Tag: Climate change

Green Tau: issue 15

Varodrig took this photo from the Ula platformFirst – gas from the Oselvar module burns on the flare of the BP Ula oil platform in the North Sea on April 14th, 2012

3rd September 2021 – revised 11th January 2023

Heating homes without carbon?

Domestic energy use, ie for heating, lighting and electrical appliances, generates around 22% of the UK’s carbon footprint. The majority of that 22% comes from heating our homes. This is not surprising when you consider that 90% of homes are heated using gas boilers. Gas, one of the main fossil fuels, is burnt to heat water to warm our homes. As it burns, carbon dioxide is released. A three bedroom house with a 30KW condensing boiler will, for every hour the boiler is running, will emit around 7kg of CO2 or over the course of year around 3.65 tonnes of CO2.

It is obvious that we cannot continue to heat our homes using gas (or oil or coal) if we are to prevent the catastrophic rise in global temperatures. The Paris Agreement signed by parties at the Paris COP in 2015 set as it goal that participants should reduce carbon emissions so as to keep the rise in mean global temperature to below 2 °C .

In April 2021 the UK’s sixth Carbon Budget set the goal of cutting emissions by 78% by 2035. This time the Budget was set to also include the UK’s share of international aviation and shipping emissions. This revised budget should put us three-quarters of the way to achieving net zero by 2050.

Parties at COP27 in November 2021 agreed that this target should be reduced further to just 1.5 °C. To achieve this target the means by which we heat our homes will have to be radically transformed. 

This can happen in surprising ways. In Islington waste heat from the Northern Line is being soused to heat 1350 homes, a primary school and two leisure centres. In addition the heat is also generating electricity that powers lifts and communal lighting in a nearby tower block. Similar district heating solutions are being developed in other parts of the country too, for example heat  extracted from a flooded coal mine in Durham will heat 1500 homes. 

Both these projects use heat pump technology. This is the most promising solution for drastically reducing carbon emission whether heating a large office block or the average house. A heat pump is a scaled up fridge that works in reverse. Its refrigerant liquid absorbs heat from the air – or the ground – outside the building. This is compressed and transfers inside the building  where it is released as heat via warm air or via warm water (for radiators or underfloor heating). The heat pump is powered by electricity. Heat pumps, in terms of energy used and heat produced, are at least 3 times as efficient as gas boilers. In terms of running costs, the carbon footprint of a heat pump will depend on the source of the electricity it uses. Electricity from a wind farm has a carbon footprint of 10-20g/KWh compared with 450g/KWh for electricity from a gas fired power station. 

The Government’s net zero carbon targets anticipates the installing of 600,000 heat pumps a year by 2028. However in 2021 only 42,779 heat pumps were installed make this target look questionable.

There needs to be an expansion of both the production capacity of heat pump manufacturers and of the number of qualified heat pump installers, as well as improved Government finance to make the switch affordable for everyone.

The other approach to reducing the carbon footprint arising from heating our homes, is to insulate them. The better insulated a property is, the less additional heat is needed to achieve a comfortable level of warmth. Thus less energy is needed and one’s carbon footprint is reduced. A well insulated home also reduces draughts and cold spots which makes spaces feel warmer. 

Home insulation options include:

  • cavity wall insulation 
  • External wall insulation suitable for buildings with solid walls
  • Loft insulation 
  • Draught proofing doors and windows 
  • Double – or even triple – glazing windows
  • Underfloor insulation
  • Thermal external doors
  • Fully enclosed porches

Information on the potential cost savings of upgrading home insulation plus available grants can be viewed in various websites including https://www.which.co.uk/reviews/home-grants/article/insulation-grants-aGAZv8p9hGkY

NB Relevant information is constantly changing.

Count Down


 Action 42: Plant spring bulbs: the ideal time for this is between now and November. This is also the time to plant summer bulbs such as lilies and alliums. Plant a variety of bulbs from the earliest flowering crocuses to the later flowering tulips to ensure an ongoing supply of nectar for insects as well as scents and colours that will bring us joy too. 


As we continue to mark the days until the COP26 climate conference you might like to subscribe to the United Nations climate change news letter. https://news.un.org/en/newsletter/climate-change

Stop the World!

Stop the world!  

I want to get off!

I can’t cope with climate anxiety, 

with the knowledge that we are still 

polluting the atmosphere with CO2.

Stop the world!

I want to get off!

I can’t cope with the politics

that we continue to ignore –

that let the rich grow richer & the poor poorer.

Stop the world!

I want to get off!

I can’t cope with the cycle of hate and war,

with our conviction that being tough 

will bring peace and reconciliation. 

Stop the world!

I want to get off!

I can’t cope with the pursuit of profit 

that says ‘I’m worth it’

 whilst resolutely destroying our world.

Stop the world!

I want to get off!

I can’t cope with myopia 

that can’t see the spread of global suffering 

because we are safe in our wealth.

Eternal God,

Give me some hope to aim for, 

courage to continue,

and peace to regain strength.

Amen.

Count Down

 Action 40: Check out high visibility clothing. With schools terms starting and the evenings drawing in, it is a good time to think about staying visible as both pedestrians and cyclists when it is dark. After dark even light coloured clothes do not make the wearer clearly visible to other road users.  Fluorescent markers on bags and coats, cycles, helmets, wrists and ankles are all good options.

New! Starting a from tomorrow and everyday during creationtide (1st September – 4th October) I will be posting a picture of something from the natural world to encourage us to ‘fall in love again with creation’. These will feature under the new heading added to the menu ‘Falling in Love’

Turning your garden into a carbon sink 

Our back garden

As well as minimising the amount of carbon we emit/ consume/ use we need also to do all we can to keep as much carbon locked away undisturbed in the ground. Our gardens can be made into carbon sinks ie net absorbers of carbon. 

  1. Don’t buy or use peat. The UK’s peatlands are an important carbon sink (1 hectare of peatland  can absorb up to 2000 tonnes of CO2 per year). Digging up and removing the peat seriously damages these fragile habitats. 
  2. Don’t buy plastic plant pots whether with or without plants (plastic is made from oil). Instead use pots made from plant fibres, paper or clay. The Hairy Plant Pot Company grows plants for sale in coir pots. The whole pot with plant  goes straight into the solid where the coir will decompose over time.  
  3. Don’t use artificial fertilisers, pesticides or herbicides. These have a high carbon footprint and are damaging to natural ecosystem.
  4. Make a compost bin and fill it with garden waste and plant based kitchen waste. Once well rotted, the bin’s contents will provide soil enriching natural compost that locks the carbon into the soil. Compost bins can be made from wood (eg recycled pallets), wire mesh or you could buy a plastic bin made from recycled plastic. 
  5. Plant trees and shrubs as these will, by their size, be able to absorb more carbon as they grew. 
  6. Opt for perennial plants over annuals. The perennial plant both develops a larger root mass and has a longer growing season enabling it to absorb more carbon. Interestingly you can opt for perennial varieties of vegetables rather than growing them each year from seed: spinach, watercress, kale, perennial leeks and onions, cabbage etc.
  7. Choose plants that will be happy in the micro environment that your garden offers. You can waste time, energy and carbon, trying to make plants grow where the conditions are unsuitable. Grow together plants that form a natural ecosystem so that they help each other. 
  8. Avoid over digging the soil as this can release carbon locked into the soil.  
  9. Avoid leaving the earth bare as carbon from the soil can easily be lost into,the atmosphere. Instead cover the earth with a mulch or with a cover crop.
  10. Let your lawn grow. Frequent cutting of the grass requires the input of water and fertilisers to keep it green and the lack of depth of  cover makes it susceptible to drying out during periods of drought. Instead let the grass grow longer – you can still run over it, sit on it and play on it.
  11. Transform your lawn into a meadow by introducing a greater variety of plants, especially flowering ones. These extra plants will tend to have longer root systems enabling more carbon to be absorbed by the soil.
  12. Avoid or replace hard surfaces, especially concrete ones. (Concrete has a particularly high carbon footprint). Hard surfaces leave the soils underneath compacted and bereft of mini beasts and micro organisms that absorb carbon. Use gravel and bark in preference to paving stones, or even bricks set in sand. 
  13. Build a pergola so that you can grow climbing plants to provide shade in the summer. Consider adapting any garden sheds so that you can plant them with a green roof. The more we plant, the more carbon our garden can absorb.

Green Tau issue 14

Carbon Sinks

28th August 2021

The world has several natural carbon cycles all of which function to maintain a balance between carbon dioxide in the atmosphere and carbon locked away within element earth and its inhabitants. During in the geological time span of the earth there have been peaks and troughs giving rise to to eras when the earth is climate was positively tropical and eras when much of the earth was trapped in an ice age. But since the last true ice age, fluctuations in global temperature have been small scale and prior to the start of the Industrial Age carbon dioxide levels in the atmosphere stood at around 278 ppm. 

Some of the earths carbon cycles are short term: eg plants absorb carbon dioxide from the air during the process of photosynthesis to cellulose which becomes the building blocks for stems, leaves, roots etc. As the plant respires it will release a small portion of carbon dioxide back,into the atmosphere. When the plant dies, these parts of the plant fall to the ground and decay. As the plant decays some of the carbon is released into,the atmosphere as CO2 whilst some is drawn down into the soil where it remains.  

This short term cycle does vary in length. If the plant life consists of, say, grass it can be an annual cycle. If the plant life is an oak tree, the cycle can last in excess of 1000 years. The cycle can be lengthened if the plant is eaten by a creature that will use the carbon products to provide both energy for the creature and to build up its own body using the carbon to form bones and muscles etc. Whilst some carbon will be released back into the atmosphere as the creature breathes, most is locked away until the creature dies and its body goes through the process of decay.

Others are long term cycles: eg volcanic eruptions emit carbon dioxide into the atmosphere that may originally have kicked started basic plant life. Decaying plant remains and the bones and shells of creatures (which have a significant carbon content) build up as layers in the soil or on ocean beds. Over time these carbon based materials become compressed into rock strata eg chalk, coal  and oil. Here carbon is locked away for millennia until is released through erosion or volcanic action. 

However things have changed with the onset of the Industrial Age when initially coal, and then later oil, have been extracted from the earth and burnt releasing large amounts of carbon dioxide into the atmosphere at a rate faster than could be absorbed by natural processes. The increased levels of carbon dioxide in the atmosphere led to an increase in global temperatures for carbon dioxide acts like a blanket keeping warmth trapped within the earth’s biosphere. This increase was initial small and gradual but as fossil fuel based energy and products have increased, has rocketed. As of July 2021 carbon dioxide levels in the atmosphere stood at 417 ppm. 

Our current global climate crisis arises from this rapid increase in carbon dioxide levels in the atmosphere and its consequential affect on global temperatures. The current consensus is that if carbon dioxide emissions (and other similar gases that caused global warming) can be brought to a level of net zero by 2050, it may be possible that the rise in global temperatures will be limited to  between 1.5 and 2C. 

This problem can be tackled from two angles: limiting our carbon emissions and increasing the earth’s capacity to absorb carbon dioxide. Most of the earth’s carbon is already locked away in rock strata. Our interest here is with those parts of the earth where increasing amounts of carbon dioxide can be stored. These are called carbon sinks and include:

Oceans 

Boreal forests and rain forests,

Grasslands and peatlands 

Coral reefs

Wetlands and lakes

Salt marshes

Each of these habitats can and does absorb significant amounts of carbon dioxide. Some are under threat of destruction due to human operations, including expanding requirements for land to be used for farming and construction. In South America large areas of the rain forest have been cleared to make way for cattle ranches. In the UK significant areas of ancient woodland have been cleared or are under threat from the contraction of HS2. 

Two courses of action are needed. Firstly to preserve and maintain existing habitats that are significant and effective carbon sinks. This must include stopping the destruction of such habitats and alongside this, ending further extraction of coal and oil deposits. Secondly to restore and expand such habitats to increase the earth’s capacity to absorb carbon dioxide. 

13.2% of the UK’s land surface is covered by trees but this compares with 35% across the EU. 30 year old woodland can store approximately 250 tonnes of carbon per hectare and 100 year old woodland approximately 450 tonnes per hectare. 

Peatlands cover about 10% of the UK’s land surface but of these 80% have been severely damaged by mismanagement such as draining the land for planting trees or other farming purposes, burning on grouse moors, and overgrazing by sheep and deer. Peatlands can store up to 2000 tonnes of carbon per hectare.  

Various charities and other bodies are involved in maintaining and expanding natural habitats in the UK which are effective carbon sinks – eg Woodlands Trust, the RSPB, the National Trust, various local Wild Life Trusts including the Cumbrian Wild Life Trust which is busy restoring Lakeland peatlands. We can support their work through donations and volunteering. The Peatland Action Programme for Scotland estimates that it costs a little over £2000 to restore a hectare of peatland. 

Count Down

Missing from yesterday! Action 35: Set aside part of your garden for wildlife. Climate  change places extra pressures on wildlife so give them a helping hand by encouraging wild plants (weeds) to colonise part of your garden. Nettles are very good for ladybirds and butterflies, dandelions flowers are good for bees and dandelion seeds are tasty food for goldfinches.


 Action 36: Make next week a vegan week. Stock up on beans and pulses, tofu and nuts, assorted types of rice and pasta. Make a shopping list with plenty of seasonal fruit and vegetables.  Add miso pastes, chutneys, yeast flakes and herbs for extra flavours. Plan some easy meals combinations.  Be inspired by new recipes – try these from Hodmedod : https://hodmedods.co.uk/blogs/recipes/tagged/vegan