Silk Farming - Why The Bad Press?
Pro bono article published in Apparel Insider Issue 11, January 2020.
Silk has been getting quite a drubbing lately; branded cruel and unsustainable, a number of brands - including ASOS - have publicly announced that they will no longer use it, and will switch instead to what Peta helpfully point out, are cheaper alternatives, including polyester. The source for the cruelty claims is Peta itself: “Silk Production Causes Painful Death for Insects” . However, Peta also urges you to switch to a vegan diet, without once mentioning that the agricultural sector views caterpillars as pests, and kills billions every year.
Consider the fate of the Tomato Hornworm caterpillar. An important means of control is the use of parasitic wasps - bred to order by specialist companies (you can even buy them on Amazon) these wasps are used in the commercial cultivation of an array of crops. They kill caterpillars by a means so gruesome it shook Darwin’s faith: "I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars" he declared.
That being eaten alive must be painful, even to a caterpillar, I think we can all agree. Being poisoned - even with an organic pesticide like pyrethrin, which causes death through paralysis - must be painful too.
In brief the life of most tomato hornworm caterpillars - indeed of all of the millions of caterpillars and insects that attack commercial crops each year - is short and cruel. How does this compare with the life of the silkworm caterpillar? I found myself in Siem Reap, so I decided to visit Cambodia’s largest silk producer and see for myself.
The Bombyx Mori caterpillars are raised in large trays in rooms that are neither heated nor air conditioned - although water is spread on the floor during very hot periods, when workers - predominately female - may also be given electric fans. The worms consume huge quantities of Mulberry leaves, raised in bushes on the farm for that purpose. Their copious excrement is collected and used to dress the mulberries - along with manure and other fertilisers. When the caterpillars reach maturity they are transferred to wicker cocoon trays. Once cocoon spinning is completed, 20% of the cocoons are left to mature, the rest are placed in the sun. This kills the pupae and loosens them from the cocoon. Since they are in the process of metamorphosis the moths can’t be sentient - to feel one’s soft caterpillar flesh being reshaped as wings, legs, antennae... would be too painful. Unlike the benighted crop caterpillars, their death brings no pain. The dead cocoons are then dipped in boiling water for a few minutes to unravel the fibers, which are reeled manually.
The leftover pupae do not go to waste.They are an excellent source of protein in what is, like almost all silk producing nations (with the exception of Japan and South Korea) one of the poorest countries in the World. Deep fried silkworms are a local delicacy and some sustainability analysts suggest insects should increasingly form a part of everyone’s diet.
As for the lucky 20% of the cocoons allowed to continue on to maturity: they hatch, mate, and lay eggs for the next round of cultivation. Since, like many moths, including the famed Atlas, Bombyx Mori have no mouth, their adult life lasts only a few days. They also can’t really fly.
Clearly, to claim that silk farming is more cruel to caterpillars than crop cultivation is nonsense. If you want to ban silk on those grounds, you must first ban tomatoes, aubergines, corn, viscose, cucumbers, cotton...
But that silk is cruel is not the only myth being spread; many claim silk is also unsustainable. The sole source for this claim appears to be the Sustainable Apparel Coalition's (SAC) Higg index. This is used by Kering, H&M, Pulse of the Fashion Industry and many more, to evaluate sustainability progress in the apparel sector. Higg actually increased the impact of silk - from 128 per kilo in 2018, to 681 in 2019! The next most unsustainable fabric, Higg claim, is Alpaca, on 283. All the most sustainable fabrics are the fossil fuel based types produced by the Higg founder members and others. Predominantly various types of Poly, these are claimed to have an impact of only 37 to 44 per kilo.
For silk, the Higg claims that 641.5 of the 681 impact per kilo, is accounted for by raw silk production and reeling - or the processes that I observed in Cambodia and have just described.
The study the Higg claim is based on, was produced by a private company - Quantis - and is not available to the general public. The SAC tells me that they cannot share the data as it is not theirs to give, and Quantis did not reply to my enquiry. Did the study include the value of silk byproducts - pupae protein, and fertilizer? Did it calculate the carbon sequestration afforded by the mulberries - which are a fast growing hardwood tree? I have asked the SAC these questions several times. As I pointed out to them, since they do not reply, I conclude that the answer is no, and that the impact of silk production has been inflated as a consequence.
Moreover, by looking at the Higg page for Silk, raw, from silkworm we can see that the bulk of the impact is derived from water scarcity, this is claimed to be 367.7 per kilo. Another 51.8 comes from raw silk’s fossil fuel impact.
How does this water scarcity impact compare with those made for other fibers? The Higg claims organic cotton has an impact of only 6.3 per kilo, or less than 2% of the water scarcity impact claimed per kilo of silk, despite the fact that a significant percentage of global organic cotton comes from Xinjiang, where rainfall is only 72mm per annum. Other important organic cotton producing areas are Rajasthan on 300-700mm of rain pa.; Tamil Nadu and Andra Pradesh, each with under 1000 mm pa.; and Madhya Pradesh on 1000 - 1300 mm of rain pa.
The main silk producing area in India, on the other hand - southern Karnataka - averages 1,100 to 3,500 mm of rain pa; Siem Reap gets about 1300 mm (many areas are also flooded when Tonle Sap is at peak); the main silk producing areas of China receive 1000-1400mm of rain annually... I could go on, but I think you catch my drift: the relative water scarcity scores for silk and organic cotton provided by the Higg are inconsistent with the relative rainfall data by a huge margin - 368 to 6. How is this possible?
If we consider the raw material fossil fuel impact we see that per kilo of polyester - which is fossil fuel based - this is said to be only 5.8, whilst for silk it is 51.8, nine times higher! How can that be? I can see no way in which these values were derived from the producers that I visited. The mulberry trees are rainfed and the only power consumption I saw was in boiling water, in which to dip the dead cocoons in order to unravel the fibers. Most if not all of this can be easily provided by solar energy, so where is the huge fossil fuel impact for global raw silk production coming from? I have, of course, asked the SAC these very questions, but they have not replied.
I visited just one farm and factory, and my evidence is purely anecdotal but, as we shall see, it does match the claims made by some of the world’s major silk producing agencies - the Higg data does not.
BRAC, the world's largest non-governmental organisation, The Indian Government and the International Sericultural Commission (ISC) all promote sericulture as an important vehicle for achieving The UN Sustainable Development Goals, based on its environmental and socio-economic characteristics.
These characteristics include the Mulberry tree's capacity - as a deep-rooted perennial, able to cope with salinity - to be raised in vacant lands, hill slopes and watershed areas, contributing to soil conservation by root stabilisation, and improving air and water quality. Mulberry is also easily intercropped, and provides firewood and valuable protein-rich fodder as well.
As a labour intensive and predominantly agro-based activity, all three of these agencies claim machine pollution is minimal.
They also contend that sericulture is an effective tool for poverty alleviation due to the high labour force participation rate, minimal investment, and relatively quick and high returns generated. With job opportunities for all family members, especially women and the elderly, they believe it is unique in converting family labour into income, and so helping poverty stricken families in rural areas, especially the marginalised. The ISC assert studies undertaken in China, Thailand, and India show that sericulture is an ideal tool for female empowerment and gender equality, as well as an ideal programme for weaker sections of society including landless and tribal minorities.
All of these benefits would accrue to some of the poorest people - farmers - in some of the poorest countries in the world, and it is hard to understand where and how this huge disconnect between the development community’s view of silk cultivation, and that of the fashion sector took place. Is a rethink required?