September 28, 2015, by Brigitte Nerlich
About three years ago, in 2013, I became aware of discussions around the ‘pause’ (a period of relatively little change in globally averaged surface temperatures) and since then I have been observing goings-on around this new talking point in the climate change debate. I was a bit surprised by how much trouble a wiggle in a wiggly (upward) trend line could cause.
I noticed several things since I first became aware of ‘the pause’ (and I oversimplify of course):
- Some of those who reject significant tenets of mainstream climate science and/or policy have used the pause as ‘evidence’ for saying that global warming has ‘stopped’.
- Some mainstream scientists have tried to find explanations for the ‘pause’.
- An interdisciplinary team led by cognitive scientists has tried to show that (1) has influenced (2).
Questions about what came before (1) and what happened between (1) and (2) have puzzled me for some time, but I just didn’t have the time and patience to sit down and dig. In today’s post I’ll try to delve into these issues a bit more, building on work by Max Boykoff, Roz Pidcock and Chris Mooney, for example. I have to admit that things became much more complicated than I had thought (and the post became longer and longer as a result).
The rise of the pause
In order to ascertain who first used the word ‘pause’ in the context of global warming and when, I searched Scopus (a database for science articles) and Lexis Nexis (a database for news articles). This means that there are limitations to my digging and I’ll probably have missed things, but it’s a start.
When you put ‘pause’ AND ‘global warming’ into Scopus, you’ll find that articles began to use that phrase rather slowly, with one in 2004, one in 2007, two in 2010 (one very relevant, as we’ll see), one in 2011 (not relevant), two in 2012, five in 2013, nine in 2014 and eight in 2015 so far. This is, of course, only the tip of the iceberg exposed by using Scopus and using a rather narrow search phrase; for overviews of all the numerous other scientific articles dealing with the ‘pause’, see here and here.
According to my search, the most cited articles on the ‘pause’ were published in Nature/Nature Climate Change (in 2014 Nature Climate Change also published a special issue on the ‘pause’ and science communication which didn’t show up in my search). The paper with the most citations so far (25) was published in January 2014 in Nature Climate Change by Kevin Trenberth et al. and entitled “Seasonal aspects of the recent pause in surface warming”.
All this seems to show that there has been an increase in attention to the issue of the ‘pause’ by scientists since around 2013. Several things happened that year. The pause was briefly discussed in the IPCC report and the Met Office published a report entitled ‘The recent pause in global warming’. I’ll come back to that later. What happened before 2013? And what happened in the media?
Let’s first look at the two early scientific articles that Scopus unearthed, published in 2004 and 2010. In 2004 a team of Russian scientists published an article “On climate oscillations over the last 150 years” and predicted a pause in the future. This article did not spark any debate.
In 2010 a team of Chinese scientists published an article entitled “Does the global warming pause in the last decade: 1999-2008” (using ‘pause’ as a verb!). The beginning of the article is interesting, as it refers to a report published in August 2009 in the Bulletin of the American Meteorological Society on “State of the Climate in 2008”. Even more importantly it refers to an article by Richard Kerr that appeared in October 2009 (that is, a month before climategate and COP15) in the journal Science and asked: “What happened to global warming?”. As the Chinese team points out: “In Kerr’s article, he analyzed the time series of global mean SAT for 1999–2008 using the Had-CRUT3 dataset [Brohan, 2006], as shown in Figure 1, in which the red line stands for the warming trend of 1999–2008, which tends to be zero.”
As far as I can see, “State of the climate 2008” doesn’t use the word ‘pause’ and neither does the Brohan et al.’s 2006 article. However, the figure that appeared in the October 2009 Science article certainly shows a visible ‘plateau’. In the article itself Kerr points out: “The blogosphere has been having a field day with global warming’s apparent decade-long stagnation. Negotiators are working toward an international global warming agreement to be signed in Copenhagen in December, yet there hasn’t been any warming for a decade. What’s the point, bloggers ask? Climate researchers are beginning to answer back in their preferred venue, the peer-reviewed literature. The pause in warming is real enough, but it’s just temporary, they argue from their analyses. A natural swing in climate to the cool side has been holding greenhouse warming back, and such swings don’t last forever. ‘In the end, global warming will prevail,’ says climate scientist Gavin Schmidt of NASA’s Goddard Institute for Space Studies (GISS) in New York City.”
I haven’t properly tracked the discussion about the pause in the blogosphere, but a 2009 Real Climate post shows how things were hotting up around 2007/2008 and who the main protagonists in the debate were. Let’s now go to the news as captured by Lexis Nexis.
Alongside Scopus, I searched Lexis Nexis (‘All English Language News’) on 25 September, using the search phrase ‘pause in global warming’ (I could not use ‘pause’ AND ‘global warming’ as two search terms, as things became much too messy). I got 510 hits (476 when you remove duplicates). Just in the last five years, that is, since 2010, 504 news items used this phrase (470 when you remove duplicates), mostly in the Daily Mail and mostly in 2013 and 2014 (so over the last five years we have three articles in 2010, one in 2011, 23 in 2012, 138 in 2013, 147 in 2014 and 102 in 2015 up until 25 September).*
Graph of ‘Newspapers’ using the phrase ‘pause in global warming’ in ‘All English Language News’ (search carried out 25 September, 2015; I cut off a long ‘tail’ of newspapers that only mention the issue in one or two articles)
The reference to the August 2009 report by the American Meteorological Society in the 2010 article by the Chinese team, quoted above, is interesting, as the first relevant attestation of ‘pause in global warming’ in my overall corpus of news items can be found on 26 September 2009 in an article by Andy Ho for The Straits Times (Singapore) entitled “Spot-less answer to global warming”. The article is about speculations that sun spots may cause climate change. What’s important in all this is the following question posed by Ho: “Does the sun’s present quiescence presage a coming mini ice age then? Last month, the American Meteorological Society noted that there has been a decade-long pause in global warming from 1999 – even as greenhouse gases rose.”
After this article there was what one may call a relatively quiescent phase in media reporting on the ‘pause in global warming’ until 2012, when there was a sudden eruption of articles, as demonstrated by Boykoff, with a spike in 2013. So what happened then?
2012 began with two events in the US and two press articles in the UK press that might have contributed to the ‘pause’ becoming a climate change talking point (and there might be more events…). At the end of January 2012 the Oregon chapter of the American Meteorological Society organised a meeting. Some members of the chapter seem to doubt some aspects of mainstream climate science and use the ‘pause’/’hiatus’ to discredit it.** A journalist for The Oregonian pointed out that this “helps spur skepticism”. Another announcement probably also contributed to the spike in media attention in 2013 but did not show up in my searches. This was a 2012 temperature update by James Hansen et al. published in January 2013 and which contained an unfortunate section heading: “Global Warming Standstill” (see here for an interesting write-up). The same year the Global Warming Policy Foundation published a report by David Whitehouse with the same headline.
At the same time, and even more importantly perhaps, the Met Office updated some of its datasets which prompted David Rose at the Daily Mail to write an article entitled “Forget global warming – it’s cycle 25 we need to worry about” (29 January, 2012). The article points out that the planet hasn’t warmed for 15 years, “that the rising trend in world temperatures ended in 1997”, that we might be heading for a mini ice age, and that the scientific consensus has been shaken. Cycle 25 refers to solar cycles. The article goes on to say/quote: “‘We’re now well into the second decade of the pause,’ said Benny Peiser, director of the Global Warming Policy Foundation. ‘If we don’t see convincing evidence of global warming by 2015, it will start to become clear whether the models are bunk. And, if they are, the implications for some scientists could be very serious.’”
Another article by Rose appeared on 14 October 2012 under the title “Global warming stopped 16 years ago, reveals Met Office report quietly released… and here is the chart to prove it”. It says: “The world stopped getting warmer almost 16 years ago, according to new data released last week.” The article uses the words ‘pause’, as well as ‘plateau’. It quotes Judith Curry as saying “that the computer models used to predict future warming were ‘deeply flawed’.”
Both articles were picked up by the Met Office which discussed some errors they contained on its ‘blog’ ‘Met office in the media’, with a post on 29 January and another on 14 October 2012. And, of course, this ‘dialogue’ was widely discussed in the blogosphere. You can read a summary of various rebuttals of Rose’s claims that global warming has stopped on the Carbon Brief Blog of October 2012.
This flurry of activity, of claims and counter-claims, contributed to putting the ‘pause’ squarely on the public agenda.
In hindsight, it is easy to say that when ‘the pause’ was used by some commentators as evidence for rejecting some basic tenets of climate science, scientists might have been well advised to stop using the word ‘pause’. However, this did not happen. On the contrary, both the Met Office and the IPCC published reports that tried to deal with ‘the pause’. One Met Office report was entitled ‘The recent pause in global warming’; the first part of the IPCC report, published in September 2013, contained a discussion of the ‘hiatus’ (p. 61); and IPCC authors talked about the ‘pause‘ (see Mooney’s paper cited above).
Furthermore, “at the Science Media Centre in London in July 2013, journalists met Met Office scientists and were given a briefing document with three papers on ‘the recent pause in global warming’ in surface temperatures.” (Wikipedia)
A first longer article on the ‘pause in global warming’ to appear in The Independent was published on 17 November 2013, that is, a year after the Daily Mail had put the topic on the media agenda (see figure above which shows The Independent as the second most active newspaper on the topic, but obviously from a different perspective). The article was entitled “What is the global warming ‘pause’ and does it mean we’re off the hook?” It was set out in a Question and Answer format. One question was: “Does this mean that global warming has stopped?” and the answer was: “No. The UN’s Intergovernmental Panel on Climate Change, which is the combined expertise of thousands of climate scientists, says that each of the past three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the northern hemisphere, the period from 1983 to 2012 was likely to be the warmest 30-year period for the last 1,400 years.” One other answer says: “Simply put: the pause does not really exist”. But by then the horse had bolted, so to speak.
Now, when I searched Scopus and the Lexis Nexis news database I used the phrase ‘pause in global warming’ as a search term. I therefore didn’t find some articles from 2006/2007, which are however, highly relevant in this context, as they antedate the announcement by the American Meteorological Society, the scientific articles from 2009 and 2010 and the media furore that erupted in 2012/13. One article was written by a well-known climate contrarian, Bob Carter, for The Telegraph and entitled “There IS a problem with global warming… it stopped in 1998”. The article responds, I believe, to the 2006 paper by Brohan et al. entitled “Uncertainty estimates in regional and global observed temperature changes: A new data set from 1850” published in the Journal of Geophysical Research (which also precipitated blog discussions from that time onwards). Carter doesn’t use the word ‘pause’; neither does David Whitehouse in a 2007 article for The New Statesman entitled “Has global warming stopped?”. So it seems that when the word ‘pause’ began to be used in 2009/2010 in scientific circles, the ground was prepared for shaping the meaning of the word and its use in wider society.***
It is also interesting to look at Google Trends and see how often and when people searched for ‘pause in global warming’ and ‘global warming stopped’. As you can see from the featured image above (I searched Google Trends on 26 September), there were spikes in the searches for ‘global warming stopped’ in 2009/10 and in 2012/13 which coincide with spikes of attention to the ‘pause’ in science and the media. Small spikes in searches for ‘pause in global warming’ can only be found towards 2014/15, that is, when the existence/importance of the ‘pause’ began to be more seriously discussed. There is slightly a higher search volume for ‘global warming pause’ than for for ‘pause in global warming’. Searches for ‘global warming pause’ started at the beginning of 2014 and quite a few question the existence of a ‘pause’. For more info, see Mooney’s article quoted above and this article by Lewandowsky et al. which has just appeared in the Bulletin of the American Meteorological Society). All this needs more scrutiny though, as does the rest of my ‘research’ for this post!
Some tentative conclusions
According to the Oxford English Dictionary a ‘pause’ is “an act of stopping or ceasing for a short time in a course of action; a short interval of silence or inaction, esp. one arising from uncertainty, doubt, or reflection; an intermission; a delay, a hesitation.” I won’t here go into the issue of time and what ‘short’ may mean. However, as one can see, it is quite natural to take some easy inferential steps along a semantic path that goes like this: from ‘pause’ as something stopping for a short time interval in a course of action, or in this case a statistical trend, to something stopping completely, to something no longer being an issue of concern or interest, to something no longer existing. It is very difficult to see this inferential semantic path emerging wile it is being walked by the users of the words ‘pause’ or ‘stopped’ and to stop them, or indeed pause them, from following that path. As we have seen, the path began to emerge mainly in the blogosphere and in the mainstream press after the publication of Brohan et al. (2006) (when contrarian writers seem to have jumped almost immediately to the second step on our inferential path, from ‘ceasing for a short time interval’ to ‘stop completely’). As far as I can make out, the topic was then taken up in the science literature in 2009/10 before exploding more fully in the mainstream press, especially the Daily Mail, in 2012/13, when scientists began to publish more on the topic of the pause, thereby inadvertently giving ‘it’ more credibility and entrenching the inferential pathway from pause to stopped to unimportant or non-existent.
*I also searched Lexis Nexis for ‘global warming pause’, but I haven’t analysed the data set yet; excluding duplicates there were 211 articles, of which 202 were published in the last five years, that is, since 2010; at first glance results seem to overlap with my findings achieved using ‘pause in global warming’ as a search term.
**I haven’t charted the use of ‘hiatus’, but in the news ‘hiatus in global warming’ first appears to have been used in passing in 2005, then more frequently from 2011 onwards; 200 times in the last five years, excluding duplicates 152 times. I also haven’t looked at stagnation, plateau, slowdown etc.
*** Another piece of work could be carried out on a set of news items that use the phrase ‘global warming stopped’. A Lexis Nexis search reveals that (as of 26 September) 794 articles (excluding duplicates) in ‘All English Language News’ have used that phrase.
PS: And the ‘pause’ has resurfaced again in 2016: Nice overview in this article by Graham Redfearn http://www.theguardian.com/environment/planet-oz/2016/mar/03/did-global-warming-really-slowdown-have-a-large-injection-of-nuance-and-a-side-order-of-abuse