An environmental benefit of natural fibre yarns like wool, cotton, mohair, alpaca, linen and silk is that they are made from renewable resources. Acrylic yarns are made from plastic-like materials which use scarce petroleum resources and are not biodegradable.
Wool is naturally flame-resistant and a woollen blanket can promote a better night's sleep according to this research from the University of Sydney because wool is naturally breathable, making it a good temperature and moisture regulator.
Reduce the need for new wool by checking in secondhand/charity shops first.
Buy natural fibre wool where possible, as acrylic wools are made from environmentally-unfriendly components and do not biodegrade.
If you have wool surplus to your needs consider on-selling or donating to a secondhand/charity shop.
Wool can also be taken to the ReUse Academy for redistribution.
Unravel knitted garments, wash and reuse the wool for a new project.
Keep acrylic wool from landfill wherever possible.