The Pause in 2017 - Part 4 : The Whitehouse Pause

Introduction

This is another post, possibly the last, in my series looking at the pause that this been claimed happened in the early part of the 21st century.

Last time I looked at a post from Watt's Up With That, by Dr David Whitehouse, NEW STUDY CONFIRMS: THE WARMING 'PAUSE' IS REAL AND REVEALING . (Archived version here, as the original is currently missing graphics.) I looked at the specific claim of global warming stopping in 1998, made by Bob Carter, and pointed out that apart from being a very short period, it required a huge increase in the overall rate of warming.

In this post I'll look at yet another claim of a pause made by Dr Whitehouse in the article. This pause starts in in 2001 and lasting 13 years.

Meet the New Pause

Dr Whitehouse's pause is introduced when he talks about the Nature report saying there are multiple definitions of the pause:

What the authors miss, with their three definitions of the pause, is a simple fact we have often pointed out. Look at HadCRUT4 from 2001 (after the 1999-2000 El Nino/La Nina event) until 2014 (before the start of the recent El Nino event) and you will see the temperature is flat. Apart from the recent El Nino there has been no global increase since 2001, even though there have been El Ninos and La Ninas in that period. Now that's what I call a pause.

Dr David Whitehouse

Here's the graph he uses:

Skeptical Science: Temperature Trend Calculator

So why does Whitehouse start his pause in 2001, when Carter was convinced warming had stopped in 1998? The answer is that Whitehouse wants to insist that all the warming over the last couple of years was the result of a strong El Niño, and should not be included in any warming trend as it is not caused by humans. As he says,

The pause ended not because of gradual global warming but because of a natural weather event whose temporary increased rate of global warming was far too large to be anthropogenic.

There's some truth in that; it would be completely wrong to look at the past 7 years and claim it shows accelerated warming when you are ending on a couple of unusually hot years. If you did, you could claim that the world has been warming at a rate of over 5 °C / century since 2011, 3 times the rate since 1970. Of course, no-one would claim a 7 year trend as having any meaning.

Trend for HadCRUT 4, since 2010.

Whitehouse doesn't want to allow a Strong El Niño to be counted as part of a trend, but it would then be a touch hypocritical to point to Carter's Pause - which started on a strong El Niño - as evidence of no warming.

By shifting the start of the pause to 2001, Whitehouse is trying to show that the pause doesn't depend on the 1998 El Niño. His pause doesn't start with an El Niño, and is just an arbitrary period of 13 years that contains both El Niños and La Niñas.

The problem is he's still being very selective in his starting point. Why not look at the trend from 1999 if all you wanted to do was discount the 1998 El Niño? Because then he would have a modest amount of warming (0.87° / century). Or why not calculate the trend including both El Niños? Then the trend would be 1.33 °C / century. The period 2001 to 2013 is selected precisely because it gives a 13 year period of near zero warming. It is a cherry-pick.

Before and After the Pause

What Whitehouse's pause does illustrate is that whilst 1998 has a big impact on the rate of warming, it isn't the only factor. To illustrate the problem let's play my usual game of asking what impact these 13 years of no-warming had on the overall rate of warming. I'll follow Bob Carter's definition of the warming period and look at the trend starting in 1970.

The trend before the 1998 El Niño, from 1970-1997 was 1.56°C / century.

By the start of the Whitehouse Pause the 1970-2000 trend had risen to 1.66.

Skeptical Science: Temperature Trend Calculator

Whitehouse could argue that this rise was only due to the natural 1998 El Niño and the trend up to 1997 was the true rate of global warming, but the difference is minor and I'll assume that the figure of 1.66 is the underlying rate of warming before the pause. So what would you expect to happen to the trend by the end of the 13 year Whitehouse Pause?

Skeptical Science: Temperature Trend Calculator

Amazingly, the trend up to the end of the Whitehouse Pause is identical to the trend to the start of the pause. This is purely a coincidence - choosing different start years would have produced different results. But it does illustrate the point that all these pauses have had no significant effect on the overall trend. This is not what you would expect if global warming had really stopped, or slowed down.

Annotating the Pause

To explain how it's possible that Whitehouse can show 13 years of zero warming, yet it not have any effect on the underlying trend I'll take a painfully long look at the HadCRUT temperatures, year-by-year. The following graph shows annual anomalies since 1970 to 2000, just before the start of the Whitehouse Pause.

Annual HadCRUT4 anomalies, 1970 - 2000. Trend from 1970 - 2000.

The trend line is the trend from 1970-2000, projected up to the current day. If, at the end of 2000, you felt that this trend was a reasonable model of how warming would continue - that is you were not expecting a pause, you would expect future years to be close to the trend line, rising slowly, but with roughly as many years below the line as above it.

In all the following graphs this trend line is unchanged, that is it represents the trend as it would have been predicted from 2000. Years belonging to the Whitehouse Pause are marked in red. Let's just look at the first year of the pause, 2001.

Annual HadCRUT4 anomalies, 1970 - 2001. Trend from 1970 - 2000.

2001 was hot, remarkably so considering it was not an El Niño year. It was the second warmest year on record, marginally warmer than 1997 and much warmer than any year before 1997. It's also warmer than the trend, which starts to explain why it is the first year of the Whitehouse Pause. Now jump forward to 2007, half way through the Whitehouse Pause.

Annual HadCRUT4 anomalies, 1970 - 2007. Trend from 1970 - 2000.

This is where it gets interesting. 2001 was warm, but 2002 was warmer, 2003 even warmer, and 2005 warmer still. If it hadn't been for 1998, HadCRUT would be showing 4 record breaking years in a 5 year period. In fact 2005 is a new record, narrowly beating 1998.

More importantly, each of the first 7 years, is above the trend line. That's an unusually long run of warm years, and it's no coincidence that this is the first half of the Whitehouse Pause.

Now at this point, if you were an observer at the end of 2007, you might be wondering if something had happened to the climate - had the rate of warming accelerated, had we moved into a new phase of warming where temperatures were going to be warmer even than the post '98 El Niño suggested? Or was it just a chance that there had been 7 hot years in a row? If it was chance and the trend was a good estimate of future warming there would be a good possibility of cooler years appearing later.

And that's exactly what we see over the next 6 years.

Annual HadCRUT4 anomalies, 1970 - 2013. Trend from 1970 - 2000.

During the next 6 years, 4 were below the trend, only 2 above it. The two coldest years, both La Niña years, were well below the trend, though there was also one record breaking El Niño year in 2010.

I find it difficult see any evidence that HadCRUT temperatures between 2001 and 2013 were not in keeping with the trend up to 2001. Compared with the projected trend, there were more warmer than cooler years, but not significantly more. The only reason Whitehouse can claim any sort of pause is that more of the warmer years happened at the start of the period, and more of the colder years happened in the later half.

Here's the up to date graph.

Annual HadCRUT4 anomalies, 1970 - 2016. Trend from 1970 - 2000.

The last two years have been very warm, and yes this is in part because of the recent El Niño. But, they are not so far above the trend line as 1998. If you accept warming has continued unabated since 2000, there is nothing too surprising here - the absolute warmth of the last two years are a result of the strong El Niño, on top of the underlying trend. But, if you believe that global warming stopped in 2000, then the El Niño was exceptionally warm, which raises the question of why it was so extreme.

The above is what the 20th century looked like compared with an unchanged rate of warming. The following shows what it looked like compared with a trend that stops in 2000, as Whitehouse is implying.

Annual HadCRUT4 anomalies, 1970 - 2016. Trend from 1970 - 2000, with phony pause trend from 2001 in red.

Every year of his pause was warmer than what would be expected if the pause was real. Of course, this isn't the pause Dr Whitehouse shows. He shows the actual trend through the 13 years without the context of the previous years, giving the impression that warming simply stopped in 2000. Here's what the actual pause trend line looks like.

Annual HadCRUT4 anomalies, 1970 - 2016. Trend from 1970 - 2000 in blue, and trend from 2001 - 2013 in red.

As with other pauses, the flat line requires a big rise in temperatures at its start.

The Pause in 2017 - Part 3 : Carter's Pause

Introduction

Another episode in my ongoing series looking at aspects of the claimed global warming pause, and what it looks like in 2017. In this post I start to look at a May 2017 post in Watts Up With That - NEW STUDY CONFIRMS: THE WARMING 'PAUSE' IS REAL AND REVEALING . (WUWT capitalization and quote marks).

The post is by Dr David Whitehouse, Science Editor for the GWPF, and refers to an article in Nature, Reconciling controversies about the 'global warming hiatus' . Dr Whitehouse says this paper confirms the pause was real, but it doesn't exactly say that. Rather, it says it depends on how the term is defined. For example, it starts

Between about 1998 and 2012, a time that coincided with political negotiations for preventing climate change, the surface of Earth seemed hardly to warm. This phenomenon, often termed the 'global warming hiatus', caused doubt in the public mind about how well anthropogenic climate change and natural variability are understood. Here we show that apparently contradictory conclusions stem from different definitions of 'hiatus' and from different datasets. A combination of changes in forcing, uptake of heat by the oceans, natural variability and incomplete observational coverage reconciles models and data. Combined with stronger recent warming trends in newer datasets, we are now more confident than ever that human influence is dominant in long-term warming.

The Pause Begins

There are a couple of points made by Dr Whitehouse I want to look at. Here I'll look at what he says about the origin of the pause claim. In the next article I'll look at Whitehouse's claim about a longer pause.

The Nature report says that the pause was first claimed by outsiders about 2006.

Some years after the record warm global-mean surface air temperatures (GMSTs) in 1998, claims were put forward by voices outside the scientific community that [global warming] stopped in 1998, arguing on the basis of the HadCRUT3 dataset that was available then that GMST had not increased over the period 1998–2005.

Dr Whitehouse objects, saying

The authors say the pause started with claims from outside the scientific community. Well, yes and no. It was tentatively suggested in 2006 and 2007 by climate sceptics many of whom were experienced scientists and quite capable of reading a graph and calculating statistics. A decade after it was raised, every time the 'pause' is debated it is a tribute to those who first noticed it and faced harsh criticism. It was the sceptics who noticed the 'pause,' and in doing so made a valuable contribution to science. For years it was only analysed and discussed on the blogosphere before journals took notice.

Whitehouse tries to paint those who first pointed to the pause as pioneers, putting forward a tentative hypothesis that global warming had stopped, who were ignored by climate scientists who couldn't accept challenges to their authority.

This claim is nonsense. These skeptics were doing what those trying to avoid measures to stop global warming have always done, looking for any vague argument to muddy the waters. They were not being tentative in their arguments, and were not saying anything new Scientists were right to ignore any argument that global warming had stopped when such arguments were based on a very brief period following a very strong El Niño.

One of the first claims that global warming had stopped (that is stopped, not paused), was Bob Carter. This was in a Daily Telegraph article from early 2006 - There IS a problem with global warming... it stopped in 1998 . There's nothing tentative in the headline, and the rest of the article is just as assertive.

Consider the simple fact, drawn from the official temperature records of the Climate Research Unit at the University of East Anglia, that for the years 1998-2005 global average temperature did not increase (there was actually a slight decrease, though not at a rate that differs significantly from zero).

Dr Bob Carter

Whitehouse objects to the harsh criticism directed at such claims, but the criticism was completely justified at this point - it's a meaningless claim. We are talking about just 8 years, starting with a very warm year caused by a strong El Niño. You can find many examples of 8 year declining trends, and quickly accelerating trends. It means little or nothing to the long term rise in temperatures.

Carter is using HadCRUT data, which at the time was at version 3. This shows less warming than the revised version 4. Here's what Carter's period of no warming, or slight cooling, looks like.

The Eight Years Bob Carter claims there was no global warming.

He starts the claimed pause on a very warm year, yet is still wrong to claim there has been no warming. The linear trend for the 8 years 1998-2005 was rising at the rate of 0.99 °C / century. This is almost identical to the trend of the preceding eight years, 1990-1997, of 1.09 °C / century.

And yet, as so often happens, splitting trends into smaller sections gives a very misleading picture. The 8 years leading up to 1998 and the 8 years following 1998 were both warming at a slow rate, but joining the two together gives a 16 year trend of 2.39 °C / century. More than double the rate of warming of either 8 year period looked at in isolation. Here are the two trends in context, which shows where the problem is.

Bob Carter's 8 year pause, compared with the previous 8 years.

Pause Comparisons

By the third paragraph Carter makes a curious argument:

In response to these facts, a global warming devotee will chuckle and say "how silly to judge climate change over such a short period". Yet in the next breath, the same person will assure you that the 28-year-long period of warming which occurred between 1970 and 1998 constitutes a dangerous (and man-made) warming. Tosh.

Dr Bob Carter

It's a false equivalence to compare a 28 year period with an 8 year one. The warming since 1970 is statistically significant - it's very unlikely to have occurred by chance The trend over the much shorter pause period has very little significance at all.

But in comparing the two periods he seems to be accepting that his claim that global warming has stopped for the past 8 years is tosh. He's implying his 8 years is as meaningful as the alarmist's 28 years, and so both are meaningless - the pause that so many skeptics have been clinging onto was originally just a parody.

But lets look at the warming since 1970 in more detail. It's interesting he starts in 1970 as the first 8 years (1970-1977) really did show a slight negative trend. By Carter's argument global warming had stopped before it started.

But by 1998 the trend over Carter's 28-year-long warming period was upwards, at a rate of 1.42°C / century. So if global warming stopped in 1988, how much does adding the 8 years of no warming reduce the warming since 1998? In fact the warming rate over the 36 years from 1970-2005 increased to 1.74°C / century. The effect of Carter's eight problem years was to add almost a third of a degree warming per century.

In this case there are two problems with the skeptics claim - the trend over the 8 year period did not stop as claimed, but was rising at a slightly slower rate, but, more importantly, it ignores the big increase in temperatures required for their cherry-picked period. This graph illustrates the problems.

Bob Carter's pause in relation to the previous 28 years of warming.

As a final aside, if you think it is fine to take an eight year period as evidence of temperature trends, and if you think it's OK for such a period to begin or end on an unusually warm year, you would presumably be interested in what's been happening recently. Take, for example, the nine years 2008-2016. According to HadCRUT4, temperatures have been rising at the rate of 4.02°C / century. Needless to say this is much faster than the long term trend - and is as meaningless as the pause.

In the 11 years since Bob Carter announced global warming had stopped, temperatures have been rising at 2.63 °C / century - more than a degree per century faster than they were before the pause. If Carter was still around, he could now be writing articles saying There IS a problem with the global warming pause... it ended in 2007.

Conclusion

Contrary to Whitehouse's suggestion, there was absolutely no reason in 2006 for scientists to take seriously, claims that global warming had stopped. These claims were for meaninglessly short periods, they were not based on any statistical foundation, and they required starting at the record breaking El Ni&ntile;o year of 1998. It should have been obvious to anyone with a degree of skepticism that claims of a pause were unsustainable, and were probably being raised to distract from the evidence that warming had if anything accelerated in the early part of the 21st century.

Moreover, there wasn't anything especially original in the pause argument. Skeptics had long argued that global warming had stopped, or never existed. For example, in 2001 Alan Caruba was stating that there had been no warming since the 50s:

Listen closely. The earth warmed about one degree Fahrenheit between 1850 and 1950. Since then, not one single piece of scientific data, largely collected from meteorological satellites, as well as radiosonde balloons, has supported the lies that the earth is warning. A half-century has passed since the last, brief warming and the only thing the current data points to is a slight cooling. Indeed, back in the 1970's, the Greens were writing books predicting a new Ice Age.

Alan Caruba - The biggest liars on Earth: The UN's Global Warming Panel

In 2000 Dr Fred Singer was saying the balance of the evidence showed no warming since about 1940, and there was overwhelming evidence that there was no warming trend since 1980. (He made the claim again in Watts Up With That recently.)

The only reason the idea that there had been some sort of hiatus in global warming started to be given any credence were some cooler the years after 2006, which allowed the appearance of a pause to be extended for longer, possibly more significant periods.

The Pause in 2017 - Part 2: Monckton's Pause

The Great Pause of Monckton

This is the second part of a continuing series, looking at claims about the pause in 2017 (and already far behind schedule). In this episode I'm revisiting Christopher Monckton of Brenchleys Great Pause articles on Watts Up With That. These were a series of monthly articles, lasting almost two years, in which he would inform the public exactly, to the month, when the Great Pause started, how many months it had lasted, and how if only it would continue, the climate scare will become unsustainable.

The first Monckton pause article appeared on the 4th March 2014 in WUWT - No global warming for 17 years, 6 months>. This put the start date for the pause at September 1996. This was a very short piece, just two paragraphs, and says nothing about why he chose that month for the start of the trend, although it's obvious he cherry-picked it to get the result he wanted. In later, much much longer posts, he confirmed he was cherry-picking the start of each pause by calculating the earliest starting month that would still give a non-positive trend. By his final post on the subject in February 2016, the start date had moved forward 9 months to June 1997.

This is how Monckton starts his 2014 post

Seventeen and a half years. Not a flicker of global warming. The RSS satellite record, the first of the five global-temperature datasets to report its February value, shows a zero trend for an impressive 210 months. Miss Brevis, send a postcard to Mr Gore:

Saying there's not been a flicker of global warming, shows how misleading looking at a trend line in isolation can be. The graph fails to show the huge amount of global warming needed to reach the start of Monckton's pause.

The pause starts almost 0.25°C above the previous trend. Curiously, in Monckton's next pause article, No global warming for 17 years 8 months, he calculates how much warming there should have been during the pause, saying there should have been 0.22°C warming since September 1996. Yet if his pause trend is to be believed more than enough warming happened in a single month than his dubious calculations require.

This is what his original pause looks like now.

The trend since September 1996 is now stronger than the trend leading up to it. But both trends are a lot less than the trend over the entire satellite era - this is entirely due to the broken trend line resulting from cherry picking a meaningless split in the overall trend. By contrast, if you split the trends at the start of 1999 you can get a continuous pair of trends.

The later trend is 1.1°C / century, slower than the previous trend of 1.53°C / century, but the difference is not statistically significant, and there's still no firm evidence that a simple trend throughout the entire run is the best fit.

Cherry-picking the Data

All of Monckton's Pause claims are based on choosing RSS 3.3 satellite data. In a Pause update shortly before UAH 6.0 was released in beta format - El Niño or ñot, the Pause lengthens again, Monckton was insisting that RSS 3.3 was the least unreliable data set, and insisted that there was little statistical difference between the RSS and other datasets over the 18-year period of the Great Pause. This is true, but only because the confidence intervals for any trend over the last 18 years are very large, especially for satellite data. But this fact just highlights why it makes no sense to choose the set with the smallest trend and claim it as reality.

Waiting for the Return

Monckton's main goal has always to find the longest possible pause and attaches an odd significance to it one day reaching 20 years. At the end of his final article he puts it in the form of a Freedom Clock, saying

Finally, how long will it be before the Freedom Clock reaches 20 years without any global warming? If it does, the climate scare will become unsustainable.

Presumably as the pause stopped before reaching 19 years the climate scare is still sustainable, which is why there seems to be a lot of hope among true believers of the pause that it will shortly return. In Moncktons final article he says:

The current el Niño, as Bob Tisdale's distinguished series of reports here demonstrates, is at least as big as the Great el Niño of 1998. The RSS temperature record is now beginning to reflect its magnitude. If past events of this kind are a guide, there will be several months' further warming before the downturn in the spike begins.

However, if there is a following la Niña, as there often is, the Pause may return at some time from the end of this year onward. Perhaps Bob could address the likelihood of a la Niña in the next of his series of posts on the ENSO phenomenon.

I doubt there was ever any likelihood of the pause returning by the end of 2016. As things currently stand, even if temperatures were to drop to the levels seen during the La Niña years following the '98 spike, Monckton still won't see his pause return until 2019. But so far there's no sign of satellite data dropping to 1999/2000 levels.

In the mean time, it's possible to cherry-pick in the opposite direction - deliberately look for long stretches of fast warming trends. For example, using RSS 3.3, the earliest starting point where the trend was greater than 1.5°C / century is currently January 1982 - so for the past 35 years and 4 months temperatures have been rising at an accelerated rate (faster than the overall rate of warming) despite 18 years of that being the Great Pause.