An atomic bomb analogy

I want to ask my lovely readers what they think of an analogy which uses atomic bombs to help describe an amount of energy. The graphic below uses Hiroshima atomic bombs to convey the rate at which the Earth is currently accumulating energy, which is a lot. It was created by Skeptical Science – a climate science communication website.


Atomic bombs are often used to quantify energy. The meteor that crashed into Siberia earlier this year was described as the energy equivalent of 30 Hiroshima bombs. The Mag. 6.5 earthquake in Cook Strait, New Zealand in July this year was described as the energy equivalent of 100 nuclear bombs.

Personally, I think this is a useful tool for helping people understand that our Earth is currently absorbing more energy than it is releasing into space. Any thoughts?

46 thoughts on “An atomic bomb analogy

  1. … our Earth is currently absorbing more energy than it is releasing into space.

    Why not simply state that? If you want to get sciency you could add that unbalance is minor, in the order of 1 %. The only reason why the number of SkS bombs sounds so large is because the Earth is unimaginably large. I am not sure if that is the message we want to spread. That was the message, which made people dump waste in the ocean and think it would be gone for ever.

    The comparison is not a good one because in an explosion the energy is released in a short period and a small place. That is the reason it is destructive. The same amount of energy spread over the Earth is no problem whatsoever, not even noticeable. (Except if you keep on doing that, as in global warming.) The dose makes the poison.

    And you mainly think about the consequences of Hiroshima, not of the energy contained. You think about the radiation that killed and maimed people and of the radioactive pollution causing cancers afterwards.

    And personally I find it inappropriate towards the Japanese that suffered. Just like you should not compare everything with the holocaust, you should not compare everything with Hiroshima, that trivialises this terrible moment in history.

    If I am allowed to make a consensus statement: As far as I can judge most scientists that are blogging about climate see the unit Hiroshima’s per second as inappropriate for global warming.

    1. Thanks, Victor. I saw your tweet of disapproval about this so was hoping you would elaborate here.

      If the Japanese find the analogy offensive, then this is enough reason for me to abandon it. I don’t think this is the case though. I had a Japanese friend in Christchurch who did not appear at all bothered by the earthquake/Hiroshima analogy. It may be that she was just being polite but if it is offensive then couldn’t we simply say atomic bomb rather than Hiroshima bomb?

      I’m not really convinced by your other arguments though. Yes, the energy is accumulating slowly unlike an atomic bomb which is a quick explosion. Does that really matter?

      1. Wouldn’t it be like getting a one cubic meter ice ball on your head instantly as opposed to having it build up over a period of time? You still end up with a one cubic meter ice ball on your head but in one case it appears instantly, in the other it takes time.

      2. I would argue your suggestion points to a problem in the analogy.

        Hiroshima per second is a flux, a flow of energy. As you rightly point out, the problem is not this flux, but its accumulation.

      3. Victor says “Hiroshima per second is a flux, a flow of energy. As you rightly point out, the problem is not this flux, but its accumulation.”

        And the widget says “Our climate has accumulated …”

        Am I missing something here?

    2. “that unbalance is minor, in the order of 1 %”. 1% is not a minor energy imbalance. It is that imbalance that is at the heart of AGW.

      “The same amount of energy spread over the Earth is no problem whatsoever, not even noticeable.” That is simply not true. The buildup of heat in the oceans is quite noticeable which is why it is currently a major focus of climate science.

      It is also a major problem. While the strict attribution has yet to be done, the build up of heat in the oceans was arguably a significant factor in cylone Haiyan. There is a detailed discussion here

      “You think about the radiation that killed and maimed people …” You may but the widget does not. Nor does the supporting web site. And the widget makes it clear as does the backing discussion that “hiroshimas”, “sandys”, “earthquakes” etc. are being used as a measure of energy and not as a measure of how many people were killed.

      “And personally I find it inappropriate towards the Japanese that suffered.” Again you may but there is simply no evidence that the Japanese do. You are claiming to speak on behalf of the Japanese without any evidence at all. There is also a very large anti-nuclear sentiment in Japan so I would suspect that very many Japanese would find it quite appropriate.

      You do not object to the use of “Hurricane Sandy”? What if they used the 1970 Bhola cat 3 cyclone in Bangladesh that killed 500,000 people, many more than the Hiroshima bomb. Would that be inappropriate?

      “As far as I can judge most scientists that are blogging about climate see the unit Hiroshima’s per second as inappropriate for global warming.”

      I see a few people I respect make some valid points but I also see the usual campaign of denigration from the cranks, the deniers and the fakes who hate SKS precisely because they are very good communicators. And it is SKS with the cognitive science and communications expertise, not the critics.

      The widget is not the start and end of the discussion – it just another brick in the wall. Like all analogies, it is not a perfect representation of reality. That is why it is called an analogy. But it is a useful conversation starter where the strengths and weaknesses of the analogy can be discussed.

      What I am really over is the obsessive hand wringing that has gone on over this widget. But I suppose in that sense it has achieved its goal.

      I am not sure whether this site has been updated since AR5 but this is the “widget” that scares the hell out of me,

      1. The same amount of energy spread over the Earth is no problem whatsoever, not even noticeable. (Except if you keep on doing that, as in global warming.)

        You forgot to cite the bold part and then made the argument in the bold part. As you seem to put me in one category with the climate ostriches, may I remark that that kind of miscitation is rampant among those fools.

        In a recent discussion at the climate union (Klimazwiebel) I proposed the definition of Climate “skeptics” and “alarmists” as those people who use science as cannon fodder in a political fight. (Where the former do not seen AWG as a problem and the latter do.) If one starts acting as if the mean justifies the means, one is on a slippery slope towards WUWT and Co.

        Even if someone only cares about the results, I would worry about the effect on someone impressed by Hiroshima’s who then later learns that the energy imbalance is actually very small. That would result in a loss of trust and then people will start doubting every word you say.

        I would also object to Sandy’s per second or lightning bolts per second. Maybe less emotionally. But it would still give the wrong impression and compare a high entropy phenomenon with a low entropy one.

      2. The “miscitation” was not intentional Victor. And I am still confused about what it is that you are trying to say.

        The widget clearly shows the **accumulated** Hiroshima atomic bombs. It is currently showing 2,000,000+ Hiroshima bombs.

        So when you say “The same amount of energy spread over the Earth is no problem whatsoever, not even noticeable.” what are you talking about? Are you not criticising the widget? If you are not, what are you criticising? What am I missing here?

        And no I do not consider you a climate ostrich. It is sad that you need to say that simply because I disagree with your opinion.

        But I do find your claim ” If one starts acting as if the mean justifies the means, one is on a slippery slope towards WUWT and Co.” unhelpful. And you have made the same claim at the Hot Whopper blog so it is not an issue of miscommunication.

        The SKS have earned the right to be treated with respect.

        You assume that **you** are the one in the right on the science. You are unwilling to accept that other people may have a different point of view also based on science so you start assigning motive.

        Eli has no issue with the widget. Is the rabbit also on the slippery slope to WUWT?

        And you are wrong to claim the energy imbalance is small. Historically it is not. That is the whole point.

      3. My apologies for becoming somewhat impolite. The misquotation put me in a hostile WUWT mind state.

        Yes, the widget shows accumulations, 3 billion Hiroshima’s since the 70-ies. That makes the number even more incomprehensibly large and abstract. And the effect of climate change since the 70-ies has been nowhere near the effect of one atomic bomb dropped on every second person. Sounds to me more like a number to scare as to educate.

        An argument from authority from Eli:

        Hey Eli,

        You’re a little late on this one. The twitter was a twitter, and much support for the hiro amongst the climatists there was not.

        You wouldn’t make the mistake of thinking that someone is wrong because you dislike them, would you?

        Doug McNeall

        The SkS crew is doing good work. Still I do not agree with them on this point and fear that it is counter productive on the long run. Dana claimed he is the expert for climate communication. Does not sound like they will listen to the majority of climatologists. Even if they would only do this type of stuff, they would still not be at the level of WUWT. At least they got the math right. That is why I only wrote “towards”.

      4. Victor, the bit in Eli’s post about mars bars has made me wonder what the analogy might be in terms of weight gain say for a person weighing 80kg? If they ate the same amount in calories – but proportional to their size – since 1998, how heavy would they now be?

      5. At least also in obesity the energy imbalance is very small, a few percent at best, I once estimated. Makes the claim that the obese should just stop stuffing themselves very weird. The imbalance is nearly impossible to perceive. (If you see something then it is that a larger body needs more fuel and ignoring what your body tells you leads to hunger and illness.)

    3. “Dana claimed he is the expert for climate communication.”

      I read his tweet. I assumed that he was referring to Prof Lewandowsky who is a cognitive scientist of significant standing and John Cook who is a physics graduate and the Climate Change Communication Fellow for the Global Change Institute at the University of Queensland. Cook and Lewandowsky both presented at the AGU conference on climate communications.

  2. Yep, it’s a useful analogy. Most people would understand what it means and that is important.

    One of the the major problems is that the entrenched sceptics don’t want to understand. Such analogies provide the anti-sceptic with an impressive argument that they can employ in any group discussion. It is not so much a case of changing the mind of an entrenched sceptic, it is more a case of preventing them from spreading their notions to others.

    It’s all grist to the mill and every little bit of truth helps.

    1. Every little bit helps. I definitely agree with that. If this analogy – however inaccurate it may be – aids people’s understanding of the problem then that must be a good thing.

  3. Having visited Hiroshima, and having met a hibakusha (A-bomb survivor) and heard her account of the day, I can only say that on a personal level I find the Hiroshima analogy very uncomfortable. As Victor says, people associate that bomb with its direct consequences, not the amount of energy. And so, like the holocaust, Hiroshima is a bad analogy. However…simply “atomic bomb” I think works better since this more easily brings to mind mushroom clouds, houses being blown over, etc without necessarily the connotations of war-justified mass murder.

    What the SkS widget has done though in using Hiroshima as a metric is to generate publicity and elevate it perhaps beyond the level of interest it would naturally have generated. In that regard it has been successful, but I don’t know how the little old lady who lost her friends and her sister would think about that…

    P.S. People forget to mention too that the widget has other metrics, such as lightning bolts, which are less controversial.

  4. That there was so much death and damage at Hiroshima makes it more rather than less apt. The broad mass of people have yet to take on board just how bad climate change is already going to get, and especially how bad it could get. They need to, the sooner the better. It’s hard to see how frightening them isn’t going to be part of the picture.

    Free Dictionary has: “a. Similarity in some respects between things that are otherwise dissimilar. b. A comparison based on such similarity.” Fair enough.

    The options on the widget provide excellent context, but the whole thing would lack punch without at least one analogy to large-scale death and destruction.

    But can everyone who has a problem with the Hiroshima bomb analogy suggest one they think would be better? Victor?

    1. Thank you for being honest, that for you the new unit is not thought to communicate the problem in a clearer way, but to scare people.

      The energy imbalance is currently 4 Hiroshima’s per second. Do you see any ” large-scale death and destruction” going on right now?

      My apologies that I do not have a scary analogy for the energy imbalance. I would argue that a minor Energy imbalance in the order of 1 % would be a quite good way to communicate this small value. Such a percentage is something people can understand. As soon as you scale it up to the entire Earth it becomes an incomprehensible abstract large number. Converting that to Hiroshima’s does not make it much easier to understand.

      If you want to scare people you have to look at the cumulative effects. Isn’t a temperature increase of the same magnitude as the previous ice age sufficiently bad? Heatwaves kill a lot of people. It will lead to stronger precipitation, sea level rise and loss of biodiversity.

      And the longer the ostriches block progress, the more drastic the measures will have to be to prevent such a temperature change. That will also not be fun.

      1. Victor,
        If I didn’t know more about this and someone said to me that the energy imbalance was of the order of 1%, I would probably dismiss it as nothing to worry about it.

      2. If I may make another analogy: The climate ostriches act as if 400 ppm CO2 is no problem because it is even less than 1%. In that case we rightly say, that it is the consequences and the change that is important.

  5. I don’t like the sensationalism or including Hiroshima, but maybe it will give those who have no idea about the magnitude of the energy the Earth is absorbing something to think about, though I’d prefer if they just said four atom bombs as Kit suggested..

  6. Victor, information about past climate and current energy imbalances is enough to properly scare you, me and probably most people reading this, but unfortunately that’s not most people (or policy makers).

    You point out that the analogy is imperfect. Agreed, but IMO an analogy that does not scare people is inherently less clear.

  7. Re a general use of atom bombs, there’s a rather large range between Hiroshima and Tsar Bomba, so one would have to be a bit more specific. I suppose an alternative would be to go to the kT TNT equivalent, which IIRC would be 80 kT/sec. But that’s still too abstract IMO. The analogy needs to reach people emotionally..

      1. Victor,
        Belsbror lives in the Philippines, a place likely to suffer badly under AGW. And Belsbror, Victor is right in saying that the impact of climate change is likely to be worse in poor, developing countries.

      2. Instead of quarreling over terms, I think we should combine our efforts to protect our environment. Instead of building bombs for destruction, we should put the money in science research to uplift the plight of the poor in developing countries.

  8. I don’t object to the Hiroshima comparison being made when describing the destructive impact of a single localised event, such as a tornado or earthquake, and I don’t really think that it’s disrespectful to the victims of Hiroshima to do so.
    I’m not such a fan of its use to describe the accumulation of energy by the earth because I don’t think it’s a very meaningful metric in that context, as compared to the earth’s overall energy balance one Hiroshima is such a tiny amount. I don’t think the intention is to scare people though – I think the guys at SkS are genuinely trying to communicate to people the amount of energy involved, and I don’t think it implies that climate change is currently causing widespread death and destruction. Anyway, having said all that, I can’t say I object strongly enough about it to make too much of a protest.

    Still, although the reaction of the “skeptics” has been predictably shrill and silly, a number of perfectly sensible people such as Victor have been making more considered arguments against it so I think the guys at SkS should take their objections seriously.

    1. Andrew,
      There are quite big differences between comparing earthquakes with atomic bombs too. Most of the energy released during a fault rupture is absorbed by the Earth’s crust. It isn’t released above ground as is the case for an atomic bomb so the damage is far less. I guess I’m trying to say that nothing is going to illustrate Earth’s energy imbalance perfectly. But I understand what you and Victor are saying about the percentage imbalance being very small.

      1. Rachel,

        I guess it can kind of work both ways. Yes, four Hiroshimas a second sounds like a huge amount of energy but is actually pretty tiny in the overall scheme of things. But then a 1% energy imbalance doesn’t sound like much of a problem so I can understand why people might want to find a way to explainy to people that it actually makes a lot of difference. So although I’m still a bit dubious about using that particular metric I’m not going to criticise the SkS guys too much for trying to put across the subject in terms people can understand and I think it’s certainly unfair to accuse them of scaremongering.

      2. I SkS would not do such an important job, I would have written this tweet:

        If atomic bomb for energy imbalance is effective communication, let’s use number of shredded kittens per second for CO2 emissions.

        And would add a picture like this.

        Retweet this or I'll kill these kittens.— God (@TheTweetOfGod) December 7, 2013

        That would be effective climate science communication. In the sense that it would grab peoples attention and I do not think the Hiroshima app can claim a much broader interpretation of effective.

  9. Using “atom bombs” instead of “Hiroshimas” would be fine but it does make me think of…

    “Daredevil, Flying Fool and All-Around Good Guy.”

    That’s how Roger Ramjet was introduced to his viewers every week in this underappreciated superhero satire. The show followed the adventures of a research scientist who, after taking his Proton Energy Pill, was endowed with the AMAZING power of twenty atom bombs.

    Where’s Roger now when we need him?

  10. Greetings from the USA. I am a semi-retired physicist quailfied in “Radiation Safety”. I don’t see the relevance of “Hiroshimas” to the global warming debate.

    I used to correspond with John Cook at SKS until he imposed censorship at his site. If the facts were on his side, censorship would not be needed. My name is Peter Morcombe and I have relatives in Australia. I blog under my nickname of “gallopingcamel” that derives from my less than graceful running style (wing three-quarter).

    Here are some of my comments that SKS deleted:

    1. A have a serious question for you. I too am a physicist, not semi-retired though :-), and am somewhat fascinated by the idea that a physicist does not see the relevance of “Hiroshimas” to the global warming debate. The fundamental point about global warming is that the entire climate system (oceans, atmosphere, land, ice) is gaining energy. The rate at which it is gaining energy is equivalent to the energy released by 4 Hiroshima bombs every second. I happen to be slightly on the fence with regards to whether or not we should be using such an analogy, but that doesn’t change that – in energy terms – it is quantitatively correct (ignoring an element of uncertainty, admittedly). So, if you don’t mind answering a basic question; what were you suggesting when you said I don’t see the relevance of “Hiroshimas” to the global warming debate?

  11. This is interesting. I think analogies in general are the best way to convey climate change science and impacts. I, too, am trained in physics, so I see the scientific value of measuring energy in units equivalent to atomic bombs.

    However, I hesitate on this one because I think it may lead to other misconceptions. I think something like atomic bombs brings to mind instantaneous disaster, while climate change is much more incremental, so it may not seem as obvious in daily life as an atomic bomb exploding surely would. On longer timescales, atomic bombs conjure thoughts of radiation poisoning and subsequent health effects. Climate change poses a public health risk, too, but in a much different way. In the end, I don’t think most people are used to thinking about atomic bombs in terms of an amount of energy released, even if that’s fundamental to what they are.

    No analogy is a perfect replacement for understanding the science itself; analogies are meant as a simplification of a complex problem. But it’s important to keep the audience in mind. I think in certain circumstances, this analogy may miscontrue the information more than simplify it.

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