Two years ago there was a strong El Niño, which combined with ongoing global warming, resulted in 2016 being the warmest year on record, in all data sets. February 2016 in particular had the warmest anomaly for any month with GISTEMP showing an anomaly of 1.34°C, two tenths warmer than the previous month which was also a record. In fact using GISTEMP thee 7 months from October 2015 to April 2016 were all more than a degree Celsius above the 1951-1980 base period, the 7 warmest months on record up to that point. Since then monthly temperatures have been up and down, with more months over the 1°C mark in 2017, and never lower than 0.69°C.
The one point this really enforces is that global warming never went away, despite the many cherry picked pauses
.
But inevitably a record breaking El Niño can be the start of a new pause, or even a cooling trend, when as is inevitable temperatures fall below the trend.
But that's too far away for some people who need to distract from how warm the globe has become.
Welcome to the two year hiatus, or rather the greatest cooling event on record.
This all started with an article on a website called RealClearMarkets, by someone called Aaron Brown. He appears to be a financial author, and a self confessed libertarian. He asks the question Did You Know the Greatest Two-Year Global Cooling Event Just Took Place? Now he insists in this article that nothing he says should argue against global warming, that he's simply asking why there is no media attention about this event. I'll give him the benefit of the doubt, but in any event his arguments are incredibly silly.
He starts,
Would it surprise you to learn the greatest global two-year cooling event of the last century just occurred? From February 2016 to February 2018 (the latest month available) global average temperatures dropped 0.56°C. You have to go back to 1982-84 for the next biggest two-year drop, 0.47°C—also during the global warming era.
He's already had to add a qualification, it's not the greates event ever, just in the last 100 years.
Then he starts describing the big chill in terms of two little chills
and claims that if this big drop were to continue we would be back to 1980s levels in a few months.
I'm not sure if this is correct, but it probably isn't going to happen, so why mention it now?
The 2016-18 Big Chill was composed of two Little Chills, the biggest five month drop ever (February to June 2016) and the fourth biggest (February to June 2017). A similar event from February to June 2018 would bring global average temperatures below the 1980s average. February 2018 was colder than February 1998.
Context
The dog that didn't bark in this article or any of thw many posts copying it is any attempt to put this in context.
In particular there is not a single graph showing what this cooling event looks like.
Nor does he mention that the anomaly in February 2018 was still 0.78°C warmer than the 1951-1980 average, that this was the 7th warmest February on record,
or that it is still warmer than 4 years ago.
He makes the point that it is colder than February 1998, but doesn't say by only about 0.1°C, or point out that this means that even after the greatest two year cooling event temperatures are only slightly lower than the record breaking temperature of 20 years ago.
It would be easy to read this talk of a cooling
event as implying temperatures are now cold, when they are still some of the warmest on record.
Here's the graph of GISTEMP data with the start and end points of the greatest teo year cooling event marked in red.
Of course the really obvious point is that this is only the greatest cooling because it started on such a warm month. To put this in even more context, using Brown's technique you should also point out that the two years leading up to this great cooling saw the greatest two year warming event, not just in the past 100 years, but since records began. That this warming event was over 0.8°C, far bigger than his cooling event. More than 0.25°C bigger than the comparative two year warming event of the great El Niño event of 1998.
Then there's this puzzling description of two little chills. Here's a graph of the last few years, with the start and end months marked.
There's a quick drop from the peak month in February (the first little chill), but this actually gives us all of the cooling, temperatures in November 2016 were lower as an anomaly than they currently are. His second little chill ignores the fact there was a rise in temperatures leading up to the second drop. But that just echos what happened in the years leading up to the big chill - it was preceded by a much bigger warming.
At this point it should be realized that all Brown's descriptions of chills are based on simply comparing the start month to the final month, and ignoring everything that happens in between. This is a very bad way of assessing what temperatures are actually doing. Monthly data is very variable and any difference over two years are likely to be down to chance rather than an actual trend. In this case the problem is in Brown claiming that the last two years have set a record. This is true if you ignore a bigger drop 101 years ago, but it depends entirely on this arbitrary two year period. This graph shows both the 1998 and 2016 strong El Niños, with the peak February temperature and the subsequent February tewo years later.
The obvious point here is that February 2000 was somewhat warmer than January 2000. If brown based wanted he could have taken the cooling from February 1998 to January 2000 and found it was greater than that from February 2016 to February 2018. It's arbitrary, and self serving, to call the last two years as the greatest cooling event this century.
A better way of determining cooling trends would be to look at the actual trend over a two year period, using linear regression. This is a standard technique, though it still doesn't make much sense to look at a two year period it does at least take into account all the data over that period. The problem is, if you do that Brown's argument that there was anything unusual about the last two years goes out the window. The fastest recent cooling two year trend was around 17°C / century. This sounds dramatic, but between 1998 and 2000 it was over 23°C/ century. More importantly there have been 7 periods over the last century with two year trends faster than the post 2016 big chill, and many more almost as steep.
This graph shows every 2 year trend over the history of GISTEMP.
Strong two year chill rates happen all the time, just as do strong warming events.
It's about Bias in the Media
Brown's main point is that this is not about the reality of global warming, but about bias in the media.
My point is that statistical cooling outliers garner no media attention. The global average temperature numbers come out monthly. If they show a new hottest year on record, that's a big story. If they show a big increase over the previous month, or the same month in the previous year, that's a story. If they represent a sequence of warming months or years, that's a story. When they show cooling of any sort—and there have been more cooling months than warming months since anthropogenic warming began—there's no story.
Now I wouldn't disagree that the media has biases, and that in reporting on climate change they are often wrong or simplistic. I'd also agree that it is a problem that reporting on climate change is often limited to mentioning when record breaking years, and focusing on statistical outliers, rather than the more important concerns of ongoing warming.
But, constant complaints of bias often show more about the accusers own bias. They want the things that support there beliefs to be reported.
Brown tries to argue that the recent two year cooling event should be as newsworthy as 2016 being the warmest year on record based entirely on the statistical likelihoods of the two events. He says that the cooling event was a three sigma event, something that only happens rarely, whereas warmest years happen every 8 years or so.
But apart from the fact that the two year cooling event isn't really a 3 sigma event, one you understand the large amount of cherry picking associated with it., the problem is on wanting to decide what stories are covered based only on how likely the event is. He thinks events that are rare are more newsworthy than events that are important. Record breaking hot years might happen 12% of the time, but that's still an important news story given both what it tells us about global warming and the effects on the planet. By contrast his great cooling means nothing except the planet is back on it's regular warming track.
Aftermath
Aaron Brown's piece has had an odd history since it appeared on the 24th April. Almost immediately James Delingpole was ripping it off for Breitbart, in a piece called Earth in ‘Greatest Two-Year Cooling Event in a Century’ Shock, 26 April. This essentially repeats what Brown says, but more forcefully, and adds even more confusion. Delingpole tries to put the shocking event in context:
To put this temperature drop in context, consider that this is enough to offset by more than half the entirety of the global warming the planet has experienced since the end of the 19th century.
This is a common trick, point to a drop lasting a few months, claim it wipes out a certain percentage of the last century of warming, fail to distinguish between long term warming averaged over decades and a single month, and ignore the fact that the actual drop was from a much higher starting point, so that even after this drop nothing has been offset. In fact February 2018 was over a degree warmer than the late 19th century average - far from offsetting any warming it has added 25% to Delingpole's claimed warming.
He finishes by asserting that
As we know from long experience, if it had been the other way round – if the planet had warmed by 0.56 degrees C rather than cooled, the media would have been all over it.
Except we don't have to imagine that, the world did warm by far more than that, between February 2014 and February 2016 the world warmed by over 0.8°C, over 50% more than the shocking cooling, and adding as much warming as all the warming of the past century. Yet no-one seems to have mentioned that fact, as they were too busy talking about how February had been the warmest month on record.
Three weeks after the Brown piece, something called Investor's Business Daily had an editorial called Don’t Tell Anyone, But We Just Had Two Years Of Record-Breaking Global Cooling again referencing the Brown piece and complaining that no other news outlet had picked up on it in three weeks. GWPF reproduced the editorial, WUWT copied the GWPF copy of the original without acknowledging either.
The WUWT article prompted me to add some graphs putting the record breaking global cooling
in context in their comments.
Had an usually large set of angry responses, suggesting I might have hit a nerve.
The main complain was that I was using GISTEMP, which I was repeatedly told was garbage, and not caring that that was the data set Brown uses.
In fact different data sets won't show the record.
Then we had Tony Heller, suddenly pointing out that there had been the greatest two year drop in temperature in a century - two months after it had happened and without acknowledging Brown's original, or any of the other articles that had already mentioned it. In his post Earth Cooling Fastest In A Century – Since Trump Took Office, he makes a lame joke about how all the cooling happened under Trump.
Last year, scientists said Earth was record hot and it was Donald Trump’s fault. But they had it backwards. The prior warming was Obama’s fault, as Trump wasn’t in office yet. The cooling since 2016 is under Trump’s watch.
Not that it matters but this isn't really true. Most of the cooling happened before Trump was elected. Temperatures went up after his election.
Yet it's strange that whilst every one is complaining about the press not noticing or caring about the greatest two year cooling event
, even the sceptical websites failed to report on this momentous event until someone else pointed it out to them.
