Archive for the ‘Media’ Category

Fusion Energy breakthrough? Not so much.

December 15, 2022

Click on Image for a larger version. The ‘breakthrough’ was the front page of the BBC News Website. Apparently this was the most important story in the world.

Friends, I find myself lost for words. Why? Because I am apoplectic with disappointment at the breathtakingly bad reporting about the recent ‘fusion breakthrough’ in the US.

Every media organisation whose output I have read has simply regurgitated the line they have been fed by the press office of Lawrence Livermore National Laboratory (LLNL). The BBC made this their headline story with the byline:

The technology is a potential source of near-limitless clean power….

In this article I will outline what actually happened in this ‘breakthrough’, and then explain why this technology will never ever, ever, ever, ever, ever, ever, ever, ever be useful as a power source.

At the end of the article is a list of resources I consulted. Links below to the panel discussion are to timed locations within the video.

The Experiment

The experiment comprised firing a bunch of lasers split into 192 beams at a tiny, hollow, diamond sphere suspended inside an open-ended cylindrical metal capsule. Both the sphere and cylinder were manufactured to extraordinary specifications in terms of their dimensions and surface finish. These extreme specifications are necessary to ensure that the energy is reflected from the inner surface of the cylinder onto the sphere uniformly.

Click on Image for a larger version. Left. The cylinder with the diamond sphere at it’s centre. Right. Illustration of the way in which ultraviolet lasers illuminate the inner surface of the cylinder, which then bathes the diamond sphere in X-rays.

At the panel discussion which followed the press conference, Mark Herman, the LLNL Director for Weapons Physics and Design refused to assign a monetary value to the target, but reasonably it must be on the order of a million dollars per target.

This sphere and cylinder were placed with nanometre precision in the centre of a chamber, and cooled to cryogenic temperatures (less than 20 K). At these low temperatures, the inside surface of the sphere was coated with roughly 60 micrograms (~0.03 mm) of a solid mixture of deuterium and tritium.

When the ultraviolet laser blast hit the metal cylinder, it vaporised and irradiated the sphere with X-rays. The pressure of this blast was so great and so uniform that it rapidly compressed the 4 mm diameter diamond sphere to around 0.1 mm ( from a “basketball to a pea“), accompanied by extreme heating to temperatures in excess of 100 million degrees Celsius.

This extreme temperature and pressure were sufficient to transiently cause the nuclei of deuterium and tritium to collide and fuse, with each fusion releasing 17 MeV (million electron volts) of energy. In more familiar units this amounts to 2.8 x 10^-12 joules per fusion event.

The energy in the laser pulse was estimated to be 2.05 MJ (million joules). I’m afraid I don’t know how that was measured. The energy of the resulting explosion was estimated to be 3.15 MJ. This estimate is made in several ways, but one technique involves putting a metal sphere near the fusion centre. When irradiated by neutrons from the fusion reaction, nuclear reactions cause the metal sphere to be come transiently radioactive, and measurements of this induced radioactivity allow an estimate of the number of neutrons to which it was exposed. This neutron flux is directly linked to the number of fusion events.

The difference between 3.15 MJ and 2.05 MJ = 1.1 MJ is inferred to come from deuterium-tritium fusion reactions. Dividing this yield by the energy per fusion reaction suggests that there were roughly 3.9 x 10^17 fusion reactions. At the panel discussion it was stated that this was 4% of the number of possible fusions, and so this allows us to estimate that there around 10^19 molecules of D and T in the sphere with a volume (in the solid state) of around 4 cubic millimetres.

Energy and Power

Is 1.1 MJ a lot or a little? The answer depends on what you compare it with.

A familiar unit of energy for consumers is the kilowatt hour (kWh) – the units in which we are billed for our gas and electricity. One kilowatt hour is 3.6 MJ, so 1.1 MJ is an appreciable amount of energy. Enough to boil around 3 litres of water.

1 MJ is also the typical energy content of a stick of dynamite. A stick of dynamite weighs ~ 190 grams whereas this same energy was released by ~ 60 micrograms of deuterium-tritium mixture. This gives a sense of the extraordinary power density available in nuclear reactions, and why they make such powerful explosives.

Unsurprisingly, these explosions damage the chamber in which they occur and the optics of the laser used to focus the beams onto the target needs to be repaired after each shot.

Breakeven: the problems emerge.

The hype surrounding this event arose because for the first time an experimental fusion reaction  produced more energy than was required to initiate the reaction.

As was made clear at the panel discussion, this 1.1 MJ of excess energy was the result of the laser imparting 2.05 MJ to the experiment, but the laser itself consumed roughly 300 MJ of electrical power, and this itself would have been derived from around 600 MJ of primary energy, mostly from burning methane in gas-fired power stations.

If we wanted to “improve” this facility so that the same laser produced enough thermal energy to run a power plant that could generate the electrical energy (at 33% efficiency) to run itself, then we would need to increase the yield by a factor 3 x 300 MJ/1.1 ~800. Where might this gain come from?

  • Only 4% of the deuterium-tritium in the experiment reacted so we could gain a factor 25 by arranging for the all the deuterium-tritium charge to burn. Now we just need a factor 33.
  • We might increase the efficiency of the laser from 1% to (optimistically) 20% and then we would just need a factor 1.6 from ‘somewhere’ to break even.

For the sake of argument, let’s assume we got that factor 1.6 somehow – perhaps by increasing the charge of deuterium-tritium. We would then have a system that could in raw energy terms sustain itself. But we would not yet be generating any extra energy at all!

At this point we would have an experiment that once every few weeks could produce an explosion yielding 900 MJ i.e. the equivalent of 900 sticks of dynamite or about 200 kg TNT.

No feasible path to a reactor.

Let’s suppose we want a fusion reactor which can produce 100 MW of electrical power to an external load. This is a small generating plant on a national scale – the UK peak requirement is around 40,000 MW (40 GW) and the planned Hinkley C reactor (if it ever operates) should produce 3,200 MW (3.2 GW).

To achieve 100 MW of electrical output we would need to generate around 300 MW of thermal power to operate a turbine and generator set with an output of 100 MW of electricity. This means that having gone to considerable trouble to generate energy via fusion we would then throw away two thirds of it as heat!

300 MW of thermal power corresponds to 300 MJ/second so assuming that we can (somehow) produce 900 MJ explosions, we need one explosion every 3 seconds to generate enough electricity to ‘breakeven’ i.e. just to operate the plant! So an additional 300 MW of heat would be required to make electricity for other uses: this would require an explosion every 1.5 seconds.

So to summarise, to produce a power plant outputting 100 MW of electricity the designers would need to:

  • Find a way to manufacture tritium.
  • Find a way to capture the energy of the explosions and turn it into heat.
  • Improve laser efficiency by a factor 20 and improve repetition rate by a factor 80,000 from around 1 laser pulse per day to around 1 laser pulse per second.
  • Build a chamber which could withstand a small nuclear explosion (0.2 tonnes of TNT equivalent) every second for (say) 30 years. Remember that the reaction chamber itself would become intensely radioactive and no human could enter it once its service life began.
  • Within this chamber a cryogenically-cooled target must be put in place with nanometre precision once a second.
  • No debris from the previous explosion can remain because this would affect the path of the lasers.
  • To achieve electricity output at a cost of $1 per kWh – around 10 times current use US prices – the cost of the target could not exceed $40. More realistically – considering the other costs involved, the target would need to cost ~$4 and around 58,000 would be required every day.

In short, there is no feasible path to turn this physics experiment into a reactor. And even if all the achievements above were somehow solved, the electricity would still be extraordinary expensive.

Why the hype?

Friends, we are being ‘gaslighted‘.

As Wikipedia puts it:

This term may also be used to describe a person (a “gaslighter”) who presents a false narrative to another group or person, thereby leading them to doubt their perceptions and become misled, disoriented or distressed. Often this is for the gaslighter’s own benefit.

Lawrence Livermore National Laboratory is a nuclear weapons research institute, and one can see how being able to create ‘mini’ nuclear explosions might be useful for them. And that is what this facility is for. As Mark Herman, the LLNL Director for Weapons Physics and Design said in the panel discussion .

“... the ignition work we’re doing is for stockpile stewardship. Our thermonuclear weapons have Fusion ignition … and so studying Fusion ignition is something we do to support the stockpile stewardship program.

In other words it is a technology which allows the US to design and test nuclear weapons without contravening the Comprehensive Nuclear Test Ban Treaty.

Any attempt to frame this technology as having any application whatsoever to energy generation is a deception.

The answers to our energy needs are already available to us.

And finally…

My comments in this article refer to Inertial Confinement Fusion (ICF). In contrast, Magnetic Confinement Fusion (MCF) does have an unlikely, but conceivable path to making a power plant.

In July 2020 I wrote about MCF in this article: Are fusion scientists crazy? The article includes a précis of (and a link to) an excellent talk from Zach Hartwig which I think is the best summary of all approaches to fusion that I have seen.

My other articles about fusion – dating back to 2013! – can be found here:

If you liked this article, you will likely be disappointed with the following articles that I looked at while preparing this:

Summer Science

May 26, 2018

Video Capture 2

For some months now I have been preparing for the Royal Society Summer Science Exhibition.

We have been working with the fabulous team at Science Projects on developing seven demonstration experiments – one for each of the seven SI base units.

Being so distracted, the deadline for submitting a video almost passed me by. In fact my colleague Andrew Hanson and I remembered with just one day to go!

So after a necessarily short planning phase, Andrew and I shot the video below on Andrew’s iPhone.

The background noise on some of the sections was problematic and Andrew had to do a great deal of filtering to get anything close to intelligible.

But given that everything was shot in’one take’, we were pretty happy with it, even if it came out a bit long (5’20”)

The end of the film was forced on us because my colleagues from the ‘length team’ were both absent when the end of the film was shot at about 7:30 p.m.!

After feedback from the team at the Royal Society we were asked to shorten the video and we took that opportunity to re-shoot the start and end of the movie with a proper microphone.

And here is the final shortened version (2’34”) which should be on the Royal Society site next week.

I hope you enjoy it.


Thanks to everyone who helped: Andrew Hanson, Brian Madzima, Rachel Godun, Stuart Davidson, Robin Underwood, Teresa Goodman, Lucy Culleton, Masaya Kataoka and Jonathan Fletcher


1001 grams: Film Review

March 19, 2016

Scene from the film ‘1001 grams’ showing delegates to the BIPM ‘Kilo Seminar’ holding their respective national kilograms.

It has been one year, 5 months and  23 days  since I posted a trailer for the Bent Hamer movie “1001 grams”. And this week I finally saw the film.

I had sought it out many times with no success, but a couple of weeks ago I managed to obtain a DVD encrypted as DVD Region 1. And so when the DVD arrived, I then needed to buy a new multi-region DVD player just to watch the film!

The story follows Marie, who works at the Norwegian National Measurement Institute, her relationship with her metrologist father, her trip to Paris with the Norwegian prototype of the kilogram, her adventures with the kilogram and her relationship with Pi, a scientist who is now a gardener.

Sadly I have to report that although I enjoyed the film, I was disappointed.

The whimsy and insightful observation that characterise Hamer’s films is certainly there. But whereas it is concentrated in the trailer, it is diluted in the film itself.

The film has many great features:

For this metrologist as least – it had many many laugh-out-loud moments. The casting and characterisation (caricaturisation?) of the delegates to the BIPM meeting (i.e. people like me and my colleagues) is shockingly perfect; the scene in which the camera fleetingly captures two delegates asleep in a seminar is also true to life.

The metrologist’s obsession with minutiae and attention to detail is well-captured, both in Marie’s day-to-day work calibrating ski-slopes and petrol pumps – and in relationship to the kilogram. The moment that the delegates peer in to see the ‘Mother of all kilograms’ is exquisite.

And the cinematography is beautiful. The filming of the metrological artefacts and activities is delightful, and the depiction of the International Bureau of Weights and Measures (BIPM) is charming.

And I have to admit that tears did fill my eyes at the point where the meaning of the film’s title is revealed.

But overall I felt the film was just a little light on content, in both the storyline and dialogue. This may be because I lack Hamer’s Norwegian perspective. Or perhaps silence is a bigger part of personal interactions between Norwegians than it is between English people.

The lingering shots at the start and end of scenes that establish a sense of continuing stillness can eventually become irksome for the non-auteur. After a while I got the sense that these were simply padding to get the film past the 90 minute mark.

But overall, I do not regret the £62 I spent to see the film!

Back in 2014 I wrote:

Bent Hamer’s films about IKEA researchers and retired railwaymen were not really about IKEA researchers or retired railwaymen. And I am sure this film is not really about the kilogram.

It is probably about the same thing that every other Bent Hamer film is about: the weirdness of other people’s ‘normal’ lives, and by implication, the weirdness of our own lives. And how important it is to nonetheless grab whatever happiness we can from the passing moments.

I was right.

You can catch a more detailed review with spoilers here


Still hopeful about the Daily Mail

July 23, 2015
Daily Mail Despair 2

The Daily Mail still thinks that the Earth’s changing climate is a point-scoring game.

On Tuesday I expressed some hope that the Daily Mail had begun reporting climate change developments as ‘straight news’.

I didn’t have to wait long to have my hope apparently dashed by the Daily Mail leader comment on Wednesday (quoted in full below).

But in fact I am still hopeful. This is not because I am a dullard but because there are genuinely reasons to be hopeful about the Daily Mail’s attitude. Read on for my reasons.

Daily Mail Leader Comment Wednesday 22 July 2015

In a major report last year, the Intergovernmental Panel on Climate Change gave a grave assessment of how man-made global warming was rapidly destroying the Arctic ice cap.

Steadily increasing temperatures had made the pack ice contract by up to 12 per cent between 1979 and 2012, leading to rising sea levels which threatened to swamp coastal regions – not to mention endangering stranded polar bears.

By the middle of the century ‘a nearly ice-free Arctic Ocean’ was likely for a large part of the year, the report predicted.

How interesting then, that the latest analysis of 88 million measurements from the European Space Agency’s Cryosat satellite show the northern ice-cap INCREASED by a staggering 41 per cent in 2013 and, despite a modest shortage last year, is bigger than at any time for decades.

Of course, the climatologists will come up with explanations – as they did for the fact that global temperatures have barely changed since the year 2000.

They’ll say 2013 was a freak year, that in spite of temporary fluctuations long-term trends remain the same, that cooling ‘episodes’ are as much a feature of climate change as warming and so on.

But the more they juggle their theories to fit the inconvenient truths, the more the public will question whether these prophesies of global doom are based on genuine science, or guesswork.

And they will rightly wonder whether solemnly committing to climate change targets while saddling ordinary people with a raft of spurious green taxes serves any real purpose – other than being an expensive exercise in gesture politics.

The sheer perniciousness of this article offends me. I feel as though the Daily Mail has spat in the face of truth.

I have three responses: two graphs and comment

Here are two graphs that genuinely summarise the situation we all face.

First of all here is the data on which the Daily Mail are reporting. This is a graph of arctic sea-ice volume – the product of the area of sea-ice, and its thickness.

Notice that it goes up in 2013 – that’s the ‘staggering’ 41 per cent increase to which the Daily Mail refers. This is what the Daily Mail report as an ‘an inconvenient truth’.

Arctic Sea Ice Volume

And to the best we can understand it is ‘true’. But it is not so much ‘inconvenient’ as ‘irrelevant’.

The graph below shows arctic sea-ice area – a much simpler thing to measure and something for which we have data stretching back to 1979.

Arctic Sea Ice Extent

It is clear that since roughly 1995 sea ice has been disappearing. Whereas we used to have around 7 million square kilometres of sea ice in September at the end of the annual melt, we now have only around 4 million square kilometres. That’s 3 MILLION square kilometers of missing sea ice!

In this context, the increase in Sea Ice extent and volume in 2013 can be seen for what it is: a blip on a downward trend.


There appears to be a power struggle at the Daily Mail

While the Leader Comment on Wednesday was the usual pernicious material one expects, since Tuesday there have been no less than four ‘straight’ stories about Climate Change.

When institutions change their position there is inevitably a period of flux in which the  institution cannot ‘speak’ coherently.

Despite ample cause for despair, I am still hopeful that the Daily Mail’s powerful influence over Middle England can be a force for good.

If Darth Vader can abandon the Dark Side, then so can the Daily Mail.


July 21, 2015
Map of the world showing regions that in June 2015  were warmer or cooler than they 'normally' are. Dark red shows record warm regions. Source NCDC - see text for link. Click image for a larger version.

Map of the world showing regions that in June 2015 were warmer or cooler than they ‘normally’ are. Dark red shows record warm regions. Most of the Earth is warmer than it has been historically. Remember that June is the height of Southern Hemisphere winter. Source NCDC – see text for link. Click image for a larger version.

Sometimes it is difficult to stay hopeful.

And the NCDC ‘State of the Climate’ report for June 2015 is so shocking that I really should feel no hope at all.

What does it say to put me in such a mood? Well it is authoritative and detailed, but here’s a taster.

June 2015 also marks the fourth month this year that has broken its monthly temperature record, along with February, March, and May. The other months of 2015 were not far behind: January was second warmest for its respective month and April was third warmest. These six warm months combined with the previous six months (four of which were also record warm) to make the period July 2014–June 2015 the warmest 12-month period in the 136-year period of record, surpassing the previous record set just last month (June 2014–May 2015). … the 10 warmest 12-month periods have all been marked in the past 10 months.

In short, the surface temperature of the Earth is dramatically warm and it looks likely that the calendar year 2015 will be the hottest ever.

And yet I feel hopeful. Why?

Because this is how the Daily Mail reported this news (Link)

June warmest EVER recorded globally as forecasters warn 2015 set to be a record breaking year

That’s right, the Daily Mail reported this as a completely straight news story. It is not spun. It is not used to imply that Climate Scientists are corrupt or left-wing. No jokes are made about hiatuses or the growth of arctic sea ice.

I honestly never thought I would live to see the day that the Daily Mail reported serious climate change news as serious climate change news. And yet here it is.

If newspapers such as the Daily Mail can really break their links with climate change deniers then the fear, uncertainty and doubt that they spread will begin to dissipate. And then we can all get busy actually solving problems rather than arguing.

It’s one reason to be hopeful. And for now, that’ll do.


The Figure is from NOAA National Centers for Environmental Information, State of the Climate: Global Analysis for June 2015, published online July 2015, retrieved on July 20, 2015 from

Did 28,000 people die from air pollution in 2012? Part 3

May 28, 2015


COMEAP needed to estimate how many percent excess mortality would be caused by 10 micrograms per cubic metre of PM2.5 air pollution. To do this they just asked themselves what they thought the answer was. The details of this 'elicitation' process are described below.

The Committee on the Medical Effects of Air Pollutants (COMEAP) needed to estimate how many percent excess mortality would be caused by 10 micrograms per cubic metre of PM2.5 air pollution. To do this they just asked themselves what they thought the answer was. Their answers range from -1% (i.e. air pollution prolonged life) to 17% excess mortality. The details of this ‘elicitation’ process and the meaning of excess mortality are described in the text.  This graph represents their consensus view: individual estimates are shown at the end of the article. (SOURCE COMEAP 2009 Page 160.)

Continued from PART 2

In Part 1 we saw that is untrue that air pollution annually causes 28,000* deaths of otherwise healthy people.

In Part 2 we described the qualitative effects of air pollution.

We now look at how the Committee on the Medical Effects of Air Pollutants  (COMEAP) estimate the effects of air pollutants, and how they have chosen to communicate their estimates.

What I have written below is the result of staring at reading two extremely technical documents, an activity which I invite you to share:

The factual basis…

The COMEAP studied hundreds of scientific papers but singled out one for special mention: the American Cancer Study (ACS) [COMEAP 2009 Page 2: Point vii]

The ACS uses measurements of soot particles called PM2.5 as a ‘proxy’ for all the other forms of air pollution.

It does this because PM2.5 s are easy to count and the concentration of the other air pollutants is more difficult to quantify, but they are typically correlated with PM2.5s.

So we don’t know which part of the pollution is actually the active cause of any effect – a shortcoming the experts consider exhaustively in their 2009 report.

The ACS finds a correlation such that there is a 6% rise in all-cause mortality for a 10 microgram per cubic metre increase in PM2.5 concentration.

I haven’t been able to read the ACS but extraordinarily, COMEAP report no uncertainty in this 6% figure.

Perhaps it is because of this that they decide to make their own estimate. And to do this they used a procedure called elicitation.

What is elicitation?

Wikipedia defines elicitation as:

the synthesis of opinions of authorities of a subject where there is uncertainty due to insufficient data or when such data is unattainable because of physical constraints or lack of resources. Expert elicitation is essentially a scientific consensus methodology… [it] allows for … an “educated guess”.

Each expert on the committee was asked:

  • “What do you think is the chance that the correlation is not a 6% increase in mortality for a 10 microgram per cubic metre increase in PM2.5 concentration, but some other figure?

The experts were asked in turn:

  • What do you think is the chance that the true figure is greater than 0%?
  • What do you think is the chance that the true figure is greater than 1%?
  • What do you think is the chance that the true figure is greater than 2%?
  • etc. until they arrived at the figure of 17%, beyond which possible correlations were discounted as highly improbable.

The results are shown in the chart at the head of this article and in the chart at the end of the article.

And the results…

The results of this elicitation form the basis of all the mortality estimates that you have read in the previous two articles.

The results are literally, an educated guess. None of the fancy maths changes this.

The average estimate was 6% and experts considered that the true answer was ‘95% likely’ to be in the range between 0% and 15%

Since the level of PM2.5s in the UK is typically just under 10  microgram per cubic metre, it is this figure of 6% of the roughly 500,000 deaths per year that directly links to the estimate of 28,000* deaths per year.

The range of expert opinion is that the true figure could lie between 0 and 55,000: every one of the seven experts considered it marginally possible that there was no effect of pollution i.e. that the excess mortality was 0% or less.

Although the experts considered a plethora of studies – and their report is exhaustive and exhausting – in the end, this is just their opinion.

How to express their results?

COMEAP consider at length how to express the results of their elicitations. Mostly they considered that the effect on life-expectancy (a few months for most people in the UK) is clearest.

However they do specifically endorse the use of mortality to express the effect of air pollution. But they note:

… the result expressed in terms of attributable deaths or additional deaths may easily be misunderstood or misrepresented. This calculation is not [their emphasis] an estimate of the number of people whose untimely death is caused entirely by air pollution, but a way of representing the effect across the whole population when considered as a contributory factor to many more additional deaths.

...consequently we consider it unrealistic to view air pollution as the sole cause of death in a number of cases equal to the population attributable deaths.” [COMEAP 2010 Page 3]

Regarding the actual estimates COMEAP explicitly recommend that the excess mortality estimates should always include the full uncertainty estimate – i.e. including the possibility that the excess mortality may be zero.[COMEAP 2009 Page 3 Point xiii]

And my conclusion…

I agree with COMEAP that the expression of the effects of air pollution as excess deaths per year can be “easily misunderstood”. In fact I think it is nearly universally misunderstood.

And given that their recommendation that the full limits of uncertainty – which include the possibility of no effect – are generally not quoted – I think this gives quite the wrong impression.

The possibility that air pollution – mainly from traffic – might be killing 28,000* people a year – 17 times more than are killed in car accidents – is horrific.

But in fact it appears that air pollution of itself kills nobody.

Rather, when we are near the end of lives – which are now longer than they have ever been in human history – our lungs do not function as well as they might otherwise have done.

As a result, our demise – from whatever cause – is hastened.

Somehow this reality is not quite as scary as COMEAPs vision.

Other Figure

The graph as the top of the page was compiled from the responses of 7 experts. These graphs show the cumulative probabilities ascribed to a particular sensitivity coefficient by the each of the 7 experts.

The graph as the top of the page was compiled from the responses of 7 experts ‘A to G’. These graphs show the cumulative probabilities ascribed to a particular sensitivity coefficient by each of the 7 experts. Looking at any particular line, the graph tells you, in the opinion of that expert, the likelihood that the coefficient exceeds any particular % value. (SOURCE COMEAP 2009 Page 159)


* COMEAP 2010: Page 5: Point 18 estimate 29,000 deaths per year, but this is sometimes reported as 28,000. Given the large uncertainty in the figure, I have taken the lower estimate throughout.



Did 28,000 people die from air pollution in 2012? Part 2

May 27, 2015


Complicated graphic showing the correlation between 'excess mortality' and a pollution event in New York in 1962. The excess mortality is shaded in red and reduced mortality in following days is shaded in blue. Click for larger image - see text for details.

Complicated graphic showing the correlation between ‘excess mortality’ and a pollution event in New York in 1962. The excess mortality is shaded in red and reduced mortality in following days is shaded in blue. Click for larger image – see text for details.

 Continued from PART 1.

In Part 1 we saw that it is untrue that air pollution causes 28,000 deaths each year in otherwise healthy people.

But could these deaths be ‘linked to’ air pollution? Let’s look at the adverse effects of air pollution.

DEFRA list the effects of very high levels of some key pollutants (link):

  • NO2, SO2, O3 (Ozone): These gases irritate the airways of the lungs, increasing the symptoms of those suffering from lung diseases
  • Particles: Fine particles can be carried deep into the lungs where they can cause inflammation and a worsening of heart and lung diseases
  • CO (Carbon Monoxide):This gas prevents the uptake of oxygen by the blood. This can lead to a significant reduction in the supply of oxygen to the heart, particularly in people suffering from heart disease

So all these pollutants can be expected to harm us. But how much harm they do? This question – the quantitative expression of the harm caused by air pollution – is at the heart of this issue.

Broadly speaking, we can expect short-term and long-term effects. However, it is possible for air pollution to have both kinds of effects in the same person.

Short Term Effects

The US National Institute of Health (NIH) host this 1966 paper by McCarroll and Bradley looking for excess mortality coincident with air pollution events in New York City in 1962.The paper is notable for its readability.

McCarroll & Bradley analysed 3 pollution ‘events’ and the figure at the top of the page summarises the general nature of their analysis: they note excess mortality coincident with air pollution events, and a reduction in mortality for subsequent days. They note specifically that the drop is “…never of sufficient degree to compensate for the excess of deaths on the preceding day.”

So the general mechanism in action here is that air pollution has ‘brought forward’ people’s deaths: some by just a day or so, but others by unknown periods of time – probably weeks to months. These would be people with an underlying medical condition which itself may possibly be a long term effect of air pollution

Long Term Effects

Long-term effects are more difficult to assess since we do not have identical healthy populations that differ only in their long-term exposure to pollutants. However such effects can be estimated by so-called cohort studies.

So by analyses similar to McCarroll & Bradley and by cohort studies we can begin to estimate how much air pollution causes how much excess mortality.

Combined Effects

Short-term exposure to air pollution appears to bring forward some deaths – the actual number is unknown.

Long-term exposure to air pollution also appears to also shorten life.

For the UK population, a committee (COMEAP) estimates this to amount to 350,000 person years per year. What?

  • For a population of 60 million this amounts to about 2.1 days per person, per year of life.
  • So if the ‘natural lifetime’ of a person born now is 80 years, then exposure to typical air pollution for their lifetime is estimated to shorten their lives.
  • The shortening is calculated to be 80 years x 2..1 days ≈ 6 months less than they might otherwise have lived.

So now I think I understand the nature of this excess mortality. There are three components

  • Air pollution has adverse physiological effects,
  • People susceptible to heart attacks or with respiratory diseases (from other causes) can be brought into a cycle of distress which brings forward their death.
  • Additionally chronic prolonged exposure to air pollution can induce respiratory complaints that may make people susceptible to acute air pollution events.

Estimating and Communicating these effects

In PART 3 we will see how that estimate is made, and you can judge for yourself whether to be alarmed.






Bent Hamer and the Kilogram

September 25, 2014

Tonight I find myself a thousand miles from home in a hotel in Espoo, on the outskirts of Helsinki. Outside it is raining and the temperature is just 10 °C.

I am here to discuss with colleagues from around Europe some of the minutiae associated with a new definition of the units of temperature: the kelvin and the degree Celsius.

You really don’t want to know the details: we worry about them so that you don’t have to. 🙂

And the day is auspicious. Thursday 25th September marks the 125th anniversary of the adoption of the kilogram as the international standard of mass. You can read NPL’s commentary on the anniversary here, And there is a new film release ‘about metrology’

The movie at the top of the page is a trailer for a film by Bent Hamer which appears to use the kilogram as a metaphor for… well I haven’t seen the movie yet.

But the mere existence of the movie does indicate that the ‘kilogram problem’ has entered popular culture – at least to some limited extent – and that is >fantastic<.

My wife and I have admired Bent Hamer’s previous films and sought them out at out-of-the-way cinemas. And we shall probably have to do the same with this one.

Bent Hamer’s films about IKEA researchers and retired railwaymen were not really about IKEA researchers or retired railwaymen. And I am sure this film is not really about the kilogram.

It is probably about the same thing that every other Bent Hamer film is about: the weirdness of other people’s ‘normal’ lives, and by implication, the weirdness of our own lives. And how important it is to nonetheless grab whatever happiness we can from the passing moments.

But I am filled with excitement at the prospect of this film. Parts of it are definitely shot at the International Bureau of Weights and Measures (BIPM) which is a thrill for us ‘insiders’ to see.

And he has certainly caught something of the obsessive personality disorder that  – if not actually required – tends to accompany an interest in metrology.

I suspect that Hamer’s fondness for humanity would probably lead him to sympathise with a statement such as

Man is measure of all things 

And if I met him I would probably have to disagree.

The fact that I can type this article on a computer in Finland and have it appear on a server hosted in the United States, and be viewed wherever you are viewing this, rests on agreed measurement standards that are not amenable to different people’s opinions.

And the whole purpose of almost everything I do in my work – including this meeting – is to move beyond situations where correct answers are ‘a matter of opinion’.

But nonetheless, to see metrology dramatised in this way brings a smile to my face, and yields a frisson of simple pleasure.

I can’t wait for ‘1001 kelvin’.


Live Fish; Live Music; The importance of being there.

August 1, 2014
This picture shows a gigantic tank of jellyfish with people silhouetted in the foreground. Picture taken at teh MOnterey Aquarium, California.

A gigantic tank of jellyfish with people silhouetted in the foreground. Picture taken at the Monterey Aquarium, California.

I hope you like the picture above. As you look at the picture you probably can’t tell if the vivid colours are on a screen or whether I took the picture of people in front of  a real tank of jellyfish

But I was there. And the jelly fish were very real.

I gazed in open-mouthed wonder at the delicacy of the structure of their bodies. And I desperately wanted to capture something of the experience.

Now when I look at the picture I recall that feeling of wonder but I don’t really know what you feel.

Two musicians playing Jazz at 'The Melt' a small cafe on Columbus AVenue, San Francisco.

Two musicians playing Jazz at ‘The Melt’ a small cafe on Columbus AVenue, San Francisco.

The picture above shows two musicians who happened to start playing at ‘The Melt’ on Columbus Avenue in San Francisco just after we stopped in for a snack. As you look at the picture you probably wonder what they were playing or if they were good.

But I was there. I remember being so happy that we had chanced upon this place.

And I remember my son’s happiness when we all recognised the beginning of ‘So What’ by Miles Davis. I left a $5 tip for them.

I mention these two occasions because  as I looked at the photographs I realised that the photographs did not capture my happiness or wonder.

And I just thought I would make a note – largely for myself – about how pictures communicate something – but what they communicate is not always the experience of the photographer.

And that there is really no substitute for ‘being there’.

Why headlines matter

July 22, 2014

Consider the following:

  • Imagine a hypothetical country in which the president made a decision to change the rules by which medication for heart disease was prescribed.
  • And suppose that in this country a woman died from a heart-related problem and her grieving son blamed his mother’s death on the President’s decision.
  • And further suppose that a reporter interviewed the son who said: “I feel as though the President has stabbed my mother through the heart”.
  • And finally imagine that a newspaper ran this reporter’s story with the headline at the start of this article:

President stabs woman through heart

Now if I read that headline I would assume that it was an assertion of a fact. But in fact it isn’t. And once I read the article and discovered that this was a quote from a grieving individual I would ask:

  • How did that headline, with its misleading and negative view get written?
  • If the newspaper wanted to highlight this important issue, why did they pick this misleading headline which undermines their own credibility?

So back to reality, and a letter from Thom Davis (reproduced in full at the end of this article) who thinks that I have been unfair in my comments on his article in The Independent.

I called attention to the fact that the article’s headline asserted that as a result of the Chernobyl disaster there were ‘cemeteries the size of cities’. This is completely untrue. And to me it raised the same two questions I highlighted above.

I am not sure of the timeline, but as I recall it, when I tweeted the author for more details he went quiet and when I looked again at the article, the headline had changed to something which was not an untruth. It may have been as a result of my questioning that the headline was changed. The newspaper made no record that the article had been changed.

Months later Thom wrote to me arguing at length that I should conclude nothing from the fact that a misleading headline was placed above his article: that it was just an editing mistake. I beg to differ.

Reading the article itself, without the misleading steer of its headline one can hear Thom’s genuine concern for the plight of these refugees. And I am happy to accept that the headline was indeed not of his choosing.

But in what Universe could a junior editor claim the existence of hundreds of thousands of dead people? The answer is: only in a Universe where nonsense is believed and propagated as easily as in a school playground. And I find it hard to believe that anyone in that profession could be unaware of its potential impact on UK readers.

The point of my article was to highlight this misleading headline and the fact it was changed without any record of the change. And that The Independent has a history of doing this.

The Independent did Thom a disservice in choosing a headline which exposed their own editorial prejudice and undermined his article’s credibility.

The headline of an article sets the tone and expectation for an article. And it matters.

P.S. (A blog is not a newspaper article, but for the sake of accuracy, I edited the text in red on Tuesday 5th August 2014)


  • My original article is here
  • Thom’s article – with its modified headline – is here
  • Thom’s reply to my article is reproduced in full below

Dear Protons for Breakfast,

I am the author of this article.

I did not choose the original title. As I believe I pointed out in a following tweet (not shown above).

As Vanessa rightly suggests, it is standard practice in journalism for the titles and taglines to be the choice of the editor. As soon as I read the title, I immediately emailed the editor to get it changed. Which he promptly did, within minutes. I agree with you, to put “cemeteries the size of cities” in the title like this is obviously misleading, as this is not what the article is saying – and precisely why I had the title changed immediately. It seems in your critique of the article you have focussed upon this.

For what it is worth I do not think the editor did this on purpose as some kind of anti-nuclear (or in your words ‘Nuclear Nonsense’) agenda – but was merely the consequence of a misreading and rushed deadline. As Vanessa suggests:

“An alternative approach might be to acknowledge the possible devaluing of an otherwise informative article from a specialist author by a flawed editorial process – and perhaps even to credit the editors for the fact they changed the headline quickly.”

As is quite clear is you read the text, the cemeteries quote comes from an interview with a research participant who was stressing how Evacuation and forced displacement has killed more people, in his opinion, than living with the constant threat of radiation. Like many others who live near the Exclusion Zone, he believes more people have been killed through forced evacuation than from staying to live with the radiated landscape.

It is a widely held opinion that the stress of becoming an environmental refugee has negatively impacted the lives and health of the hundreds of thousands who were forced to abandon their homes. Something supported by other academic research on other disasters, and from many interviews I have conducted with evacuees.

The revised title, made minutes after I emailed the editor now reads:

“Ukraine’s other crisis: Living in the shadow of Chernobyl – where victims receive just 9p a month and are left to fend for themselves”

This is something I stand by 100%. And I am grateful for The Independent’s swift action on this.

I am guessing your following critique is based on the briefly shown original erroneous title:
“by making unjustified and hyperbolic claims, the whole article becomes discredited: which parts should we believe?”

It is clear (from reading the main text) that the original title is an editorial error. If you believe other parts of the article are in anyway hyperbolic or unjustified I would very much like to hear, as this is a topic I take incredibly seriously. I very strongly dispute for example that what I have written counts as ‘Nuclear Nonsense’. It is based on three years of in-depth ethnographic research with communities throughout Ukraine.

Your assumption that the point of the article was “to cause people to think twice about nuclear power in the UK” is also unfounded. As the author of this article, I can tell you that the point – would you believe it – was to draw attention to the plight of people I have spent years getting to know in Ukraine, who are continuing to suffer from nuclear disaster. Something I believe this article achieves.

You say that the “article [is] seeking to conjure a horrific vision, which is just nonsense, and not true.” I would love to know on what basis you think what I have written is both ‘nonsense’ and ‘not true’?

I am glad this article, for whatever reason, has caused a discussion, as I believe it is an important subject, especially for those involved.

If you are interested further in my research on this subject, I can suggest reading this peer reviewed academic article:

Best wishes,

Thom Davies

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