Seiff digs down into what "sustainability" really means, the yarn carbon footprint, and even third and fourth level issues like which vegan yarns are best. What she uncovers is - unsurprisingly - a lot of confusion and ambiguity, which is often muddled by a combination of good intentions and marketing spin.
I learned a lot from Knit Green, even though I didn't expect to. I consider myself pretty well-versed in the topic of green knitting. Even so, it hadn't occurred to me that so-called "Peace Silk" is not actually very peaceful. Seiff devotes an entire spread to the topic.
Silkworms are a domesticated animal, like sheep and chickens. You don't go out into the woods to harvest wild silkworms. They are raised on farms. Silk comes from the cocoons that the silkworm larvae spin around themselves when they pupate.
Traditional silk boils the larvae alive, then unreels the cocoon. (The larvae inside is then usually fed to a local carp farm, or eaten directly by the producers as a protein-rich delicacy.) In "Peace Silk" (which I have also heard called "tussah silk" the worms are allowed to pupate and cut themselves free of the cocoon naturally. This results in a much shorter staple, but creates what is theoretically a cruelty-free fiber.
Problem being, what happens to the moths afterward? A moth that escapes from a cocoon will go lay hundreds of eggs. On a silk ranch, you can't allow that to happen to more than one out of every thousand cocoons, else you'll be overrun with silkworms and unable to feed them all. Imagine if one day an egg farm let all the eggs be fertilized and hatch - the farmer would soon be hip deep in chickens. Same deal with silkworms.
Seiff stops short of proclaiming that Peace Silk ranchers probably trap and kill the emergent moths. But I think that's pretty obvious, if you stop to think about it. Which I had never done before.
Seiff also digs into the history of why naturally colored cotton was pushed off the market early on (white cotton has a longer staple length), what you should use to stuff your knit cushions (old rags and t-shirts), why acrylic yarn may not be AS ecologically wretched as most of us think (it's made from byproducts that might otherwise go to waste), and which vegan yarn is probably the "greenest" (spoiler: Lyocell, hemp, linen, and ramie).
I also really liked Seiff's take on recycling yarn. Most books go straight for unraveling the thrift store sweater, and Seiff mentions this as well. But she also has a project (a large toy basket) knit from a thrift store flat sheet, which you cut into one long strip in a spiral pattern. Fascinating, and a really lovely-looking result.
Overall, this was a really great read, and highly recommended!
White Folks Percentage: 84% of the models pictured are white.