Heat pumps are a low-carbon alternative to gas boilers, but are a new and unfamiliar technology to a lot of us. Come to the SOW talk on Wednesday 25th January to find out more about air source and ground source heat pumps from three village residents who have installed them.
Hear how they work – what to consider before getting one – what the advantages and disadvantages are – where to start if you want to install one.
7:30pm at the church hall, Wednesday 25th January, all welcome, just turn up.
In the UK, we have lost 97% of our flower-rich grassland over the last 100 years, mostly due to monoculture farming, and with pesticides in the mix, insects are in serious decline. Being at the bottom of the food chain, we need to help EVERYTHING connected to insects to mitigate collapsing populations of wildlife.
Here are some simple ideas, most of which are nice little projects that you could do with children (or not!):
Flowers
The debate about native vs non-native persists… just be aware of what you buy to plant. In particular, a huge proportion of plants in garden centres that claim to be bee friendly, are actually laced with pesticides! D Goulson recommends seeds from Emorsgate. As a group we may be buying some in bulk to save £. More to follow on that.
There are LOT of ideas online and kids can get really creative with these. (I have an old bookcase I my garden stuffed with bug-friendly things!) Put them in a damp, shady spot.
Bee Hotel
Drilling holes into a log is simple! 2-10mm wide, 2cm apart, 7-15cm deep. Place it in the sun, keep it dry and at eye-level. Using natural stems is nice too – see the Wildlife Trusts website.
Can roam up to 2km a night! Put a hole in your fence 13 x 13cm. Make (or buy) a house for them out of solid material, not sticks/willow (they can get stuck in those).
Wildlife in/around rivers
If you are swimming, use reef-safe suncream. Avoid putting pollutants in water that kill fish and other wildlife – use eco washing liquid etc.
Flea treatments for dogs (and cats) are a neonicotinoid insecticide – 1 dose kills 60,000,000 honey bees! – avoid prophylactic treatment and waterways after treatment.
Ponds
Where there’s water, there’s life! Even a tiny pond will bring wildlife to you. (I think this needs to be another talk on it’s own… )
This can be a life-saver. A shallow dish with pebbles in is also great for insects.
Invasive species
They should be controlled (and they taste good!) Grey squirrel, muntjac deer, signal crayfish (we have LOTS of these in the brook ), for example, are all damaging to native wildlife.
Birds
Feed them and give them somewhere to live!
There are countless templates online for boxes, so lots of fun can be had with that. Put your box about 2m high, facing N or E. More information on the BTO site.
Watch bird-box and bee-hotel building demonstrations, with templates to take home and make your own. Plus videos and discussion on what we can do to boost biodiversity – bring your ideas, questions and tips! (And kids!)
Wednesday 30th November, 7:30pm, St Andrew’s Church Hall, Oakington
Talk by Paul Kershaw and Philip Garsed about Retrofitting Eco Homes, 25th October 2022
Both Paul’s and Philip’s homes featured in this year’s Cambridge Eco Homes tours.
There are various paths to achieving an “eco home” – new-build or (in his and Philip’s case) retrofit, all at once or in stages. There are also various standards (eg Passivhaus, Enerphit Standard).
The two core principles of energy efficiency are insulation and ventilation. Helpful tools include the EPC certificate (not especially good), a thermal camera, an airtightness test, using an incense stick to detect draughts, existing energy bills and your own experience of living in a property.
Paul’s retrofitting project had as its aims: considered quality of living design, eco-friendly products, and energy efficiency. He explained how, by having an overall plan drawn up, he was able to take advantage of grants and trials when they arose. Considered quality of living design includes such aspects as wider doorways, ergonomic design, assisted bathing facilities by design not a bolted-on eyesore, and air quality through ventilation and lower VOCs. Eco-friendly materials included natural materials such as marmoleum flooring Materials were reused where possible. There is provision for a future grey water system; for the present, water-saving shower and taps. The gas (“methane”) supply has been cut off along with the standing charge!
There were some eco-friendly compromises which had to be made. Clay plaster was prohibitively expensive but clay paint has some of its advantages. A sedum carpet can form a green roof without having to structurally alter an existing flat roof. There are pros and cons to internal and external wall insulation and different materials for the latter. Cork was chosen for the rear but more visually appealing woodfibre boards and scotlarch cladding for the front.
Ventilation is necessary once a house is sufficiently air-tight to prevent a build-up of moisture, and options range from “natural” ventilation (windows and doors) through passive stack (chimney flue via fire heat or wind), mechanical ventilation and mechanical ventilation with heat recovery (MVHR).
Paul’s key pointers: educate yourself, plan, and stand firm to your ideals.
Philip says he is often asked what the payback time on his house improvements will be, but that question ignores the very tangible benefits of living in a much more comfortable house in the meantime. Eco-houses are comfortable: super insulation, air tightness and MVHR result in stable temperatures, constant humidity, fresh air and quiet homes.
What makes us feel cold? Draughts, cold feet, colder surfaces (eg windows), changes in temperature as we move from one room to another. An eco-home does not have these, so can feel warmer than the actual temperature. Plus they are cool in summer.
Homes which are too dry or too damp are bad for health – the optimum humidity is 40-60%, which the MVHR maintains. Other benefits are being able to dry washing indoors, cook without steam, no bathroom mould, and a nicer living environment.
A lot of discussion followed. One question was about steps you can take if you are not able to launch into a full retrofit. LED lights and, when replacing appliances, choosing ones with good energy ratings. There was debate about the merits of battery storage. On the one hand, they make solar panels more worthwhile because stored solar energy can be used at times of the day when electricity is expensive (time-of-use tariffs will become normal.) On the other, in summer you can’t use all you store and in winter you can’t make enough.
Talk by Ann Mitchell of Cambridge Sustainable Food on 28th September 2022
Key messages: our choices make a difference, and so does asking sellers about food.
Food’s environmental sustainability fits in the broader picture of health and fairness, and includes: carbon footprint, land use (& biodiversity), soil (1/3 of our arable land is degraded), animal welfare and working conditions.
We import at least 50% of our food. Food waste – up to 30% of the food produced globally is wasted. A lot of waste caused because we expect well-stocked supermarkets. The world does produce enough to feeds its population but it’s not fairly distributed. 8.8% of UK households suffered food insecurity (Jan 22). Obesity in the UK has doubled in the last 20 years.
Impact of our food choices. Not straightforward. Ann used the example of plant-based milk. 1 pint of cow’s milk results in 1.9kg of greenhouse gas emissions, plus concerns about animal welfare in the huge dairy industry. 1 pint soya milk causes 0.5kg, 1 pint oatmilk 0.5kg, 1 pint almond milk only 0.3kg, BUT almonds have become a huge monoculture in California, using precious water resources and requiring imported bees. Soya milk concerns are that the soya is grown in Europe, not on land cleared from rainforest. Oatmilk sludge can be eaten by local pigs but is instead sent to an anaerobic digester to keep the oatmilk completely vegan.
Lots of variation in carbon footprint. A lot of land is used to grow animal feed. Beef reared in the UK has a lower carbon footprint than some beef reared elsewhere, because mainly grass fed.
Where to get protein from? Lab grown meat is coming but not commercially viable yet. Mealworms are a low-impact source of protein and can supplement the diet of animals including in pet food. Wild meat (venison, rabbit, muntjac) from animals that have to be culled anyway (because we don’t have top predators roaming about) is another option. Ann brought examples of vegan alternatives: tinned beans (no soaking required), dried lentils and split peas of various types (ditto) – Hodmedod is a Suffolk grower of dried beans and peas; mushroom also contains protein and chopped up resembles mince; brocolli. Meat intake can be reduced by mixing minced meat and one of these alternatives in dishes like bolognese, shepherd’s pie.
Miscellaneous: British tomatoes in March/April (hothouse-grown) are at least as bad as green beans flown in from Ethiopia. Rice grown in paddy fields has a high carbon footprint, wild rice eg from Italy grown differently is better.
Tips for a Sustainable Diet
Eat less, but better, meat and dairy
Choose seasonal and local
Avoid air freighted goods (shipped is much more sustainable)
Eat everything you buy (use judgement, not best before dates)
Cook from scratch BUT
Be aware of the carbon cost of cooking! (Eg put lids on pans)
Finally – demand to know where your food comes from and make your views known. Consumer power! (Eg speak to manager, tweet larger companies)
Recommendations: “Food and Climate Change without the Hot Air” by S.L. Bridle – free to download. Updated edition of “How Bad are Bananas” by Mile Berners-Lee. For website recommendations see below.
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), for example, are all damaging to native wildlife.
Sustainable Oakington and Westwick 