The ecological footprint of fabrics depends on many factors. Here’s the quick and dirty summary for the impatient: Natural fibres have a lower footprint than synthetics. Of all the natural fibres, those that are certified organic have a lower footprint than those that are grown conventionally.
A few numbers (don’t believe the graph, peeps)
According to this WRAP study, wool has a higher carbon footprint than even viscose. Much of this is owed to sheep being ruminants (they burp lots of methane). However, the data above do not consider the stewardship of the land and the amazing ability of soil and vegetation to sequester carbon, and thus mitigate climate change. Lets take a closer look:
Grasslands are even more reliable carbon sinks than forests, and some wool growers work hard on making their farm carbon-negative (meaning that their annual carbon emissions are lower than the amount of carbon pulled from the atmosphere each year and stored in the farm’s soil and plant matter). When sourcing your wool, look for extensive grazing, or better yet, intensive rotational grazing (best for carbon sequestration and biodiversity).
Cruelty in wool production: Definitely make sure your wool is mulesing-free. Mulesing is the practice of peeling skin off the lambs’ buttocks. Yes, you read that right: peeling skin off.
All the merino wool in my yarns is mulesing-free. The video below shows the sheep and people behind my Tasmanian merino:
The environmental footprint of silk is beautifully low: Mulberry trees necessary for the cultivation of silk worms can pull more than 700kg of CO2 from the atmosphere per kilogram produced silk fibre. No pesticides are needed to grow mulberry trees.
But isn’t silk harvest cruel? We can’t ask the silk worms, but here’s what I think: Yes, billions of silk moth pupae are killed every year in sericulture. They die when they are dormant, undergoing transformation from larva to adult. Their death is quick, and their bodies are subsequently used as a protein source.
The less cruel version is “Peace Silk” – where the lifecycle from egg to caterpillar to moth is not interrupted. I used to think the term is a marketing gag. Boy was I wrong. Eri, tussah and muga silks are traditionally non-violent silks. In rural and tribal areas of the Assam region, eri silk worms are tended like half-wild pets by the women in the family to provide them with fibre for spinning and weaving.
About a quarter of the pesticides applied globally are used on cotton farms, and the GOTS certificate isn’t always a guarantee that cotton is grown sustainably. For example, India’s GOTS certified cotton got under fire recently, because GM cotton was found mixed into many batches of certified-organic cotton. And the promised reduction in pesticides needed to grow genetically engineered cotton is an illusion.
Water is another problem in cotton farming. On average, 10,000 Litres of water are used to grow 1kg of cotton. In counties where water is scarce, such as Egypt – which has an even higher water consumption per kg cotton than the rest of the world – the ecological and social costs are tremendously high.
Is cotton cruelty-free? To set up a huge mono-culture (be it cotton, corn, wheat, or other crops), you have to destroy an ecosystem and the majority of its animal and plant species. Plus, conventional cotton production is notorious for child and slave labour. So no, conventional cotton is unlikely to be cruelty-free.
Sourcing sustainably-grown cotton (sustainable in the ecological and social sense) is very difficult.