Fundamentals of Sustainable Fashion

Fashion contributes to 7% of climate change

more than international flights and ocean shipping combined

The 1.3 trillion dollar clothing industry accounts for 6.7% of global carbon emissions. In additional to its contribution to climate change, the fashion industry also produces approximately 40 million tons of textile waste annually.

When thinking about climate action, many people think about flights, but few people think of clothing. The fashion industry makes up more carbon emissions than international flights and shipping combined. Aviation makes up about 1.9% of carbon emissions and shipping 1.7% of carbon emissions.

Where do all these greenhouse gases come from?

Main contributors of climate change

The primary raw material in clothing is oil

Most of our clothing is made from plastic-based fibers and derived from oil. While plastic-based fibers do not use agricultural land of water to produce, they stem from a non-renewable resource, and are extremely energy intensive.

This includes polyster, nylon, acrylic, and elastane. Polyester makes up a majority of clothing, at 50-55% of total raw materials. The spread of polyester has accelerated through fast fashion since it is cheaper than other fabrics.

Nylon emits nitrous oxide, a potent greenhouse gas. Elastane (also known as spandex) is extremely stretchy but prevents fabric from being recycled when it makes up over 3% of a garment.

Plant-based fibers include those dervied from cotton and wood.

Traditional plant-based fibers can be water and chemical intensive. Cotton requires a large amount of pesticides and fertilizers to grow. Viscose, a wood-based fiber, releases highly toxic chemicals.

The most sustainable fabrics include flax, hemp, and jute which require very little water and fertilizer. They are also grown on land unsuitable for food production.

Lastly, animal-based fibers make up less than 2% of the overall industry including wool, silk, and leather.

Manufacturing is an energy-intensive and chemical-intensive process

Manufacturing covers the processing of raw inputs (polyester, cotton) into finished products.

Yarn preparation and fabric preparation both represent about 6% and 8% of carbon emissions, respectively.

Dyeing is the most carbon-intensive step (15% of overall emissions), requiring energy to heat large amounts of water.

Assembly, which entails cutting the fabric, sewing together pieces, and adding trims (zippers, buttons, etc.) is another 4% of carbon emissions.

The main countries of production including India, China, and Bangladesh utilize coal and natural gas as energy sources.

How we use garments matters

Historically, fashion companies released two collections a year, Spring-Summer (SS) and Fall-Winter (FW). Fast fashion has accelerated this trend when Zara started introducing 24 collections per year and H&M offered 12-16 collections per year, with weekly refreshes.

Garment prices have fallen in the US, even while prices of other goods increased. This led to consumers treating clothing as disposable and keeping them for half as long.

Washing and drying 1kg of clothing over its life also requires 11kgs of greenhouse gases. Consumers who choose to wash clothes in cold water can reduce their impact.

Lastly, current technologies are not able to turn waste products into new goods. It is estimated for every 5 garments produced, 3 end up landfilled or incinerated each year.

In conclusion, to be more sustainable we should:

  • Choose organic or recycled materials which have lower carbon emissions impact
  • Look for renewable energy, low-chemical, or low-dyeing processes
  • Select high-quality garments that will last longer, so we can consume less