Surprise, but not Shock

The extremity of global temperature anomaly in February this year has shocked some people:

nasa


But — I have an explanation which downgrades the “shock” to mere “surprise.”

Of course global temperature has a trend, and of course it also shows fluctuations. Thing is, some of the fluctuations have known causes: el Niño, volcanic eruptions, solar fluctuations. Other temperature variations also occur, and are added to those due to known factors.

My regular readers know that I’ve adjusted temperature for known factors before. Let’s do so again, this time including data through February 2016.

Here’s the data (black line) together with the model (red line) based on el Niño, volcanic eruptions, solar fluctuations, and a simple (piecewise linear) trend for global warming:

nasa2

The known factors account for much of this year’s increase, but not all of it. Here are the residuals:

nasa_res

Now we can see that in terms of the fluctuations not due to known factors, February’s value is definitely up there, but by no means shockingly so.

We can see the same thing if we plot adjusted data, with the estimated influence of known factors removed:

nasa_adj

The blue line is a piecewise linear fit to the adjusted data, the red line is a lowess smooth (hard to see because the blue line is on top of most of it). Again, February is high enough to be a surprise, but not a shock.

Whether or not the most recent months are the harbinger of a “tectonic shift” in the global warming trend, remains to be seen. But the evidence for that isn’t in yet. The recent extraordinary heat could well be, I might even say probably is, a continuation of the present trend plus extra-hot fluctuations from both known and unknown factors.

Which doesn’t mean there’s no cause for alarm. The present trend is plenty alarming.


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38 responses to “Surprise, but not Shock

  1. Welcome to the “Alarmist Club”!

    Recent weather tells us that there is plenty of water vapor in the atmosphere, and water vapor is a good greenhouse gas. Methane concentrations in the atmosphere have not declined as assumed by the climate models. All in all, there are good physical reasons, not included in most climate models, why recent temperature curves may have kinked upward.

    If this is true, then your noting of the upward kink in temperature is merely good observation, and your application to the “Alarmist Club” is denied. To actually be accepted into the “Alarmist Club”, you will need to make bold claims of impending doom based on sparse data.

    This is too bad, because we need more Alarmists. This is the first time we have run this warming experiment, and the data is sparse. If we do not have a few false alarms, then the watchmen are not being adequately vigilant.

    It is better to “cry wolf” whenever wolves are seen, and have a few false alarms, than to lose the whole flock to wolves because of a fear of false alarms. Our reticent academics are more afraid of false alarms, than they are of wolves, bears, bad harvests, cyclones, mosquitoes, Ebola, or sea level rise.

    And the public needs to know that good watchmen, do raise a few false alarms. In fact, mere act of crying “wolf”, may frighten the wolves off.

    Signed,
    Your Loyal Alarmist

  2. JMA is very late with the February anomaly, anyone know why?

    • It’s there now. The Japan Meteorological Agency’s global land-ocean temperature anomaly estimate for February 2016 is:

      +0.62°C vs 1981-2010

      That is about:
      +0.88°C vs 1961-1990 (as used by HadCRUT)
      +0.97°C vs 1951-1980 (as used by GISTEMP)
      +1.3°C vs 1850 (~pre-industrial)

      February is not a new all-months record anomaly in the JMA series; that was December 2015 at +0.66°C vs 1981-2010. Possibly that’s because JMA’s Arctic coverage is a little poorer than other series (even less than HadCRUT), and the Arctic was extremely warm last month.

      It doesn’t affect record relativity, but the JMA series has also been tracking somewhat below the other series in recent years — by about 0.1°C over the last 5 years (when shifted to a common anomaly base period). It’s unclear why, but the difference may be in their sea surface temperature estimates, which they derive independently.

  3. Thanks for the clarification, was a pleasure to read.

  4. The recent extraordinary heat could well be, I might even say probably is, a continuation of the present trend plus extra-hot fluctuations from both known and unknown factors.

    If that is the case, which I would agree is the most likely explanation, then we can expect that the record that will be set this year will not be broken again for a long time. It will be 1998 all over again.

    • Harry Twinotter

      zebraphile.

      Yes, get ready for the “no global warming since 2016” reports for the next 10 years :-)

  5. Michael Hauber

    With the adjustment there are about 5 months as hot in 50 years, so very roughly a 1 in ten year value for non-enso factors. The current el nino is one of the warmest 3 ENSO years out of say 60 years of records, so roughly a 1 in 20 year event. So putting both together does that make this a 1 in 200 year event?

    Its what I’d categorise as ‘borderline statistically significant’. Perhaps statisticians could argue exactly which side of the 95% significance level it falls, depending on which noise assumptions are used etc. Or a physical connection could be sought. As far as I know there has been no recent major loss of ice albedo, or emmission of permafrost methane, or massive vegetation die off which could correlate with such a sudden shift upwards in temperature, suggesting in my mind this is part of the noise that might lie just a little outside the typical 95% confidence interval.

    Unless of course the pause is real, and wasn’t so much a pause when measured against a flat upward trend, but a pause against an upwardly accelerating trend? It will be interesting to see when (if?) temperatures fall back down again following this el nino.

  6. Chris O'Neill

    that we can expect that the record that will be set this year will not be broken again for a long time.

    Like 7 years (1998 to 2005).

    Let’s hope so. Even 7 years is bad enough.

  7. The adjuctments appear to be for specific physical factors. How surprising are these data if autocorrelation is also factored into an analysis?

  8. Yes, way too soon to espouse that the last few month’s high temps, and the latest, represent a “tectonic shift.” The record Feb anomaly was inevitable at some point because it’s getting warmer. We’re going to see more low and high spikes ahead but we know which direction we’re headed.

    It’s way to soon, also, to posit that obs are tracking models better due to the last few months, or are running warm compared to models, as some have done. This is as illegitimate as the short-term stunts critics pull that we’re all familiar with.

    It’s tempting to jump on one or a handful of consecutive warm events to fling it back at the shysters, but it drags the messaging down to their level. As soon as some cold anomalies come along they’ll be at it again, and pointing at sensational reports from the “alarmists” to justify them doing it. Then the battle is on their terms. Keep the message (truth) consistent – the wiggles are not the trend. Expose the trick, don’t utilise it.

    In that light, thumbs up for this post. Something I can point out to critics. Yes, February was record-breaking hot, but it’s not a shock, it was expected at some point. And it’s going to happen again and again. Because the Earth’s surface is getting warmer.

  9. Martin Smith

    The Pause in the Pause: There has been no Lord Monckton spam for 0 years and 3 months.

  10. Sheldon Walker

    I have just published an article called “Investigating global warming using a new graph style”.

    It describes a new type of graph that I have developed, called a global warming contour map,

    With a global warming contour map, detecting a slowdown or speedup, is as easy as spotting a cloud in the sky.

    If you are interested, please read the article, and see if you can find any errors. If you think that you have found an error, please leave a comment with the details of what you have found. I will try to reply to comments.

    This article introduces the global warming contour map. The next article will use the global warming contour map to discuss the slowdown in detail.

    The article can be found here:
    http://wattsupwiththat.com/2016/03/12/investigating-global-warming-using-a-new-graph-style/

    [Response: It’s not a new graph style. It was used, e.g., in this paper. Like its author, you’ve done nothing more that make a pretty colored graph; you can get the same kind of “results” from applying this kind of analysis to random noise (as demonstrated in this paper).

    If you want to test the idea of a “slowdown” you need to apply some real statistics. That too has already been done, in this paper and this paper (on page 6).

    You have (at least) two problems. First, you’re not willing to subject your own “analysis” to rigorous scrutiny, try applying some of that much-vaunted skepticism. Second, you overestimate your own ability, by a lot. A little modesty might serve you better.]

    • Harold Brooks

      I was going to be a little more charitable than Tamino, at least in the intent of the graphic. I recall seeing something very much like this figure looking specifically at global temperature in 2 or 3 places in the last year (Nick Stokes just had one.) The important message of the figure is that at short trend lengths (~1.2 K/century, marking a clear departure from the earlier period.

      Sheldon’s interpretation of his figure isn’t particularly insightful, as he focuses mostly on the noise and not the signal, but the graph isn’t bad.

    • Chris O'Neill

      to discuss the slowdown in detail

      Why would anyone other than an ancient historian be interested in discussing ancient history? The slowdown is dead. Get over it already.

    • Here is Nick Stokes Trend Viewer, mentioned by Harold Brooks.

    • I have just published an article called “Investigating global warming using a new graph style”.

      You didn’t “publish” an “article”, you posted a blog piece on a non-scientific internet site.

      This article introduces the global warming contour map.

      Erm, no, it doesn’t introduce anything new. I told you (at Sou’s I think), that I and others have played with this format in the past, and Tamino and others indicated above that Nick Scafetta and Nick Stokes have previously and conspicuously used this format.

      The next article will use the global warming contour map to discuss the slowdown in detail.

      This should be entertaining. Uninformed and incorrect, but entertaining neverthless. Except for the bit where you are a part of the machinery that is causing the decades-delay in responding to a problem that is more urgent than you are intellectually-equiped to comprehend, or that you simply don’t care about.

      Still, have at it. I’m curious to see how well you can sift out and accurately comment on some of the information that is embedded in this format, and how you might spin the rest.

  11. It may not be all that much of a surprise. We’ve had a long period of predominantly La Niña or ENSO-neutral conditions, with the OHC data showing an acceleration since about the year 2000, so there has been more accumulated heat to contribute to surface and atmospheric warming during the current El Niño. Wouldn’t that be the main explanation for the strength of the current anomaly?

    • Its a little bit more difficult, the heat was sink into deeper layers of the ocean, or in other words, the vertical transport between mixing-layer and deeper ocean has increased due the negative PDO and more La-Nina. Therefore the heat in the upper ocean then not increased strong, its slowed down a bit… since ocean and atmosphere in the real climate is strictly interacting, the warming of atmosphere slowed a bit(but not in any significant way).

      Well, now we see the same with other sign, the temperature in the upper ocean is like a sky rocket now or see here: http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/3month_mt/T-dC-w0-100m10-12.dat

      Why is that so? Some part is only due the less mixing rate, but another part is due the strong Imbalance in climate system, so you can also say, the upper ocean do a rapid adjust to a more balanced state and its very likely that we enter a new stage of Global Temperatur, this means, we will never (only under strong vulcanic erruption) come back in Temperature to the state before, also if next La-Nina is coming, the temperature will not fall on a state of La-Nina 2011, its more likely it will only drop down to 2014.

      And its because the stronger mixing due La-Nina is only strong enougth to caputure out, the increased warming due El-Nino in the upper ocean, but not the part of antropogenic warming.

      • One thing, the PDO is in play, 13-14, much earlier with the 15-16 El Nino than it was in the 97-98 El Nino. 15-16 is taking place in an already warmed ENSO environment.

  12. JCH,

    PDO: http://research.jisao.washington.edu/pdo/PDO.latest

    Shift was early 2014, not 2013-2014, 2013 is uneffected by positiv PDO, increase in Temperature before 2016 was more due to PDO, now in 2016 we get both together and its a effect by time, the longer the vertical mixing under the mixed layer is weakens, so stronger will become the effect.

    2016 will likely become wärmer than 2015 ( i speculate little above 1K to the GISS-Reference) and by 1998 we know what will happen, when La-Nina is forming and PDO goes negativ. In 1999 the Globals only went down by 0.2K and the same we will see in 2017 (if La-Nina is coming) and therefor, we would went down arround 0.70-0.80K

  13. Why are the lead graphs from this post and the prior post different, yet both are labelled with the authoritative “NASA” title?

    [Response: Same data, different time span. The graph in this post doesn’t start until 1951 (the time at which the adjustments for ENSO, Volcanic, and solar begin). The other starts in 1880 (when NASA data begin).]

  14. David B. Benson

    By the Blue Skies test (looking out the west facing windows), there are much fewer aerosols from East Asia, all the way from NNW to SSW along the horizon, in the past few months. A quick search finds

    China’s coal use falling faster than expected
    http://www.reuters.com/article/china-coal-idUSL3N0WL32720150326

    which is from before the recent slowdown in the Chinese economy.

    Reducing aerosols will immediately raise the surface temperature due to albedo change. So does this help to explain the large January and February temperature increases?

    • Since climate sensitivity is so low, I can’t see how.:)

      March could continue this. Maybe even April. At some point, low estimates of climate sensitivity has to have an observations problem, right?

    • I doubt it, David, though we’d need to see some actual figures. Recent anomalies are big short-term jumps, while declining aerosols, I imagine, would have a more gradual effect. Seasonal energy use/aerosol loadings should be factored in, too to estimate China’s contribution to recent temp spikes. I’d guess it would be very minimal.

      • Perhaps so, but aerosols affect the incoming energy budget so can cause a very rapid change. When aerosols and cloud lives enhanced by aerosols decrease, there is immediate warming.

        This is one of the major problems with Solar Radiation Management approaches to geo-engineering.

  15. Just quietly, at the rate of warming over the last four decades, and with a residual excursion such as observed last month, the planet will likely see a monthly mean in excess of the landmark 1.5 °C above pre-Industrial baseline by 2025, and in excess of the 2 °C “line in the sand” by 2050.

    Now, monthly anomalies have a different ecological/climatological implication compared with annual and decadal anomalies, but if the underlying causal factors remain on current trajectories then this difference is moot. It’s very likely already moot.

    One can’t help but recall Douglass Adams’ falling whale, which learned the hard way that the “thing suddenly coming towards [it] very fast doesn’t want to be friends with you”…

    • likely see a monthly mean in excess of the landmark 1.5 °C above pre-Industrial baseline by 2025

      The GISS baseline is 1951-1980 so their February 1.35 is already more than 1.5C above pre-industrial.

      • Thanks for the reply Paul. Good catch. I meant to stipulate that such temperatures would be reached at the mean trend level rather than during El Niño events, but in my haste to post I didn’t proof read.

        And the 1.5 °C limit is already effectively locked in with the system momentum plus inescapable near-term fossil fuel use. At the current rate of CO₂ emissions 2°C will probably be effectively baked in within a couple of decades. The reality is that we’ve essentially failed to have any real possibility to achieve even the higher COP21 target before the ink was dry in Paris…

        It’s probably time that we stop discussing how we’re going to avoid dangerous climate change, and start talking about what we need to do to minimise the amount of dangerous climate change that we’ve chosen to inflict on the planet in the coming decades, centuries, and millenia. We should be very clear about what we’re already unavoidably going to lose, and how much more we’re going to lose with each passing year of ineffective cessation of carbon emissions.

        The above isn’t really pessimism, it’s pretty much a consequence of following the numbers. My pessimism starts with the feeling that human nature, politics and culture, such as they have been to date, will unlikely change much until such warming has been comitted to that coherent global society – and many species and ecosystems- are committed to catastrophic collapse.

        Coincidentally, I found this Climate Reality Check by David Spratt just after I finished typing the first two paragraphs above. It’s worth a read:

        http://media.wix.com/ugd/148cb0_4868352168ba49d89358a8a01bc5f80f.pdf

  16. Tisdale’s response to this (on that denier site) is rather desperate. He’s literally jammed every surface and troposphere record he can find into the same graph, and cut them all off at 1998 in order to minimise the rise. It’s what I’d show first year students to teach them about dishonest graphs.

  17. Yes the 1981 Nino and the follow up is a great constraint in selecting the response function. Still it could be extra large ninos are not fully acquitted, but better safe than sorry for overfitting.

  18. Martin Smith

    “But the Pause is still there. No matter what happens now, the world didn’t warm for 18 years, and that shows the models can’t predict a thing.”

    Did not see that comin’. The Pause is still there!

  19. Here’s a few queries – does the degree of autocorrelation stay the same through time in the adjusted time series? How much does autocorrelation in the residuals explain what we’re seeing today?

    The other piece of food-for-thought is that you seem to get remarkably good fit through the other El-Nino events with your model (e.g. 1998 – residuals are pretty small) but not now. I’m not on top of your model – is there some way Feb 2016 being the end of the time series makes big residuals more likely?

  20. Vendicar Decarian

    The current spike starts at the trend line since 1980 and not below (La-Nina) as has been the case in the past.

    The following La-Nina fall is typically twice the rise from the trend line.

    This points to a trend line that should be 0.2’C above the current trend line from 1980.

    This looks to me like there is a sudden 0.2’C step upward that will most likely be permanent.