“Global warming” vs “Global heating”

I was a little surprised by some of the views expressed in the comments on my previous post. I had assumed that it was fairly obvious that the term “global warming” should really be used to refer to the overall increase in energy in the climate system and not just to the warming of the surface. It is clear, however, that the scientific literature still uses the term “global warming” when referring to surface warming. It’s also clear that some seem happy with this definition (although are more than willing to acknowledge that it should then be clearly distinguished from overall warming and that it can create confusion). Some have suggested that maybe we need a new term, such as “global heating”, to refer to the overall accumulation of energy in the climate system.

In some sense, if we can clearly define the terminology then it shouldn’t matter what terms we use to define surface warming and overall warming. The problem I can see is it is not immediately obvious that the term “global warming” should refer only to surface warming. This would, typically, need to be made clear when the term is used. Also if we use “global heating” to refer to overall warming, I can see people assuming that “global warming” and “global heating” are simply two terms for the same thing. Personally, I would think that the term “global surface warming” would be a sensible option. Admittedly, I’m simply an anonymous blogger and so really shouldn’t be taken seriously. Also, there is historical precedent to consider. Scientists understand the current terminology and so there should be some kind of consensus about changes to existing terminology. I will also add that there is a scientific argument that could be made for using “global warming” when referring to surface warming. The ultimate consequence of anthropogenic global warming is that surface temperatures will rise so as to reduce/remove the energy imbalance. Hence, one could argue that associating “global warming” with surface warming is fundamentally correct.

However, another factor is that it is clear that some do use “global warming” when referring to overall warming and this, in my opinion, further adds to the confusion. What prompted me to write this was the video interview between Peter Sinclair (who runs the Climate Denial Crock of the Week site) and Kevin Trenberth (a climate scientist at the National Centre for Atmospheric Research). The original is here, but I also include it below. In the video, Kevin Trenberth says

The first thing is that global warming is occurring. It’s related to the build-up of carbon dioxide and other greenhouse gases, heat trapping gases in the atmosphere. It really produces an energy imbalance at the top-of-the-atmosphere. More heat is coming in than is going out.

Now, here, it seems that Kevin Trenberth is using the term “global warming” to refer to the build-up of energy in the climate system and not to surface warming alone (admittedly he says “related to” so one could argue that it could still be consistent with surface warming, but that’s not obvious from what’s been said). So I realise that “global warming” has often been used to refer to surface warming, but it does seem that it has also been used when referring to overall warming. In some sense I find this quite remarkable. One of the fundamental terms associated with one of the most important issues that we face today, has not been defined sufficiently clearly so as to avoid confusion. To be clear, I think I understand why this is and I’m not trying to criticise anyone for this. Some of the data is reasonably new (ocean heat content) and so in the past it made sense to associate “global warming” with surface warming given that the surface temperature dataset covered a longer period than other datasets, and was more robust than other datasets. Also, most paleo-climatological reconstructions are only associated with surface temperatures (I think).

So, I don’t really know what to make of this. Maybe some think this isn’t really an issue, but given how so much in this debate is mis-represented, I would tend to disagree. Carefully defining terminology may be advisable but I can then see some claiming that scientists are now changing terminology so as to make things seem worse than they actually are (i.e., they’re cheating and can’t be trusted). Probably the best is to simply be very clear about what the various terms mean and what aspect of the climate system is being discussed. Then again, what do I know? 🙂

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40 Responses to “Global warming” vs “Global heating”

  1. I should probably acknowledge that much of this post was related to comments made by Victor Venema. I wrote this because I find this an interesting – and relevant – topic, and not because I’m in any way critical of Victor’s views 🙂

  2. chris says:

    It’s true that “global warming” has largely been used ’til now as a term to characterize surface/atmospheric warming. Although the possibility of a significant period of forced energy accumulation without much surface was warming is implicit in standard theory of greenhouse forcing, this hasn’t been much discussed in the past as far as I’m aware.

    The important thing in science and in communication is to make it clear what we mean with the terms we use. As Alfred Korzybski said, The word is not the thing. Words are shorthand for meaning. It’s O.K. to use “global warming” as a shorthand for surface warming so long as everyone is clear of that meaning in context. Likewise “global warming” can be used to refer to global scale accumulation of thermal energy in the entire climate system. Personally I think these words could quite naturally evolve whereby “global warming” refers to energy accumulation into the entire climate system (truly global in scale) and “surface warming” is then self-evident. I don’t particularly like “global heating” because it doesn’t have an obvious distinction wrt “global warming”.

    The key point is that global warming without much surface warming is a very clear and significant phenomenon. It means that the TOA radiative imbalance driving “global warming” isn’t (for the moment) being dissipated by “surface warming”. That’s a key concept to understand since it defines a portend of very significant “surface warming” to come….

  3. Rachel says:

    I don’t particularly like “global heating” either and agree with what Chris has said. It’s my view that most climate scientists would agree that global warming refers to the overall accumulation of energy rather than just surface temperatures. For instance, Miles Allen wrote an article for the Guardian earlier this year and corrects David Rose’s mistake when talking about the “lack of warming”.

    I spent an interesting hour last Friday morning having coffee with a neighbour, David Rose of the Mail on Sunday, talking about climate change. He was preoccupied by the apparent “lack of warming” over the past decade or so (more accurately, lack of surface warming), and wondered if it was leading me, as a climate scientist, to revise my expectations for the future.


  4. Yes, you’re quite right. If everyone understands the processes then they will understand the context in which the term “global warming” is being used. One issue with writing a post like the one of written here is that it’s probably true that even if scientists had been incredibly careful with their terminology, the science would still have been mis-represented by those who wanted to do so. Even though many have put quite a lot of effort into explaining the subtleties associated with global warming, many are still unwilling to accept the evidence. Your final paragraph is very clear and yet many would still dispute it.

  5. Yes, there are many examples of where scientists have distinguished between surface warming and overall warming. Maybe this just needs to be done over and over again and eventually the message will get across. Then again, maybe not 😦

  6. toby52 says:

    I cannot read that article without smiling and wondering if David Rose and Myles Allen ever met again “.. to continue the conversation about how we solve the problem of climate change, which we both agree needs solving (after all, we live in the same flood plain), he is more than welcome. I owe him a coffee.” as Allen desired.

    Allen seems to be naively unaware that Rose has “form” in misrepresenting climate scientists.

    Any climate scientist who so much as nods in Rose’s direction is asking for trouble.

  7. toby52 says:

    I have to confess find the whole “global” thing a bit inane and pointless.

    Insisting that only surface warming is somehow relevant or “global” is like medieval doctors treating the pustules and buboes on the human body caused by plague, while being ignorant of the importance of rats, fleas and hygiene.

  8. Paul says:

    As far as I could gather from the discussion on the previous post, a primary problem comes from the dual use of surface global warming as a proxy measure of global warming, the increase in kinetic energy of the entire earth system, and as an important variable on its own. Clearly as a proxy measure it has severe limitation as you have indicated and should be superseded by improvements in ways to measure “global warming” without anyone losing any sleep. As an important variable on its own this could be indicated by the use of “surface global warming”, as you have indicated, thus eliminating any possible confusion about which of the dual uses of this term someone is employing.

  9. BBD says:

    Works for me, Paul. I try to take care to speak of “surface temperature change/warming” and or “tropospheric T/warming” as distinct from “the climate system as a whole” and OHC.

    This is more-or-less obligate as many of the “discussions” I have had recently with “sceptics” hinge on their apparent inability to understand that the troposphere *is not* the climate system as a whole.

    It seems that everybody needs to be at pains to get the distinction across, and keep it front and centre from now on.

  10. I was thinking of a post by this title myself.

    Thanks for saving me the work.

  11. At least the global part of the term is a keeper. Locally very different things can happen, even cooling.

  12. It is hard to be sufficiently clear if you are talking to someone determined not to understand you.

  13. BBD says:

    @ Victor Venema

    Funny you should say that. I have had… difficulties getting this point across.


  14. I expect that it will be hard to change the meaning of the term global warming, even if it would be better from a scientific or communication stand point.

    One reason is that most scientists are not bloggers and do not know about our weird discussions with climate ostriches. Before I started blogging I had not expected such a shadow world to exist. If you assume good faith, the term global warming is fine and you would also not claim that it stopped just because the surface temperature did not rise much the last decade. It is a word from climatology and on climatological time scales the temperature is rising, we are in the hottest decade in the instrumental record. That there is some natural variability around the increase should not even be worth mentioning, except if that is the topic of the paper. (As we now understand the mean reasonably well and because of the “pause” we may well see more papers on the natural variability coming up, something I naturally welcome as blogger at variable-variability. Variability is an under-appreciated topic.)

    The terms “global warming” or “climate change” are anyway very vague terms. You use them in an abstract or introduction to denote the general topic of the paper or if the details are not important for the paper (someone studying renewable energy systems). In the end a climatological paper will talk about the land surface temperature, the sea surface temperature, the sea air temperature, the tropospheric temperature, etc, or maybe even about changes in precipitation, glaciers, sea ice or humidity. In most cases even these terms will be too vague and you will talk about a specific period of a specific version of a specific dataset with for example land surface data, GHCNv3, HadCRUT4, GISS, BEST or about the radiosonde network or about ocean heat content measurements, raw or homogenized by a specific group, etc.

    Like I already wrote below the previous post, I do not like the word “global heating” that much myself. Feel free to come up with a better term. Changing the meaning of an existing term may cause more confusion, even if it would theoretically make everything clearer had this definition always been used.

  15. BBD says:


    I have to say that the previous thread was very good. Your posts and the commentary here are informative and thought-provoking and have made this blog a daily read for me. Thank you for your obviously considerable efforts, and thanks to the commenters who have provided so much useful discussion.

    I feel a bit awkward about piping up with this, but equally, it should be said.

    Right, encomium over. I will go back to being my usual slightly arch self now.


  16. I fully agree. Thanks for all the effort.

    And that with the additional handicap of having to stay civil in the face of it all.

  17. Rachel says:

    David Rose has a bit of reputation for misrepresenting scientists and I’m sure Myles Allen is well aware of this. I too was surprised by his overly forgiving and friendly response and my feeling is that Myles Allen is just a nice guy.

  18. Thanks to both of you. Appreciated even if not deserved 🙂

  19. What you say here is, I suspect, exactly right. Many may well be unaware of what’s going on in the blogosphere and may be unaware of how some of the work is being mis-represented on blogs like WUWT. As I said at the end of the post, I suspect the best solution is to be clear about what is being discussed rather than specifically trying to redefine terminology. Then even if some piece of research is mis-represented, one can at least point out the sentences in the paper that clarify what is being discussed and point out that the work doesn’t say what those who are mis-representing it think it says.

  20. The terms “global warming” or “climate change” are anyway very vague terms. You use them in an abstract or introduction to denote the general topic of the paper or if the details are not important for the paper (someone studying renewable energy systems). In the end a climatological paper will talk about the land surface temperature, the sea surface temperature, the sea air temperature, the tropospheric temperature, etc, or maybe even about changes in precipitation, glaciers, sea ice or humidity.

    This is correct. Climate science, like any science, consists of scientists’ work, examining specific questions and components. Concepts like ‘global warming’ arise in the grey zone between science, and for lack of better words, informed opinion, ‘Global warming’ is properly encountered in review articles, government reviews, and reports – works that are synthetic in nature, rather than in the primary literature itself. It is a meta-narrative construct that strings together available evidence in a certain way. ‘Global warming’ has more of a hold in popular, lay discourse, and/or areas with workers in fields outside who need to refer to the phenomenon.

    This is exactly what was found by the Cook project. It cannot be highlighted enough: a search for “global warming”, when used in academic databases, does not retrieve papers related to ‘global warming’. It pulls up papers with abstracts and/or keywords using the term in its popular connotation. 8,380 of the total 11,944 (70%) are mitigation and impact papers with category ‘3’ or ‘4’, i.e., those that state no position but just use the search term.

    This is the point Richard Tol and I have made. Victor Venema accidentally stumbled on it.

  21. BBD says:

    Shub, obfuscating away about irrelevancies is a rhetorical trick. The facts are very straightforward:

    – A strong scientific consensus exists that AGW is real and potentially very dangerous

    You have attempted to deny the validity of the scientific underpinnings of this consensus for several years. Now you are denying the existence of the scientific consensus itself, which is frankly foolish.

    You may think that you are being ever-so subtle, but I assure you that your tactics here are flawed, and your underlying intent is as transparent as the finest glass.

  22. BBD says:

    I wonder if Richard Tol is disturbed by the very strange bedfellows he seems to have acquired. He should be.

  23. Marco says:

    BBD, Richard is on the GWPF advisory board, so I am 100% certain he is not disturbed by any strange bedfellows. He chose them himself already.

  24. Tom Curtis says:

    Google scholar results:

    “Global Mean Surface Temperature” 4590 hits.

    “Global Mean Surface Temperature” -“Global Warming” 1310 hits.

    “Global Mean Surface Temperature” “Climate Change” -“Global Warming” 1010 hits.

    All searches excluded patents and citations.

    Total papers referring to “global mean surface temperature” and not using either of the meta-terms “global warming” or “climate change” 300 out of 4590, or 6.5%.

    But those 300 are, according to Shub, “the primary literature” with the other 93.5% being relegated to the meta-literature. Shub’s theory, which he has merely asserted and not attempted to check, does not hold water.

  25. Rachel says:

    I just saw this Yale study – http://www.motherjones.com/politics/2013/09/new-study-politics-makes-you-innumerate – which finds that politics influences your ability to do maths. This suggests that arguing with some of the contrarian commentators on your blog is pointless.

  26. t_p_hamilton says:

    The “problem ” is that scientists are not used to readers who Intentionally misunderstand the topics.

  27. Skeptikal says:

    but I can then see some claiming that scientists are now changing terminology so as to make things seem worse than they actually are (i.e., they’re cheating and can’t be trusted).

    There’s good reason for thinking that. The term ‘Global Warming’ has a long standing association with surface warming. You even stated…

    It is clear, however, that the scientific literature still uses the term “global warming” when referring to surface warming.

    The smoking gun, which captured the world’s attention, was the now infamous hockey stick… which showed us all the unprecedented rate of ‘surface warming’. Surface warming is now what people expect from global warming.

    For years and years we’ve all be bombarded with the prophecies of impending doom associated with “Global Warming”, so changing the terminology will have a profound impact on public perception. By making the term “Global Warming” obsolete, you risk making the threats associated with global warming obsolete. You’ll also have to explain why global warming is not global warming anymore… why change the name if the problem is the same?

    By continuing to use the term “Global Warming”, you run the risk of diminishing public support… people who once believed in global warming will inevitably become more sceptical with the continued lack of surface warming. It’s a tough corner you’re in.

  28. BBD says:

    The problem with your position is that you have forgotten that the strong surface warming trend will resume. Probably quite soon. And when it does, bye-bye all this warming-has-stopped crap and bye-bye all the fake sceptics who have nailed their feet to this argument – including you.

  29. Marco says:

    Nah, they’ll just repeat it again the next time there is a “hiatus”.

  30. BBD says:

    You know, Marco, you are almost certainly right.

  31. I don’t have to do this check. You guys did it!

    And you have my point exactly in reverse. When you search for “global warming” (only), you get your 2,320 ‘primary literature’ (as defined by you, owing to including the term ‘global mean surface temperature’) but the remainder and majority will be papers that are not primary literature.That number is huge in comparison.

  32. Skeptical, I think you’re rather missing the point that the term “global warming” suffers from not quite being “global”. Not that I’m actually suggesting that we should change any terms, I’m simply suggesting that we should recognise that surface warming alone is not a good indicator of overall warming (on short timescales at least). While you seem to be looking at this from the perspective of how it will be perceived and what impact it might have on the public, I’m actually looking at this from the perspective of how we most honestly present the evidence. I’d rather present the evidence as clearly and honestly as possible and hope that the public are willing to accept this evidence. What they choose to do, given the evidence, is another issue altogether.

  33. Tom Curtis says:

    “In March 2012, we searched the ISI Web of Science for papers published from 1991–2011 using topic searches for ‘global warming‘ or ‘global climate change‘.”

    The number of papers on the Global Mean Surface Temperature that would have been missed by the Cook et al search if applied to Google Scholar would have been 6.5%. There is no reason to think either Google Scholar or Web of Science are unrepresentative in this regard.

    As always, Shub, your arguments are impossible to distinguish from deliberate untruths.

  34. I don’t think you understand.

  35. Tom Curtis says:

    Shub, I understand perfectly well. You have made an evidence free claim that is rather hard to check. One way to check it would be take three samples, all IPCC WG1 authors from any of the four Assessment Reports or the 1992 supplemental report, all WG 3 authors, and all WG 3 authors. Obtain lists of all of their publications. Classify all of those publications as to whether they are primary or review literature, and then determine if there is any bias in the proportion of papers in each classification rated by Cook et al. If you are correct, the papers classified as primary literature will be under represented in Cook et al.

    I am not going to waste that much time testing your hypothesis which you are unwilling to expend any time testing. Therefore I use a search term “Global Mean Surface Temperature” which is likely to find a small sample of the primary literature, and test if Cook et al’s search terms will lead to under reporting of that papers using that search term. If you are correct, it should – but it does not. So, contrary to your claim, a search using the terms “global warming” and “climate change” does turn up the majority of this sub sample of the literature related to global warming – and given available evidence it is likely the Cook et al survey does turn up representative samples of the various types of literature related to global warming.

  36. No you don’t. What I observed is what Victor noted, and it is to be tested by pulling up a sufficiently large number of papers with the term “global warming” and checking their content. Which, incidentally, is what you and your associates did with your consensus project. There is no need to look beyond it.

  37. Shub, if you’d read Victor’s comment properly you would note that he did not claim that such terms would not appear in the abstracts of primary papers. He was simply pointing out that they are general terms that would appear in the abstract and introduction. Hence, no reason why (as Tom has already pointed out) they are not quite reasonable search terms. Although I have no real doubt that you will continue in your campaign against Cook et al., at least try not to mis-represent what others say so as to make it appear that they support your position when, in fact, they do not.

  38. ligne says:

    …or just continue asserting it, regardless of what the surface temperature is actually doing.

  39. Exactly. Naturally when you are studying a detail of a detail of a specific climatological dataset you mention global warming or climate change. It helps people find your article and it helps them understanding why this detail is still important.

    By the way, you do not notice it that much, especially if you only speak one language, but almost any term is vague and has a range of means and a halo determined by previous use and emotions it provokes.

    Even the quite specific word word has lot’s of meanings.

    Just try to translate something into another language and back. The Dutch and Germans typically have the same words for colours, but where yellow become green seems to be different. Either that or I am becoming colour blind.

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