It is more apparent than ever that we must all do our bit in the fight against climate change and that means becoming more conscious of the impact of our daily decisions, including what we wear. As people wake up to sustainability in every aspect of our lives we are seeing ever increasing claims of sustainable clothing from brands, but what exactly makes a t-shirt sustainable? We’re going to investigate this issue today.
What Makes a T-shirt Sustainable?
To make a t-shirt sustainable, the manufacturing process must be carbon neutral, any carbon emissions from the cultivation, harvesting, manufacturing and supply chains needs to be offset to achieve a carbon neutral status. The process must not pollute or otherwise cause harm to the environment, and the human impact must also be considered (workers rights and ethical working standards). Quite simply, sustainable means that you could keep on creating that item into infinity without a detrimental impact.
To make a sustainable t-shirt you must first find a sustainable material to make the fabric from, and when it comes to sustainability in fashion hemp could be our saviour! We’re going to take a look at three popular organic fabric options and reveal some things that you may not have considered before.
Is Hemp Fabric Sustainable?
Hemp fabric is the most sustainable type of fabric on the planet! For starters hemp plants are natures greatest carbon sink, meaning that they absorb more CO2 than any other plant. In a single year, one hectare of industrial hemp plants can absorb up to 15 tonnes of CO2, and hemp can even keep absorbing CO2 after it has been harvested and processed into materials such as hempcrete (a natural concrete substance for the building trade). This ability to absorb so much CO2 sets hemp off to a great start to being carbon neutral, it offsets any emissions caused in the process of turning hemp into a fabric.
Hemp plants improve the quality of soil in which they are grown. Topsoil is a delicate thing, upsetting the balance of the topsoil can have devastating effects on ecosystems for years. In order for plants to grow strong and healthy they need to have adequate nutrients. Intensive farming of the land depletes the nutrients in the soil, this is why farmers often have a fallow year during their crop rotations where they do not plant any crops, allowing nutrients to build up in the soil before they plant crops again the following year. Hemp plants have a deep tap root system. For every inch we can see above the ground, there is the same distance of roots below the surface. These roots penetrate deep into the soil, pulling up nutrients that are out of reach of other plants and drawing them up towards the surface. If the farmer leaves around a foot of stalk in the ground after harvesting, then huge amounts of nutrients are returned to the soil, improving the quality for any crops that come afterwards.
Hemp grows organically in almost any environment on the planet. It is a very hardy plant with few pests and diseases to threaten it. No chemicals are required in the cultivation of hemp, so there are no pesticides, herbicides, artificial fertilisers or defoliants to pollute the soil. The fact that no pesticides are used also allows for more insects to live in the soil, which is a key aspect of soil health. Hemp also requires less water than some other plants (around 4x less than cotton), meaning that any nutrients in the soil are not so easily dissolved or washed away as they might be with other crops that require more water. It also requires less land than other crops, requiring only around half the space compared to cotton to produce 1kg of fabric.
The processing of hemp plants into fabric is considered less intensive than that of cotton or bamboo. With cotton production, chemical defoliants are used to separate the cotton from the plants and then several more chemicals are used throughout the cleaning, weaving and spinning processes. Hemp has a much more natural story, the stalks are harvested and left in the fields where the fibres will naturally separate from the stalks in a process known as “retting”. The fibres are then spun into yarns using mechanical processes, rather than chemical ones.
It is quite rare to find a 100% hemp t-shirt, most often you will find blends of 55% Hemp 45% Organic Cotton. This is generally agreed to provide the best balance of durability and sustainability alongside comfort levels that are closest to the pure cotton t-shirts that the majority of us are used to. The other reason for hemp/cotton blends being much more common is that it keeps the costs lower for the customer. Processing technologies for hemp are not so heavily invested in, and therefore it is a more specialist procedure to create pure hemp fabrics, dirving costs up. There is a lot more competition for cotton processing, and therefore prices are lower as the manufacturers all jostle to obtain business for their mills. The good news is that just substituting a portion of the fibres in our clothing for hemp has the potential to make huge environmental gains.
Is Bamboo Fabric Sustainable?
You may have seen a lot of buzz around bamboo fabrics as a sustainable option in recent years, but we have some bad news for you. They’re not as sustainable as some may claim. Yes, bamboo grows very quickly without the use of chemicals, is great at absorbing CO2 from the atmosphere and when harvested the bottom part of the plant can be left in the soil regrowing just as quickly as before, meaning that soil is left undisturbed which is great for soil health. However, most bamboo fabric is made by using intensive chemical processing to turn the cellulose within the bamboo into a fibre suitable for making clothing. The process is known as a “viscose” process and requires highly intensive use of chemicals to make the bamboo into the soft and luxurious fibre that is most commonly used to make underwear, bedsheets and clothing. This heavy use of chemicals in the processing stage of bamboo clothing production means that any sustainability gains from the growing process are negatively offset somewhat by the manufacturing process. Also, as it is only the cellulose component of the plant that is used and only 20% by weight of the fibre, the resulting fabric looses all of the benefits you get from the natural ‘bast’ fibre.
There is a more natural form of bamboo fabric available, usually referred to as “bamboo linen”. This type of fabric is more difficult to make, more expensive and results in a rougher fabric with a coarse texture as opposed to the bamboo viscose fabric which is luxuriously soft, but comes with a higher cost for the environment.
So in conclusion, most bamboo t-shirts are not as sustainable as you may be led to believe. If you’re looking for a truly sustainable t-shirt then hemp is a much more eco-friendly option.
Is Cotton Fabric Sustainable?
Organic cotton fabrics where the cotton plant is grown and processed using no chemicals is more eco-friendly than the non-organic version, but when we compare organic cotton to hemp then we can see some major advantages to simply replacing most of our cotton with hemp.
Cotton (the non-organic kind) is responsible for 25% of ALL agricultural chemicals used worldwide. Think about that for a second, there are hundreds of different crops being planted and harvested every day for all kinds of uses from food to fabric and industrial purposes, and then understand that cotton is responsible for a quarter of all of the chemicals being used on our planet. That tells you just how much of an impact cotton production has on our ecosystems. An easy way to understand just how much chemical input there is in your cotton garment – if your garment weighs 500grams, then it has had at least 500grams of chemicals used during its journey to you.
Chemical fertilisers, pesticides, herbicides and defoliants all work their way into the soil, waterways and downstream into the oceans, polluting everything that they pass. That is just from the cultivation process, there are yet more chemicals used in the processing of the cotton into yarns and the bleaching of the fabrics. These chemicals not only have an environmental impact, but also an impact on human health. Workers in cotton production are exposed to chemicals that have serious adverse effects on their health, and can even lead to death in some cases.
Cotton production requires huge amounts of water, and organic cotton production requires even greater amounts. This water contributes to soil erosion, and can deplete nutrients in the soil by diluting and washing them away. Over time, this can lead to severely decreased soil health in cotton fields.
The carbon footprint of cotton is high, estimated at 2-4 tonnes per hectare per year, with global estimates of 220 million tonnes of CO2 produced by the cotton industry every year. Compare this to hemp, where every hectare absorbs up to 15 tonnes of CO2 and you can see why hemp is the much more sustainable choice.
Why Choose a Hemp T-shirt?
The best way to cut down on carbon emissions is to not produce any new items, but rather keep using the ones we already have. To reduce the impact of each new t-shirt, we need to keep using them for longer. The good news is that hemp is highly durable, your hemp and cotton blend t-shirt is likely to last at least 3x longer than a pure cotton alternative thanks to the incredible strength and durability of the hemp plant.
Investing in a good quality hemp t-shirt is a great idea for the planet, as well as your health. Hemp fabric is antibacterial, antifungal and antimicrobial so it’s great for keeping you fresh while contributing to improved skin health overall. The fabric is thermodynamic, meaning it’s good at keeping you cool when it’s hot, and warm when it’s not. It’s naturally moisture-wicking, meaning it is efficient at removing sweat from the surface of the skin so that you can stay dry and comfortable.
With all of these benefits along with the increased durability and the environmental benefits, it’s clear to see that buying one good quality hemp t-shirt that you can potentially keep wearing for decades (with the right care) is much better than buying new cotton or bamboo t-shirts every couple of years.