Fashion x Forests
When we think about our wood consumption, paper is often the main product that comes to mind. Yet, we find wood in many places beyond our desks, including, of course, our closets, where wood pulp is disguised in our silky fibers. Our journey through the linkages between the clothes we wear and the world we live in brings us to a new ecosystem: the forest.
What are wood-based fibers?
Some of the common fabrics in our clothing, like rayon, are known as semi-synthetic materials. Semi-synthetic fibers, which are also called cellulose fibers or regenerated fibers, are derived from a natural source, but are manufactured through a chemical process. In the case of rayon (sometimes called viscose) modal, and lyocell, the natural source of the fiber is wood pulp, which comes from trees. Some semi-synthetic fabrics do not come from wood, including bamboo, which comes from bamboo grass, and cupro, which is made from cotton linter. Overall, semi-synthetic fibers make up less than 4% of the material in our clothing, with production amounting to roughly 4 million tons of fiber per year. 
When it comes to sustainability, the production of semi-synthetic fibers involves two issues. First, the source of the raw material. And second, the manufacturing process, which often uses a lot of chemicals and water, resulting in heavy water pollution. We’ll focus here on the first issue—the toll that wood-based fibers are taking on our forests.
Let’s starting by taking a quick look at how rayon, modal, and lyocell compare. Rayon is considered the first generation of this fiber. It was first developed in the late 19th century as an alternative to silk and began to appear widely in our clothing in the mid 20th century. Modal, technically known as high wet modulus rayon, is the second generation. Rayon and modal are manufactured in virtually the same way, but modal is stronger when wet. Lyocell, which is the third generation, is similar to rayon and modal in terms of how it feels, but is manufactured in much more environmentally sustainable process. Lyocell is available commercially under the name Tencel® which is manufactured by an Austrian company called Lenzing. Through a closed loop system, Tencel® production reuses virtually all of the chemicals used to process the fiber, thereby dramatically reducing wastewater emissions.
Fibers and forests
Each year, 70-100 million trees are cut down to produce wood-based fibers. This figure is expected to grow in the coming years, due to both demand-side and supply-side forces. Demand for semi-synthetic fibers is projected to double by 2030.  On the supply side, as the world moves in an increasingly digital direction, pulp manufacturers are looking for ways to remain profitable in the future without relying on paper production.  And, increasingly, they’re betting that wood-based fibers are just the way to do that. What’s the problem with cutting down all of this wood? On the surface, it might seem that wood, which is a renewable resource, is a sustainable raw material. That’s true, but to understand the whole picture, we have to look deeper.
As with many of the natural habitats we have explored, including soil, rivers, and oceans, for all their size and might, ecosystems exist in delicate balance. Forests are no exception. The long terms health of forests must account for a basic truth: trees take time to grow. A pine tree, which might be used to produce rayon, takes 30 years to grow from a seed into its mature stage. This means that trees cannot be endlessly cut without carefully managing the stock of seeds and young trees that will grow into mature trees over time.
Ensuring the long-term health of forests is a science—sustainable forestry management. When a forest is managed sustainably, trees are cut down at a rate that allows the forest to be replenished by new trees. Efforts are taken to ensure that the forest’s natural habitat and biodiversity are also preserved. Without the application of sustainable forestry principles, forests are vulnerable to being exhausted rapidly. So rapidly that they sometimes end up losing the kind of density and biodiversity that characterize them as forests in the first place. The technical name for this is deforestation, and it is defined as the clearing, or cutting down, of trees resulting in the transformation of forests into land. Despite the fact that most countries have laws to regulate cutting down trees, forests are highly vulnerable to illegal logging. So while the wood from a well-managed forest can be considered a renewable resource, wood from an exploited forest is effectively non-renewable as it is depleting the natural habitat at a much faster rate than the earth can replenish it. The effects?
At current deforestation rates, the world’s rain forests could vanish within the next 100 years.  In Sumatra, Indonesia, pulp generation has contributed to the loss of 60,000 square miles of tree cover from 2001-2013.  When it comes to the direct contribution of wood-based fabrics, in the southeast Alaskan rainforest, demand for rayon was found to be one of the primary, direct causes of unsustainable logging.  Further, it’s estimated that 30% of the wood going into rayon is sourced from endangered and ancient forests,  which are forests that have reached old age without being significantly disturbed. Due to their rich biodiversity of both plant and animal life, endangered forests are extremely important from an ecological perspective, and their destruction is of particular concern.
Deforestation and climate change
In order to understand the effects of deforestation on climate change, it’s first necessary to understand the environmental importance of forests, which are some of the richest ecosystems on earth. Forests serve four key environmental functions: they store water, absorb carbon, structure the soil, and provide a habitat for wildlife. Altogether, forests cover 31% of the earth’s surface.  That may seem like a high percentage, but just 50 years ago, forests accounted for 60% of the earth’s surface, indicating a massive loss of the world’s forests. Considering the four key environmental functions of forests, deforestation results in:
Disrupted water cycles: Trees play an important role in transporting water from the ground into the atmosphere through the process of plant transpiration. This water makes its way into the clouds, causing rain. The rain nourishes the rainforests and fills rivers and waterways. When trees are cut down, they can no longer conduct water through the environment in this way, which results in a drier climate.
Increased greenhouse gas emissions: Forests are one of the most significant ecosystems in terms of their ability to store carbon.  According to the World Wildlife Federation, deforestation is the third most egregious emitter of greenhouse gases, after coal and oil. Deforestation alone contributes to 15% of our global greenhouse gas emissions. 
Increased soil degradation: Deforestation is the second biggest cause of soil degradation globally.  From the ground below, the root systems of trees provide structure and nutrition to the soil. When trees are cut down faster than they can be replenished, the loss of root systems throughout the soil both weakens the structure of the soil and leads to a massive reduction in the soil’s nutritional content. This weaker soil is more vulnerable to erosion.
Reduced biodiversity: Forests provide habitat for countless living creatures. In fact, they are some of the richest biological ecosystems on earth. About 80% of the world’s known, land-based species live in forests.  Deforestation threatens this diversity of wildlife, making some species more vulnerable to hunting.
Wood in our wardrobes
The best option available to us as consumers seeking to make responsible decisions about the sources of our wood is to buy products that have been approved by a sustainable forestry certification. The Forest Stewardship Council meets high standards for responsible forest management.  Look out for FSC certification when you are buying any paper-based products including journals and notebooks, thank you cards, and, of course, clothes.
- Man-Made Fibers Continue to Grow
- Man-Made Fibers Continue to Grow
- How rainforest destruction hides in our clothes
- Deforestation: Modern-Day Plague
- How rainforest destruction hides in our clothes
- Underlying Causes of Deforestation and Forest Degradation
- Deforestation for fashion: getting unsustainable fabrics out of the closet
- World Wildlife Federation: Deforestation
- Seeing Forests for the Trees and the Carbon: Mapping the World’s Forests in Three Dimensions
- World Wildlife Federation:Responsible Forestry
- Land Degradation
- World Wildlife Federation: Forest Habitat
- World Wildlife Federation: Forest Certification