January 25, 2015, by Brigitte Nerlich

Hottest year on record

OldthermometersMedia reporting on climate change has heated up a little bit over the last ten days or so, after an announcement by NASA and NOAA which read like this:  “NASA, NOAA Find 2014 Warmest Year in Modern Record”.

This was taken up by the media and, between 15 January and 25 January 2015, the phrases ‘warmest year on record’ and ‘hottest year on record’ were used 450 and 373 times respectively in All English Language News (data base: Lexis Nexis; search terms were these phrases and climate change or global warming). (I have not looked at these news items in detail and at how they used these phrases)

This information was welcomed by some and contested by others. What’s interesting is that the ‘warmest/hottest year’ meme collided with the ‘pause’ meme. Again, I have not yet had the time to disentangle how the two memes have fared, that is to say, how they were used argumentatively in the climate change debate and how, for example, an associated idea, namely statistical significance, was deployed in this context and by whom.

As one can imagine, there have been quite a few blog posts on the hottest year issue. This morning I saw one by Victor Venema, where he reflected on what the word ‘record’ may mean in the context of this debate (he also lists posts by Andrew Revkin, Gavin Schmidt and others).

This made me think a bit more about the semantics of it all. I first went to the Oxford English Dictionary to look up the word ‘record’, but as the OED is not accessible to people outside universities, I’ll stick to the really nice Google entry on the word. Interestingly, ‘record’ seems to have emerged from an amalgamation of the Greek word for ‘heart’ and the Latin word for ‘remember’ (it’s a bit more complicated, but still). More interestingly still, when you look at the various meanings of the noun ‘record’, you’ll see almost immediately that in debates about ‘the hottest/warmest year on record’ people sometimes seem to conflate the two senses, namely sense 1 and sense 3:

Sense 1: “a thing constituting a piece of evidence about the past, especially an account kept in writing or some other permanent form.”

Sense 3: “the best performance or most remarkable event of its kind”

I have the impression, but I might of course be wrong, that the debate triggered by the NOAA/NASA announcement flickered between the two meanings which caused a bit of confusion. And, of course, depending on the purpose of your article, blog post, tweet and so on and on the audience you want to reach, you can focus more on one than the other, and also use either ‘warmest’ or ‘hottest’ and so on.

Be this as it may, it is important to ‘record’, ‘remember’ and even ‘take to heart’, it seems to me, that we are dealing with a long-term upward trend or pattern with random (short-term) noise added onto it. It’s probable that 2014 is the warmest year on record, but it’s really this long-term trend that matters and 2014 is entirely consistent with this trend. It’s therefore important as a piece of evidence in a longer and larger story, and one should probably accept it as such.

Image: Old thermometers, wikimedia commons




Posted in Climate ChangeScience Communication