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Will climate change bring benefits from reduced cold-related mortality? Insights from the latest epidemiological research

Filed under: — stefan @ 11 June 2018

Guest post by Veronika Huber

Climate skeptics sometimes like to claim that although global warming will lead to more deaths from heat, it will overall save lives due to fewer deaths from cold. But is this true? Epidemiological studies suggest the opposite.

Mortality statistics generally show a distinct seasonality. More people die in the colder winter months than in the warmer summer months. In European countries, for example, the difference between the average number of deaths in winter (December – March) and in the remaining months of the year is 10% to 30%. Only a proportion of these winter excess deaths are directly related to low ambient temperatures (rather than other seasonal factors). Yet, it is reasonable to suspect that fewer people will die from cold as winters are getting milder with climate change. On the other hand, excess mortality from heat may also be high, with, for example, up to 70,000 additional deaths attributed to the 2003 summer heat wave in Europe. So, will the expected reduction in cold-related mortality be large enough to compensate for the equally anticipated increase in heat-related mortality under climate change?

Due to the record heat wave in the summer of 2003, the morgue in Paris was overcrowded, and the city had to set up refrigerated tents on the outskirts of the city to accommodate the many coffins with victims. The city set up a hotline where people could ask where they could find missing victims of the heatwave. Photo: Wikipedia, Sebjarod, CC BY-SA 3.0.

Some earlier studies indeed concluded on significant net reductions in temperature-related mortality with global warming. Interestingly, the estimated mortality benefits from one of these studies were later integrated into major integrated assessment models (FUND and ENVISAGE), used inter alia to estimate the highly policy-relevant social costs of carbon. They were also taken up by Björn Lomborg and other authors, who have repeatedly accused mainstream climate science to be overly alarmist. Myself and others have pointed to the errors inherent in these studies, biasing the results towards finding strong net benefits of climate change. In this post, I would like to (i) present some background knowledge on the relationship between ambient temperature and mortality, and (ii) discuss the results of a recent study published in The Lancet Planetary Health (which I co-authored) in light of potential mortality benefits from climate change. This study, for the first time, comprehensively presented future projections of cold- and heat-related mortality for more than 400 cities in 23 countries under different scenarios of global warming.

Mortality risk increases as temperature moves out of an optimal range

Typically, epidemiological studies, based on daily time series, find a U- or J-shaped relationship between mean daily temperature and the relative risk of death. Outside of an optimal temperature range, the mortality risk increases, not only in temperate latitudes but also in the tropics and subtropics (Fig. 1).

Fig. 1 Exposure-response associations for daily mean temperature and the relative mortality risk (RR) in four selected cities. The lower part of each graph shows the local temperature distribution. The solid grey lines mark the ‘optimal temperature’, where the lowest mortality risk is observed. The depicted relationships take into account lagged effects over a period of up to 21 days. Source: Gasparrini et al. 2015, The Lancet.

Furthermore, the optimal temperature tends to be higher the warmer the local climate, providing evidence that humans are at least somewhat adapted to the prevailing climatic conditions. Thus, although ‘cold’ and ‘warm’ may correspond to different absolute temperatures across different locations, the straightforward conclusion from the exposure-response curves shown in Fig. 1 is that both low and high ambient temperatures represent a risk of premature death. But there are a few more aspects to consider.

Causal pathways between non-optimal temperature and death

Only a negligible proportion of the deaths typically considered in this type of studies are due to actual hypo- or hyperthermia. Most epidemiological studies on the subject consider counts of deaths for all causes or for all non-external causes (e.g., excluding accidents). The majority of deaths due to cold and heat are related to existing cardiovascular and respiratory diseases, which reach their acute stage due to prevailing weather conditions. An important causal mechanism seems to be the temperature-induced change in blood composition and blood viscosity. With regard to the cold effect, a weakening of the defense mechanisms in the airways and thus a higher susceptibility to infection has also been suggested.

Is the cold effect overestimated?

As in any correlative analysis there is always the risk of confounding, especially given the complex, indirect mechanisms underlying the relationship between non-optimal outside temperature and increased risk of death. Regarding the topic discussed here, the crucial question is whether the applied statistical models account sufficiently well for seasonal effects independent of temperature. For example, it is suspected that the lower amount of UV light in winter has a negative effect on human vitamin D production, favoring infectious diseases (including flu epidemics). There are also some studies that point to the important role of specific humidity, that, if neglected, may confound estimates of the effect of temperature on mortality rates.

Interestingly enough, there is still an ongoing scientific debate regarding this point. Specifically, it has been suggested that the cold effect on mortality risk is often overestimated because of insufficient control for season in the applied models. On the other hand, the disagreement on the magnitude of the cold effect might simply result from using different approaches for modeling the lagged association between temperature and mortality. In fact, the lag structures of the heat and cold effects are distinct. While hot days are reflected in the mortality statistics relatively immediately on the same and 1-2 consecutive days, the effect of cold is spread over a longer period of up to 2-3 weeks. Simpler methods (e.g., moving averages) compared to more sophisticated approaches for representing lagged effects (e.g., distributed lag models) have been shown to misrepresent the long-lagged association between cold and mortality risk.

Mortality projections

But what about the impact of global warming temperature-related mortality? Let’s take a look at the results of the study published in The Lancet Planetary Health, which links city-specific exposure-response functions (as shown in Fig. 1) with local temperature projections under various climate change scenarios.

Fig. 2 Relative change of cold- and heat-related excess mortality by region. Shown are relative changes per decade compared to 2010-2019 for three different climate change scenarios (RCP 2.6, RCP 4.5, RCP 8.5). The 95% confidence intervals shown for the net change take into account uncertainties in the underlying climate projections and in the exposure-response associations. It should be noted that results for single cities (> 400 cities in 23 countries) are here grouped by region. Source: Gasparrini et al. 2017. The Lancet Planetary Health

In all scenarios, we find a relative decrease in cold-related mortality and a relative increase in heat-related mortality as global mean temperature rises (Fig. 2). Yet, in most regions the net effect of these opposing trends is an increase in excess mortality, especially under unabated global warming (RCP 8.5). This is what would be expected from the exposure-response associations (Fig. 1), which generally show a much steeper increase in risk from heat than from cold. A relative decline in net excess mortality (with considerable uncertainty) is only observed for Northern Europe, East Asia, and Australia (and Central America for the more moderate scenarios RCP 2.6, and RCP 4.5).

So, contrary to the propositions of those who like to stress the potential benefits of global warming, a net reduction in mortality is the exception rather than the rule, when comparing estimates around the world. And one must not forget that there are important caveats associated with these results, which caution against jumping to firm conclusions.

Adaptation and demographic change

As mentioned already, we know that people’s vulnerability to non-optimal outdoor temperatures is highly variable and that people are adapted to their local climate. However, it remains poorly understood how fast this adaptation takes place and what factors (e.g., physiology, air conditioning, health care, urban infrastructure) are the main determinants. Therefore, the results shown (Fig. 2) rely on the counterfactual assumption that the exposure-response associations remain unchanged in the future, i.e., that no adaptation takes place. Furthermore, since older people are more vulnerable to non-optimal temperatures than younger people, the true evolution of temperature-related mortality will also be heavily dependent on demographic trends at each location, which were also neglected in this study.

Bottom line

I would like to conclude with the following thought: Let’s assume – albeit extremely unlikely – that the study discussed here does correctly predict the actual future changes of temperature-related excess mortality due to climate change, despite the mentioned caveats. Mostly rich countries in temperate latitudes would then indeed experience a decline in overall temperature-related mortality. On the other hand, the world would witness a dramatic increase in heat-related mortality rates in the most populous and often poorest parts of the globe. And the latter alone would be in my view a sufficient argument for ambitious mitigation – independently of the innumerous, well-researched climate risks beyond the health sector.

Addendum: Short-term displacement or significant life shortening?

To judge the societal importance of temperature-related mortality, a central question is whether the considered deaths are merely brought forward by a short amount of time or whether they correspond to a considerable life-shortening. If, for example, mostly elderly and sick people were affected by non-optimal temperatures, whose individual life expectancies are low, the observed mortality risks would translate into a comparatively low number of years of life lost. Importantly, short-term displacements of deaths (often termed ‘harvesting’ in the literature) are accounted for in the models presented here, as long as they occur within the lag period considered. Beyond these short-term effects, recent research investigating temperature mortality associations on an annual scale indicates that the mortality risks found in daily time-series analyses are in fact associated with a significant life shortening, exceeding at least 1 year. Only comparatively few studies so far have explicitly considered relationships between temperature and years of life lost, taking statistical life expectancies according to sex and age into account. One such studies found that, for Brisbane (Australia), the years of life lost – unlike the mortality rates – were not markedly seasonal, implying that in winter the mortality risks for the elderly were especially elevated. Accordingly, low temperatures in this study were associated with fewer years of life lost than high temperatures – but interestingly, only in men. Understanding how exactly the effects of cold and heat on mortality differ among men and women, and across different age groups, definitely merits further investigations.

200 Responses to “Will climate change bring benefits from reduced cold-related mortality? Insights from the latest epidemiological research”

  1. 101
    Mr. Know It All says:

    EASY PEASY Question 1: Roughly, how many heat-related deaths have occurred during previous “normal” European summers?

    EASY PEASY Question 2: How many heat-related deaths occurred in Europe during the summer of 2003?

    If we don’t know what a “normal” number of heat-related deaths has been in “normal” summers, then we cannot make a statement that X number of “additional” or “excess” deaths occurred during summer 2003.

  2. 102
    Astringent says:

    MKIA@101 asks 2 questions but misunderstands the quoted statistics. 70k deaths in Europe during the 2003 heatwave is 70k additional deaths above the long term average for the summer months, not a total of 70k heatwave related deaths. Given observed correlations between heat and temperature and medical knowledge its a reasonable hypothesis that the heatwave played a role, and the hypothesis is backed up by medical reports etc.

    In France a ‘normal’ August might expect to see 25,000 deaths – 2003 saw 40,000 deaths, 60% above the mean.

  3. 103
    zebra says:

    #100 Kevin,

    “well defined framework”

    “clarity is really needed”

    z: “It’s the language, stupid.”

    See my comments above. Starting with the researcher, and then the peer reviewers, the editors, the reporters, the blog contributors, and self-styled expert commentators (ahem), there is a responsibility not to make things more confusing than they need to be.

    I don’t know what kind of “framework” you are talking about, but the answer to “what is being attributed to what” is in the research itself. You know very well that science works by the accumulation of very narrow “experiments”, so we should be able to write a single sentence to answer your question in each case.

    Maybe we could call it something like “an experimental hypothesis”, and maybe we could standardize the format as describing something we could call the “null” outcome.

    Waddaya think, K?

  4. 104
    Adam Lea says:

    There is an interesting consequence of the 2003 heatwave in France that occurred in the years following the heatwave.

    From what I heard many years ago, the timing of the heatwave contributed to the death toll. The worst heat occurred when many people go on holiday (I can’t remember whether or not it was a national holiday), and left their elderly relatives behind. Those elderly relatives didnt’t have family members keeping an eye on them, and older people are more vulnerable to temperature extremes, so a disproportionatly large quantity of the death toll was the elderly and frail. This toll on the elderly and the reason (many people going on holiday at the same time) was made public knowledge. This shamed the population to the point where, in following summers, they made extra effort to look after their elderly relatives. The result was that the heat related death toll during the following summers was below normal, to the point where effectively more lives were saved than were taken in the heatwave. This leads to an interesting question, was the heatwave bad for taking lives directly or good for saving lives indirectly?

  5. 105

    #103, zebra–

    Waddoeye think?

    I think it’s not so much a matter of single papers as a matter of the field of attribution studies deciding which questions they are trying to answer, why, and how that can be made explicit for readers, especially non-specialist ones.

    In theory, attribution research is, in general, supposed to answer the over-arching question “Is the human effect on climate manifested in phenomenon X, which we will now tell you about?” (Or such is my impressions–corrections from the pros most welcome.)

    In practice, various papers seem to approach that through different lenses, which lead to inconsistent and confusing answers to the question articulated above. For instance, one researcher may ask the question, “Does the particular flooding scenario observed in Colorado in the occur more frequently in association with climate warming in model runs?”

    That is pretty much the approach taken in, for example, in Hoerling et al (2014), p. 15 in the following special issue of BAMS:

    https://journals.ametsoc.org/doi/pdf/10.1175/1520-0477-95.9.S1.1

    Finding that in models runs, despite an increase in precipitable water, for Northeastern Colorado, the frequency of such storms actually decreases under warming, even though the opposite is true globally. (Vaguely analogous to the Atlantic ‘cold blob’, in a way.) Their conclusion follows:

    Our analysis of the GEOS-5 simulations leads to a diagnosis that the occurrence of extreme five-day rainfall over northeast Colorado during
    September 2013 was not made more likely, or more intense, by the effects of climate change. From an observational perspective, analogous events have
    occurred before in the Front Range, perhaps most strikingly similar in September 1938, long before appreciable climate change.

    Another may focus more on comparing the observational record with model hindcasts using various forcings. The introduction to the report puts it reasonably well, I think:

    …with success comes a new set of challenges. With the growth of the breadth of the report has come a greater requirement to synthesize across the disparate contributions involving different methodologies and different teams.

    Three different approaches to a single event, the 2013 Australian heatwave/drought, are illustrated by three different studies. (The first begins on p. 34, and focuses on risk; the second, on p. 37, on causative factors; the third, p. 41, looks at the interplay of temperature and drought, and the how the probability of the record-warm year was affected.)

    But at least all three of these papers came to similar conclusions–that human influences had a significant impact on the observed temperatures. That’s not always the case; early studies of the 2010 Russian event came to apparently opposite conclusions, due to choosing different approaches–and not articulating the effects of that choice on the ‘headline’ conclusion.

    IIRC, the ‘proxy’ questions were 1) “Was the event more probable in appropriately-forced model runs?” versus 2) “Was the event within the envelope of natural variability?” Of course, both can be true, but because it wasn’t clear that these ‘proxy questions’ were in play, rather than the ‘headline question’ “Did humans do it?”, the results were widely perceived at the time as ‘dueling’. Predictably, they immediately became fodder for a ‘warmist’/’denialist’ he-said/she-said fest.

  6. 106
    Mr. Know It All says:

    102 – Astringent
    My questions are math questions. Each requires an answer in the form of an integer. That is all I am looking for: 2 numbers. Can someone, anyone on the face of the earth, answer my 2 math questions, and not go into explanations. No explanation, statistics, etc is required. Just 2 numbers. I understand that the numbers are rough estimates – that’s fine.

  7. 107
    Carrie says:

    101 Mr. Know It All why can’t you drop your defenses and simply listen to what people say, and then go and check the information they are providing to you? I ask because your comment at 101 is like a punter complaining after the horse race was won that he didn’t know the winner was listed in the race before placing his bet. Hello?

    So for nth time 102 Astringent again points out what the facts and the reality are. Now I knew this type of information back around 2003 – would you like to know how I knew that 15 years ago? OK< I went and looked it up in scientific papers and via the media sources that led me to more academic/scientific papers.

    The question then is – KIA where have you been and what have you been doing and why are you now asking Questions about things known 15 years ago already? What Veronika Huber is offering you is a much more deeper analysis based on that very same DATA and more since 2003.

    S what is the problem here KIA with your silly EASY PEASY questions and – If we don’t know what a “normal” number of heat-related deaths has been in “normal” summers, then we cannot make a statement that X number of “additional” or “excess” deaths occurred during summer 2003″

    Those in the know know that Know It All (sic)… they have kept the Data and used it. That is how they know KIA – why don’t you KNOW IT ALL even after reading Veronika Huber’s article, the papers and the comments on this page?

    such as: 13 Carrie says:
    13 Jun 2018 at 12:17 AM
    http://www.realclimate.org/index.php/archives/2018/06/will-climate-change-bring-benefits-from-reduced-cold-related-mortality-insights-from-the-latest-epidemiological-research/#comment-705851

    40 Carrie says: [ The one misread as being full of stinging humor and insults and then obviously ignored given your EASY PEASY Questions above @101 ]
    17 Jun 2018 at 12:15 AM
    http://www.realclimate.org/index.php/archives/2018/06/will-climate-change-bring-benefits-from-reduced-cold-related-mortality-insights-from-the-latest-epidemiological-research/#comment-705956

    You are your own problem Mr KIA :)

  8. 108
    nigelj says:

    https://www.carbonbrief.org/guest-post-unprecedented-summer-heat-europe-1-5c-warming

    From Carbon Brief yesterday: “Guest post: Unprecedented summer heat in Europe ‘every other year’ under 1.5C of warming.”

    ” Dr Andrew King is a climate scientist at the University of Melbourne and Dr Markus Donat is a climate scientist at the University of New South Wales”

    “But while the summer sun sends many flocking to the beach, with it comes the threat of heatwaves and their potentially deadly impacts. Tens of thousands of people across Europe died in heatwaves in 2003 and 2010, for example, while the “Lucifer” heatwave last year fanned forest fires and nearly halved agricultural output in some countries…….”

  9. 109
    nigelj says:

    Mr KIA @106, to answer your question about simple “integers”, a question in my mind as well, Astringent said “In France a ‘normal’ August might expect to see 25,000 deaths – 2003 saw 40,000 deaths, 60% above the mean.” I mean seriously dude, don’t you read beyond the first sentence? :)

    The more important thing to me is climate change is already causing more frequent heat waves, and they are likely to get hotter. I suggest read the relevant parts of the IPCC reports, they are free online.

  10. 110
    zebra says:

    #105 Kevin,

    “the field”? of attribution studies?

    I think you are caught up in some kind of circular reasoning trap here, Kevin.

    At the end there you say that stuff “wasn’t articulated in the headline conclusions”– isn’t that what I articulated with respect to the various players in the chain of getting it out to the public?

    For me it is a simple matter: “What’s the physics?” and “Do the numbers agree with what the physics predicts, at least qualitatively”?

    Other than that, I’m not clear on what a “field” of attribution studies would be like. Each case is and should be independently studied. As we accumulate such studies, it will become clear which more generalized metrics are changing.

    Do you have some alternative suggestion?

  11. 111
    Hank Roberts says:

    Adam Lea:

    they made extra effort to look after their elderly relatives. The result was that the heat related death toll during the following summers was below normal

    Cited to “what I heard many years ago” (which is rather vague)

    I’d think it more likely that a passel of vulnerable people died — earlier than expected — during the 2003 heat wave, so weren’t among the living to be affected by subsequent summers’ heat.

  12. 112
    Keith Woollard says:

    So what do these excess heat wave deaths look like? I thought I would check for myself as I tend to not believe most things I get told. I couldn’t find the appropriate figures for 1976 or 2003, but wikipedia lists the July 2013 English heatwave with 760 “excess” deaths attributed to the 2 weeks. Not as many obviously as the 2000 listed for 2003, but not orders of magnitude different.
    There is a nice site with the weekly figures going back to 2010:-
    https://tinyurl.com/yc88o2wt

    And if you get the 2013 spreadsheet, it is trivial to plot each weeks deaths (in blue) and compare it to the average for that week for the previous 5 years (in red):-

    https://photos.app.goo.gl/QAn4NP9db3okikNb9

    If you squint you might be able to see the 760 deaths sticking up slightly above average from the week 27 mark when the heatwave started.

    What is much more obvious is the 10,000 deaths a few months earlier, and a quick google will tell you that England had an unusually cold late winter/early spring

    I think it is laughable that anyone would try to suggest that heatwaves in England are a problem

  13. 113
    NonScientist says:

    Thanks for all the previous responses. Agree or not, it’s good to hear from other perspectives. Due to health issues, I cant’ reply here often.

  14. 114
    Mr. Know It All says:

    109 – nigelj

    I did not ask about August. I asked what is the number of heat-related deaths for a “normal” or “typical” or “average” summer, and what was the number of heat-related deaths for the summer of 2003. The article made this claim:

    “On the other hand, excess mortality from heat may also be high, with, for example, up to 70,000 additional deaths attributed to the 2003 summer heat wave in Europe.”

    You cannot say there were 70K additional deaths if you don’t know the “normal” number of deaths. All I want to see are the 2 numbers! That should be a very simple request, agreed???!!!

  15. 115

    #110, zebra–

    I’m not too sure why what I’m saying is so problematic for you–particularly when I use the rather common term ‘field’, as in ‘field of study.’ In the case of attribution, I would have thought that it’s pretty clear that the overarching focus would be the detection of human influence on various meteorological phenomena. That focus would necessarily constrain, to some degree, possible approaches and conceptual frameworks.

    It is possible that consensus on such things can evolve from a bottom-up process such as you describe, and that’s all well and good. However, it’s not at all an uncommon thing for researchers to get together in conventions, workshops or symposia at varying levels of formality and universality to try and speed the process up with focused attention on the pros and cons of particular methodologies, terminologies, and conceptual framings.

    For examples, one could look to any number of entities, from, say, the Committee struck by the stratigraphers to examine the merits of formally recognizing an “Anthropocene,” right down to, say, panel discussions at state-level gatherings of researchers in this or that field. (I’ve attended a few such in my day, and in my area.)

    I’d add that you also sometimes see proposals for conceptual frameworks made in the context of review articles in the literature, which is another way that the goals and aims of attribution studies could be clarified. Of course, none of this would reduce anyone’s freedom to think up better ideas and develop new approaches. Such would still get published, and would presumably prevail through the normal process.

    Does all that help in understanding what I mean?

  16. 116
    Al Bundy says:

    Mr KillingInaction: You cannot say there were 70K additional deaths if you don’t know the “normal” number of deaths. All I want to see are the 2 numbers! That should be a very simple request, agreed???!!!

    AB: Petulant. Unless, of course, you were to PAY someone to dig up the data. Pound sand. (Hint: contacting the author of the study is a grand technique)

  17. 117
    mike says:

    TO MKIA at 114: the numbers/integers you are seeking are in this article: https://www.sciencedirect.com/science/article/pii/S1631069107003770
    you can review the abstract for free, but the complete paper is behind a paywall. The cost is $35.95 USD.

    Here is the abstract/teaser that is available for free: Abstract

    “Daily numbers of deaths at a regional level were collected in 16 European countries. Summer mortality was analyzed for the reference period 1998–2002 and for 2003. More than 70,000 additional deaths occurred in Europe during the summer 2003. Major distortions occurred in the age distribution of the deaths, but no harvesting effect was observed in the months following August 2003. Global warming constitutes a new health threat in an aged Europe that may be difficult to detect at the country level, depending on its size. Centralizing the count of daily deaths on an operational geographical scale constitutes a priority for Public Health in Europe. To cite this article: J.-M. Robine et al., C. R. Biologies 331 (2008).”

  18. 118
    Mr. Know It All says:

    It’s tough to come up with real data. And some wonder why there are skeptics. Any skeptic reading this comment thread would say – “see the scientists can’t come up with real data”! 2 integers would help the pro-AGW side, at least as far as the comments for this article are concerned.

    ;)

  19. 119
    Michael Sweet says:

    Mr KIA,

    If you want to participate in a science based blog you have to pay attention and put in a little effort.

    Scientists are required to provide citations to support their claims. In the first paragraph of the OP you will find the words “70,000 additional deaths” highlighted. That means they are the citation that supports the 70,000 deaths claim. Mike above tried to give you another link to the data. Obviously you are too clueless to understand citations since you have not read the citation yet.

    Upon finding that the article was paywalled I GOOGLED the article and found a free copy here: http://www.precaution.org/lib/heat_kills_70000_in_europe_2003.080601.pdf
    It took 30 seconds to find the free article. If you are too incompetent to find the free paper you cannot “Know it all”.

    Upon reading the paper I found that approximately 74,000 additional deaths were attributed to heat during the summer of 2003. Imagine that: the OP reduced the claim of deaths from 74,000 to 70,000!!!!! You should complain.

    The total number of deaths requires calculation from the data in the article. Using an obscure mathematical function called “division” I found 1,100,000 deaths were expected.

    It is not the responsibility of other posters to do your homework. If you are incapable of reading a simple journal article that is cited in the first paragraph of the OP you need to stop your absurd whining. You have made at least three requests for information contained in the OP.

    Mr KIA and Victor should be banned. At least 25% of posts on the two active OP’s are replies to their absurd complaints.

  20. 120
    Romain says:

    Mike,
    A reference period of only 5 years?
    Is this really what is behind these 70,000 extra deaths? They compared it to the 5 preceding years only?
    Is there an explanation as to why they think this is enough?

  21. 121
    Oscar Wehmanen says:

    People can and will adapt to higher temperatures, at least enough the tolerate day/night temps like 40/30. Crops – not so much! Primary temperature related deaths will be swamped by starvation due to failed crops driven by bad growing conditions. Climate change is not one small problem – it is multiple small problems happening at one time!If the skeeters don’t git ya then the gators will!

  22. 122
    nigelj says:

    Romain @120

    “Is this really what is behind these 70,000 extra deaths? They compared it to the 5 preceding years only?”

    The five preceding years look like a very useful number. One would be insufficient obviously as it could be an anomaly year, so 5 is useful. You want just a few recent years, because going back too many years would not be comparing “like with like”. Because social and general climate conditions would be too different.

  23. 123
    Marco says:

    Romain, the longer you go back, the more likely it is to introduce a fundamental bias due to improved health care – additional confounding issues may play a role, too, such as an improvement in weather predictions and improved warning systems over the years.

  24. 124
    Ray Ladbury says:

    My what imperious, entitled little snowflakes we have among our contingent of denialists. Mr. KIA seems to think that if we don’t drop everything and cater to his every demand, then the terrorists win, while Romain seems to deign doing math below him.

    If Michael Sweet’s number of 1.1 million deaths expected is correct and we approximate deaths fluctuating as a Poisson about that mean, that would be >70 standard deviations. That a significant enough effect for you, Romain? While I suspect the distribution is probably thicker tailed (Pareto, maybe?), it is still a clear effect.

  25. 125
    Adam Lea says:

    112: “I think it is laughable that anyone would try to suggest that heatwaves in England are a problem”

    As someone who lives in England I can say they are a problem when they happen. Any climate extreme is a problem, since societies are built around normal conditions, so large deviations from normal cause disruption. In England, we are currently in a warm/hot dry spell that has persisted for over two months. It is causing minor problems for me trying to stop the crops on my allotment from shrivelling up. It is causing far more problems for those living near the Pennines having to deal with moorland fires which, thanks to the peat soil, may take weeks to extinguish completely. It is causing problems for transport, as rail lines buckle in the heat leading to disruption on the trains (which we have had a lot of in the last few years). It is causing problems for water supplies in some counties as hosepipe bans are introduced, and it is now getting to the point where it is starting to adversely affect some arable crops. It could be a major problem in the coming decades if the SE England summer climate gets drier, and London starts seeing the sort of issues that Cape Town has had to deal with this year. Sorry, I have to disagree that heatwaves in England are not a problem.

    The prolonged dry spell here seems to be linked to the most positive April-June NAO on record, which is linked to a northward displacement of the polar jet, allowing frequent and persistent ridging of the Azores high over the UK. The only reason the temperatures are not extreme is that the current anticyclone is positioned directly over the UK, giving home grown heat, as opposed to the severe heatwaves where the high is centred just SE of the UK which results in advection of warm air from southern Europe to amplify the effects of solar heating.

  26. 126
    Keith Woollard says:

    Adam @125, obviously you didn’t look at the graph.
    Maybe I was flippant saying heatwaves were not a problem, perhaps I should have said “compared with cold snaps heatwaves are not a problem” – but really I thought that was implied because the whole thrust of the opinion piece (complete with it’s hand drawn guestimates of mortality change with temperature) was that even in cold climates heat waves cause lots of deaths.
    Nothing in the article was about train timetables – but I can absolutely guarantee that English trains are more often on time in summer than winter. I am sorry for your crops, but they aren’t really the topic of the discussion here.

  27. 127
    Mr. Know It All says:

    The article that Michael Sweet linked to (thank you Sir for “doing my homework”) has estimates all over more than any other place. I almost got whiplash trying to keep up. Here’s an excerpt:

    “A first assessment, made in
    March 2004 by the United Nations Environment Programme
    (UNEP), estimated the death toll on a European
    scale to exceed 30,000 [3]. A similar estimation
    was published two years later, although the available
    studies pertain to different periods of the summer [4].
    A range between 27,000 and 40,000 excess deaths has
    been proposed, depending on data sources, methodology
    and reference period [5]. A total higher than 38,000
    excess deaths during August 2003 has been declared in
    seven European countries [6].”

    Apparently due to the wide range of estimates, the EU instigated a study, and that’s where the 70K number is from. And based on Michael’s advance math technique which resulted in a total of 1,100,000 deaths, then the 70K additional appears to be roughly 7% above what is expected.

    70K is a lot when you compare that to a typical number of around 2 or 3,000 in the USA, but as some have indicated, AC is not in widespread use in Europe. I always wondered why people were trying to storm our borders – it’s so they can cool off! WE have electricity! And tomorrow we’ll blow up some gunpowder to celebrate – Happy Independence Day USA!

    As Romain indicates, a longer time period than 5 years would be more meaningful. 30 years would be the minimum to qualify as a “climate” study. You’d get the rate per 100,000 or 1,000,000 people and that would be what you are interested in, not the total number since the population size constantly changes, etc.

  28. 128
    Astringent says:

    MrKIA @127. The issue with mortality is thanks to the medics and public health bods, mortality changes significantly over short time periods. So lengthen the time span of comparison and you have more confounding trends. Though in Europe are health data is good enough that at root we aren’t talking about vague numbers, the experts can pin down cause of mortality quite precisely, so it’s sort of mot a statistical problem. If you read around this topic the adaptive response of populations is obviously a factor, air conditioning is one adaptive response, but it takes money and energy. Not everyone in the world is as rich as an American and using more CO2 generating energy to combat the effects of using CO2 generation is about as clever as taking the front door off your house to burn as firewood to keep warm in a blizzard.

  29. 129
    Michael Sweet says:

    Mr. KIA,

    You have shown that you are unable to read a simple citation and find out the numbers you want. Why should I believe that you are capable of giving useful criticism of a peer reviewed paper? If you are unable to find information you are given it follows that you are also unable to determine if a peer reviewed paper is accurate.

    You have to learn to walk before you can run. When you cannot access the scientific literature you cannot know how to design a research program.

    For example, your list of numbers copied from the paper. These numbers are for different countries and/or areas. As expected, as research continues health experts more accurately determined the number of deaths.

  30. 130
    nigelj says:

    Canada and America are currently experiencing a large heatwave, and multiple serious forest fires, something becoming all the more common with climate change. Mr KIA rearranges the deck chairs on the Titanic, nitpicks over numbers, and blathers on about air conditioning.

  31. 131
    Sophie says:

    We should be aware of Climate Change.
    Putting it aside will a big mistake.

    Climate Change May Have Claimed A Significant Victim – The Barents Sea

  32. 132
    Mr. Know It All says:

    130 – nigelj

    Canada and America are currently experiencing a large heatwave, and multiple serious forest fires, something that has been common at least since men started recording such things. Mr nigelj rearranges the deck chairs on the Titanic, nitpicks over numbers, and blathers on about climate change.

    :)

  33. 133
  34. 134
    tamino says:

    I’m as willing as anyone to point out how ridiculous are the ideas from “Victor.” I’m even willing to call him unflattering names (Victor the troll).

    But this business of pointing out where he lives (repeatedly) is disturbingly reminiscent of “doxing” — a reprehensible practice. Musing that he might have ties to the coal industry, with no evidence other than where he lives, is the kind of “smear by speculation” I expect from Donald Trump and his supporters.

    None of us is perfect, and all of us have crossed the line at one time. But let’s break the habit, and be better than that. We ARE better than that.

  35. 135
    Michael Sweet says:

    Mr KIA,

    If you read the numbers you would not make such uninformed comments about heat records. According to the National Climate Data center, for the USA in the past year there have been 158 all time heat records set and only 21 all time cold records. Your statement ” been common at least since men started recording such things” is simply false. If you look up the numbers (you can use GOOGLE if you knew how) you would find that the past 5 years have set records for the most acres burned.

    It is easy to claim another poster is nitpicking over numbers when you do not produce any yourself. Your claims are ignorant and uninformed.

  36. 136
    nigelj says:

    Mr. Know It All @132

    “Canada and America are currently experiencing a large heatwave, and multiple serious forest fires, something that has been common at least since men started recording such things.”

    You miss the point. Heatwaves are already increasing in frequency and intensity globally, due to agw climate change:

    https://www.skepticalscience.com/heatwaves-past-global-warming-climate-change.htm

    https://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch8s8-2-1-1.html

    And in Australia in particular:

    https://www.climatecouncil.org.au/uploads/9901f6614a2cac7b2b888f55b4dff9cc.pdf

    I could go on. And heatwaves make forest fires more likely. Do I need to explain why? :)

  37. 137
    nigelj says:

    Tamino @134, I agree about not going down to Trumps level. In my opinion especially his tendency to exaggerate, get things wrong, and abuse and bully people.

    But I think its a reasonable question to wonder aloud whether someone has industry connections, easily answered by that same person. However I won’t wonder aloud about it again!

  38. 138
    Al Bundy says:

    NigelJ: Mr KIA rearranges the deck chairs on the Titanic, nitpicks over numbers, and blathers on about air conditioning.

    AB: Actually, air conditioning is a huge issue because humans like temperatures near 70F. As long as nighttime temperatures dip below 70F it is possible to build a well-insulated house that also has high thermal mass and ventilate it at night. With this sort of system air conditioning (for that day) is not needed. This is how I currently cool my apartment. (Though, of course, not as well as a purpose-built original system.)

    But raise nighttime temperatures by 5F or so and such a system won’t work. Since global warming increases nighttime temperatures more than daytime temperatures, air conditioning becomes the only way to get comfortable in a slightly warmer world. Since ventilation spews almost no carbon and AC spews tons this small temperature change has drastic consequences.

    Note that many places do not have air conditioning because it wasn’t needed before tomorrow. I lived on Vancouver Island where folks are well off but nobody has AC. Ditto when I lived in England (though that was decades ago). The disruption caused by a small increase in nighttime temperatures is/will be huge.

    Sophie, the Bering Sea is also changing from icy to watery. Once these two’s transformation is complete, it is likely that the rest will fall. Note that as the Hadley cells drift north (and south) highly populated areas will be swept into the subtropics. Who needs plate tectonics, eh?

  39. 139
  40. 140
    nigelj says:

    Al Bundy @138, well my obvious point was air conditioning won’t fix all the problems that come with heatwaves, such as forest fires, however you are right, in that air conditioning is essential in some places.

    I dont really need air conditioning, except it gets a bit hot at night for about two weeks in summer. I have considered getting an evaporative cooler, ( a very basic air conditioner) which might use less electricity so should be less of a problem, (I must look into that).

    Altering the house and adding more insulation or thermal mass would be a major job for my house and not justified. However I know something about passive solar design, and it would be great if more houses were built that way as it basically reduces use of electricity quite a lot, in respect of both heating and air conditioning, and this is what we want. Its a huge opportunity just sitting there. Its basically a case of showing people how slightly higher capital costs save money in the long run and reduce needs for energy.

    Often all it requires is some thermal mass in the right place, some extra insulation, double glazing, getting plenty of glass in the right orientation, using thermal curtains and exterior awnings. It doesnt have to cost more than about 10% of the cost of a typical house to make a decent difference.

    Unfortunately many people are fixated on having the largest home possible, and as many ensuites so they can show off etc.

  41. 141
    Hank Roberts says:

    Quoting from the NPR story about Phoenix:

    About 40 percent of heat-related deaths last year occurred indoors. Those victims were generally women, living alone and over the age of 75. “Oftentimes, they won’t have their air conditioning on, or it will be malfunctioning,” says Sunenshine. “Because they are older, their bodies aren’t able to detect differences in temperature.”

    Phoenix is looking at installing heat alert systems in the homes of elderly residents. The idea is that they could notify first responders and other volunteers, perhaps neighbors, when the temperature inside a home reached a worrying level.

  42. 142
    Mr. Know It All says:

    Bad drought in the western USA:
    https://www.thefencepost.com/news/some-farmers-and-ranchers-in-colorado-kansas-nebraska-and-wyoming-are-looking-to-the-skies-for-signs-of-precipitation/

    I’ve heard there isn’t enough hay at a reasonable price, causing people to sell cattle which is making prices drop. Even heard of people selling off their land since it will not support their cattle.

    139 – Hank
    People dying from heat in Phoenix. Whodathunkit? Surprising thing in that article was the link to a graph showing number of heat deaths in 2017 for the USA – it was only 107 deaths. The “heat realted” deaths for the USA is 2K-3K per the CDC. Here’s the 107 graph:
    http://www.nws.noaa.gov/om/hazstats.shtml

    Yet, just recently we read about 1,000,000+ people dying in Europe in 2003. 107 versus 1,000,000+. WOW!

    On a 95 degree day you can probably kill yourself by doing a hard workout in the sun and not drinking enough water – people have been demonstrating this exact feat for thousands of years.

    137 – nigelj
    On Trump – don’t feel bad – you’re not the only one even in this list of comments. Every day before I open any news website I think to myself – wonder if the first headline will be about Trump. In almost every case for the past 3 years, it has been! :) The man is a friggin’ genius, best president in my 60+ years! Most entertaining in our history I’ll bet! :)

  43. 143
    nigelj says:

    Mr KIA @142, Trump may be entertaining, like a soap opera, or circus routine, but most of his policies are damn stupid, and will be especially hard on his blue collar supporters, but will ultimately hurt virtually everyone. This is why most economists and scientists are so critical, and even plenty of business people as well, those with a conscience.

  44. 144
    Al Bundy says:

    Nigelj: Unfortunately many people are fixated on having the largest home possible, and as many ensuites so they can show off etc.

    AB: Yes, I used your post as a segue (as opposed to a two-wheeled vehicle [Segway]). :-)

    This is easily fixed. Simply add expected utility costs to the equations during qualifying for the loan for a large purchase. Doing that will enable folks to buy a bigger house and car IF and only if they heat and cool (house) or fuel (car) their purchase efficiently.

    Tis easy to corral sheeple. The problem is how to allow non-a**holes to do the corralling. Seriously, visualize all the treasure and lives burned simply to deliberately and uselessly increase fossil fuel consumption so as to enrich leeches. As if the poor are takers. The takers are the folks who sit on their couch eating caviar while raking in millions doing nothing of value at all. IF the rich were not lying they’d be screaming for 99% estate taxes, because inheritance goes 100% against their stated beliefs of “personal responsibility” and “earning things oneself instead of being given”. Since they scream for the elimination of estate taxes, they obviously are hypocritical a**holes.

    Mr KillingInaction,

    Drumpf is the Antichrist. You are a minion. (Oops, I just did a personal attack against you. In my defense, twas accurate and appropriate.)

    And since I’m being entertaining, methinks the mods will chuckle and let this pass.

  45. 145
    Dan H. says:

    nigelj,

    I do not know how accurate you claim is about increased frequency and intensity of heat waves. Here in the U.S., the biggest change is the increased nighttime temperatures. The daytime highs and number of days exceeding high temperatures (whether it be 90, 95, or 100F) has decreased in most major cities. So, depending on whether you use a high temperature daytime cutoff or low temperature nighttime cutoff, the trend in heat waves changes considerably.

  46. 146
  47. 147
    nigelj says:

    Dan H @145, It’s not my personal claim. I gave you several reference sources on heatwaves, showing that an increase in numbers and strength has already occured. It’s not that hard to measure whether numbers have increased over time.

    The studies were global, except the third one that was on Australia. Here is another global study for you:

    http://www.chicagotribune.com/news/nationworld/science/ct-heat-wave-climate-change-study-20170619-story.html

    Provide an internet link to back up your statements about America claiming a fall in extreme temperatures. I doubt they are correct, and its no good just referring to cities, you have to look a lot wider than that at rural areas.

    This source shows heatwaves have increased in America. Its recent:

    https://abcnews.go.com/Technology/story?id=120081&page=1

    “Analyzing the temperatures from 172 U.S. weather stations over roughly the last 50 years, from 1948-1999, the study found a threefold increase in the number of heat waves across the country. A heat wave is defined as a four-day period when average temperatures are above the 85th percentile for summer temperatures in the area. That means the threshold for a heat wave in Seattle would be lower than the temperature level of a Louisiana heat wave.”

  48. 148
    nigelj says:

    Al Bundy @144, billionaires and their families are exempt from personal responsibility. That is for “other people”.

  49. 149
    jgnfld says:

    @145

    Deniers dearly love massaging data looking for cherrypicked subsets with which to misinform/disinform. Days above a particular absolute temperature–found mostly only in one season of the year, of course, is a classic.

    We are already seeing some references by deniers to the new “pause” we have seen for a score and a bit of months now as another example.

  50. 150
    Dan H. says:

    So Hank,
    Based on the epa graph of heat-related-deaths, is it fair to say there has been no change over the past two decades? Granted, the scatter far outweighs any trend.