The hidden cost of our clothes

Have you ever considered how our choice of clothes impacts the environment? A pair of denim jeans uses around 7,500 liters of water to be produced. That's the equivalent of around 50 bathtubs. Considering the land and water usage for growing the cotton, the energy intensive manufacturing process and synthetic chemicals added to the jeans during production, that's a huge environmental impact. 

The hidden water costs of the clothes we buy is not something that usually comes to mind. Cotton accounts for around 24% of global fibre production and is used to produce fabrics such as denim, jersey and velvet. It is also blended with other fibres such as polyester. The cotton plant is one of the most water intensive crops to grow. To produce 1kg of cotton uses 10,000 litres of water. The majority of cotton is produced by low income farmers in countries like India, Pakistan and Uzbekistan with many regions already under water stress. Low income farmers can't afford efficient irrigation systems and instead often have to exploit unsustainable sources. 

Water consumption isn't the only environmental cost of cotton production. Unfair prices mean farmers are under pressure to maximize yields to survive financially, so they rely heavily on cheap pesticides and fertilizers. Overuse of these chemicals creates runoff, which eventually ends up polluting water sources. 

However, swapping from cotton to synthetic fibres doesn't necessarily solve the problem and may even be worse. Unlike cotton which is biodegradable, they are produced using non-renewable fossil fuels and shed microplastics throughout their life span, taking hundreds of years to degrade. The energy used to produce garments made of synthetic materials is significantly higher. The production of polyester fibres uses around 40% more energy than cotton fibres.

The environmental impact continues, once the raw materials have been produced. Turning these fibres into finished garments requires significant amounts of energy, water and chemicals. Manufacturing of garments contributes 10% of global greenhouse gases. With a majority of factories located in developing countries, the energy used is mostly supplied by fossil fuels. 

The dyeing and finishing process of garment manufacture is inefficient and relies on toxic chemicals that persist in the environment. Not only is water used during the manufacturing process to apply the chemicals, a large amount of fresh water is required to dilute waste chemicals to safe levels before discharge. 

Technologies are being developed to make clothing production more sustainable. One such method is waterless dyeing. Air dyeing and foam dyeing can be used as low water and less energy intensive alternatives. These methods require less chemicals as they are directly applied to the garments. However scaling up these new technologies to meet clothing demand requires a large capital investment for new machinery. 

With clothing production placing such pressure on water, energy and natural resources, the choices we make as consumers can play an important role. So, what can we do to reduce the environmental impact of the clothes we buy?

There are many alternative materials which are more sustainable than conventional cotton and polyester. These include hemp, organic linen and lyocell, which is made from wood pulp based fibres. There is also clothing available made from recycled cotton and recycled polyester, however these are often mixed with virgin materials.

Organic cotton uses less fertilizers and pesticides, although it still requires a lot of water. Organic cotton made up only 2.9% of global cotton production in 2023/24. However this is projected to increase along with fairtrade and sustainable cotton production. There are companies which are centred around sustainable and ethical clothing at affordable prices. Companies such as Yes Friends only use organic cotton and non toxic dyes, while paying their workers fairly.

An even better way to reduce your environmental impact is to buy secondhand clothes or attend a clothes swap event. You can find information about Cambridge Carbon Footprint’s upcoming clothes swap events and useful resources for organising your own on their website. 

A way to extend the life of your clothes is to wash them less often at a lower temperature and lower spin. Turning clothes inside out is a good trick to prevent fading and protect prints. It is better to air dry clothes rather than using a tumble dryer to save energy and prolong the life of the clothes. If clothes do get damaged you might be able to get them repaired. You can find out more about repair cafes on the Cambridge Carbon Footprint’s website here.

Here are some questions to consider when buying new clothes: 

• Do I need it? 
• How long will I wear it? 
• How will I care for it? 
• And what will happen to it when I no longer want it?

Feeding our pets sustainably

Unsurprisingly the biggest impact of our pets on the environment is from the production of meat-based pet food. There are approximately 15.5 million dogs and 13 million cats in the UK, which comprises 78% of the UKs total pet population (Source: UK Pet Food). A study published in the Journal of Cleaner Production entitled “Estimating the environmental impact of dog foods marketed in the UK” found dog food ingredients accounted for 0.9-1.3% of the UKs greenhouse gas emissions. While there hasn't been a comprehensive study looking at the environmental impact of cat food in the UK, this is likely to be higher due to cats being obligate carnivores. With pet food having such a significant environmental footprint, what can we actually do about it without compromising our pets' health?

A study looking at the environmental impact of diets for dogs and cats found that commercially available wet food diets had a significantly greater impact on the environment compared to commercially available dry food diets. There are a number of reasons including: the use of animal by-products from the meat industry, dry food having a lower water content and therefore being lighter to ship, dry food being less likely to spoil, and the composition of dry food typically having more plant based carbohydrates.

Many pet food companies are now incorporating upcycled ingredients that would otherwise go to waste, with some brands such as Planet Pet Society purely using upcycled ingredients for their products. Raising livestock or growing grains and vegetables specifically for the pet food industry uses unnecessary land and water. By using animal by-products from meat intended for human consumption and surplus or wonky grains and vegetables instead, this land can be returned to nature. Look for words and phrases such as “surplus”, “rescued” or “sourced from the human food chain” on the product packaging to identify products utilising upcycled ingredients.

Pet food products using alternative sources of protein are becoming increasingly available. Better Origin based in Cambridge offers sustainably farmed insect based pet food ingredients for companies such as Grub Club, Tuggs and Some Grub. They also offer their own range of pet food products. Farmed insects have a small environmental impact compared to conventional livestock farming. Insects can turn waste products into a highly nutritious and protein rich product, eliminating the need for land used to produce livestock feed. There are also many plant based pet food products available. Plant based ingredients naturally lack nutrition that cats and dogs need so choosing formulated pet foods is important. Companies such as Benevo offer nutritionally complete cat and dog food. 

An additional aspect to consider when choosing sustainable pet food is how well the nutrients are absorbed. Giving your pets low-quality food means it will pass through their system without providing adequate nutrition. As a result, your pet will eat more food to compensate. Higher quality brands focus on providing the correct nutrition, as well as high digestibility so the body can easily utilise the nutrients. Products aimed for pets with food sensitivities and allergies use hydrolyzed proteins. The hydrolyzation process breaks down proteins into tiny components, making them incredibly easy to absorb as well as being very gentle on sensitive stomachs which reduces regurgitation.

Another important consideration when choosing pet food is packaging. In the UK pet food packaging has a low recycling rate, with billions of pet food pouches ending up in landfill every year. This is due to a majority of UK councils not accepting flexible plastics on kerbside collection and being unable to process multi layered plastics. Greater Cambridge Shared Waste is one of the few waste collections that accepts flexible plastics, so larger single layered pet food packaging such as dry food bags can be recycled at kerbside. Packaging consisting of multi layered materials and all pet food pouches, even single layered, are not accepted. These can be dropped off at certain supermarkets and pet stores for specialised processing provided that they are washed and dried. It is also worth considering that larger bags of dry food have less packaging per portion of pet food than trays or pouches. 

Every pet has different dietary requirements and preferences so not all products available will be suitable, however there are likely to be changes we can implement to make our pets’ diets more sustainable. Start by trying out some sustainable alternatives and if your pet likes it, gradually introduce it to your pet's diet. With any pet food, weigh out your pet's meals according to the product's feeding guide. Not overfeeding your pet reduces waste and keeps your pet healthy. Small but well-informed changes in what we buy and how much we feed can reduce the environmental footprint of our pets, without compromising their health.

Can we use water more wisely for gardens?

With climate change making warm weather and drought conditions more likely, sustainable water use is becoming ever more important. Heat warms soils and when it does rain evaporation is increased.

Sustainable water use is about balancing the use of water with the availability of water sources, while reducing the need to take water from the environment. One way of utilising water in a domestic garden would involve collecting rainwater during the wetter months, with one of the simplest ways being to install a water butt to utilise runoff from roofs and sheds, then using the water collected efficiently with the aim of minimising the amount of waste water. 

Using grey water can be used as a sustainable short term water source during extremely dry spells. Because of pollutants such as soaps and detergents in these water sources, long term use can negatively affect plants' health and it should not be used on edibles or potted plants. Bath water typically contains the least pollutants compared to dishwater or washing machine water. Grey water should be used immediately because of colonisation of harmful bacteria from food or skin particles typically found in these sources.

Retaining water within soils can be achieved in a number of ways. Keeping the height of a lawn to approximately 10cm during hot weather reduces ground temperatures and subsequently evaporation. It also reduces plant stress allowing the grass to develop a deeper root system. 

Mulching is another effective way of retaining water within the soil while also reducing water logging during heavy rainfall. Mulching reduces evaporation from the soil while also suppressing water thirsty weeds. The mulching material is less important, as long as a sufficient layer is used, although biodegradable materials also have the added benefit of slowly releasing nutrients to the soil. Mulching should be applied to bare soil when the surface is warm and moist, ideally in the autumn. This locks in water and prevents water thirsty winter weeds from establishing.

For potted plants larger containers are much better at retaining water. For smaller gardens where larger containers may not be viable you can add water absorbent granules to retain water. Plastic free biodegradable granules are just as effective and widely available.

When establishing new plants it is important to follow the water requirements. These are often stated on the labels or can easily be looked up online. Watering plants too frequently, especially during establishment, encourages shallower root systems and will hinder the plants resilience to drought conditions in the future. Not being watered too frequently encourages plants to establish deeper roots and become more self-sufficient.

If watering is necessary, timing is important. Watering during dawn and dusk when the air is cooler will reduce evaporation and allow the water to penetrate the soil. Watering should target the roots of the plant and you should avoid watering dry tolerant plants. 

Landscaping techniques and choice of plants are just as important as efficient water use. Creating hydrozones within the garden involves grouping plants with similar water requirements in different areas. This allows you to target watering to plants that need it and not overwater plants that don't need as much. Creating an arid zone with drought tolerant plants is a great place to start. Strategically planting taller shrubs to cast shade over water thirsty plants in the evening can reduce soil evaporation.

For more information on some local initiatives and creating a water wise garden here are some useful links.

RHS Waterwise Garden: Sustain Your Garden Through Drought and Flood by Tom Massey

Tom Massey - The water wise garden 

https://www.watersencam.co.uk/

Cambridge University Botanic Garden - Dry Garden, Visit our Dry Garden for water-wise planting and drought-tolerant planting inspiration

RHS sustainable water use

Deep time walk resumed

Last weekend (Sunday 31 May) Arthur (my husband) and I resumed the Deep Time Walk we started back in February. The weather was very warm but we were prepared with light clothing and hats so we were reasonably comfortable. We joined the walk where we left off before at ‘Crofters’ on Lammas land with a snack for lunch. 

Celebrating the last universal common ancestor (4.2 billion years ago).

For the Deep Time Walk 1 metre represents 1 million years. 

The idea behind the Deep Time Walk  is a walk through time with each metre representing a million years, so Earth’s history (4.6 billion years) is represented by 4.6 km. We stop at ‘earth stations’ where (when) there were significant events, either geological or biological such as ‘the great dying’ or the first plants. It is more usual to consider history compressed in time. E.g. the history of the universe (13.8 billion years) compressed into a year as in Carl Sagan’s Cosmic Calendar ) Home sapiens appeared only about 300,000 years ago so this is either about 11 minutes or 6.5 cm. Personally I find the 6.5 cm [300000 /4.6e9) * 1000 (to metres) * 100 ( to cm)] more relatable and the walk with other people is fun because you can get other viewpoints on related issues such as climate change, net zero and how we can adapt. It feels more like a community project and less like a personal problem. Amongst other things we talked about the impact of doing things as a community rather than as an individual.

The Boring Billion 

I learned that there is a period in the Earth’s history called the ‘Boring Billion’ which is about 1 billion years when there were no major climate events, tectonic plate movements or extinctions. However the walk was by no means boring. 

Human impacts positive and negative 

One thing we learn from history is that our behaviour can have huge impacts. The invention of agriculture was massively influential – not only enabling population increase but also modifying climate by removing trees. This has had serious consequences – mostly bad, but we now have examples of practical regeneration projects at community scale where water is captured, and land rehabilitated from desert to agriculture as shown in this video. 

Nature can evolve resilience, given time. 

Life is extraordinarily resilient. For example, our use of fossil fuels has polluted the air with CO2 and acidified the oceans which makes life very difficult for sea creatures with shells as the carbonates that make their shells strong dissolve in acid. However, with selective breeding over time, oysters and other shellfish have evolved protection from the acid (see https://www.stir.ac.uk/news/2019/09/farmed-oysters-able-to-protect-themselves-from-acidification/). The big problem with human induced climate change is that it happens far too fast – even when adaptation is possible.  Slowing it down to the point where nature can adapt fast enough would help enormously. (see https://theconversation.com/cop29-how-fast-is-earth-warming-244093).

Deep Time Walk preview

Yesterday, my husband Arthur (who has been doing a heroic job looking after me through the last year while I have been unwell) and I had a private preview of the Deep Time Walk which is scheduled for 1st March, organised and led by Clara Todd from Water Sensitive Cambridge. We did this partly for Clara to test it out and partly because I was not sure if I could keep up with everyone for the whole walk on the day. In fact we only did half of it – starting with the formation of the Earth (Parker’s Piece) and ending with oxygen-breathing life on Earth, albeit single cell (Lammas Land), in total about 2.3 billion years. That was enough for me, I’m afraid. The framework of the Deep Time walk comes from a team at Schumacher College.

I am writing this to recommend it to you. Perhaps you know it all anyway– but doing it with friends and the opportunity to chat and ask questions (Clara is pleased to take questions and if she does not have the answer maybe someone else will) was fun. Besides which, it is a good excuse for a leisurely walk through our beautiful city.

The walk was designed with 1 metre for 1 million years and we paused at interesting times along the way (Earth Stations) so that Clara could explain what was going on. For example we stopped for

1. Formation of the Earth (4567 million years ago)
2. Formation of the Moon (4450 mya)
3. Ocean Earth (4100 mya)
4. Origin of Life on Earth (3800 mya)
5. First Continents (3100 mya)
6. Oxygenic Photosynthesis (2900 mya)
7. The Great Oxygenation/Snowball Earth (2300 mya) 

Clara has some pictures which are obviously artist’s impressions and not photographs. These and her short explanations are very engaging. 

We took some photos on the day. The weather was fairly dry but it has been very wet recently. We avoided the puddles on Parker's Piece. 

Parker's Piece with Gulls - The weather has been very wet though on the day it was mostly dry; the way was muddy in places but the worst was avoidable. Hopefully by March it will be dryer.

View of the Cam from near Hodson's Folly. It was a grey day but mostly dry.

 I am still not well but Arthur lends me a helping hand when needed.

I thoroughly recommend this walk to you so do sign up for 1st March. 

Why I volunteer for ECCG

I went to an event at Empty Common Community Garden recently and met a lady called Isobelle who has been volunteering there for some weeks. She kindly agreed to answer some questions about her experiences - this is what she said. I hope that if you were thinking about volunteering but not sure, then this will convince you.

When did you first come to the gardens?  My first session in the garden was in late August (24th) this year and I've been every Sunday since. I first came across the garden on a walk last winter, but didn't realise it was a community project in which anyone could join in. I went to a community event by Cambridge Zero earlier in the summer and saw a flyer about the garden there, and then saw the Sunday sessions on the events page on the Transition Cambridge website. 

Reducing the mountain of e-waste

The UK produces about 6 million tonnes of e-waste annually, of which households are responsible for about 400,000 tonnes each year. That's not just phones, laptops, and computers - an ever increasing number of products and appliances now incorporate some electronics, and anything with a plug or battery qualifies as e-waste.