Category Archives: Thoughts on the World

Are British Airways a Bus Company?

'Nuff said

Are British Airways an airline or a bus company? You’d hope the answer was evident from the name, but I’m beginning to have my doubts. I’ve just done an analysis of the flights I’ve taken with them from Heathrow since 2018:

Morocco 2018. This was so ridiculous it’s laughable, but with a dark shade because it was really quite a bad health and safety failure. We sat at the gate for the outgoing flight and they called us forward by "group number". Instead of going down the ramp to an aeroplane, we had to go down several flights of steps and outside, where a number of buses were waiting. We were directly randomly to buses with no attempt to keep the boarding groups even roughly together. After a long ride we arrived at the plane in the middle of a field, which had two sets of steps set up. One bus went to the front, another to the back. This resulted in people with seats at the back boarding from the front, while some with seats at the back were boarding from the back. "Punch up" doesn’t quite cover it, the average bar fight in a film is better organised. Fortunately we managed to sort ourselves out, but literally "nil points" to the useless BA organisation, and thank the stars that no-one suddenly needed medical attention or worse.

We had two short-haul BA flights in 2019, to Belfast and Copenhagen. I can’t remember either involving a bus, but maybe I’m blanking it out.

Patagonia 2023. After a 13 hour flight from Argentina the plane landed in a field, and was met by a bus. The ride back to the terminal took so long that I noted on my blog that I wasn’t sure whether we’d actually landed at Heathrow, or Northolt!

Belfast 2023. Our scheduled flight was cancelled, and we got bumped to one next morning. Having waited on the tarmac at Belfast for about an hour we got underway, only to land at Heathrow and sit on the tarmac again. Eventually we docked at a gate, and went up the ramp, to be directed down the stairs and out of the building onto a bus. This then drove us round from the "international" side of T5 to the domestic one, a trip which took about 20 mins, despite the fact you could probably walk it in about the same time.

Las Vegas 2023. After a 10 hour flight we parked in a field, to be discharged onto a bus. The ride to the terminal wasn’t quite so interminable as some of the others, but long enough.

4/6, maybe worse.

A few years ago a comedian, I think it might have been Michael Macintyre, lampooned as peculiarly British the phenomenon of the replacement bus service, as seen through the eyes of a foreign visitor:

"But I have ticket for train?"

"Get on the bus!"

I see that BA are honouring the "British" in their name by simply extending this pattern.

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One of Those Days…

Smash the system!


I woke up at 6am this morning looking forward to my day off and my cookery course which was one of my Xmas presents

and I thought I’ll just do my VAT return, then I’ll sort out some photos before breakfast

and I go into my VAT software and it says that my subscription has expired and I have to pay for another year

and I complete the purchase form and go to make a payment, and I have to authorise the card payment with my app

and I unlock my phone, and it gets really confused with different prompts and locks up, and I have to reboot it, which for some reason always takes ages

and when it has rebooted I find that one of the prompts is a message from my credit card company saying they have detected a potentially fraudulent transaction and have blocked my card, so the payment to the VAT software company is declined

and I have to go and get another card and at least this time I can run the VAT software

and I submit my return, then notice that in the confusion I’ve missed an error and I’ve effectively overpaid HMRC about £800

and you know what, once you’ve submitted a return there’s absolutely no way to either correct or resubmit it, the official HMRC instruction is “sort it out manually next time”

and I write myself some notes so that hopefully I’ll get it right next time

and while I’m writing my notes the phone pings again and it’s the cookery school saying the chef has been suddenly taken ill and they will have to postpone the course, for which I’ve taken a day off

and I go into my email and there’s an email from the cookery school saying the chef has been suddenly taken ill and they will have to postpone the course, for which I’ve taken a day off

and I’m replying to the email to confirm I’ve received it and I get a phone call from the cookery school saying the chef has been suddenly taken ill and they will have to postpone the course, for which I’ve taken a day off

and at least we manage to agree a replacement date, but it’s in November

and I’m now no longer in the mood to sort out photos, but I think I’ll just re-rip a track from a CD which didn’t play properly last time I listened to it

and while the re-rip has worked Windows Media Player has decided to rename some of my songs so they have different filenames when I sync up to my phone

and I have to go through all my playlists and fix the problems with missing songs

and it’s now breakfast time

and I just want to sit in a corner with a blanket over my head and moan

and I’m not convinced about this nice day off business.



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Meet the Guardian!

Puff the guardian dragon
Camera: Panasonic DC-G9 | Date: 19-06-2023 20:37 | Resolution: 5184 x 3888 | ISO: 500 | Exp. bias: -66/100 EV | Exp. Time: 1/80s | Aperture: 7.1 | Focal Length: 35.0mm | Lens: LUMIX G VARIO 12-35/F2.8II

Meet the new guardian of our gradually-expanding menagerie of the sculpted and carved.

Puff the guardian dragon (Show Details)

For a name we considered Rhaegal and Viserion, Druk and Y Ddraig Goch.

But we’re children of the 1960s. So we’ve settled simply on “Puff”.

Puff the guardian dragon (Show Details)
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UK’s Strongest Man (And Woman!) 2023

Action from the UK's Strongest Man 2023
Camera: SONY DSC-RX100M7 | Date: 29-05-2023 13:17 | Resolution: 1553 x 1553 | ISO: 3200 | Exp. bias: -1 EV | Exp. Time: 1/160s | Aperture: 6.3 | Focal Length: 52.6mm (~145.0mm)

Great sport at the UK’s Strongest Man 2023 / UK’s Strongest Woman 2023. However not impressed by the new (on the day, as far as I could work out) ban on “professional cameras” which meant the G9 had to remain locked away, and I had to rely on the tiny Sony RX100 and lot of post-processing in Topaz Photo AI…

Also not impressed by the fact we both seem to have caught a cold at the Nottingham Motorpoint Arena. Outdoor venues are much better for this!

Action from the UK’s Strongest Woman 2023 (Show Details)

Action from the UK’s Strongest Woman 2023 (Show Details)

Action from the UK’s Strongest Man 2023 (Show Details)

Action from the UK’s Strongest Man 2023 (Show Details)

Action from the UK’s Strongest Man 2023 (Show Details)
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Splendidly Dodgy!

Horse Boarding at Burghley Park
Camera: Panasonic DC-G9 | Date: 28-05-2023 16:53 | Resolution: 3258 x 2172 | ISO: 200 | Exp. bias: -33/100 EV | Exp. Time: 1/250s | Aperture: 5.6 | Focal Length: 35.0mm | Lens: LUMIX G VARIO 35-100/F2.8

Welcome to a new sport, discovered on a visit to Burghley House and Park this weekend. Horse Boarding.

Horse Boarding at Burghley Park (Show Details)

You have to navigate a tight course of bends and slaloms on a skateboard. At speeds of up to 30 mph. While being towed behind a racehorse!

The wipe-outs are dramatic, but usually quite close to something relatively soft.

Horse Boarding at Burghley Park (Show Details)


I understand a small operation is required, to remove any sense of fear but leave the sense of balance intact…

Horse Boarding at Burghley Park (Show Details)
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Barbados – Mojo Reanimated

Thirs World with guest Biggie Irie at the Barbados Vintage Reggae Festival 2023
Camera: Panasonic DC-G9 | Date: 29-04-2023 00:49 | Resolution: 3400 x 2125 | ISO: 1600 | Exp. bias: -133/100 EV | Exp. Time: 1/200s | Aperture: 5.6 | Focal Length: 177.0mm | Lens: LUMIX G VARIO 100-300/F4.0-5.6II

It gives me great pleasure to announce that Barbados has its mojo back.

We’ve been regular visitors to the magical island over many years now. It was a real frustration that our 2020 trip got cancelled with only a few weeks’ notice, and we couldn’t wait to return. We were lucky enough to get back at the end of 2021, and also in 2022, but between the impacts of a year of lockdowns and enduring Covid restrictions it was somehow changed. Yes, the sun still shone and you could still get a good meal (before the 9.00 curfew), but many of the touches we value were missing. Barbados’ mojo was (as no blues song has ever put it) not in an operational state.

Suddenly, this April, it’s working again. The most visible single indicator is the triumphant return of the Reggae Festival.  On Friday we were treated to a parade of well-loved faces and voices. Local girl Wendy Alleyne (OK, she’s probably older than I am) opened her sparkling set with the hilarious “I Am Still Here” (essentially “I’m Not Yet Dead”). The Fab 5 stormed in from Jamaica with all the old favourites, even if they can’t jump as high as before and no longer have their full brass section. However the highlight of the evening was undoubtedly Third World, who’s stunning set encompassed reggae, rock, a bongo solo, Redemption Song on a cello, and the operatic “Con Te Partirò”!

Wendy Alleyne at the Barbados Vintage Reggae Festival 2023 (Show Details)

Third World at the Barbados Vintage Reggae Festival 2023(Show Details)

Third World at the Barbados Vintage Reggae Festival 2023, and no, that isn’t Romesh Ranganathan on Bass! (Show Details)

There are other signs too. New restaurants have replaced many of those which failed during Covid. The sporting agenda is more or less back to normal and we got to our first polo match in 4 years.

Barbados vs Switzerland (Show Details)

The buzz is back. Wonderful!

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Getting High (But Not That High)!

Andrew with the AirSportsBarbados microlight
Camera: SONY DSC-RX100M4 | Date: 22-04-2019 20:00 | Resolution: 4621 x 2888 | ISO: 125 | Exp. bias: -0.7 EV | Exp. Time: 1/320s | Aperture: 4.5 | Focal Length: 8.8mm (~24.0mm)

Back in 2019 I was privileged to take what is a pretty unique airborne trip. Paul Nugent of Airsportsbarbados had one of only four two-seater microlight aircraft in the Caribbean, and at that time was running tours. To make it interesting, he was based at the International airport (Barbados only has one), so we queued up for take-off behind a 747 bound for Canada, and formed an orderly queue behind a Lear Jet to land!

View back over Grantly Adams International Airport – through the propeller of a microlight! (Show Details)

Camera and lens choice was important, as I needed something light, easy to manipulate and which wouldn’t stick out too far into the slipstream. Also I wouldn’t be changing lenses! The Panasonic G9 was the ideal body, and I paired it with the jewell-like Panasonic 45-175mm. That’s a real gem: only 90mm long (and no longer, it’s an internal zoom) weighs 210g, and its tiny size means that it can be held stable in quite a strong wind.

We flew up the East Coast and back, which gave me great views of The Crane, where we stay. On a really good day I might be able to get these shots with a drone, but the prevailing wind would make it a challenge. it’s less of an issue if you yourself are 300ft up.

The Crane, Barbados, from a Microlight (Show Details)

The pools at The Crane, Barbados, from a Microlight (Show Details)

The trip also took in other well-known sights on that side of the island including Codrington College, Bathsheba and the Morgan Lewis Windmill. Being able to photograph Morgan Lewis from the air was especially entertaining as it had just re-opened after a multi-year restoration, and by coincidence we had visited it, on the ground, the previous day.

The Morgan Lewis Windmill, from a Microlight (Show Details)

This wouldn’t be for everyone, but if your phobias allow it and you ever get the opportunity to do something similar, take it!

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My New Avatar – Thanks Dall-E!

A fat bear lifting weights, by Dall-E

Thanks to Dall-E for my new avatar. The shape of the abdomen is about right…

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When You Wish … A Different Approach To Sourcing

This may amuse you. It might also scare you a bit…

First, you have to realise I have form here. Years ago, when we were fitting out Frances’ treatment room, we were having coffee with my parents. We complained that what we really needed was an avocado green vanity sink, but they had gone out of fashion. My father put down his coffee, and went upstairs. We heard  the loft door open and close, and he came back down the stairs carrying … an avocado green vanity sink!

A couple of years ago when we were planning our kitchen refit, we were having dinner with friends in Norfolk. We told them about our plans, and said “what we’d like to track down is a Neff Hide&Slide oven, but the older style with physical switches rather than a touch panel”. Nigel stood up from dinner, and said “come with me to the garage”. There, he presented me with a dirty but complete Neff Hide&Slide oven, the older style with physical switches rather than a touch panel. I had to swap it for an old lawn mower, and it needed a new element and seals, but now it’s in and works beautifully.

So, on Saturday night I was out with friends celebrating my birthday, as you do. As is the way, talk turned to work, and I complained that we are having a challenge getting a good power benchmark for our servers. I said that I know what data I need, and I’m pretty sure I could get it, but I can’t physically type commands into the ESX system, and the third-hand approach exchanging instructions with a system operator at our supplier is not working.

And Keith said, as can happen, “well, since Jill retired we no longer use our ESX server. It’s been on eBay but no-one wants it, and I was about to take it to the dump.”

Thus from Friday I will have a new, old, virtualisation server, and I can get my client the calibration data we are so desperately seeking.

Now, do I know anyone who might have an old Ferrari in the garage, and when are they free for dinner?

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This is Really Scary…

A photo of a guanaco on a paddle board on a lake in front of the Torres del Paine mountains (courtesy of Dall-E)

This morning’s subject was a “guanaco hunt”, capturing one or more of the charming Patagonia llamas in a nice pose, ideally in front of a mountain or similar.

Over lunch, as beer was consumed, we got talking about how we could improve the images we had captured. Looking at the wonderful view from the restaurant, I came up with the idea of a guanaco on a paddle board in front of the mountains.

Always up for a challenge I had my first go with Dall-E, the AI image generator. I gave it this simple prompt: “A photo of a guanaco on a paddle board on a lake in front of the Torres del Paine mountains”. Two of the four images it created were unusable, but the first was OK, the third was exactly what I had in mind. OK the guanaco’s legs are a bit odd, but the concept has been correctly interpreted and executed, and that’s the difficult part.

It really shouldn’t be that easy. Be afraid, be very afraid!

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Numeracy and Spurious Accuracy

While I’m not convinced by Rishi Sunak’s plan to improve British standards of numeracy, I wholly support the objective. I seem to be battling on a daily basis with statements which either make no sense if you inspect the numbers, or where the underlying message is confused by poor presentation.

One particular bête noir is “spurious accuracy”, where a number is quoted to a vast number of significant digits because “the computer said so”, without any thought about whether that makes any sense.

Here’s a direct quote from an email I received this morning from the Liberal Democrats:

We understand that our members may wish to move on to Monthly Direct Debit to make budgeting easier. As a result, we’re happy to be able to offer you the ability to split your payments down to £6.979166666666666 per month, should you wish.

That could scare some people as much as it helps them, no bank will support it, and it clearly demonstrates that the writer didn’t understand the subject. It should have been “£6.98 per month” (with a direct debit premium of 1p per year), or, even better, “£7 per month with an initial payment of £6.75”.

That said, being me I started thinking about whether I could make up the sum of £6.9791666 (recurring) in cash. It’s actually surprisingly easy and doesn’t involve farthings or groats (I’m not that old). £1 = 240d (old pre-decimal pennies). 1d therefore equals 0.0041666 (recurring). So the stated amount is £6.97 + 1/2p + 1d, and I am old enough to have 1/2p and 1d in my coin collection!

Now, will my bank accept a deposit of 1d?

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4g CO2 Per Email. Really???

Burning Email

Disentangling a well-known “fact” about email

There’s a lot of “received wisdom” kicking about on the internet – ideas and “facts” which are essentially presented without question on the basis of “he said it, so it must be true”. This afflicts many fields, and sustainability is no exception. One common example is that “sending an email generates 4 grammes of CO2 or more”.

There are a couple of problems with this figure. One is that it doesn’t pass what one old manager of mine called “the giggle test” – email processing sits very lightly on computers and the amount of processing, and therefore energy consumption, for each is clearly tiny. We need to understand what else is included in this figure, or run the risk of discrediting otherwise valid environmental impact analysis by using it.

The bigger problem is that this figure is then taken, without unbundling its elements, and multiplied by large corporate email volumes to come up with massive estimates for the environmental impact of email which are clearly wrong – I have seen cases where the energy saving claim for an email improvement exceeded what we know to be the power consumption of all the company’s systems put together.

Finally because this is specifically about “email” people start to believe that other mechanisms, such as instant messaging, must be more efficient when the exact opposite may be the case.

We need a better way to understand and estimate the environmental impact of emails and similar mechanisms. In this article I try to develop one.

Where Did the 4g Figure Come From?

Although the figure is “all over the internet”, dig behind it and everything goes back to the work of Mike Berners-Lee, an academic at Lancaster University (by coincidence my own Alma Mater), who researches carbon footprints and has published a useful reference for them in his book “How Bad Are Bananas?: The carbon footprint of everything”. The 4g figure is widely quoted from the original 2010 edition. A revised analysis in the newer 2020 edition quotes smaller values for some cases, but even larger values for others.

While it’s a great book, providing much food for thought, there are a few challenges with the figures, particularly in this case. Berners-Lee doesn’t really “show his working”, and each section tends to present the answers, with a small following discussion, but you are left to try and unbundle the separate elements and decide which apply in which circumstances. The email figures are dominated by “preparation time” and embedded emissions, both of which need to be treated with caution. In addition the focus on “carbon” makes it a bit more tricky to reconcile his figures with actual measurements.

Power Consumption, not Carbon

While quoting the “equivalent carbon emissions” of different activities allows wider comparison, it’s actually a bit counter-productive for things where the primary source of emissions is electric power consumption, and I instead prefer to use kWh, or equivalent, for a number of reasons:

  1. Power consumption figures are unambiguous, whereas carbon equivalence varies between locations, over time (both seasonally and with longer-term changes), and with energy-sourcing arrangements. Carbon is to some extent subjective, whereas 1 kWh is the same across time and space.
  2. Carbon figures can be “gamed”. It’s very easy to say “we have no emissions because we only buy green electricity” or “we offset all our emissions with carbon credits, so we’re already net zero”. Neither helps to understand where consumption is happening and how to reduce it.
  3. Quoting carbon instead of consumption adds a layer of opacity to the calculation. If we’re just multiplying Watts by Seconds (or some multiples thereof) the calculations are easy, if we’re then applying a variable equivalence factor then things become more difficult to follow.

At the very least carbon figures need to be heavily qualified, e.g. “1 kWh means about 193g CO2 emissions in the UK using the typical generation mix in 2022”. Working at least as far as the penultimate line in power figures is easier.

Preparation and Reading Time

Berners-Lee’s estimate is not really about “sending an email” itself, and is dominated by the use of the computer to prepare and digest the email content. I think this needs to be excluded, or at least treated separately, for two reasons:

  1. It’s not predictable: there is a direct relationship between the size of an email and the work computers and networks have to do physically processing it. That does not exist for the writing and reading stages. A funny picture at the size limit of the system may take a few seconds to send and another few for each reader to look and laugh. At the other end of the scale a 5-line email about business restructuring and possible redundancies may take the boss a morning to write, and will then sit on the screen, being processed by its recipients, for the same time.
  2. It’s nothing to do with the use of the email channel. The preparation and reading effort will be similar if the same content is sent via WhatsApp, Teams, Snail Mail or hand-delivered using a gold Rolls Royce. The first two will have a similar “delivery” carbon cost to email, but I can promise you that the others start to get much larger!

The best way to handle this is to separate out two things. The first is the energy cost of sending and receiving the email. This is calculated, based on real measurements, below. Then there’s the “cost of using a computer for office work” (to distinguish it from more expensive variants like gaming or complex modelling). A modern PC with something like a 24” monitor and typical home or office networking uses around 50-70W. For an 8 hour working day that’s a total of about 0.5kWh, or about 100g CO2 using the current UK electricity generation factor, say 12g per hour for all your computer activities. If you’re just working on a phone, or on a low-spec laptop with the screen dimmed the figures will be much smaller again.

Embodied Emissions

Embodied emissions are those generated in the manufacture and delivery of a device. Berners-Lee quotes figures around 400kg CO2 for a range of laptops. Compared with the runtime emissions that’s enormous – if a laptop consumes an average of 20W and is left on 24 hours a day its annual power consumption is about 175 kWh, or about 34kg CO2 at the current UK equivalence (0.193kg / kWh). If it’s more efficient, and off or in a low-power state when not in use, then the power consumption is going to be a small fraction of the embedded emissions.

The challenge with including embedded emissions in something like a “per email” figure is twofold. First you need to choose a realistic, consistent life-cycle and duty-cycle over which to allocate them, and small changes in those rules will make a massive difference to the per-use emissions, dominating other considerations. For example, do you average them over the typical 3 year life and 10 hours per working day of a new corporate PC, or over the much longer actual lifetime of a typical PC including the second-hand phase, possibly 10 years or longer?

The other problem is they don’t scale, except in the most gross terms. If you have a system (PCs, servers and network) comfortably capable of handling 40,000 large emails per working day (see boring details below) then the embodied emissions are exactly the same whether your daily email volume is 40,000, or 4. If you do something dramatic and reduce your email volume by a factor of 100 then the “per email” emissions increase by the same factor. Even if you get rid of email altogether if the same people still have a PC then the reduction in embodied emissions is limited to maybe one server.

What you absolutely cannot do is take a relatively high “per email” figure and then multiply that up by a large volume to get the total. If the same system is able to handle that large volume, then the embodied emissions element simply does not change.

Unless you are comparing options for a device which will only ever be used for a single task (e.g. email) then it’s probably best to exclude embodied emissions from any task-specific calculation, but consider them alongside the general environmental cost of the computing infrastructure.

A Better Estimate for Email Processing

My initial approach was to try and come up with a theoretical model based on known power characteristics for typical computing equipment. The problem is that those models generate figures around a thousand times lower (milligrammes rather than grammes of CO2 per email), and I came up against repeated challenges of the form “but the internet says it’s 4g per email”.

To try to short-cut these arguments I’ve actually measured power consumption sending and receiving test emails, and derived some practical guidelines from the results. The approach taken is as follows:

  1. Measure power consumption of a test PC, and test duration, while sending and receiving a number of test emails
  2. Measure CPU activity on the email server used to process the emails
  3. Calculate the power usage for the test, both as a total value and as an increment over background consumption
  4. Derive an average energy cost for emails of different sizes, and the related estimated carbon emissions

The focus is on the physical creation of the emails (equivalent to pasting prepared text), sending, processing and receiving them. The time to write the email and other content, or to read after receipt, are not considered for the reasons set out above.

The following table shows the results from tests with various email sizes and volumes. The top section shows the total power consumption, the lower section the incremental consumption over background:

The following should be noted:

  • The test PC (a Dell XPS 9500) has a relatively high specification and consumes more power than average office devices, so the total power figure is higher than quoted above. However it is expected that the greater processing power should result in a faster test execution, and therefore to some extent cancel out in the additional power model.
  • Sending and receiving were automated using Microsoft Outlook, and therefore the PC processing should be representative of typical office or home environments.
  • The email server is an AWS t3a.small instance with 2 vCPUs and 2GB RAM. Email processing is Linux-based, but does include some moderately complex routing and spam filtering, and is therefore broadly indicative of generic email processing.
  • I use a figure of 200g CO2 emissions per kWh for simplicity. The DEFRA recommended emissions factor for the UK in 2022 is 193g.

The following observations can be made:

  • For smaller emails gross power consumption is of the order of a few kWh per million emails.
  • Average emissions per email are therefore <1 milligramme (mg), even allowing for other elements such as the PC’s monitor and networking
  • The incremental power required to process an email on a system already in use is even smaller, <1kWh per million, substantially less than 1mg per email
  • Power consumption and therefore emissions rise roughly linearly with the size of the test email, giving a gross estimate of 8 kWh per million emails per MB. For emails at the maximum practical size of around 20MB this gives an estimate of 160 kWh per million.
  • The proportions between the different elements are very consistent except for the smallest emails, at about 82.5% send, 13.5% receive, 4% server processing

Recommended Estimating Approach

I recommend the following estimating basis. For the actual email processing:

  • To send emails estimate 7kWh (~1.4kg CO2) per MB average size per million. For small text-only emails allow 0.5kWh / million
  • To receive emails estimate 1kWh (~0.2kg CO2) per MB average size per million. For small text-only emails allow 0.5kWh / million
  • For email processing estimate 0.6kWh (~0.12kg CO2) per million. This allows for each email passing through two servers, one sending and one receiving, which is fairly typical.
  • The proportion of the above figures which represents the power dedicated to email processing (above background activity) is about 20-25%.

These figures give a total end to end equivalent carbon emissions cost of about 1.6mg per 1MB email, assuming one recipient.

To include preparation and reading time, use a figure of 0.5 kWh (100g) per working day, which covers a typical modern PC, monitor and network, or an equivalent alternative figure if your arrangements are different. Then think about the number of emails each user processes per day and what proportion of their time they spend doing that. For example, if a typical user spends 20% of their working time on email and sends or receives 50 emails per day then their “per email” figure is (0.5 * 20%) / 50 =  0.002 kWh per email, or about 0.4g CO2. We need to double that to get the full send and receive picture.

I’d recommend keeping the embedded emissions separate, because they are fixed and tend to distort the picture. However for completeness if the PC has embedded emissions of 400kg CO2, has a complete economic life of 10 years, and is used 200 days per year then each working day equates to about 400 / (10 * 200) = 0.2 kg/day, or about 0.8g CO2 per email per user on the same basis as above.

Can a Figure of 4g or Above Be Justified?

Yes, but with significant caveats. Now we have a better understanding of the elements we can see a number of ways to get to a figure of 4g, or even much larger, although whether these are true typical “per email” figures which can then be multiplied up is somewhat dubious:

  1. Include processing time and embedded emissions, but average the embedded emissions over a much shorter time and fewer emails. If we take our PC with 400kg embedded emissions but only consider a typical 3 year corporate life-span and also use a lower figure of 25 emails per day we get a net figure per email something like 6g per email. However as noted above it’s incorrect and misleading to scale up a figure including embedded emissions.
  2. Have a high-spec PC sitting powered on but idle most of the day, just used for occasionally checking email. If the machine sends and receives 25 emails per day then the power consumed per email is 0.02 kWh, or about 4g emissions. If it’s on 24×7, not just in the working day this goes up to about 0.05 kWh per email. However this is a far from typical arrangement, and the figures break down as soon as the PC is also used for anything else, or a sensible power management scheme is put in place. Again you shouldn’t scale up from such an atypical figure.
  3. Setting aside processing time and embedded emissions, it is possible to get to 4g total power consumed per email – simply send a 20MB email to 1000 recipients!

How Can We Reduce The Impact of Email?

It’s important to keep things in context. A short textual email sits lightly on the world, using a tiny amount of electricity for its processing, and making no difference to already-present embedded emissions. Email is arguably a very efficient mechanism for such messages – some instant messaging programs are much heavier on PC resources. Saying “thank you” or “I agree” is not going to single-handedly melt the ice caps as “How Bad Are Bananas?” seems to imply.

Conversely, while blocking spam and encouraging the reduction of other “low value” emails is absolutely the right thing to do for usability and security reasons, the emissions impact is relatively small.

If the same content has to reach the same people then ultimately all electronic mechanisms are going to be broadly similar, but there are some additional considerations for larger documents. If most recipients use an email program like Outlook which downloads the whole email to the PC in one go, with attachments, then use that mechanism. The attachments are downloaded once, in the background so there’s no waste of either human or PC time waiting for them to download, and can be re-opened from local storage as many times as required. By contrast sending a link to a central location means the user has to wait for the attachment to download and open, potentially many times. There are other good reasons for sending a link, for example to ensure users see the latest information in a live document, but it may be less efficient.

If, however, not all recipients of the email need to see the full document then the best practice is to send a short textual summary in the covering email, and let each reader decide whether they need to download and open the full document. To do this the summary needs to explain what the document covers and significant findings/details. Compare:

Please find attached the progress report [Att: PrgRep.pptx, PrgRep.xlsx]


The Emissions Progress Report is now available. We have completed our submission for an extra £50k budget. All workstreams are green except Email Emissions which is amber, and should return green with the publication of the report this week. Please see Emissions Project October 2022 [PPT] for details

This strategy has usability benefits, but potentially also materially reduces the amount of data being shipped around.

You can go further – for example set up your email client to only download pictures and attachments on demand – but there’s a trade-off between marginal energy savings and a significant usability impact, and if the user has to sit waiting for the attachments then the energy saving may be wasted.

Generally good email etiquette aligns with efficiency – don’t send emails to large circulation lists unless absolutely necessary, and let the recipients decide whether they need to dig into detail or not. Think about the convenience of your recipients, not your own.

All electronic communications do have an environmental impact and in this energy-conscious world it’s our duty not to waste it. However ultimately the impact is small, significantly smaller than the “received wisdom” asserts, and I’d suggest that the value of communicating clearly and politely outweighs other considerations.

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