The Met Office yesterday confirmed that the warm record of 2016 was mainly driven by a very strong El Nino.
Guest essay by Dr David Whitehouse, GWPF Science Editor
Not that you would have heard this fact in the news. But Peter Stott, Acting Director of the Met Office Hadley Centre, said in no uncertain terms that, “a particularly strong El Nino event contributed about 0.2°C to the annual average for 2016.”
By removing this temporary El Nino contribution from the Met Office’s 2016 data, it becomes obvious that global average temperatures would be essentially identical to where they were in 2014 (see fig 1). Since the El Nino warming is fading and global temperatures are dropping rapidly, they are close to being back to where they were before the latest El Nino started.
There are two ways to look at the just released global temperature of 2016 and press releases from NASA, NOAA and the Met Office work hard to reflect only one of them.
The emphasis is on long-term warming with the press releases stressing that we are living in the warmest decade of the past 150 years (since instrumental records began) concluding that global warming is continuing unabated. This is one way of seeing the data, but it is not the main lesson which comes out of studying what 2016 adds to the picture of recent warmth.
2016 was clearly among the warmest of years, but what distinguishes it from the previous years in this century? Everyone agrees it is the strong El Nino. But how strong was its influence?
The NASA GISS dataset has the global temperature of 2016 at 0.99 +/- 0.1°C compared to 0.87 +/- 0.1°C for 2015, a difference of 0.12°C. However, NASA’s Gavin Schmidt said that their estimate of the boost to global temperatures given by the El Nino in 2016 was 0.12°C, that is the difference between 2015 and 2016.
The press release from the Met Office says that 2016 is one of the warmest two years on record and that according to the HadCRUT4 dataset it was 0.77+/- 0.1°C above what it calls the long-term average, which is actually calculated between 1961-1990. 2015 was 0.76+/- 0.1°C making 2016 and 2015 statistically indistinguishable from one another.
However, Peter Stott, Acting Director of the Met Office Hadley Centre said, “A particularly strong El Nino event contributed about 0.2°C to the annual average for 2016.” This means that without the El Nino 2016 would have had a global temperature of about 0.57+/- 0.1°C which is the same as 2014 and within the errors of 2010 (0.56) and 2005 (0.54). It would also have been in the 95% confidence range of 2013, 2010, 2009, 2007, 2006, 2005, 2003 and 2002. In other words, using the Met Office’s 0.2°C El Nino (ENSO) correction 2016 has not been a record warm year but statistically in the same region as the previous 15 years. Gavin Schmidt of NASA disagrees, saying on Twitter, “Oh my. What tosh. In ENSO corrected data-sets 2016 is still record warm.”
According to NOAA 2016 was 0.07°F warmer than 2015, which is 0.04°C. Considering the error in the annual temperature is +/- 0.1°C this makes 2016 statistically indistinguishable from 2015, making any claim of a record using NOAA data specious.
Fig 1 shows the HadCRUT4 data for the so-called “hiatus” period. The recent El Nino years of 2015-16 are prominent. Also on the graph is the 2016 temperature without the El Nino contribution, as calculated by the Met Office. 2015 – a year with an equally strong El Nino effect – is cautiously interpolated – although the 2016 El Nino estimate is the main datapoint, (NASA Giss says that the correction for 2016 is 0.12°C and 0.05°C for 2015. The Met Office has a figure almost twice as much for 2016 which represents a significant difference of opinion between the Met Office and NASA). However, even with just the 2016 El Nino compensation the data shows that the pause hasn’t gone away. It has simply been interrupted by two very strong El Nino years. Note that there were moderate El Ninos in 2002-3 and 2009-10. Compensating for those El Ninos as well as the one in 1998 would make very little difference to the graph, and certainly would not invalidate the pause in the data. In fact it would make the temperature flatter.
Time will tell how far global temperatures will drop in the next couple of years. But there is a good chance that the pause will be re-established once the El Nino warmth tails off.
The Berkeley Earth team also confirmed that the 2015/2016 El Niño was responsible for a record year – read here
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The temperature data set wars are fun.
It is only logical that if the world is warming, and very few people deny that, temperatures should be higher, not lower.
It is only logical that temperature records are broken by a bigger margin during strong El Niño years, as it took place in 1998.
So what is the problem? The world has been warming since about 1650 when the Little Ice Age was at its bottom, and more noticeably since 1815. This has been tremendously positive both for the world and humans. The hypothesis that more global warming is going to be so negative as to become dangerous has no support by evidence. 2016 was also the record year for wheat crop.
The hypothesis that global warming should accelerate due to the increase in CO2 has not proven correct, and since 2003 to 2014 the warming rate has been smaller, not higher. Obviously including and ending in El Niño warming will bias the results, but it is clear that after the El Niño, temperatures are going down to where they were before. The rumor that the hiatus has died is premature. Two or three more years of data are needed.
We don’t need more years. Just chart ENSO neutral months.
“Just chart ENSO neutral months.”
You can’t reasonably do that: The interaction between ENSO and global temperature over time is too complex. Just because a given month is ENSO neutral doesn’t mean that the temperature that month isn’t still strongly influenced by ENSO values up to 12 months earlier (or more). To illustrate that look at this chart (fingers crossed this works):
http://imgur.com/a/CE5Qs
Here I have taken a typical satellite global data set (RSS) and done a cross-covariance analysis against the unsmoothed monthly ENSO value for the Nino 3.4 region (from http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_change.shtml). Because ENSO values are anomalies versus the long term trend (NOAA subtract a sliding 30 year reference period), I subtracted a simple linear fit to the RSS data. This gives the short term (monthly) anomalies relative to any long term trend over the whole data set. I used RSS 4.0 TTT, but you get similar results for other satellite series. Basically what this shows is that the strongest correlation between the tropospheric temperature and the monthly ENSO value will occur with a lag of 5 months. But note that the correlation remains positive and significant (i.e. high ENSO=high temperature and vice versa) for well over a year (the blue lines are 95% confidence intervals). 12 months is a long time in the evolution of ENSO events – they can completely reverse from El Nino to La Nina in that time, so its really not possible to say that the temperature in any given month is ‘due’ to a given El Nino index.
Thanks Dave, good job!
UAH indeed has a 4-5 month lag wrt MEI .
Dave, that is true but the lag works for both El Nino and La Nina and hence tend to cancel each other out. Yes, the lag does introduce a slight influence depending on starting and ending dates.
Just for fun I looked at the trend of all the ENSO neutral months from 1-1997 to 12-2016. The trend came out to an insignificant .01 C / decade which was most likely due to the fact the start date is preceded by a La Nina and the end date by El Nino (the lag effect you mentioned). Still the bottom line is the trend is flat which means according to this type of analysis the pause is still in effect.
Forrest Gardener, you enjoy talking in riddles, and not answering questions which you are asked (I have put a couple to you). I think that the matter of the global temperature anomaly has been explained a hundred times. Check again.
I object to the use of words like anomaly. That suggests that something is wrong. A better word would be index. Better still, just use degrees C, or degrees K. When you plot either of these on a chart from zero, the whole thing stops looking so scary.
For those of you in the Northern Hemisphere monitoring your snow this northern winter, you will be surprised to learn that we here at latitude 40 South in New Zealand have just witnessed a fresh snowfall on the mountains near us down to 4,000ft. In nearly 60 years I have seen only two other January mountain snowfalls and they were in the first week of the Januaries following the last ‘Grand El Nino’ in 1998. Today’s snowfall would be like getting snow in the N.H. on July 20th when normally it is all over by mid May!
Cool! 🙂 (thanks for sharing that — truly intriguing and great observational evidence**!)
**Note to AGWers: I did not say it proved conclusively, it is, nevertheless, UNLIKE YOUR STUPID MODELS (boy, did it feel good to say that, heh), is valid data.
Hey Ian! Your news has been reported to the appropriate U.S. and UN agencies who advise as follows: Do not exit your home and do not attempt to touch the “snow”. This is obviously warm snow which was predicted by several recent computer models ( VERY RECENT!). Teams from NOAA and NASA have been dispatched and it will be gone by morning ( is there somewhere out of sight we can put it?). Please forget we had this conversation and do not discuss this matter with family or neighbours.
Mr. Gardner, I would just like to say (coming from me, I realize it isn’t worth much to you, but, anyway) that it is obvious to us ALL that your fine brandishing of your shining steel sword of truth has UTTERLY vanquished Troll Frank.
Well done!
Too late John, I posted it on FB. It’s gospel now (with pictures of course!)
Mr. Gardner – it is my personal opinion that the only way to determine meaningful temperature trends is by measuring at specific locations, as many as possible all over the globe where accurate measurements can be made. Analysis of data for each location will tell us more than a single “global average.”
What a strange comment!
All specific locations’ data is available on the Net, e.g. in
http://berkeleyearth.lbl.gov/city-list/
or anywhere else: NASA GISTEMP, NOAA (you know, all these manipulators, pause busters etc etc).
You only need to search for information… but my impression is that for many people it is more easy to complain about that information be missing than to look for it.
In the end all one can do is say ‘hey guys, how many of you were around 50 years ago? Is the weather to day noticeably warmer than it was then, or not?’
Its just as cold in the mornings now as it was then, the only difference being I now have central heating and dont have to get up and go to school at 8 a.m.
I would like to see trend lines concerning the current pause originating with the beginning of the pause in 2002 not from an earlier point during the previous warming period. Doing so gives a false picture of the trend during the pause. I also realize that the intent of originating the trend lines before the start of the pause is apparently an attempt to mislead the viewer into believing there is no pause in the warming. Standard alarmist behavior.
William Everett on January 20, 2017 at 6:19 am
http://fs5.directupload.net/images/170120/rhkgs4zm.jpg
William Everett on January 20, 2017 at 6:19 am (bis)
But I suppose what you expected be rather something like this below, isn’t it?
http://fs5.directupload.net/images/170121/yjck4zns.jpg
Because this chart is for so many people a proof of the pause.
This pause undoubtedly existed.
But to discover its real extent requests not only to exclude the two stronger recent El Niños, by placing the chart’s time period inside of them as I did here; you also have to extract all El Niños and La Niñas present within the chart’s period.
For example, by using the R code extracting ENSO and volcano signals, published in 2011/12 by Foster & Rahmstorf. I’m too lazy to do, maybe Bill Illis comes around and does the job 🙂
Dr. Whitehouse: As science editor for the GWPF, you aren’t doing you organization’s credibility (with this reader, at least) by presenting a grap where some cherry-picked points are corrected for ENSO and most others are not (1998 in particular). Even with these adjustments, the last three years are all warmer (or as warm 2010 2005) than any for the past 19 years – and the preceding century.
Every record in the satellite era shows long-term warming. The only important question is how much less warming that the IPCC projected.
Thanks Fonzi… but just a line commenting the plot would be so welcome.
v’
An important effect is being ignored, here. The non-explosive Icelandic volcano Bardarbunga erupted continuously from August 2014 to February, 2015, the largest such eruption since Laki in 1783. This delivered a lot of HCl and HBr into the atmosphere, which would have depleted stratospheric ozone when photodissociated on polar stratospheric clouds in late winter. This would have admitted more solar UV-B. causing global warming, including the recent El Nino. Since both Cl and Br destroy ozone catalytically and thus have a long residence time in the stratosphere, it is unsurprising that global temperatures should remain elevated in the “hiatus.” because it will take a long time for these halogens to clear out. The effects are quite logical, yet in the unfounded hyperbole to blame carbon dioxide for warming, no one talks about this.