Nica Richards7 April 2024 | 9:30

Hemp is not a climate change cure – but conscientious consumer choices could be

The natural fibre is often punted as a natural solution to climate change. But research comparing it to other textiles has proven that much more than hemp is needed to reverse the effects of climate change.

Hemp is not a climate change cure – but conscientious consumer choices could be

A large hemp plantation. Picture: © Bastiaanimage Stock/stock.adobe.com

JOHANNESBURG - While the world scrambles to find ways to reach zero carbon emissions by 2050, a number of industries have a unique opportunity to diversify their current product offerings.

One such sector is textiles, which according to a study published last year accounts for up to 8% of the planet’s carbon emissions – more than all international flights and maritime shipping combined.

The fashion industry is costing the planet dearly and shows no signs of slowing down, with the World Bank estimating that greenhouse gas emissions could surge by more than 50% in the next six years.

Fast fashion exacerbates this, with even discarded clothes releasing carbon emissions as they decompose. This decomposition could take decades, or even centuries, depending on the materials. In the United States alone, the American Textile Recycling Service estimates that around 17 million tonnes are discarded annually.  

Another significant concern is the pollution of clean water sources and releasing microplastics into the environment. This year, European Parliament estimated that textile production alone accounted for roughly 20% of global clean water pollution and that up to 35% of microplastics released into the environment could be traced back to textiles.

And with a very small percentage of clothes actually being recycled, owed to apathy and a lack of technology, consumers are either caught in a whirlpool of guilt or are unaware of just how much a simple t-shirt contributes to the Earth's global warming woes.

The signs are obvious: things need to change. But change within an industry so powerful would not only disrupt economies but would leave already vulnerable workers out in the blistering heat.

Over the past few years, there have been suggestions that one textile could provide some relief to the toxic cycle this industry has spun itself into – hemp.

However, the heavy burden of putting faith in an alternative, instead of analysing consumer behaviour and greening industrial processes, could set a dangerous precedent for generations fighting to keep the Earth alive, and their existence sustainable.

THE SILVER BULLET?

Earlier this year, campaign group Changing Markets told AFP in a progressive feature that reusing cotton, a main textile in the production of clothes, is not a feasible answer.

The group's campaign manager, Urska Trunk, told the publication this was because the end product of recycled cotton compromised the quality significantly, resulting in it having to be woven with other materials, resulting in mixing fabrics, which makes clothes even harder to recycle.  

Some have begun to turn to hemp as an alternative to cotton, citing its resilience as a plant, fast growth rates, and lesser dependence on pesticides.

The European Parliament estimated in March that it takes 2,700 litres of fresh water to make one cotton shirt - enough for one person's drinking water requirements for two-and-a-half years.

International Cotton Advisory Committee (ICAC) chief scientist Keshav Kranthi provided Eyewitness News with a different figure, estimating that roughly 2,000 litres of irrigation water is required to make one kilogram of cotton fibres.

However, delving into the data of how water-intensive cotton actually is has yielded contrasting data sets.

In 2015, the University of Twente in the Netherlands estimated that 36% of the world's clothes come from cotton lint. In their study on industrial hemp's water footprint, they said crude studies from previous years showed that on average, industrial hemp required three times less water than cotton textiles.

Ten years prior, the Stockholm Environment Institute cited in their analysis of the ecological footprint of cotton, hemp, and polyester, that between 9,788 litres and 9,958 litres of water are required for one kilogramme of cotton lint.

This paints cotton in a negative light, making it a scapegoat for textile pollution.

An organisation called the Transformers Foundation released a report in 2021, in association with the ICAC, to debunk some lingering myths about cotton, including widely cited data only recently retracted that 20,000 litres of water are needed to produce one kilogramme of cotton.

Although it is difficult to pinpoint the exact amount of water needed to produce cotton, owed to different farming regions, and the use of irrigated water versus rainwater, Kranthi's estimate is calculated using global averages.

SUCKING OUT THE BAD

Problematic greenhouse gases (GHGs), namely carbon dioxide (CO2), trap heat and regulating the earth’s temperatures. But GHGs absorb roughly 90% of the infrared light earth received, and reflects it back to our planet, which causes global warming.

The higher the GHG levels in our atmosphere, the higher earth’s temperatures will soar to.

Plants can capture carbon through photosynthesis, a process agricultural processes can disrupt. Lush landscapes such as forests suck in CO2, but there are also arguments that hemp is more sustainable than cotton because it is able to sequester more CO2 – a statistic far from being proven at this stage.

Carbon sequestration rates of hemp are also hard to quantify, with reliable data sets requiring monitoring for at least 100 years, according to Textile Exchange.

This is where the age of the cotton industry is significant – data has been gathered on various processes involving this plant for decades.

Kranthti’s data found that in total, cotton, including stalks and lint, sequesters 6.47 tonnes of CO2 per hectare.

Although hemp fibre was first used in China 5,000 years ago, the United States Department of Agriculture Foreign Agricultural Service cited in a 2019 report that the modern hemp industry only dates back nine years.

China is currently the world's largest hemp fibre producer, supplying nearly half the world with a variety of versions of plant components.

The stem of this rapidly growing plant contains 0.445 tonnes of carbon absorbed from the atmosphere, with one tonne of hemp representing a carbon dioxide (CO2) sequestration rate of 1.6 tonnes, according to The European Industrial Hemp Association.

According to GoodEarth Resources in Australia, one hectare of industrial hemp can absorb 22 tonnes of CO2. And being a rapidly growing plant, with rates suggesting up to four metres in 100 days, this carbon sequestration rate appears promising.

Western Cape-based Bien Donné cannabis research centre director Natie Ferreira told Eyewitness News that eight tonnes per hectare on average was at present the most accurate estimate the industry currently had.

But the statistics are complex when it comes to carbon sequestration, with much research still needed to calculate how much carbon is left in the field after harvesting, and how much each part of the plant sequesters.

“Hemp is not the type of fibre to compete with cotton. Cotton comes off the plant as cotton. Hemp needs industrial process, which I cannot see as being less invasive,” Ferreira explained.

If this is the case, why is hemp often punted as being a potential alternative to cotton?

For Ferreira, this misses the point: “Polyester is the enemy. Whether organic cotton or hemp, if it is sustainably and responsibly produced, it must still play a role. The natural fibre sector needs to be developed. Other sources of fibre are being ignored.”

T-SHIRT MATERIAL COMPARISONS

Before an item of clothing reaches your cupboard, raw material is extracted, it undergoes industrial manufacturing and is transported to its destination. After your purchase, your garment is washed numerous times before it is discarded.

Each step in this process accounts for a significant amount of GHG, and pollution.

Consumers are able to make more informed decisions when they know how the materials they choose to wear impact the planet.

At face value, it appears that natural fibres rank high when calculating CO2 equivalent emissions. However, the rate at which the fibres of materials decompose is an integral factor to consider when checking the label of your next fashion purchase.

Materials with little to no biodegradability abilities pose greater risks for the planet, as do the processes required to create them. This is in part what makes fast fashion a debilitating thorn in the side of the fashion industry.

If fashion has taught us anything, it is that trends resurface, but the fast fashion phenomenon, courtesy of the 1990s, flies in the face of this lesson.

And Earth is paying the price.

Long-term solutions must include renewable energy alternatives to manufacturing processes. Sustainable transportation methods would also not go amiss. And embracing a more earth-conscious natural fibre sector the world over, as suggested by Ferreira, would be a significant step towards lessening the textile industry's carbon footprint. It is clear there is no one textile that could help turn Earth's soaring temperatures around.

But the most powerful catalyst for unsustainable fashion choices remains consumption, which is something consumers can control.

So, how can fashion fans make a difference?

SOLUTIONS

In a study published in 2021, researchers analysed what factors would best inform consumer decisions. The conclusions drawn are both practical and cost-effective.

  1. Wash your clothes at lower temperatures. This uses significantly less energy.
  2. Air dry your clothes. Ditch the tumble dryer for the great outdoors. Tumble dryers consumer on average five times more electricity than washing machines, and cotton fabrics take a long time to dry.
  3. Do not use detergents in tablet form. Out of liquid, powder, capsules and tablets, the production of these generated the highest greenhouse gas emissions. If possible, opt for biobased detergents. These are cleaning goods that use natural, renewable components sourced from renewable sources, such as plants.
  4. Thrift, re-use and sell. Give your clothes to organisations or second-hand stores that could pass it on to someone else, to prolong their lifespan.
  5. Most importantly, consume less. Temptation is everywhere, but so are the markers of climate change.

Eyewitness News reached out to the Department of Agriculture, Land Reform and Rural Development for comment, but no responses were received by the time of publication.