Cottoning Onto Pollution

It’s no secret that the global textile industry is one of the most polluting out there. Some reports indicate that it contributes more to climate change than aviation and international shipping combined, and it’s a growing problem. 

Global fibre production has more than doubled in the last 20 years and looks set to continue unless there are big shifts in the current model of production and consumption. Fortunately, it’s not an entirely bleak picture, and there are great examples of good practice that seek to mitigate the negative impacts of the industry and offer positive solutions. This article focuses on the story of cotton and its global water impact, from the negative consequences of its production and processing, to the realistic hope for a better alternative.

It is important to recognise that whilst this article focuses on one impact of textile production in relation to water, to understand the long-term sustainable solutions for the future, we inevitably need to take in the bigger picture. We need solutions that address several challenges all at once – from water, to pollution, to biodiversity, to soil health, to tackling social inequality and workers’ rights, not to mention the most fundamental problem of all – our massive overconsumption of clothing. This is important if we’re to find lasting solutions, rather than just shifting problems elsewhere.

The growing problem

Cotton is the most widely used natural fibre in the world and accounts for about 24% of all fibres produced worldwide (the biggest overall share is polyester which accounts for over 50% of all fibres). The production of textiles uses around 93 billion cubic metres of water a year, making up 4% of global freshwater withdrawal. Cotton production represents by far the biggest part – 69% – of this overall water footprint, with one kilogram of cotton taking as much as 10,000-20,000 litres of water to produce, depending on where in the world it is grown.

The World Economic Forum has identified water scarcity as one of the top ten global risks to society over the next ten years. If we continue our current trajectory, it is likely that two-thirds of the world’s population will face water shortages by 2025. Extreme weather events, such as heatwaves, droughts, and flash flooding as a result of our rapidly changing climate are also having a major effect on farming activities and livelihoods across the globe.

“if we continue our current trajectory, it is likely that two-thirds of the world’s population will face water shortages by 2025”

Despite this, most cotton is grown in countries that are already facing severe water stress. Cotton is often grown in arid areas that require irrigation with water from surface or groundwater sources (blue water), rather than relying on rainwater alone (green water). Irrigation diverts water away from rivers, lakes and aquifers, often with devastating impacts on local ecosystems and communities. The drying up of the Aral Sea is a well-documented example of the risks and unintended consequences of diverting water away from rivers to irrigate cotton.

Demand for irrigated water is only likely to increase as temperatures rise and weather patterns become increasingly unpredictable. It will bring increased competition between agriculture, domestic and industrial users. As water becomes scarcer, irrigation will become more expensive, as more energy will be required to pump water to where it is required.

It’s not just a matter of how much water is needed to grow conventional cotton, but also how much is needed to water down the pollutants involved in its production. The majority of the water footprint of cotton comes from farming, not only in growing the crops, but also diluting the large amounts of pesticides and fertilisers which are washed into waterways. Cotton uses a disproportionate amount of pesticides. It is grown on just 2.5% of agricultural land worldwide, but accounts for 16% of all insecticides sold globally. Many of these chemicals are highly hazardous and can pollute groundwater, lakes and rivers – directly impacting communities and the environment.

The problem of processing

The water impacts of the textile industry don’t stop at the field, they come from the factories, too. Processing of cotton into fabrics, garments and home furnishings requires considerable quantities of water – as much as 200 tonnes of water for every tonne of textiles produced.

In addition to dyeing, cotton must go through several water-intensive processes before the finished fabric can be used to make final products. Each stage of this process can also involve the use of dyes and highly toxic chemicals that are used to remove dirt and grease from the cotton fibres; bleach fibres to a uniform colour before dyeing; improve absorption of dyes; improve the final texture of the fabric; and provide desirable qualities in the fabric such as crease and stain resistance. Such chemicals and dyes often end up in high concentrations in wastewater. Pesticides used in the production of conventional cotton also find their way into waterways at the processing stage as residues are washed from the raw fibre.

“cotton uses a disproportionate amount of pesticides. It is grown on just 2.5% of agricultural land worldwide, but accounts for 16% of all insecticides sold globally”

It is estimated that 20% of global industrial water pollution is attributable to the dyeing and treatment of textiles, including cotton. Whilst efforts are often made to treat this effluent, standards and regulations are often difficult to enforce and vary from country to country. Many persistent and highly toxic chemicals cannot be removed even by the most effective available forms of water treatment. Added to this, most of the world’s textile wet processing operations are based in developing nations, such as Bangladesh and India, which lack the infrastructure and resources to tackle the effluent pollution produced by factories.

This results in the pollution of ground and surface water, which is relied on for drinking water and food production in the communities living near factories. The impacts can be far reaching, as rivers and streams can carry pollution thousands of miles to the ocean.

In Bangladesh, which has a large concentration of textile mills around the city of Dhaka, sustained extraction of water for textile processing is causing the long-term decline in groundwater levels. This groundwater depletion has had wide ranging environmental, social and economic effects, including drying of wetlands and the loss of wetland plant and wildlife species; decreased access to drinking water for local communities; decreased access to water for food production; and higher pumping costs to communities and businesses.

A better alternative

Despite the seemingly intractable problem of our thirst for fashion and the problems this creates, there are existing alternatives which deliver far reaching benefits in relation to water, as well as climate, nature and health. Leading the field is organic cotton, which offers a compelling and scalable answer to the daunting challenges posed by the majority of cotton production.

Organic cotton is grown using a holistic systems-based approach. This means working with natural processes, rather than against them. Most conventional cotton tends to be grown as a ‘monoculture’, relying on synthetic inputs to maintain soil fertility and to manage pests. As synthetic fertilisers do not help to maintain or improve soil structure, conventionally managed soils are more prone to soil erosion.

Instead of using synthetic fertilisers to stimulate plant growth, organic farmers use organic matter, such as farmyard manure and compost, to enrich and build their soils. This means organically farmed soils are generally much higher in soil organic matter (SOM). Soils higher in SOM are better at holding water than soils that are managed with artificial chemical inputs. Healthy soil can store as much as 3,750 tonnes of water per hectare, the equivalent of one and a half Olympic swimming pools. In fact, studies have shown that organically farmed crops often yield better than conventional crops in times of drought, something that will become increasingly important in our changing climate.

In addition, organically farmed soils are more biologically diverse and active, which also plays an important role in a soil’s capacity to store water. Mycorrhizal fungi in rich soils improve ‘plant water relations’, allowing plants to access more water from the soil, and use water more efficiently, increasing the drought resistance of host plants. These fungi are often less prevalent in conventionally farmed soils because pesticides, fungicides and herbicides used on conventionally grown cotton destroy these beneficial networks. 

Organic farmers use soil management techniques such as crop rotation, green manures and cover crops to naturally boost the soil. Cover crops not only improve soil fertility, but they can also reduce soil erosion, as their roots hold soils in place. They can also mitigate the effects of drought in the long-term by preventing evaporation of moisture and improving soil structure, which increases their ability to absorb more water.

Eighty percent of land producing organic cotton is in areas which are predominantly rainfed, reducing the need for blue water. In addition, many organic farmers employ a wide range of techniques to conserve water, including rainwater harvesting, selecting drought resistant seed varieties, and good soil management. A comparison between a Life Cycle Analysis (LCA) for conventional cotton and an LCA for organic indicated that organic cotton requires up to 91% less water to produce from farm to bale.

Organic has something to offer when it comes to textile processing, too. Factories certified to the Global Organic Textile Standard (GOTS) must meet strict environmental criteria at every stage of processing. This includes only using low impact chemicals, ensuring wastewater is properly treated prior to release, and ensuring energy and water use is strictly monitored. The most well-known inputs associated with textile production, like toxic heavy metals, formaldehyde, aromatic solvents and azo dyes are banned. Even in very small quantities (<1ppm) azo dyes in water have been found to alter the physical and chemical properties of soil, killing beneficial microorganisms and affecting agricultural productivity. They are also toxic to aquatic flora and fauna and can break down to form cancer-causing compounds in humans.

Supporting a better future

In the face of the twin and interconnected threats from climate breakdown and biodiversity collapse, we need a full suite of urgent solutions to address the damage being caused by the global textile industry.

In order to achieve long-term meaningful change, the textile industry needs to work together to support farmers to produce cotton more sustainably. It’s clear that organic offers long-lasting, regenerative benefits to people and the planet, both in terms of what it promotes and what it prohibits, but as well as organic, there are other schemes out there that are seeking to make improvements to practice.

Brands and retailers can also demonstrate their commitment to sustainable sourcing by signing up to the Sustainable Cotton Challenge, which requires 100% of cotton to be sourced sustainably by 2025. Several cotton certification schemes are recognised within the Challenge, these include organic as well as BCI, Cotton Made in Africa and REEL, which all represent steps on the road to more sustainable cotton production.

The bigger picture

What makes organic really stand out is that it takes a systems-based approach, which leads to a range of benefits across the board. These include boosting biodiversity, providing a safer and more secure food supply for farmers and a more effective way to sequester carbon in the soil. It’s this kind of systems thinking that is needed to underpin meaningful long-term action to address the challenges we face across the global textile industry.

There are countless examples of where a single-issue approach has caused problems elsewhere. When brands and retailers have switched from conventional cotton to polyester to reduce their water footprint, this has contributed to a new set of problems, from micro-plastic pollution to an increase in greenhouse gas emissions, as polyester is derived from fossil fuels.

Fundamentally, we need to change the way we consume textiles. Not only do we need to be consuming less overall, we also need to move away from the current linear model of take-make-use-dispose towards a more circular approach that sees garments recycled, reused or repurposed and kept out of the waste stream.

It’s not an either/or approach, we need to be doing all these things, focussing on changes that are available now, like organic, in the first instance, otherwise there is a risk that solutions will always stay beyond the horizon and we’ll only realise that there are things we could have been doing when it’s too late.

Look for the logo

For brands and retailers looking to have a positive impact – they should source organic cotton certified to GOTS. Citizens and consumers can show their support by looking for the GOTS logo on textile products. Sourcing organic is one important step that we can make to support a better future for ourselves and our planet.

Case Study: Dirty denim in Mexico 

Mexico is one of the largest producers of denim in the world.
A 2012 investigation by Greenpeace collected wastewater samples from two major denim manufacturers to provide a snapshot of the type of hazardous chemicals being discharged into Mexico’s waterways. 

Chemicals found included: 

• Nonylphenol – a persistent pollutant with hormone disrupting properties 
• TMDD – a persistent pollutant which reduces the surface tension of water and is toxic to aquatic life with long-lasting effects 
• Anilines – readily soluble in water and toxic to aquatic organisms. Some are carcinogenic to humans and animals 
• Phthalates – widely pervasive in the environment and often found in human tissues. Some are known to cause problems with human reproduction. 

Greenpeace has been working since 2011 to detox the fashion industry, securing commitments from suppliers, retailers and international brands to eliminate hazardous chemicals from their supply chains. In response to this campaign a number of major fashion brands, value chain affiliates and associations set up the Zero Discharge of Hazardous Waste (ZDHC) Foundation, which oversees the implementation of the ZDHC Roadmap to Zero Programme. This programme helps businesses reduce and eliminate hazardous chemicals from their value chains and operate safer chemical management practices. 

Information taken from ‘Toxic Threads: Under Wraps. Exposing the textile industry’s role in polluting Mexico’s rivers’ published by Greenpeace in 2012