Despite recent claims by Justin Gillis in this NYT piece that the plateau in surface temperatures is misunderstood by scientists…
…given how much is riding on the scientific forecast, the practitioners of climate science would like to understand exactly what is going on. They admit that they do not, even though some potential mechanisms of the slowdown have been suggested. The situation highlights important gaps in our knowledge of the climate system, some of which cannot be closed until we get better measurements from high in space and from deep in the ocean.
…and that it is just some start point issue…
As you might imagine, those dismissive of climate-change concerns have made much of this warming plateau. They typically argue that “global warming stopped 15 years ago” or some similar statement, and then assert that this disproves the whole notion that greenhouse gases are causing warming.
The starting point is almost always 1998…
It can be shown that the plateau may extend further back than that, and that nature still rules the climate system, more so than man. I’m not sure why Gillis thinks 15 years is the number people use starting at 1998, I don’t know of anyone making that claim recently. Even CRU’s Phil Jones admitted in a BBC interview that there had been no “statistically significant” warming since 1995, a point also brought up in 2008 by Dr. Richard Lindzen at WUWT when he said: “Why bother with the arguments about an El Nino anomaly in 1998?”
More importantly, the kickoff point for this most recent discussion by The Mail’s David Rose started 16 years ago, in 1997. The 15 year/1998 choice seems like a purposeful misdirection by Gillis. Using 1997 as preferred by Rose, we are fast approaching Dr. Ben Santer’s 17 year test, and if we use Jones and Lindzen’s 1995 start point, we’ve passed it. What will Gillis say then? – Anthony
More here in this essay By Dr. David Whitehouse via The GWPF
The absence of any significant change in the global annual average temperature over the past 16 years has become one of the most discussed topics in climate science. It has certainly focused the debate about the relative importance of greenhouse gas forcing of the climate versus natural variability.
In all this discussion what happened to global temperature immediately before the standstill is often neglected. Many assume that since the recent warming period commenced – about 1980 – global temperature rose until 1998 and then the surface temperature at least got stuck. Things are however not that simple, and far more interesting.
As Steve Goddard has interestingly pointed out recently using RSS data going back to 1990 the Mt Pinatubo eruption in 1991 had a very important effect on global temperatures.
The Pinatubo eruption threw more sunlight-reflecting aerosols into the stratosphere since the Krakatoa outburst in 1883. Its millions of tonnes of sulphur dioxide reduced incident sunlight and had a maximum of 0.4 deg C cooling effect on global temperatures and an influence that lasted for several years.
The result of this temperature decrease is to increase the difference between the global temperatures of the 1990s and the 2000s. Removing this volcanic dip reduces quite significantly the temperature increase seen over the 1990 – 2013 period. When the errors are taken into account it is not impressive.
There was another very important volcanic eruption in the 1980s – El Chichon in 1982 – whose aerosols actually reduced solar irradiance by an even greater extent than Pinatubo.
Removing this volcanic signal also reduces the statistical significance of the rise in temperature seen since 1980. (In fact, statistically speaking, one is hard-pressed to find any statistically significant warming between 1980 – 1995.)
The El Chichon eruption is interesting because one of the strongest El Nino events, some say the strongest ever, occurred just after it. These two events had an interesting interplay for it seems that the global temperature rise induced by the warm water of the El Nino was offset by the cooling effect of the stratospheric aerosols from El Chichon. It is interesting to speculate what might had happened if El Chichon had not gone off. Would the 1982 El Nino have been as dramatic as the 1998 one? And would it have left in its wake elevated global temperatures, as 1998 seems to have done? What would have been the impact on environmental thinking, and on James Hansen’s global warming warning in 1988?
In the post-1980 global temperature data the effects of the El Ninos and La Ninas are obvious both as discrete events and as a source of ‘noise’ in the temperature of the past 16 years. The statistically significant increase in global temperature since 1980 occurred in the years after the Pinatubo eruption’s dip had ended, and before the onset of the strong 1998 El Nino. If strong El Ninos are a mechanism for changing global temperatures in a stepwise fashion we may have to wait for another strong one before the current temperature standstill ends. Perhaps we should also be looking at the link between the lifting of the post-volcanic aerosol burden and its possible effect on the initiation of El Ninos.
The Unthinkable
One of the interesting aspects of the current temperature standstill is that it persists despite several El Ninos and La Ninas.Since 2006 the influence of these events has been more pronounced in satellite data; El Ninos in 2007 and 2009-10, La Ninas in 2008, 2010–2012. These events have increased the ‘noise’ of the global temperature data in recent years.
(Courtesy Dr Roy Spencer – www.drroyspencer.com)
Removing this noise is tricky, but without it there is a hint, just a hint, that sans El Nino/La Nina effects and volcanic dips, the global temperature might be reducing. As usual, five more years of data will be fascinating to analyse.
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The bottom line still remains; CO2 isn’t the climate driver it was made out to be. If we’re all going to freeze or fry, it won’t be due to CO2.
The NYT article by Justin Gillis is another example of moving the goal posts.
If you remove the Pinatubo dip and the El Nino hike, you are left with fairly stable temps until about 2001/2. However, after that 2001/2 hike (if you do this on RSS on woodfortrees) you get a slight drop of tropo temps since 2002 on RSS and a straight line on UAH. Rather than CO2 causing steady rises in temp, what we appear to get are ‘hike-ups’. The same applies to the Central England Temperature at the 1980 point. That rise is really quite striking. http://www.metoffice.gov.uk/hadobs/hadcet/ What causes these rather sudden ‘hike-ups’? As a layman, that’s what I see when I look at graphs of temperature. Is this what you would get if CO2 is forcing – it seems odd to me. Again, as a layman I would have expected a steady forcing up if the physics is accurate. Hikes seem attributable to something else.
I already predicted no warming for 30 years by 2020. OK, maybe a bit on the cold side, but I still stand by it. That means the trend 1990-2020 will be ~flat.
http://www.woodfortrees.org/plot/hadcrut4gl/plot/hadcrut4gl/from:1990/trend
I’m only getting the top half of the last graph.
The link to Dr. Spencer is a dead end at GWPF
Perhaps the plateaux goes back over 2000 years ! The “Yamalia” tree-ring chronology recently published by Briffa et al. 2013 shows remarkably stable temperatures in arctic regions. There is a recent warming trend but not significantly greater than that which occurred around 250 AD.
see graph here
Speaking of global cooling – I seem to recall the Washington Post in 1971 carrying a story about the coming ice age. I believe they quoted scientists who were using Jim Hansen’s Venus Atmosphere model and predicted an ice age in the next 50 years due to fossil fuel emissions. I wonder if that means Hansen’s software demonstrated that fossil fuels are so evil they will either boil us or freeze us. There again it might mean his modelling is just crap.
Mr. Gillis, the longer the standstill persists or cooling commences the harder it’s going to be to accuse sceptics of cherry picking. Global warming has stopped, it is a dead parrot (for the time being at least). Is Phil Jones a cherry picker?
Met Office Blog – Dave Britton (10:48:21) – 14 October 2012
“We agree with Mr Rose that there has been only a very small amount of warming in the 21st Century. As stated in our response, this is 0.05 degrees Celsius since 1997 equivalent to 0.03 degrees Celsius per decade.”
Source: metofficenews.wordpress.com/2012/10/14/met-office-in-the-media-14-october-2012
I disagree with everything Ryan is going to say 😉
It seems more and more likely that the publicly funded modellers have wrongly guessed the ranges, and/or perhaps the polarity of climate sensitivity. They are fully aware that scientists, sceptical of their models, have floated this idea for years.
The posting by Dr. Whitehouse concludes with “Removing this noise is tricky, but without it there is a hint, just a hint, that sans El Nino/La Nina effects and volcanic dips, the global temperature might be reducing.”
Well … I thought this had been done? Foster & Rahmstorf (http://tinyurl.com/czdx6va) do exactly that and address this issue with disturbing results.
I wonder if Dr. Whitehouse might comment on the Foster & Rahmstorf paper, perhaps unpacking how and why his conclusions differ?
Note that merely using the oxymoronic phrase “warming plateau” you already concede the argument. The phrase “temperature plateau” is descriptive (and even still contains the implication that the flat stretch is high rather than low). The correct way to phrase it is “interval of neutral temperature changes” (for example) — this correctly implies the slope of the curve without making assertions about whether or not the neutral slope is the interruption of an ongoing warming trend (that will eventually resume), a true maximum in the complete timeseries (certainly not true for any timeseries that stretches back more than 2000 years), a flat peak about to descend (which is what a plateau technically is, so in one sense this is a poor word choice even for those seeking to twist perception). Of course we don’t know what future temperatures are going to do. They could spike up/resume warming. They could extend the “plateau” (neutral interval). They could descend, representing global cooling. All three are within the normal bounds observed on the planet in the past.
The wordsmiths who present CAGW and a fair number of its defenders are rather articulate and, by framing the dia- — I mean monologue in terms of phrases like this, they win the battle with many even before the discussion or presentation starts.
If by any chance temperatures do descend, I am certain that we will hear it described in the media as a “warming descent”, or a “warming hiatus” or a “pause in the warming” — anything but calling it cooling, any more than anyone describes the present as an interval of stable temperatures.
rgb
The children of Central England won’t know what snow is. 🙂 This claim for the UK was brought to you by a climate modeler at CRU called Dr. David Viner. Why should I give any weight to what these Climastrologists have to say.
“Mean Central England Temperature Annual anomalies, 1772 to 9th June 2013”
http://www.metoffice.gov.uk/hadobs/hadcet/
“So, if past is prologue, this current plateau will end at some point, too, and a new era of rapid global warming will begin. That will put extra energy and moisture into the atmosphere that can fuel weather extremes, like heat waves and torrential rains.”
For the still-Faithful, hope springs eternal. Deep down though, they know the very basis for their manmade warming/climate/weather is crumbling. You can smell the fear and desperation as they cast about wildly for excuses and maybes, all the while keeping up a steady barrage of the use of varying forms of the word “denial”. Oddly, it is they who are denying the situation, and who are in classic psychological “denial” mode.
We can argue about the plateau, but what I find significant is their admission that they haveno explanation. In other words, they really don’t know everything about what drives the climate. Therefore why should I believe their hypothesis that the globe will continue to warn in the future when they couldn’t predict the plateau?
I sure am glad we have global warming here. June 12th 5:32 AM MDT and we are at a record setting high of 4C.My goodness.By noon we may hit 10C and all fry! Opppsss,time to go feed the two mallard ducklings on my front deck.Funny thing.Seems their parents left this hot clime for some place cooler.
“There was another very important volcanic eruption in the 1980s – El Chichon in 1982 – whose aerosols actually reduced solar irradiance by an even greater extent than Pinatubo.”
The way this is worded one would get the impression that a volcanic eruption would have an effect on the Sun itself. These volcanic aerosols reduce INSOLATION.
Okay…. no, even without Pinatubo forcing the temperature would be a bit lower than the “plateau” one. Or you would be disproving Bob Tisdale and his El Nino Step Change theory. But honestly I don’t see it there in my wildest fantasy.
But I also find disputes about length of the “plateau” about as important as disputes about numbers of angels dancing on a needle tip. The important fact is that real world values more and more significantly deviate from model projections and that happens regardless of whether we want to see a plateau in the data or not.
Furthermore, if we use 1979 as the start of the recent warming, then we have warming between 1979 and 1997 (18 years) and plateau/hiatus/insignificance between 1997 and 2013 (16 years). If we use 1996 as the inflection point, then both periods meet the Santer criterium. So if anyone claims that is too short to be significant, then I suggest the warming period is also too short to be significant.
Understanding climate requires realistic thinking using realistic models. Neither are used at present. Clearly reality dictates that GHG’s do not drive climate.
“…given how much is riding on the scientific forecast, the practitioners of climate science would like to understand exactly what is going on.”
Well, there you have it – the central reason for the corruption of climate science. These people (specifically the CAGW warmists) have so much “riding” on their “forecast” that they will stop at nothing to pervert the science to make it come true…
I wnder about the surprise at step wise temperature increase with el ninos. If the “normal” temperature trend were an increase in El Niño and a decrease in La Niña, and if we overlaid a gradual warming on that, wouldn’t the result be:
– in La Niña years, the natural cooling offset by underlying warming = static/plateau
– in El Niño years the natural warming + underlying warming equals sudden increase.
I’m not saying this is happening, I’m just surprised that people keep saying the model doesn’t predict this behaviour. Surely it’s exactly what the model predicts?
fredb says:
June 12, 2013 at 3:42 am
“The posting by Dr. Whitehouse concludes with “Removing this noise is tricky, but without it there is a hint, just a hint, that sans El Nino/La Nina effects and volcanic dips, the global temperature might be reducing.”
Well … I thought this had been done? Foster & Rahmstorf (http://tinyurl.com/czdx6va) do exactly that and address this issue with disturbing results.”
Foster & Rahmstorf would rather drop dead than using UAH data.
Tom in Florida says:
June 12, 2013 at 4:50 am
You can probably put that one down to me. I used the term ‘irradiation’ in my comment over at Real Science:
http://stevengoddard.wordpress.com/2013/06/09/twenty-two-years-of-no-actual-global-warming/#comment-234526