Archive for the ‘Personal’ Category

Tips for talking about Climate Change

August 8, 2022

Friends, isn’t it funny how sometimes you come across something at just the right time.

And since I have now become one of the ‘mad people’ you have to avoid eye-contact with as you walk past me in the street, I was happy to come upon these notes on Talking about Climate Change.

The notes were prepared by Richard Erskine as part of his work to raise consciousness of Climate Change in his local area. And the aim is to simply share some experiences and ideas about dealing with some of the most common situations one encounters.

  • You can find Richard’s blog here
  • You can follow him on Twitter here.
  • And you can download the notes as a pdf file here.

There is no point in me re-writing what Richard has written, but I thought I would just highlight some of the things the document covered that I felt were especially delightful. And the main feature I liked was the subtitle: you don’t have to be an expert.

On my first day out, I went equipped with a laptop loaded up with key graphs and animations. On contact with the public it immediately became obvious that these would not be needed. Talking to people in the street is absolutely NOT about lecturing clearly. And although Richard’s notes include some well-referenced ‘facts’, it is not about knowing the very latest facts.

The point of speaking to people in the street lies in the power of conversation, and the sheer pleasure humans take in ‘having a chat’. And meeting someone who is honest and straightforward and concerned, and not trying to sell anything is a pretty powerful event in most people’s days.


The document starts with some tips on starting conversations and some key Climate Facts. And then there are 10 questions which I have listed below together with my précis of the Richard’s more expansive comments.

Q1. CO2 is only a trace gas (0.04%) of the atmosphere. How can that affect the climate?

  • This drink contains 0.04% cyanide, would you like some?

Q2. CO2 is used by plants so isn’t more of it a good thing

  • Yes, CO2 is used by plants, but it also affects the climate, and many plants can’t cope with heat-induced stress. Look at the grass…

Q3. We’ve had heat waves before (1976) so what’s the fuss?

  • Heat waves have become more likely year-on-year, and this one has extended across much of the northern hemisphere. Reaching 40 °C in the UK would have been impossible without the underlying warming.

Q4. Aren’t Electric Vehicles (EVs) environmentally bad?

  • EVs are much better for the environment than petrol and diesel cars, but they are not perfect.

Q5. Don’t we need better public transport rather than Electric Vehicles (EVs)?

  • This is not an “either-or” decision.

Q6 What about China; our emissions are tiny compared to theirs?

  • China’s per person and historic emissions are much lower than ours, and they have become the factory of the world. Many items you own were probably made in China. 

Q7. The problem is population growth, so what can we do, and is it even worth trying?

  • This places the blame on the poorest people in the world who have NOT caused global warming. The problem is caused by our society’s consumption.

Q8. “What’s the big deal about the world warming by 1°C or 2°C?”

  • Like your body, the climate and ecology of the Earth are adapted to living at a particular temperature. Just like you, a rise in temperature of 2  °C or 3 °C is very serious.

Q9. Arctic methane and other tipping points have already been crossed, so we need to now just prepare for the worst, don’t we?

  • We don’t have runaway Climate Change yet – and we want to avoid that. So every action matters, every bit of warming matters, every choice matters.

Q10. I am not a denier, but we can’t afford to rush it; Net Zero by 2050 is just an arbitrary target, we need more time

  • It is not a choice between the economy and climate change measures. With consistent policies and investment in a low carbon economy, we can actually have a flourishing future, good for jobs and the planet.


Friends, Climate Change is real and terrifying, and it is easy to feel petrified into inaction. But having honest conversations with friends and acquaintances is a great way to clarify one’s own thoughts and to help others clarify theirs.

But our conversations have been seeded – deliberately I believe – with false narratives that

  • either deny that Climate Change exists,
  • or if it exists that it is important,
  • or if it is important that it’s our responsibility,
  • or if its our responsibility that we can afford to do anything
  • or if we do anything that it is just as bad as everything else

These notes might just help you to avoid getting sucked into those awful conversational paths.

Good Luck!

Climate Communications

July 27, 2022

Friends, as you may know I am frustrated at the inappropriately slow response of our government to the climate emergency we all face.

And I have had a dawning realisation that no superbly written blog article, no gem of a Tweet, and no YouTube presentation is going to change things.

So this week, I took a step inspired by a (completely fictional) scene in the movie The Darkest Hour. In this scene, Winston Churchill ventures onto the London Underground in search of ‘the mind of the people’.

Similarly, in search of grasping ‘the mind of the people’ I spent a few hours this week standing by a small table on Teddington High Street asking passers by what they thought about about our Climate Crisis.

Unsurprisingly, a solid 99% of people politely ignored me. But a few people did stop by and I took pains to note down what they told me. And below is a non-fictionalised account of what happened.

In search of ‘the mind of the people’ on Teddington High Street. 

Monday 25th July

10:45 I set up in front of the sorting office at the end of Elmfield Road.

11:10. A lady stopped by to ask “What can we do?” The lady lived locally and came back a few minutes later and gave me a Bakewell slice she had just bought from the bakers. She said I looked lonely! I was touched by her kindness.

11:50 A DHL driver asked where Nando’s was?

12:00 A South African gentleman stopped by to tell me he didn’t believe climate change is caused by humans but that it was a natural process caused by volcanoes. I told him that humans emitted more CO2 than volcanoes and asked him where he thought the balance was between volcanoes and people in terms of emissions. As he left he told me solemnly that the “World will end with fire”.

12:10 A lady approached me to tell me about a neighbour of hers who was an architect with multiple cars. She also spoke of the Beckhams and their celebrity lifestyles with multiple flights, the Cambridge’s and their palaces that they use helicopters move between, the evil of people keeping dogs, and the many flights and helicopters associated with racing horses. 

13:00. A single lady aged 73 stopped by with lots of positive ideas. She had looked up installing a heat pump but thought she needed to change absolutely everything in her flat. At the same time a lady I had seen earlier with a Fortnum and Mason’s bag wanted to complain about the tactics of extinction rebellion which she thought just put people off. She had herself been delayed by an Extinction Rebellion protest on the way to a funeral

13:30 Stopped

Tuesday 26th of July.

10:51 Set up outside CarpetRight

11:09 A man passed by and said he didn’t want to talk about the climate crisis because it was upsetting

11:21 A nice lady stopped for a chat. She was very sympathetic, acknowledged that this was really a crisis of capitalism and consumption, and was sympathetic to extinction rebellion. She had been off meat for many years and had avoided flying for eight years. She had no real idea what we could do collectively.

11:30 A lady stopped by who seemed know everyone, E.g., the Pope, and Greta Thunberg, and she spoke to me for a long time.

11:40 My neighbour and one-time colleague at NPL, Gordon Edwards stopped by and said hello.

11:54 A nice lady was concerned and knew all the regular things one could do, but agreed that it didn’t quite match the scale of what was required. She was depressed by the previous night‘s Tory party debate in which nobody paid any attention to the climate crisis. Or indeed the crisis in health and social care.

11:58 A young man with a rucksack, nodded his head and said good morning. But didn’t stop

12:19 Interesting talk with lady from a nearby road. She was very worried and very concerned but didn’t know what to do. She lived a very frugal life, and she and her husband had no children but said that if she had children she would be very concerned for what they would inherit

12:31 Another one-time colleague stopped by. He said that it seemed like there was a cloud hanging over the world in the form of climate change, politics, and geopolitics. We agreed that it was important just to keep raising the subject when one had friends who are sceptics: Silence was an enemy.

12:44 A lady who works at TearFund, (a Christian International Development Charity with its headquarters in Teddington) stopped and said they have a kit to allow local churches to declare climate emergencies. She spoke about how Tear Fund saw action on a Climate Change as a theological issue (I said I think I would call it moral issue), because it involved justice and fairness and inequality.

13:07 A young man stopped by who is doing marketing and PR for a company called PATCH which is looking to market direct carbon removal for different companies. He suggested many things including that I focus on the monetary aspect of going green. He was enthused by the fact that private companies were becoming involved in the face of government inaction.

13:20 Stopped.


Friends, I don’t know what to make of this experience, but I felt it was valuable and I will keep doing it.

For the 99% of people who passed by, I feel they saw a person raising the issue on the street. Many would be embarrassed or fearful to stop and talk, but they saw the words ‘Our Climate Crisis’.

Of the 1% of people who stopped, several were profoundly concerned and were doing what they could in their personal lives, but they had more or less abandoned hope of coherent and serious government action on this.

In Winston Churchill’s fictionalised visit to the London Underground, the ‘mind of the people’ became apparent to him in just a few minutes, and with dramatic clarity. I am finding it a little more difficult to decipher their message, but I intend to keep trying.

40 degrees Celsius

July 15, 2022

Click image for a larger version. Met Office forecast on Friday 15th July 2022 for temperatures on Tuesday 19th July 2022.

Friends, I am sitting down to write on Friday 15th July 2022, having just read warnings that next week the temperature somewhere in the UK is likely to exceed 40 °C for the first time since… well almost certainly several thousand years.

Despite the fact that this is hardly a surprise, it is still a shock. I feel sick.

Rising Tide

I am reminded of the situation of visiting an unfamiliar beach, and wanting to know if the tide is coming in or going out. Sometimes it’s obvious. But at other times things are not so clear. The waves breaking can obscure the slow steady rise or fall of the tide.

So typically one would pick a ‘fiducial marker’ – perhaps a rock that is very definitely not wet. And one then watches this for a few minutes to see if the tide moves towards it or away from it.

Passing 40 °C is like the tide reaching the fiducial marker on the beach. It confirms that the tide of rising temperatures is still rising with a sickening and merciless inevitability.


Click for a larger version. This is the summary of part 1 of a recent talk I gave to teenagers.

As I mentioned in a recent talk to teenagers (link) the climate in which their parents grew up is gone forever. It will never return. And to most of my readers – that’s the climate that you and I grew up in.

As I wrote the slides for that talk I again felt sick at confronting these children with the magnitude of the misfortune they will face.

It’s a misfortune that was once avoidable, but which is now inevitable.

And yet as I write, leading UK politicians are still competing with each other to reduce our response to this challenge.

I am bewildered at their madness.

What else can I do?

July 14, 2022

Friends, while writing the slides for my recent talk to teenagers, I became very aware of the awfulness of the future facing the children I was addressing – and my own children who are only around 8 years older.

This awareness took the form of something between panic and gloom. And it caused me to reflect on my own efforts to reduce carbon dioxide emissions, and to ask myself “What else could I do?”.

In case you are short of time I will summarise my conclusion here: I have eliminated most of carbon emissions from my life that can be cut by simply spending money! To go further, requires significant lifestyle changes. And maybe trying harder to influence other people.

What am I doing already?

As summarised on the ‘My House‘ pages of this blog and this video, I have spent most of my life-savings (aka my ‘Pension Tax-Free Lump Sum’ of around £60,000) on steps to reduce carbon dioxide emissions from my house in Teddington.

Briefly, the money has been spent on:

  • Triple Glazing & External Wall Insulation reducing the heating demand by half.
  • 12 Solar Panels generating ~3,500 kWh/year of electricity, Together with a battery, this is enough to take us off-grid for roughly 90 days a year and to substantially reduce the use of grid electricity in all but the darkest months.
  • A heat pump eliminating the use of gas for heating.

Altogether, these steps have reduced CO2 emissions associated with the house by around 80%, from 3.7 tonnes per year to about 0.8 tonnes per year.

And our lifestyle has not been impacted at all: in fact the house is more comfortable: warmer in winter and cooler in summer – cooled with solar-powered air conditioning.

These carbon emissions are real reductions of emissions – actions that result in no CO2 being emitted into the atmosphere when compared with the alternative of not taking these actions. And after the carbon payback period, emissions associated with the house will be around 3 tonnes less per year than they would have been.

But in this calculation I have not included three other things that could notionally be included.

  • Exports: Each year the house exports ~900 kWh of electricity to the grid. One can argue about how much this reduces emissions from other people’s use of electricity.  But this probably reduces emissions by between 0.2 to 0.4 tonnes per year.
  • Direct Air Capture: Each month I pay the Climeworks foundation £40 and in return they promise to directly capture 50 kgCO2 from the air and turn it into carbonate rock deep beneath the surface of Iceland. I really don’t know how well-validated this process is, but Climeworks promise that within 6 years of my payment, they will permanently remove 600 kgCO2/year from the atmosphere ‘in my name’. Notice this is not ‘offsetting’ which I believe to be tantamount to fraud.
  • Wind Farm: Earlier this year my wife & I paid Ripple £2,000 to buy a share of an 8-turbine wind farm they plan to build in Scotland. This share is sufficient to generate roughly 3,500 kWh/year of electricity – 100% of the electricity the house draws from the grid each year. It’s scheduled for completion in November 2023 and from that point onwards, the carbon emissions nominally associated with the house will fall by very roughly 600 kgCO2/year.

In accounting terms, this means that – as the graph below shows – the household could possibly be classified as ‘carbon negative’.

Click on image for a larger version. The graph shows cumulative carbon dioxide emissions from the house up to the year 2040 based on several different assumptions. The red line shows expected emissions if I had not done any work on the house. The green line shows the effect of those works. The dotted black line shows the effect of my paying for Direct Air Capture of CO2. And the dotted blue line shows the effect of my purchase of a fraction of a ‘Ripple’ Wind Farm. The carbon embodied in the modifications to the house is now (July 2022) just about paid off.

What else could I do?


There is only limited scope for further work on the house. Installing underfloor insulation could reduce the heating requirements by perhaps another 20%. And there is room for a few more solar panels and more batteries. However neither change would alter the graph above dramatically.

Additionally I am keen not to adopt a techno-utopian stance – forever consuming more of the latest tech to enable me to humble-brag about some sexy piece of equipment.

So what about emissions from other aspects of my life – Transport, Consumption and Pensions.


My wife and I still own and drive a car and we drive around 3,500 miles/year which corresponds to just over 0.8 tonnes of CO2 emissions.

It pains me every time I drive – wasting 70% of the energy in the petrol and emitting CO2 directly. However, although my wife might be able to afford an electric car, with our low annual mileage, the 10 tonnes of CO2 emitted during the manufacture of an EV is hard to justify.

Probably our the best strategy is just to reduce the amount we drive – cycling and using public transport even more than we do.

I guess at some time I will be obliged to travel by air again – but until that becomes necessary, I will simply try to avoid this. Although the idea of international travel is intermittently attractive (particularly to my wife), to me it seems too appalling to emit tonnes of CO2 in an afternoon on nothing more than a whim!


I have given up taking milk in my tea (and coffee) and this has resulted in our using 1 litre of milk less each week – saving 50 litres per year. Using figures from Our World in Data, this – apparently – reduces our annual carbon footprint by ~ 0.15 tonnes! Other sources suggest that UK milk does not have such high emissions, and the avoided emissions are more like 0.075 tonnes (75 kg). Whatever the actual answer is, I have made the switch and I don’t intend to switch back. And even 75 kg per year up to my planned date of death is 18 x 75 = 1,350 kg CO2.

My wife and I have both changed our diet significantly in recent years: reducing beef purchases to zero, and only eating other meats perhaps once a week. We eat vegetables and salads much more than we used to, including food from my wife’s allotment which has low associated ‘food miles’. However, we still eat eggs and cheese.

I am trying to buy fewer ‘things’. And as my perspective has slowly shifted, I have realised I really need very few new objects.


As I lamented in an earlier article, the money invested on my behalf by Legal and General and USS probably generates many tonnes of CO2 – probably more than all the other categories combined.

After writing that article, a correspondent suggested to me that considering emissions from my pension savings was double-counting. In other words, I was counting emissions from say petrol purchases already under the ‘travel’ category, so counting those again as part of a share portfolio that probably includes oil companies was not consistent. This is a fair point. The emissions associated with an oil company’s activities can either be assigned to the consumers of their products, or the shareholders, but not both.

However, my money is still invested in ways I would not personally choose. But I feel so unsure of myself as an investor that I am not confident that switching investment funds would result in an improvement.


Aside from emitting as little CO2 as I can, I also want to live a life which includes joyful activities and is not a relentless drudge.

But it seems that I am approaching the limits of what I can do personally to live a life with minimal emissions of carbon dioxide.

There are still actions I can take, – and I will – but at this point it seems that probably the most significant thing I can do is to try to influence other people to take action to reduce their carbon dioxide emissions.

Mmmmm. I will have a think about how best to do that.

Why I am sceptical about Geothermal Energy

June 6, 2022

Friends, some people are of the opinion that geothermal energy offers practically unlimited opportunities for the generation of electricity with low carbon dioxide emissions. For example,

  • The US Government’s GeovisionReport is an extensive and overwhelmingly positive assessment of the potential for geothermal energy generation in the US.
  • This IEA video describes new drilling technologies and possible applications in Germany.

For a more general overview, take a look at this video on the ‘Just have a think‘ channel, or read these 10 pages on How Stuff Works.

And there are indeed real possibilities. However I am sceptical that such opportunities are ‘practically unlimited’, particularly in the UK.

And since we are in an emergency situation and need to act urgently, I am doubly sceptical of novel technologies which might steal investment from known solutions.

Allow me to explain….

General Situation

Below the surface, the temperature of Earth increases at typically 25 °C to 30 °C per kilometre of depth. So a few kilometres below the surface, rocks are typically at several hundred degrees Celsius. And this thermal energy represents a potential energy resource.

The US Government’s Geovision Report outlines a number of ways in which this geothermal energy might be extracted. These are summarised in the graphic below.

Click on image for a larger version. The Geovision summary of geothermal potential.

The large-scale projects typically involve four parts.

  1. The injection of cool water down a drilled well to some hot rocks.
  2. Percolation of water through the hot rocks.
  3. Extraction of hotter water from a second well.
  4. Generation of steam and electricity.

Despite the very large volume of hot rocks available under our feet, there are two basic difficulties that all these schemes face.

  • Firstly, rocks of all kinds have a poor thermal conductivity. So if we extract heat from the surface of a rock, that surface will cool down. However heat will only flow back into the cooled rock slowly. This limits the rate at which heat can be extracted.
  • Secondly, except in a few geologically exceptional places, the upwards geothermal heat flow from the deep Earth is very low – typically less than 0.1 W/m^2.

Given these difficulties, there are a lot of technological tricks that can be exploited to optimise extraction of heat in particular circumstances.

For example in Enhanced Geothermal Systems (EGS), engineers ‘frack’ a volume of rock which increases the surface area over which water can flow. As water percolates through the rock it is then able to extract heat more efficiently.

However, no technological advance can overcome the basic fact that the heat flux from the interior of the Earth is – in most places – very low. This means that the technology is essentially ‘one-shot’ i.e. the heat extracted from the rock will be only slowly replaced by heat from the interior of the Earth.

This means that once a geothermal plant has ‘harvested’ the geothermal energy from a block of rock, it will need to move on to a new block. So the big question is: “How long will that ‘one-shot’ last?”

Simplified Model 

I have constructed a spreadsheet model to assess how much electricity could be generated from one cubic kilometre of rock, and how long that extraction could go on for. The model is illustrated in the graphic below.

Click on image for a larger version. A simple model considering how much energy could be extracted from a cubic kilometre of rock, a few cubic kilometres under the Earth. I have illustrated a cubic kilometre at a depth of 3 kilometres, but in most places the rocks would don’t reach that temperature until nearer 10 km.

The model is very crude. For example, it does not capture the dynamics of the extraction process. But it does represent a simple way to assess the resources available. I’ll discuss the shortcomings of the model below.

Details of the model are given at the end of this article, and here I just describe the results.

One cubic kilometre of rock

The model considers one cubic kilometre of ‘fracked’ rock through which water can easily percolate, and be warmed by 100 °C.

The total heat available to be extracted is ~1.6 x 10^17 joules or 45 billion kWh_th. The “_th” suffix indicates thermal energy.

If we suppose that we wish to generate 100 MW_e of electricity, then using a typical generating efficiency of 33%, we need to extract heat at a rate of 300 MW_th. The “_e” suffix indicates electrical energy. This corresponds to a very high flow rate of around 0.7 cubic metres of water per second.

Based on a uniform extraction rate, the thermal resource would be exhausted after ~17 years, a lifetime which could be extended by extracting energy at a lower rate.

But once exhausted the time to restore this thermal resource is tens of thousands of years.

Once the thermal resource has been extracted, the cubic kilometre of rock will have shrunk sufficiently that the land above it will subside by roughly 0.6 metres.

One might also usefully compare the 100 MW_e generation from 1 cubic kilometre of rock with the Solar PV generation from 1 square kilometre of the Earth’s surface.

Assuming that 1 square metre of solar panels generates 1 kWh/day in summer, then a square kilometre of solar panels will produce 1,000 MWh_e/day which can be compared with the 24 x100 = 2,400 MWh_e produced from the rock below.

If one reduced the rate of extraction by a factor 2.4 to 42 MW_e to match the solar PV generation, then the lifetime would be extended to about 40 years – similar to a normal power plant.

What might a geothermal plant look like?

The geothermal resource can be used alongside the  solar PV and wind generation to produce year-round, reliable low-carbon electricity.

If one cubic kilometre of rock could generate 42 MW_e for 40 years, then to generate say 3.5 GW_e – similar to the output of Hinkley C –  we would need roughly 3,500/42 ~ 82 square kilometres – or an area ~ 9 km x 9 km – which is a large amount of land, but small compared to our total land area of the UK.

The geothermal surface plant need not occupy much of this area, but all the area would be potentially affected by subsidence, and/or small earthquakes during the fracking process.

Additionally, the geothermal energy produces a large amount of waste heat, which might also be available for district heating or warming crops.

Discussion of the Model

I have used figures from the report  which suggest that injecting water at 200 °C and withdrawing at 300 °C represent useful operating parameters. The water would be used in a so-called ‘binary’ plant to heat a secondary fluid which would then power a generator.

The idea of warming water by 100 °C is pretty optimistic since the thermal gradient within the Earth is only 25 °C/km. And in most of the UK one would need to drill to ~10 km to reach rocks at this temperature, something which is extremely challenging. So I have just assumed that somewhere in the UK, hotter rocks are available nearer the surface.

I have also not considered any impacts on groundwater flow.

The most obvious criticism of the model is that extracting heat energy at a uniform rate is unrealistic. In practice, the heat would be extracted easily at first, and over years the rate of heat extraction would fall exponentially. This could be used to boost initial power output as the expense of a shorter lifetime. But the calculated amount of heat is the maximum energy that could be removed over the lifetime of the well.

One could of course remove heat from a greater vertical depth, but this would leader to greater subsidence, and in the UK we do not have large areas over which subsidence is acceptable. In old mining areas, subsidence is a considerable blight, and so this could only really be considered in the most isolated of places.


Drilling deep wells is hard work and so expensive. One figure from the ‘How stuff works‘ article suggests $20 million dollars per 10 km well.

So to extract heat from a 9 km x 9 km area would require (I guess) around 81 boreholes and so the capital cost would be in the range £1 billion to £2 billion. Even with the additional costs of generating plant, the cost would likely be less than a nuclear station (£20 billion). And the plant could be enlarged slowly with new blocks being drilled as the first blocks came on line.

So geothermal energy is a large but still finite resource from which heat is harvested and then wells are abandoned and the plant moves on to new areas., after perhaps a decade or so. And so we could imagine plants slowly ‘grazing’ across the country under areas which were insensitive to subsidence or earthquakes.

This is a rather different proposition to that which is marketed by geothermal advocates in which geothermal energy is considered as practically infinite and having negligible impact on the land. It may make sense in the western US, but I am sceptical that it makes sense at scale in the UK, especially given the potential risks.

And as I mentioned at the start we are in a Climate Emergency and need to act urgently. And this makes me doubly sceptical of novel technologies which might steal investment from known solutions.

In contrast, investments in wind and solar and batteries will definitely bring electricity costs down, reduce carbon emissions and reduce – but not yet completely eliminate – the use of gas.



Details of the spreadsheet model

The spreadsheet model can be downloaded here and is described below. I apologise in advance for any errors I have made.

Click on image for larger version. These are the basic parameters used in the model

Click on image for larger version. This section of the spreadsheet calculates the thermal properties of one cubic kilometre of rock.

Click on image for larger version. This section of the spreadsheet calculates the operational parameters of a geothermal power plant assuming a constant rate of heat extraction.

Obviously the properties of rocks vary greatly, and the hottest rocks often occur under very hard rock – very different from the rocks through which oil and gas companies normally drill.

However, I think the spreadsheet model captures the correct order of magnitude of the geothermal resource. It’s large, but finite.

Everything Was Forever, Until It Was No More

June 2, 2022

Friends, I have been struggling to understand why our governments are not responding adequately to the Climate Emergency that we are facing. It seems like madness!

And thinking about this failure put me in mind of other massive events to which governments failed to anticipate.

Everything Was Forever, Until It Was No More

Friends, one of the most shocking world events to have occurred in my lifetime was the collapse of the USSR and the breakdown of the Iron Curtain.

  • Before it was built, the idea of building an Iron Curtain must have seemed unimaginable.
  • While it existed, it seemed unimaginable that it would ever fail.
  • And after it was swept away, it seemed unimaginable that it should ever have existed.

Clearly, a very prolonged failure of imagination. And not just on my part. As far as I can tell, no intelligence agency on Earth – inside or outside the Iron Curtain – saw it coming.

I have been curious about this for sometime, and last year I read “Everything Was Forever, Until It Was No More“: a fascinating anthropological insight into how – from the perspective of ‘ordinary people’ – the collapse of the Soviet Union was both a profound shock, but also not particularly surprising.

The book focuses on one particular aspect of soviet life – formal communications from the Communist Party.

In particular, the book referred to great announcements of policy changes. These were often trailed in advance, and anticipated with great excitement, but in fact they were either content-free, or are designed to hide the important aspects of the announcement. Sound familiar?

It is a difficult and highly academic text, but I persisted in reading it because the more I read the more I could see parallels between practices in the USSR and modern ‘communications’ in the UK, both corporate and governmental.

Here are some examples of the style of communication I am talking about.


Further to the policies of the 44th Meeting of the General Committee of the Communist Party, and enabled by the glorious achievements of the seventh 5-year plan, the General Secretary of the Moscow (North) Communist Party has put forward plans to the legislative council that will consolidate the strength of the revolution in our workplaces.”.

UK: Government

In our Manifesto, we promised the British People that, if elected, we would build a better Britain. And so, humbled by the trust placed in us by hard-working families from right across our great country, we have placed before her Majesty, a Bill to increase economic growth by freeing entrepreneurs from red tape.”.

UK: Corporate 

Our company was founded on principles of innovation, dynamism, and fairness. As Sir Charleston Hobnob himself said, ‘Our people are our greatest strength’. And since I was appointed I have seen how true that is across the business. And seeing this resilience first-hand has been humbling, and has convinced me of the need to build on Sir Charleston’s vision for the company.”.

Can you see the similarities? As adults, we recognise this as content-free ordure, as did people in USSR. But we put up with it – as Soviet citizens did – because that’s just ‘the way things are’.

But what this style of announcement fundamentally communicates is that ‘Nothing is changing: existing power structures based on historical precedent are secure‘.

And the reason I am mentioning this here is that as I look at the Climate Change to which we have already committed ourselves, I don’t see any genuine appreciation of the scale of the difficulties that we are facing.

And the very structures of government and their ‘communications’ teams seem to be incapable of acknowledging the reality of what we are facing.

I appreciate that it’s a tough message for politicians. They are happy to speak grandly of concern for global problems, but no one wants to explain to people that we in the UK need to urgently change the way we live: for example, by insulating our homes, flying and driving less, and eating differently.

Even Capitalist Institutions such as Deloitte acknowledge that change is required!

We have the technologies, business models, and policy approaches today to deliver rapid decarbonization and limit global warming to as close to 1.5°C by century’s end. 

We cannot afford to waste another year, another month, debating the merits of doing something versus doing nothing. As leaders, every choice, every day is a chance to speed the realization of that vision.

But the simple truth is, that our government is not acting urgently and it seems incapable of truly changing. It is still allowing new fossil fuel ventures and has no policy to insulate homes. It is completely failing to acknowledge the truly awful reality we face if we continue as we are.

And I am writing this now because I think the scale of the climate change we face will be such that political and economic structures in the UK or anywhere else will crumble.

And from the perspective of ‘ordinary people’ – just like in the Soviet Union – this collapse will be both a profound shock, but also not particularly surprising. We all know that something is deeply, deeply, wrong.

But if we don’t collectively acknowledge that the way we live needs to change – in some ways for the worse – then climate change will simply overwhelm us in the most basic of ways. And it will force us to change the way we live in ways which currently seem unimaginable.

Hadrian’s Wall

I remember visiting the remains of Hadrian’s Wall a few years ago and being impressed by its extent and complexity. Clearly it represented an immense amount of work and in its time it must have seemed utterly and absolutely permanent.

And yet there came a time when the last Roman garrison must have just walked away, leaving the locals to make of it what they will.

Friends, Romans, countrymen, lend me your ears. As Jupiter has guided our actions, our armies have conquered the whole of the known world. And you legionnaires have fought well, defeating the Picts and earning your right to return and live peacefully in your homeland. And I, Caesar, will welcome you home earlier than we had planned.”.

“Off-Grid” or Not “Off-Grid”? That is the question.

May 26, 2022

Friends, it’s May, and slightly later than last year, our house is now ‘Off-Grid’.

Click on image for a larger version. Graph shows the daily household consumption of electricity (kWh) since the March 2021. Also shown is the amount of electricity drawn from the grid (kWh). Both quantities are averaged over ± 1 week.

By ‘Off-Grid‘ I mean that the combination of…

  • 15 kWh/day of solar electricity, and
  • 13.5 kWh of battery storage in our Powerwall,

…is enough to allow us to…

  • consume 10 ± 2 kWh/day of electricity and
  • export on average 6 kWh/day

…without having to draw any electricity from the grid. Almost


On the graph above it looks like in this happy situation, we draw zero electricity from the grid.

However, if one looks closely one can see that electricity usage is low, but not quite exactly zero.

The figure below shows half-hourly electricity usage (watts) over 4 consecutive days in May. This data was acquired using the highly pleasing Powershaper software.

Click on image for a larger version. Chart showing electricity used by the Tesla Powerwall throughout 4 consecutive days in May 2022. Averaged over half-hour periods through the day, the Powerwall draws around 1 watt, but occasionally draws as much as 20 watts. Over a day it adds up to less than 0.1 kWh costing between 1 and 2 pence.

I don’t know why the Powerwall is doing with this: it typically has a battery filled which electricity which it could use!

My guess is that it uses the grid to help it meet transient demands. I suspect that if we could look more closely then we would see that rather than consuming 1 watt continuously, it would instead be consuming no power most of the time, but then occasionally it would a draw a kilowatt or so for just a second or so.

The software that controls the battery does have a ‘True’ Off-grid mode which apparently would isolate the house completely from the grid. But in honesty, I have been too scared to push the button!

Being ‘practically off-grid is enough of an adventure for me.

Update: 26 May 2022

The 9-minute video below explains the effect I am describing with admirable simplicity.

Why global warming affects the poles more than the equator

May 8, 2022

Friends, welcome to Episode 137 in the occasional series of “Things I really should have known a long time ago, but have somehow only realised just now“.

In this case, the focus of my ignorance is the observation that the warming resulting from our emissions of carbon dioxide affects higher latitudes more than lower latitudes.

This is a feature both of our observations and models. But what I learned this week from reading the 1965 White House Report on Environmental Pollution (link) was the simple reason why.

[Note added after feedback: In this article I am describing an effect that makes the direct effect of increase CO2 levels more important at high latitudes. There are also many feedback effects that amplify the direct effect and some of these are also more  important at high latitudes. Carbon Brief has an excellent article on these feedback effects here, but that is not what I am talking about in this article.


The two gases responsible for majority of greenhouse warming of the Earth’s surface are water vapour and carbon dioxide. But the distribution of these two gases around the planet differs significantly.

  • The concentration of water vapour in the atmosphere depends on the temperature of the liquid surfaces from which the water evaporates. Because the Equator is much hotter than the poles, there is much more water vapour in the atmosphere at the Equator compared with the poles.
  • The concentration of carbon dioxide in the atmosphere is pretty uniform around the globe.

This is illustrated schematically in the figure below.

Click on the image for a larger version. There is more water vapour in the atmosphere in lower latitudes (near the Equator) that at higher latitudes (near the poles). In contrast, carbon dioxide is rather uniformly distributed around the globe.

Of course the truth is a bit more complex than the simplistic figure above might imply.

  • Water vapour from the Equator is transported throughout the atmosphere. But nonetheless, the generality is correct. And the effect is large: the atmosphere above water at 15 °C contains roughly twice as much moisture as the atmosphere above water at 5 °C.
  • Carbon dioxide is mainly emitted in the northern hemisphere, and is then uniformly mixed in the northern hemisphere within a year or so. The mixing with the Southern Hemisphere usually takes two or three years. The variability around the globe is usually within ±2%.

The uniformity of the carbon dioxide distribution can be seen in the figure below from Scripps Institute showing the carbon dioxide concentrations measured at (a) Mauna Loa in the Northern hemisphere, and (b) the South Pole.

Click on the image for a larger version. The carbon dioxide concentrations measured at (a) Mauna Loa in the Northern hemisphere, and (b) the South Pole. Notice that the data from South Pole shows only small seasonal variations and lags behind the Northern Hemisphere data by a couple of years.

Because of this difference in geographical distribution, the greenhouse effect due to carbon dioxide is relatively more important at higher latitudes where the water vapour concentration is low.

And that is why the observed warming at these latitudes is inevitably higher.

Click on the image for a larger version. The observed temperature anomalies shown as a function of location around the Earth for four recent years. Notice the extreme warming at the highest latitudes in the Northern Hemisphere (Source: UEA CRU).

Once I had read this explanation it seemed completely obvious, and yet somehow I had neither figured it out myself nor knowingly read it almost 20 years of study!

2022 to 1978: Looking Back and Looking Forwards

May 3, 2022

Friends, it’s been two years since I retired, and since leaving the chaos and bullying at NPL, retirement has felt like the gift of a new life.

I now devote myself to pastimes befitting a man of my advanced years:

  • Drinking coffee and eating Lebanese pastries for breakfast.
  • Frequenting Folk Clubs
  • Proselytising about the need for action on Climate Change
  • Properly disposing of the 99% of my possessions that will have no meaning to my children or my wife after I die.

It was while engaged in this latter activity, that I came across some old copies of Scientific American magazine.

Last year I abandoned my 40 year subscription to the magazine because it had become almost content free. But in its day, Scientific American occupied a unique niche that allowed enthusiasts in science and engineering to read detailed articles by authors at the forefront of their fields.

In the January Edition for 1978 there were a number of fascinating articles:

  • The Surgical Replacement of the Human Knee Joint
  • How Bacteria Stick
  • The Efficiency of Algorithms
  • Roman Carthage
  • The Visual Characteristics of Words


  • The Carbon Dioxide Question

You can read a scanned pdf copy of the article here.

This article was written by George M Woodwell a pioneer ecologist. The particular carbon dioxide question he asked was this:

Will enough carbon be stored in forests and the ocean to avert a major change in climate?

The article did not definitively answer this question. Instead it highlighted the uncertainties in our understanding of the some of the key processes required to answer the question.

In 1978 the use of satellite analysis to assess the rate of loss of forests was in its infancy. And there were large uncertainties in estimates of the difference in storage capacity between native forests, and managed forests and croplands.

The article drew up a global ‘balance sheet’ for carbon, and concluded that there were major uncertainties in our understanding of many of the physical processes by which carbon and carbon dioxide was captured (or cycled through) Earth’s systems.

Some uncertainty still remains in these areas, but the basic picture has become clearer in the subsequent 44 years of intense study.

So what can we learn from this ‘out of date’ paper?

Three things struck me.


Firstly, from a 2022 perspective, I noticed that there are important things missing from the article!

In considering likely future carbon dioxide emissions, the author viewed the choices as being simply between coal and nuclear power.

Elsewhere in the magazine, the Science and the Citizen column discusses electricity generation by coal with no mention of CO2 emissions. Instead the article simply laments that coal will be in short supply and concludes that:

“There is no question… coal will supply a large part of the nation’s energy future. The required trade-offs will be costly however, particularly in terms of human life and disease.

Neither article mentions generation of electricity by gas turbines. And neither makes any mention of either wind or solar power generation – now the cheapest and fastest growing sources of electricity generation.

From this I note that in it it’s specific details, the future is very hard to see.


Despite the difficulties, the author did make predictions and it is fascinating from the perspective of 2022 to look back and see how those predictions from 1978 have worked out!

The article included predictions for 

  • The atmospheric concentration of CO2
  • CO2 emissions from Fossil Fuels

Click on image for a larger version. Figure from the 1978 article by George Woodwell. The curves in green (to be read against the right-hand axis) shows two predictions for atmospheric concentration of CO2. The curves in black (to be read against the left-hand axis) shows two predictions for fossil fuel emissions of CO2. In each case, the difference between the two curves represents the uncertainty caused by changes in the way CO2 would be cycled through (or captured by) the oceans and forests. See the article for a detailed rubric.

The current atmospheric concentration of carbon dioxide is roughly 420 ppm and the lowest projection from 1978 is very close.

The fossil fuel emissions estimates are given in terms of the equivalent change in atmospheric CO2, and I am not exactly sure how to interpret this correctly.

Atmospheric concentration of CO2 is currently rising at approximately 2.5 ppm per year, and roughly 56% of fossil fuel emissions end up in the atmosphere. So the annual emissions predicted for 2022 are around 2.5/0.56 ~ 4.5 ppm /year, which is rather lower than the lowest prediction of around 6 ppm/year.

The article also predicts that this will be the peak in annual emissions, but that has yet to be seen.

The predictions did not cover the warming effect of carbon dioxide emissions, the science of which was in the process of being formulated. ‘Modern’ predictions can be dated to 1981, when James Hansen and colleagues published a landmark paper in Science (Climate Impact of Increasing Atmospheric Carbon Dioxide) which predicted:

A 2 °C global warming is exceeded in the 21st century in all the CO2 scenarios we considered, except no growth and coal phaseout.

This is the path we are still on.

From this I note that the worst predictions don’t always happen, but sometimes they do.


The final observation concerns the prescience of the author’s conclusion in spite of his ignorance of the details.

Click on the image for a larger version. This is the author’s final conclusion in 1978

His last two sentences could not be truer:

There is almost no aspect of national or international policy that can remain unaffected by the prospect of global climatic change.

Carbon dioxide, until now an apparently innocuous trace gas in the atmosphere may be moving rapidly toward a central role as a major threat to the present world order.


First Winter with a Heat Pump

April 27, 2022

Friends, our first winter with a heat pump is over.

Last week:

  • I switched off the space heating, and…
  • I changed the heating cycle for domestic hot water (DHW) from night-time (using cheap-rate electricity) to day-time (using free solar electricity).

From now until the end of July, I am hopeful that we will be substantially off-grid.

Let me explain…

No Space Heating 

The figure below shows the temperatures relevant to our heating system for the week commencing Saturday 9th April.

The week started cold, with overnight temperatures close to 0 °C and daytime temperatures peaking at 12 °C.

But the week ended with much warmer temperatures, and even in the absence of any heating flow, the household temperature rose above 21 °C. At this point I decided to switch off the space heating. You can see this on the monitoring data below.

Up to the 15th April, the heat pump would operate each evening – you can see this because radiator temperatures oscillated overnight as the heating circuit struggled to deliver a very low heating power.

From the 16th April – with the space-heating off – you can see the radiator temperatures simply fell after the DHW water heating cycle.

Click image for a larger version. Graph showing four temperatures during the week beginning 9th April 2022. The upper graph shows the temperature of radiator flow and the domestic hot water (DHW). The lower graph shows the internal and external temperatures. In the colder weather at the start of the week, the radiator flow temperatures cycled on and off. In the warmer temperatures at the end of the week, heating stopped automatically. On 16th April I switched the space heating circuit off.

Heating DHW during the day 

The next graph shows the same data for the following week. Now there is no space-heating in the house, but the insulation is good enough that household temperature does not fall very much overnight.

On the 20th April I switched from heating the domestic hot water at night (using cheap rate electricity) to heating during the afternoon (using electricity generated using solar PV).

My plan was that by 2:00 p.m., the battery would be substantially re-charged, and heating the hot water at that time would:

  1. Minimise exports to the grid and maximise self-use of solar-generated electricity.
  2. Heat the domestic hot water using air that was ~ 10 °C hotter than it would be at night – improving the efficiency of the heat pump.

Click image for a larger version. Graph showing four temperatures during the week beginning 16th April 2022. The upper graph shows the temperature of radiator flow and the domestic hot water (DHW). The lower graph shows the internal and external temperatures. The radiator flow was switched off. On 20th April I switched from heating the domestic hot water at night to heating during the day.

One can see that household temperature has fallen a little during the week, but only to around 19 °C, which feels quite ‘spring-like’ in the sunshine.

The big picture 

The graph below shows:

  1. The amount of electricity used by the household
  2. The amount of electricity drawn from the grid

It covers the whole of 2021 and the start of 2022 up to today (almost) the end of April. The graphs show running averages over ± 2 weeks.

Click image for a larger version. Graph showing the amount of electricity used by the household each day (kWh/day) and the amount of electricity drawn from the grid each day (kWh/day). Over the 8 months of the winter heating season, 27% was supplied by solar generated electricity.

The 4 kWp solar PV system was installed in November 2020 and was just beginning to make a noticeable difference to our electricity consumption in the spring of 2021.

In March 2021 we installed the Powerwall and immediately dropped off the grid for just over 2 months! In mid-summer we had a run of very poor solar days and we began to draw from the grid again.

In July 2021 we installed a heat pump and this extra load (for DHW) coupled with the decline in solar generation caused us to need to draw a few kWh from the grid each day.

Over the 8 month heating season from the start of August to the end of April, the household used 4,226 kWh of electricity for all the normal activities (~ 2,200 kWh) plus heating using the heat pump (~2,000 kWh). Over this period the heat pump delivered just over 7,000 kWh of heat for a seasonally averaged COP of around 3.5.

However, even in this winter season, only 3,067 kWh were drawn from the grid – mostly at low cost. The balance (27%) was solar generated.

Summer and Winter Settings

The optimal strategy for the Powerwall is now becoming clear.

In the Winter season, daily consumption can reach 25 kWh/day and solar generation is only ~ 2 kWh day. So in this season:

  • We operate the household from the grid during the off-peak hours.
  • We time heavy loads (dishwashing, tumble drying and DHW heating) to take place in the off peak hours.
  • We buy electricity from the grid to fill the battery (13.5 kWh) with cheap rate electricity – and then run the household from the battery for as long as possible. Typically we would need to draw full price electricity from the grid only late in the day.

Click image for a larger version. Images showing the time of day that we have drawn power from the grid (kW) in half-hour periods through the day. Each image shows the average for one month. The graph was assembled using data from the fabulous Powershaper software (link).

In the ‘summer’ season, daily household consumption is ~11 kWh and average solar generation is typically 15 kWh/day. So given that the battery has 13.5 kWh of storage, we can still stay ‘off-grid’ even during a periods of two or three dull days.

So during this period

  • We switch the battery from ‘time-based’ mode to ‘self-powered’ mode.
  • We time heavy loads (dishwashing, tumble drying and DHW heating) to take place in the afternoon.

This year and last year 

Last year (2021), as soon as we installed the Tesla Powerwall battery, we dropped off-grid within days.

But this year (2022) we have an additional daily electrical load. Now we are heating DHW electrically with a heat pump which requires ~ 1.5 kWh/day.

Nonetheless, I hope it will be possible to remain substantially ‘off-grid’ for the next few months. Time will tell.

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