Wool vs Organic cotton
Wool carries the methane and land footprint of the sheep that grew it. For warmth, recycled synthetic fill, hemp and lyocell blends match performance at a fraction of the impact.
Per per kg fibre
Greenhouse gaseskg CO₂e / kg
Wool
46
Organic cotton
3.8
Land usem² / kg
Wool
370
Organic cotton
24
Animals usedrelative
Wool
1
Organic cotton
0
Biodegradableyes/no
Wool
1
Organic cotton
1
Source: Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central
Verdict
Organic cotton, hemp and lyocell all beat wool on climate and land by an order of magnitude.
Questions people ask
What is the warmest vegan fibre?
Recycled polyester fill and plant-down alternatives such as kapok match wool's warmth-to-weight for most climates.