupported generic environmental claims and sustainability labels not backed by qualifying certification schemes or public authorities.
The headline 30% figure should nevertheless be interpreted carefully. The study is predominantly a literature review, has not been peer reviewed, and was initiated and funded by DIRT Charity, which is developing a biodynamic textile standard with Demeter International.
Its most consequential message remains broader: textile sustainability measurement is moving upstream—from “Which fibre?” toward “Where, how and with what verified impacts was it produced?”.
