Last year was the second, third or fourth warmest depending on whom you speak to, with by far most of the warming occurring in one region of the planet, the Arctic.
We’ve just lived through the warmest decade in at least 170 years, probably longer. The past five years have been the warmest, dominating the statistics of the past decade. What does it mean? Will it go on this way? There is no shortage of comment and certainty from many scientists and commentators, but the lesson drawn from experience is that, in the short-term, nobody knows.
While the debate goes on isn’t it about time for some common standards in the temperature reports? A standard baseline for comparison would be good. Is there any good reason for not having one? Also, the inclusion of error bars in graphs would seem to be an obvious thing to do, after all if a science student presented a report on an experiment without error bars they would be failed!
Including error bars would show the temperature changes in a different light. It would stop the scientific nonsense of claiming a year’s rank by a margin far less than the size of the error. Indeed, spurious accuracy – sometimes quoting temperatures to a thousandth of a degree with an error of a tenth of a degree – is ridiculous. If an agreed protocol was observed (it can be found almost everywhere in science) the global temperature would be rounded to the nearest 0.1° C then the temperature changes of the past few decades would give a different impression.
El Nino vs global warming
Interannual changes are not important for climate change. They show weather especially the effects of El Nino and La Nina events. The temperature of the past decade – the warmest since accurate records began – is the story of the 2016 El Nino. It’s influence spans many years. It is nonsense to say that 2016 was a very warm year because of an El Nino — but a year or two later was climatically important because it didn’t have a strong El Nino and has a temperature independent of what happened in 2016. El Nino’s are not confined to an arbitrary definition of the start and end of the year. After all, the warmth of 2019 was heavily influenced by El Nino conditions that lasted nearly half of last year.
It’s obvious from the way the temperature has behaved that there was a thermal build-up to the El Nino and a relaxation after it (remember what was being said in 2015 about seeing the start of runaway global warming). The temperatures over the warm last five years are because of the 2015/16 El Nino, not despite of it. We need to look at annual temperatures over a longer period to see what’s really going on.
The last decade was the warmest mainly because of what happened in the latter part of it. This has been driven by El Nino conditions, not climate, and it does not tell us much about what may happen in the future. If anything, it tells us once again that El Nino effects are currently much stronger than long-term global warming.
As for the global temperature of 2020, the UK Met Office foresees no El Nino and says that the rising levels of carbon dioxide in the atmosphere will continue to drive global temperatures upwards. I predict that the global temperature of 2020 will be well within the error bars of the previous years.
As for what carbon dioxide in the atmosphere has been doing this century and the global temperature is shown in this indicative graph below. Where do you think the global temperature will go in 2020? Why not enter our competition and place a bet.
PS. Last year we published a similar graph to the one below and faced comments that its axies had been rigged to make it difficult to see any correlation between carbon dioxide and global temperature. We responded by plotting it several other ways. In none of them is the correlation seen any better. I wonder from those that claim it is a “denier” tactic, how would they plot such a graph?