If the holiday sales are tempting you to refresh your wardrobe, consider the environmental footprint of buying a new jacket and throwing away your old one. Today, about 80 billion new pieces of clothing are made each year—400 percent more than 20 years ago, while the world’s population only grew about 30 percent. That growth has a huge environmental cost. The Danish Fashion Institute named fashion “one of the most resource-intensive industries in the world, both in terms of natural resources and human resources.” Designer Eileen Fisher has called it “the second largest polluter in the world… second only to the oil industry,” and while that fact has been disputed, a 2010 research paper found that the industry is responsible for almost 10 percent of global greenhouse gas emissions.
Moreover, once clothes have been made and worn for a short while, they’re thrown away. A new report from the Ellen MacArthur Foundation found that cumulatively around the world a truckload of clothes gets dumped every second. The average American tosses about 82 pounds of textiles a year, much of which ends up in landfills or incinerated. Of the clothing that reaches second-hand stores like Goodwill—only 15 percent of all discards—some is recycled into shoddy (filling for cheap furniture) or upcycled into things like denim insulation, but most of it is shipped to poorer countries. However, they too have limits—African countries including South Africa and Nigeria recently banned Western castoffs, which have overwhelmed their markets, causing the decline of their local fashion business.
Replacing Old stock fabrics With New Biopolymers
Two types of textiles—petroleum-made polyester and field-grown cotton, often woven together—have been the fashion industry’s darlings for decades. “Much of [what we wear now] is a blend of PET, a petroleum-based fiber, and cotton fiber,” says Ramani Narayan, a professor in the Department of Chemical Engineering and Materials Science at Michigan State University. But these hipora fabric have their issues. Cotton, which makes over 30 percent of our clothes’ yarns, is a natural material, but it’s a thirsty crop that siphons 3 percent of the fresh water, and accounts for almost 20 percent of pesticides and 25 percent of the insecticides used in agriculture worldwide, before it’s even picked. Processing cotton—knitting, weaving, and dyeing—also takes water and energy, yielding more pollution. The production of polyester, the demand for which has doubled in the last 15 years, is an energy intensive process that requires a lot of oil and generates harmful emissions, including volatile organic compounds, particulate matter, and acid gases, like hydrogen chloride, all of which contribute to respiratory disease. “Adding PET to a textile gives you better performance—it makes taffeta fabrics more moisture-resistant and gives them more washability,” says Narayan, but these textiles don’t break down naturally, and instead fill up our landfills and oceans. Polyester threads discarded from washing machines have recently been found in fish, including some species we eat. Unless PET threads are decoupled from cotton and recycled, they don’t decompose, but separating fibers is very difficult.
That’s where biopolymers come in. Biopolymers are macromolecules—long chains of smaller molecular units strung together. These basic units can be amino acids, nucleotides, and monosaccharaides. The most common biopolymer is cellulose, which makes up one third of all plant material on earth. Cotton is 90 percent cellulose, but there are other, less polluting alternatives.
“Obviously it’s better to use plants and biomass to make products,” says Narayan, “because then the plants fix the carbon and when you make a product from that you have removed carbon dioxide from the environment.” Using biopolymers in clothing can reduce energy and freshwater use and may help mitigate climate change resources. Plus, as the following examples show, some biopolymers can take the creativity of fashion design process in a whole new direction.
Seining Sweaters from the Sea
AlgiKnit uses kelp, a type of seaweed, to produce a biopolymer called alginate, which is then used for textile production. Kelp grows all over the world, forming offshore kelp forests. Some kelp species grow quicker than the fastest-growing terrestrial plant, bamboo, and are inexpensive to farm. As it sprouts, kelp cleans water too—absorbing phosphorous, nitrogen, and five times more carbon dioxide than land plants—so farming it near seaside cities can improve polluted local waters. Like any plant, kelp absorbs carbon to grow, so when used in durable materials, it is also a carbon sink.
AlgiKnit extracts alginate from kelp by adding certain salts to the seaweed base. After the so-called “salt bath” pulls the alginate from the kelp’s cell walls, the biopolymer is extracted from the seaweed residue, dried into a powder and fused into a yarn that can be turned into a variety of stretch fabric types. “The process is similar to that of synthetic materials, where one long continuous strand is produced,” says Tessa Callaghan, the co-founder of AlgiKnit. “The filament can be plied and twisted to increase strength, or cut into short fibers for other purposes.” AlgiKnit won National Geographic’s Chasing Genius Competition for developing this technology.
