walnut 🌱 (@walnut)

Hey, I just had a convo that reminded me of a question I have.

I keep seeing people claim that cotton is bad for the environment because of how much water it consumes, and hemp and linen are to be preferred for that reason.

That's super eyebrow-raising because I know that cotton, famously, grows in arid places like Egypt, Spain, and Tamil Nadu, while both hemp and flax (from which we get linen) were staple crops in northern and central Europe, and as such are much, much more demanding of moisture.

Furthermore, unlike cotton, hemp and linen are what is known as mast fibers, and cannot be liberated from the stalks in which they grow without extensive processing, which uses a lot of water.

Does somebody have a study about this somewhere? Because, boy, is that a surprising claim if you know anything about textile production. I mean, it could be true, chemical engineers keep coming up with interesting new industrial processes, maybe modern cotton is way thirstier than I thought – everything I know on this topic is approximately 500 to a thousand years out of date.

Absent actual evidence, this sure sounds like a lot of people got exposed to some sort of anti-cotton propaganda and just kind of assumed that it didn't also apply, only more so, to other familiar botanical fibers.

(I don't know the first thing about bamboo fiber production, but given that it didn't exist prior 1600 CE, or to my knowledge prior 2000 CE when I largely checked out of textile geekery, I assume the only way to get textile fibers out of bamboo are with some horrendous chemical process, same as rayon, which is made from trees.)

@siderea
Got nerd snipped for five minutes, I'm not an expert.

Water Footprint in Cotton 2020-2024: A Global Analysis - International Cotton Advisory Committee
www.publicnow.com/view/CCB3C30C31DE9705ECBD1880A5B7FFE598A8B865?1742503677

Cotton production is often misrepresented, particularly regarding its water consumption, and is frequently labeled a "thirsty crop" based on calculations of water use efficiency-measured as the total water (rainfall plus irrigation) required to produce one kilogram of lint. This study revealed that the annual average water used to produce one kilogram of cotton lint was 8,927 litres, comprising 6,582 litres/kg lint from rainwater and 2,346 litres/kg lint from irrigation water.

Small antidote on a single farm in North Carolina. It seems we still grow cotton without irrigation at all in some places. This is probably really unusual and seems like the kind of thing you'd need to deliberately look for in a farm.

Since the Burlesons don’t irrigate, the wheat cover crop proves particularly beneficial for maintaining crop moisture in hot, dry years. But Andrew says the greatest benefit is that it returns organic matter to the soil.

www.farmprogress.com/cotton/burlesons-southeast-high-cotton-award-winner

This doesn't have exact numbers at all, but it's the gold standard peer reviewed* "hemp industry daily" so meh, I'd expect them to be promoting it if anything
“I’ve heard a lot of people promoting hemp as a low-water-use crop, and from what I’ve seen, it’s pretty high compared to other crops,”
hempindustrydaily.com/myth-busting-hemp-needs-more-water-than-many-think/

Cotton as a textile also just isn't a 1:1 replacement for wool (re: the other thread), but I don't think any other plant textiles are either. A shame. But on water use, wool is so much worse than cotton. Probably literally anything from plant fibers is like an order of magnitude better than wool.

*note: not being serious

@walnut Thanks! Re wool: honestly approximately anything is a substitute for wool. Pretty much the moment we had wool substitutes the wool industry cratered, because nobody wants to wear wool if there is any alternative.

No, the real question is: if not cotton, then what? There is a reason cotton became king.

@siderea @walnut Cheap synthetic fabric is the other side of that. Cotton is good in warm climates, synthetics like polyester are what mostly replaced wool in the cold and damp. In my opinion wool still performs better most of the time but it is significantly more expensive.

@mirth If you ever get a chance, try out silk-lined linen in a cold weather environment. I found it eye opening.

Alas, linen doesn't have the water shedding property of fulled wool. I'm not sure if that's fixable.

@walnut

@siderea @walnut Curious. I'll keep an eye out, I've never seen that combination

@siderea @walnut Unless you have a wool allergy, woollen socks are the bomb, ditto woollen jerseys. Naturally fire-resistant, and still insulating even when wet. Many folks choose wool over alternatives.

How can linen be so chemically problematic? It's a really old production technique. I love this thread, btw.

@GinevraCat

How can linen be so chemically problematic? It's a really old production technique.

First of all old doesn't mean not chemically problematic. The traditional technique involves retting, which uses water. The waste water of this process will of course have any of the pesticides sprayed on the plants. Wikipedia also notes "Waste retting water, which requires treatment to reduce harmful toxic elements before its release, is rich in plant minerals, such as nitrates, and can be used as liquid fertilizer.[1]"

But I was thinking about the possibility that modern processes may have developed to avoid water retting, which takes literal days or weeks, by means of, say, industrial detergents.

@walnut

@siderea @walnut Thank-you for this clear explanation! (And without being even a little patronizing, which is a rare.)