How can we use Artificial Intelligence more mindfully and sustainably?

Artificial intelligence has become embedded into the fabric of our everyday lives, transforming how we communicate, work, and find out information. Instead of existing only in high-tech labs, AI now powers the everyday tools we rely on. Simply searching a question on Google automatically comes up with an AI overview.

The environmental impact of artificial intelligence is defined by two heavily energy-intensive phases: initial development and mass everyday usage. First, training AI systems demands massive amounts of electricity, as thousands of high-powered computers run continuously for weeks or months just to teach a model how to perceive and reason. Once a model is built, it shifts to the operational phase, where it processes daily user requests; while running a single prompt uses very little energy per person, this operational footprint multiplies substantially when scaled across the billions of people now relying on AI every single day. 

Do we need to use AI for every task?

If everyone considers if they actually need to use AI to complete simple everyday tasks we can collectively reduce our energy use. In fact, finding out or generating information ourselves makes us more likely to remember the information by generating stronger cognitive pathways.

It is worth considering that more complex and time consuming tasks can actually use less energy when performed by AI compared to humans. Image generation and searching through large amounts of information are two tasks where AI is more energy efficient. A 2024 study looking into whether the carbon emissions of writing and illustrating are lower for AI than for humans found AI image creation had a significantly lower carbon footprint. The AI system DALL-E2 emits approximately 2500 times less CO2e creating an image than a US-based artist, and AI system Midjourney emits approximately 2900 times less CO2e creating an image than a US artist. This was also the case with writing a page of text. 

Energy efficient prompts 

AI’s operational environmental footprint is not only determined by how much we use AI, but also how we use it. There are a number of simple steps we can take to reduce the environmental impact including designing prompts more wisely.

One easy step is to use concise and unambiguous language when generating prompts. For example, instead of asking an AI model to analyse a research paper, you could ask it to summarise the research paper in three short sentences focusing on the key findings. Avoid using vague words or phrases such as ‘analyse’ or ‘make better’ and don't include abbreviations. When designing prompts, adding sentences to describe what not to do can also be helpful, along with describing the format of the output.

If you don't require a long answer, you could tell it a word limit. If you need more information you can always ask it a follow up question. In the case of image and video generation specify a lower resolution or frame per minute if you don't require high resolution.

In AI a Token is a single unit of data, this could be four characters of a word or a part of an image. Both input and output of an AI model uses tokens. The higher resolution of an image or the longer a piece of text, the more tokens are used. It is also worth noting more obscure words also use more tokens. Token length is a key driver of AI energy consumption, so designing prompts in a way that creates short and concise answers reduces energy intensive data centre use.

Choosing the right language model

You might ask yourself why you are using a particular AI tool. Choosing an AI model which is tailored to your specific needs reduces its environmental impact. Small Language Models such as Google Gemma and Microsoft Phi run on fewer parameters and are carried out locally on your device, whereas using more complex and general Large Language Models such as OpenAI GPT-4 or Google Gemini Pro require a larger number of parameters, heavy external cloud servers and GPU clusters, increasing energy consumption.

While each prompt and message asked may have a negligible impact, multiplied by the billions prompts and messages carried out each day these add up. By being mindful of our use of AI and implementing these small changes, we can have a substantial impact in reducing our carbon footprint.

If you are interested in finding out more information please see United Nations University - Institute for Water, Environment and Health, Environmental cost of AI's energy use, Carbon, Water and Land Footprints

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.

Working with Contractors - update

Depending on what you want to do, retrofitting your house could involve for example changing your heating system or installing solar power. This can be simple or quite complicated, possibly including hiring several contractors, and maybe a project manager too. You may be taking a ‘big bang’ approach or doing it in phases. Selecting competent, reliable contractors that you can trust and maintain a good relationship with is very important. This page is not a step-by-step approach to your retrofit but general advice about how to choose and work with contractors. Much of the advice on this page came from pooled experiences from the Energy Group members and friends.

Improvements in energy efficiency in buildings since 2000

This post is largely based on the article Advances Toward a Net-Zero Global Building Sector in Annual Review of Environment and Resources 2020 [1]. The article is open access so anyone can read it for free. It explores why energy efficiency is important for net zero emissions and charts improvements since 2000 in different regions of the world. It briefly compares the Passivhaus standard with other standards widely used for low energy buildings. The focus is on the UK although much of the evidence comes from elsewhere, primarily Europe.

The Environmental Cost of AI

With the UK Government's recent announcement about investing heavily in AI, it's appropriate to ask: what is the environmental footprint of all the computing infrastructure that this AI requires?

The answer is simple: it's massive. While there are huge uncertainties, some of the projections have the AI boom causing data centres to generate more carbon emissions than Africa and South America combined. 

The recently announced plans for AI expansion lead to huge increases in resource requirements, and on relatively short timescales. The power needed by AI might exceed that used in all the world's current data centres within 3 years.

That's going to need a lot more electricity, which is likely to increase carbon emissions in the short term, before renewable generation ramps up – and that’s not to mention the carbon footprint of putting up such massive buildings to house the servers and manufacturing the servers that go into them. 

For the longer term, some of the tech giants are starting to look at small modular reactors (SMR, i.e. small nuclear reactors) to power their data centres. Microsoft is trying to bring one of the reactors at Three Mile Island back online. Even if you can generate the electricity, generally there isn't enough grid capacity to get it to the right place, which is one reason why there's such interest in putting the generator, such as an SMR, right next to a data centre.

It's not just drawing electrical power that's a problem. Gargantuan amounts of water, already a scarce resource, are needed for cooling, as all this electricity gets converted into heat.

All this environmental damage leaves open another question: will the benefits from AI outweigh the environmental damage it causes?

For a good overview of the issues about AI and sustainability, this report from the Green Web Foundation is a good read, and this article from UNEP closes with five recommendations to “rein in the environmental fallout of AI”. A great book on the topic is the “Atlas of AI: Power, Politics, and the Planetary Costs of Artificial Intelligence” by Kate Crawford.

To find out how to turn off AI in your search engine or on your device, just search the phrase “how to turn off AI on…” and instructions often come up.

Blog post by Peter Tribble. Peter also has a personal website: https://ptribble.blogspot.com/

Improving your web experience - and saving carbon emissions

We spend a lot of our time browsing the web, but have we thought of the carbon emissions involved in getting a web page to be shown on our screen?

There's a long chain involved. The web page has to be stored on a server, potentially processed for consumption, sent out across the network, being passed through multiple devices on its path to you, before finally being processed by your own device so as to look just right for you to read it.

Fortunately, much of the work involved in calculating the environmental impact of the web has been done for you. Sites such as Website Carbon and Ecograder can estimate the carbon emissions due to viewing a web page. This takes a range of factors into account, from storage and processing of the page, transmitting it across the network, but also whether the server is powered by electricity from renewables or fossil fuels.

Review of 2024

How was 2024 for you? Do you even remember? Reviewing our achievements helps to give us a boost for the year to come. So here is a boost for all our members, and an enticement for anyone considering joining in, of how much fun we have..

This is mostly based on the report for the AGM in October, including some highlights that appeal to me. You can look at the slides in full here.

Repair Café (partners with Cambridge Carbon Footprint).

The Repair Café project, which is a partnership with Cambridge Carbon Footprint (CCF), now has more than 40 groups in Cambridgeshire so there are several repair cafes a month depending on how far you are prepared to travel (see events coming up). This year on International Repair Day (19th October) there was one in partnership with the Grand Arcade and there were also ones in Cottenham and in Haddenham on the same day. Of the three we had the highest rate of successful repairs, though admittedly not by much. The picture below was taken before the end. Our final figures were 40 items and 73% repaired.

Picture credit to Sandy and CCF

These events would not happen without the repairer volunteers and this year we are especially grateful to the team from Sentec who have proved keen supporters. Also during the year we signed the Repair and Reuse Declaration calling for more support for the circular economy including making repair more affordable, expanding regulations to cover more consumer goods and setting repairability standards.

Empty Common Community Garden and the Resilience Garden

Empty Common Community Garden continues to thrive, and the hut is ever more popular as a venue – sometimes for cover for a rainy day – sometimes for a party.

This year we launched the Permaculture Trail on the website, linking a virtual tour of the garden with permaculture principles. 

Charlotte who runs the ECCG is also in charge of the Garden of Resilience by the Guildhall - another demonstration of permaculture.

Water usage survey

What do you do to save water? In recent years we have seen our chalk streams suffering due to lack of water because we take too much for our taps. Also, we use a lot of water for hygiene, perhaps more than we need. This year we ran a survey, asking some quite intimate questions. Read the results here.

Water Sensitive Cambridge

Also on a water theme, we were partners with Water Sensitive Cambridge, which was seeded by Transition Cambridge and is now a CIC. Their aims are to make places for water and nature, and change how we think about and treat water. They made their first on-street rain garden this spring in East Chesterton and it proved itself in a downpour soon after, with reduced flooding that dissipated quickly - as we reported on this blog.

Reduced flooding and rapid dissipation of the rainwater after a storm

See more pictures and videos on their website.

Films

We showed four films this year at Storey's Field Community Centre, all on an environmental theme and well attended. Each film was followed by a discussion with the audience and in most cases with input from members of the team that made the film. In February we showed Pure Clean Water which is about Hobson's Brook and how our overuse of the chalk aquifer has affected it - and what can be done. This showing was the inspiration for the water use survey. In the Autumn we ran a season of three films: Six Inches of Soil, Once you know, and Fugolburna. We'd like to do more so let us know if you have ideas for films to show.

Other groups and partnerships

Other projects continue to thrive such as:

• Energy Group – this year’s topics included DIY energy saving, air quality and inter-seasonal storage
• A Toys Life and Beyond - swapping childrens’ toys and learning about the circular economy while supporting young families.
• The Environmental Discussion and Reading Group 

Also we are delighted when groups we have spawned continue to grow. The Resilience Web is now a CIC and has directories for eight distinct nexuses of community groups including Cambridge (3 webs), Bath, York, Durham, Norwich and South West London. The new "A Penny Saved" web highlights groups in Cambridge that help save money alongside their environmental or social justice aims.

We hope some of these things will inspire you to take action on climate change. Perhaps you will get involved in one or more of our groups, or perhaps you will browse our website for advice such as the Permaculture Trail or the Energy Group Advice pages. The important thing is to take some action. We are making progress on climate change but not fast enough.

How to use the Christmas break?

Many of us get a week or so off over Christmas (whether we celebrate Christmas or not). For two days there are no shops open, though there is always online shopping and social media to keep us amused. But don’t you think the winter break should be special?

Special means different. Different can mean different things but it needs to involve a change of pace and a change of focus. I like to take a walk and see what I can see, or meet up with friends and have a natter with no distracting mobiles. The important thing is to slow down and look outside of yourself – at people you (think you) know well, or complete strangers, or just the world. The main thing is to look and to listen.

 

I am no photographer but here are some pictures I have taken on my walks around Cambridge at Christmas time.

 

This picture was taken on Christmas Day last year. The saddle cover must be 9 years old because the pantomime is dated 2014.

 

Frosted spider web, woven on temporary fencing by Jesus Lock, which was under maintenance.

An attic window which has frozen up on the outside. These frost patterns seem to be increasingly rare, presumably due to climate warming.

 

Not Christmas Day - Feb. 2024- but it's a lovely picture anyway. Floods are getting more common but it is still possible to have fun like this little boy (click on the picture for a larger version).

Transition Cambridge likes to celebrate the new year with a gentle walk. Next year we will meet by the Green Dragon bridge. All welcome, old friends and new.

Transition Cambridge New Year's meander last year (or was it the year before?) From the Chisholm Trail, near the football ground. From the left, Ben, Liz, Anna, Sam, me (Nicola), Charlotte, Tamsin, Rory and Jacky.

Making Halloween and Christmas fun *and* sustainable

I saw a ghostly crisp packet in the road last night – it seemed to be positively luminous but it was just reflecting the street lights. This, plus a black dog in evil demon costume, reminded me we are fast approaching Halloween, which is a great opportunity for harmless fun. Ghoulish costumes to startle passers-by, sweets to enjoy, maybe some ancient magic spells …

Photo by Beth Teutschmann on Unsplash

However, like the plastic crisp packet, Halloween and Christmas can be very wasteful - if we are not careful. Cheap (plastic) spooky costumes that we wear once and then throw away and sweet wrappers that do not get recycled – these are the main sources of extra waste at Halloween. WRAP has much to say about this.

Here are some easy ways to reduce waste at Halloween and Christmas:

Making a rain garden

This new little garden is flooded after the storm - but no worries because it is a rain garden and this is meant to happen. The idea is to take water off the road - hence the kerb cuts to allow water to flow into the three new sunken gardens along the grass verge. Fallowfield has poor drainage and floods regularly after heavy rain, but this time there was much less flooding than usual and it dissipated more quickly. The plants need to tolerate both floods and droughts, as that is the weather we get these days.

After the rain, Fallowfield rain garden number 1

Why a water usage survey?

Transition Cambridge is running a survey on how we use water, and what water saving measures we take. Why? Water shortage has been a concern for some time but seeing the film Pure Clean Water reminded me again of the acute need for us to reduce water demand. Lack of water has recently stymied government plans for growth but even with no extra homes or businesses we do not have enough water. I could go on but perhaps you know already – or you can read about it here.

Suffice to say, climate change means more extreme weather – wetter winters like this one but also drier ones and longer droughts. Our water supply from the chalk aquifer under the Gog Magog hills buffers some of the variation but has its limits – and our current level of demand has already caused irreparable damage to chalk streams which is why Nine Wells is no longer an SSSI [1].

Our water is incredibly cheap: in Cambridge the average water bill (excluding sewerage) is currently £163/year – 45p/day - which is 29% lower than the national average [2]. This price hardly reflects its value to our health and wellbeing, and does little to encourage water saving, even if you do have a meter. However there is a lot we can do with little or no effort. How often do you wash your clothes or bedlinen? Do you save water from cooking vegetables to pre-soak the dirty dishes? Do you flush the toilet every time you have a pee?

A Christmas wish – community heating in Cambridge?

District heating is a potential low carbon option for some homes, though it is hard to say at the moment which homes (if any) will have the opportunity. Compared to switching to a heat pump or getting an electric storage boiler, district heating can be a low hassle option - as villagers in Swaffham Prior have discovered and it seems likely that residents of Grantchester will also get the opportunity too. Compared to air source heat pumps, community heating is quiet, less bulky and you don’t need space for an outside unit; also it is a lot less weighty than an electric storage boiler: a 40kWh Tepeo weighs 375kg. A community heating system means digging in the street and into your home for the pipework. Apart from that you swap your boiler for a heat interface unit that provides you with heat and meters your consumption. Depending on the setup, you may also need hot water storage. There is no need for an annual service, as you should have with a gas boiler.

Transition Cambridge at 15

Transition Cambridge is now 15 years old. Here is an extract from our AGM, listing the various activities we have been doing over the past year.

 

Hydrogen for domestic heating is not going to happen

Experts have been saying for years that hydrogen is not a sensible solution for home heating on any scale. However gas suppliers and gas suppliers are very keen to convince us of the opposite. This has been going on for a long time and the government has been sitting on the fence. The Heat and Buildings Strategy published in 2021 delayed the decision until at least 2026 – after trials at village and town scale. However, the village trial – at Whitby – has been cancelled after massive opposition from the residents. Now Grant Shapps, the Energy Minister, has indicated that it is ‘less likely’ that hydrogen would ever be piped into people’s home, because of issues on cost, safety, and continuing reliance on fossil fuels.

What are the other options?

Do you have a low carbon heating strategy for your home? Have you been crossing your fingers and hoping for hydrogen? Unfortunately this is looking ever more unlikely. Alternatives include various sorts of heat pump, electric storage boilers and direct electric radiators. For a small proportion of homes, bottled biogas could be a solution but supplies for biogas are limited and they will also be in great demand for industrial uses. (There will be an Open Eco Homes talk on low carbon heating options on 9th October. This should be announced mid August.)