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

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 , and preferably no more than 1.5 °C. To achieve this Theresa May announced in June 2019 that the UK would set itself the target of cutting its carbon emissions to net zero by 2050. To achieve this Government 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 this target will be hard to meet unless there is an that expansion of both the production capacity of heat pump manufacturers and of the number of qualified heat pump installers.

Surprisingly the cost per KWh for gas is less than that of electricity –  this can impact on the cost of running a heat pump. Part of the higher cost of electricity is due to the government’s carbon tax designed to fund renewable energy developments. Whilst this tax is levied on electricity it is not levied on gas!  

If you would like to petition the government to reverse this situation go to

To some extent the cost of running a heat pump can be subsidised by applying for the Renewal Heat Incentive scheme. This makes payments according to how much heat you generate via a renewable source such as a heat pump, but as they say, ‘conditions apply’.

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

Some grants are available for low income households to improve the insulation of their homes through the Energy Company Obligation scheme. Further information can be found here:

However the Government’s Green Homes Grant that would have seen an upgrading of the insulation of 600,000 homes has been cancelled. 

Next week’s Eco Tips will feature ways of keeping warm at home.

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.


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:


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 :  

Count Down

 Action 34: Green your insurance. Insurance companies, pension companies and banks are amongst the biggest investors in fossil fuels and related industries – yet it is the continuing use of fossil fuels  that is accelerating our climate crisis. It would be far better if our monies were invested in green industries that are and can increasingly actively decarbonise our economy. Switch to a  home insurance company that does not underpinning the fossil fuel industry. Check out the Ethical Consumer’s Guide on home insurance:

Count Down

Action 20: Take a photo of the youngest person in your family – this  is my 4 month old grand nephew. How old will that person be in 2030? By then we hope the world will have reduced our greenhouse gas emissions by at least 55% below 1990. This should keep the rise in global temperatures to 1.5C. Try and imagine what their world then will be like? Will summers be even hotter and even wetter than now? Will there be more and stronger storms and floods? Will houses be better insulated? Will they have been adapted to cope with heat waves? Will transport system be all electric? Will they have been adapted to cope with floods and landslides? Will there still be the same diversity of wild plants and animals that we see now or will some have been pushed out of their niche in the  ecosystem by climate change? Will schools be solar powered? Will school leavers be finding jobs in a burgeoning green sector? 

What kind of future are we creating for the next generation?

The Green Tau: issue 10

A question of justice: what is climate justice? Part 2

What then of climate justice?  What is the upright behaviour, the righteousness behaviour that God expects us to show vis a vis the climate?

Photo by Tobias Bju00f8rkli on

And God said, “Let there be lights in the dome of the sky to separate the day from the night; and let them be for signs and for seasons and for days and years, and let them be lights in the dome of the sky to give light upon the earth.” And it was so. God made the two great lights—the greater light to rule the day and the lesser light to rule the night—and the stars.  God set them in the dome of the sky to give light upon the earth, to rule over the day and over the night, and to separate the light from the darkness. And God saw that it was good.  And there was evening and there was morning, the fourth day. (Genesis 1:14-19)

The writer of Genesis tells us that the climate and its seasons, shaped by the sun, is a key part of the world God created. Both creation stories in Genesis give humankind a key role in occupying and caring for and tending the world that God created. Humans are given a role of responsibility vis a vis the fish of the sea, the birds of the air and all living things that move on the earth. They are given the task of cultivating the land and the plants which God intended should transform the earth from the bare form with which it began. And they are instructed to multiply and be fruitful ensuring generations of humans to come. 

Have we looked after all the fish, the birds and living things? The decline in biodiversity with a third  species threatened with extinction, suggests not. 

Have we cultivated the earth and maintained its greenness? The expansions of deserts, the destruction of rainforests and temperate woodlands, and the loss of native plants suggest not. 

Have we provided for the well being of generations to come? Currently the world is on track for an increase in global temperatures of some 3 to 5°C by the end of the century which would render large parts of the earth uninhabitable for humans – so no!

If we were to hold up a plumb line to measure how upright our living on the earth has been, we would see a world that is on the verge of collapse, a world which will be in a worst state than when we inherited it, and a world in which life for our children and grandchildren would be very bleak. 

The diagram below is the equivalent of Amos’s plumb line. It was put together by the government’s Climate Change Committee  an independent, statutory body established under the Climate Change Act 2008) is part of their review of the progress being made tickling the climate crisis. It shows with a blue dotted line the target reduction in carbon emissions agreed by Parliament. The grey band shows the levels of emissions that  current policies will achieve. The gap between the two is the shortfall where new, firmer polices are needed. Just as plumb line measure how true a wall is, so this diagram shows how adrift we are of doing what is right for the climate and the world. 

Prophets like Amos and Jeremiah called out to those in power when  they were not meeting God’s standards. They also called out examples of wrong behaviour by merchants/ business leaders and those who abuse their power to oppress the vulnerable. They also called out those who falsely prophesied that all would be well and that no one need to repent and amend their patterns of behaviour! 

Climate justice requires us to call our government and business leaders  to account when policies and actions fail to address the climate crisis and rather allow the state of the earth to decline. We can write to our MPs and our local councillors asking what they are doing to avert the climate crisis, asking not just for wishful statements, but for concrete actions with measurable results. We can write to businesses, both multi nationals and our small, local businesses and ask  what they are doing to achieve net zero carbon by 2050. Kiss the Hippo, coffee roasters in Richmond is a carbon negative coffee company – we can  sign petitions  and join one of the many groups campaigning on the climate crisis issue – eg Friends of the Earth, XR,

Climate justice requires us to look at our own lifestyles and measure whether they improve or damage the earth and the heritage that we will pass onto future generations. There are numerous suggestions on the internet about what we can do. This will be the topic of the next issue of the Green Tau.i

Eco Tips

Active Travel

 Active travel is getting from A to B using our own person power – be that

pedalling a cycle, wheeling a chair, pushing a scooter or simply putting one foot in front of the other. It gets us from home to school/the shops/ the gym/ the railway station … and back. It keeps us fit and it keeps our environment fit – free from air pollution, congestion and carbon emissions. 

  • Dress for the weather:
    • waterproof shoes/ boots;
    • waterproof over trousers and jacket
    • sunhat/ beanie/ helmet
    • gloves, scarf
    • comfortable shoes
    • something reflective for after dusk
  • Maintain your wheels
    • keep tyres fully pumped
    • get a puncture repair kit
    • clean and oil chain and gears regularly
    • check and adjust/ replace brake blocks
    • boom a regular 4-6 monthly service
    • invest in a extra strong bike lock
    • use bike lights from and back
  • Carrying things – eg shopping
    • Fit your cycle with panniers or a basket
    • find a basket that is comfy to lift and hold
    • try a pull along basket/ trolley
    • use a back pack to spread the load more evenly
  • Route planning
    • Find local cycle routes where you feel safe with other traffic.
    • Cycle with a friend if initially you lack confidence
    • Choose a route that you will enjoy walking/cycling.
    • Find out where there are short cuts for when you in a hurry
    • Work out how long your active journey will take and leave in good time.
  • Make active travel a habit
  • Fuel
    There is never such a thing as too much cake, only not enough active travel!