Natural fibers are better for the environment than synthetics — at least, that’s been a long-held tenet of fashion sustainability. But what if that’s not the case?
A new research paper, co-authored by Fashion Revolution co-founder Carry Somers alongside both academic and citizen scientists, challenges fashion’s historical assumptions that natural fibers are inherently biodegradable.
In a sample taken from the sediment of Rudyard Lake in Staffordshire in the UK — long fed by rivers lined with textile mills, color mills, laundries, and dye houses — researchers found the majority of fibers recovered were natural, with cotton accounting for over 70% of the 150-year fiber record.
The research is the latest in a string of papers from across the last decade that have highlighted the staying power of natural fibers in the environment. It’s a direct blow to fashion’s narrative that natural materials like cotton are better alternatives to microplastic-shedding synthetics. The new paper, published in iScience, directly addresses fashion’s use of natural fibers to make ‘green’ claims, and specifically calls upon the industry to heed the results to ensure sustainable fashion narratives are led by science, not assumption.
“We have to get away from this extreme that if plastics are bad, natural [fibers] must be good,” says Somers, whose recent book The Nature of Fashion investigates how plants have shaped fashion.
A battle rages between synthetic fiber producers and natural fiber producers, campaigners, and activists and policymakers as to which fiber category is less harmful to the environment. According to the Product Environmental Footprint (PEF) methodology — used as the basis for validating green claims in the EU — synthetics have a lower environmental impact than certain natural fibers such as cotton, due to factors including using less water in production, requiring less land, not requiring the use of pesticides, and higher durability. This position is fiercely debated, with critics arguing that such comparisons overlook key points such as the impact of fossil fuel extraction and processing for synthetics, the renewable nature of natural fibers, and the potential benefits of regenerative agriculture.
In 2024, more than 900 signatories representing over 500,000 farmers globally stated that the PEF methodology posed a significant risk to the livelihoods of natural fiber producers by “misrepresenting natural fibers as harmful to the environment”. Meanwhile, a 2026 paper published by the Bremen Cotton Exchange took aim at how select UN agencies allegedly underplay the impact of oil-based synthetics.
Consumer sentiment among those wanting to shop more sustainably has been to avoid plastic-based clothing in favor of natural materials. What should the industry — and shoppers — make of this new research? The authors say that the intent is not to exonerate plastics, but to avoid the risk of seemingly quick fixes such as swapping synthetic for natural fibers leading to unanticipated and more complex problems.
Tunnel vision
As the production of synthetic fibers has grown to take 69% of global fiber market share, and International Union for Conservation of Nature (IUCN) estimates place synthetic clothing as the leading single contributor to ocean-based microplastics — accounting for 35% of what’s released — synthetic fibers have become a major focus of research and campaigning. Studies showing that microplastics (tiny plastic fragments, including synthetic fibers, which have shed from clothing) have been found in almost every environment tested, from lake beds and remote mountain ranges to soils and sea spray, raised concern. Research into the potential environmental harms, such as slowing the growth of algae and making soil less fertile, not to mention the potential impact on human health, further compounded that concern.