Tuesday, December 15, 2015

Watching the global thermometer - year to date GISTemp with a very hot November 2015

Sou | 1:12 PM Go to the first of 40 comments. Add a comment
Every month since March, I've posted a chart of the progressive year-to-date global average surface temperature, from GISS. This is the update with October included. I'll repeat the explanation with each update and add what seem to be things to watch.

Worth noting: Hottest November on Record by 0.25 °C

  • 2015 is by far the hottest year on record so far.
  • The progressive year to date average up to and including November is 0.84 °C above the 1951-1980 mean.
  • November was an average of 1.05 °C above the 1951-1980 mean and is the hottest November on record. The next hottest was November 2013 (0.8 °C).
  • June, October and November this year were the hottest on record for the respective months. (June was the equal hottest June with 1998). 
  • The highest anomaly this year is October, now at 1.06 °C, followed closely by November at 1.05 °C.
  • The lowest anomalies this year so far were April, now 0.73 °C, and July now also 0.73 °C above the 1951-1980 mean.
  • To drop below the hottest year on record, 2014 (0.75 °C), the average anomaly for December would need to be around minus 0.41 °C. 

Explaining the chart

The chart is a progressive year to date average, or running mean, for all years from 1995 to the present. What that means is for January each year, it just shows the anomaly for January. For February it shows the average of January and February for each year. For March, its the average of the monthly anomaly from January to March.

If you look at December, each year shows the annual average temperature for the full year. For November, each year has the average for the year up to November, not including December. (As before, I've made it extra large because of all the fine detail.)

Data Source: NASA GISS - GHCN-v3 1880-09/2015 + SST: ERSST v4 1880-09/2015

2015 is well above all other years. The years to watch were 2014, 2010 and 2005. I've plotted them with slightly thicker lines so they stand out more easily.

The coldest year of the lot was 1996, which still ended up being 0.35 °C above the 1950 to 1981 average.  The next time someone tries to tell you that "it hasn't warmed since 1996" then show them this chart :)

Below is the global mean surface temperature chart with 2015 the average to November, which is 1.1 °C above the 30 year mean from 1881 to 1910.

Data Source: NASA GISS - GHCN-v3 1880-09/2015 + SST: ERSST v4 1880-09/2015

Related updates

Some charts showing how temperatures evolved in previous El Niño years can be seen in this article: Why Christopher Monckton is getting nervous about global temperature.
[Update] Here's an update to the GISTemp chart for El Niño years from that article. (In past years, GISTemp peaked in February/March the second year of the El Niño.):

Here is the link to the table for the Year to Date chart.


  1. Hottest climatological year on record. Bob Tisdale is crying in his beer and trying to explain why this is not the hottest year on record.

    1. This is where after 18 years of forgetting the deniers suddenly remember El Nino. [insert rude word of choice here]

    2. "We’re still waiting for the El Niño-related upsurges in the global lower troposphere temperature data. They should be coming soon." ~Bob Tisdale, posted on WUWT an hour or so ago.

      The requisite bellyaching about Karl (2015) is there, as well as trashing GISS for interpolating in contrast to Hadley which doesn't.

      So of course, the model/obs plots use HADCRUT4, which comparison is prefaced by this gem:

      "Alarmists happily ignore the fact that it is easy to have record high global temperatures in the midst of a hiatus or slowdown in global warming, and they have been using the recent record highs to draw attention away from the growing difference between observed global surface temperatures and the IPCC climate model-based projections of them."

      I couldn't make this stuff up.

    3. In order for Bob to maintain his stance about "growing difference", he has excluded the last 2 1/2 years of global mean surface temperature. He does this by presenting the data "smoothed with 61-month filters", which means he cuts out the past 30 months of rising surface temperature.

      Lesson 1,126½ in how to be a science disinformer, featuring Bob Tisdale

  2. To clear up one slightly subtle point that many readers here probably grasp, when Gavin Schmidt tweeted that the "probability of 2015 being a record year is >99.999%" he was referring to the numerical GISTEMP anomaly. The monthly value for December (which is currently running ~0.15°C warmer than October or November) would have to be 1.50°C cooler than those months to tie 2014. That's just not going to happen; not even a one in a million chance of an asteroid impact or surprise supervolcano eruption.

    The other probability calculation is more interesting, namely given the GISTEMP or NOAA yearly anomalies and their associated statistical uncertainties, how likely is it that 2015 is actually warmer than any of the other 1880-date years? I simplify the NOAA's methodology and calculate the cumulative sum of the high tails of the previous years overlapping the low tail of 2015 (all Gaussian distributions with a standard deviation of 0.0285°C, consistent with the NOAA estimate of 0.02-0.03°C for modern years and giving similar results to NASA and NOAA for 1880-2014 years).

    Using reasonable anomaly values for December gives a calculated probability that 2015 will be 98% (NASA) or 99% (NOAA) likely to have been the warmest year on the instrumental record of the past 135 years.

    In a sensible world that would quiet down the denialists, but there's a 95% chance it won't. At least there's a Paris Agreement and eastern North America is currently baking instead of chilling in Arctic outflows. Maybe that will silence Republican deniers running for reelection in 2016; politicians don't mind playing voters for fools but they usually don't like looking like fools themselves.

    1. soyouretellingmetheresachance.jpg

      At the release of the most recent value I took the liberty of finding the relatively obscure packages in R - segmented and strucchange, fwiw - that (I think) Tamino has been using to do slope CPA for previous blog posts and papers. As he has shown extensively already, there is nothing to suggest a significant trend-change across 1970-present. But what I find very amusing is that this part year has been SO warm that the function "segmented" does actually pick out a single breakpoint in a piecewise linear regression for annual GISTEMP surface data from 1970 to present (taking 2015 at present value). That breakpoint is estimated basically at the 2014/2015 juncture. The result is, as I said, not close to statistically significant, but my oh my what a field day we could have if we wanted to be as brazenly dishonest as "skeptics" have been.

    2. Thanks, Magma.

      Deniers will most likely put up two protests. One thing they'll run with is their misrepresentation of the likelihood it's the warmest year. Like they did with 2014, when both NASA and NOAA showed that the chances that 2014 was the hottest year on record was greater than that any other year was the hottest.

      Then they'll try to argue that it's just El Niño. What they won't explain is why this particular El Niño should have resulted in the hottest year, when there have been lots of El Niños in the past that were *not* hotter than 2015. Why this one? It's only because El Niño is on top of the global warming trend.

      Since the early 20th century, almost every successive El Niño and La Niña has been hotter than the one before.

    3. I also tried a similar methodology (random sampling of gaussians with your chosen SD and means of -0.11 and 0, to represent the two most recent climatological years for 2014 and 2015, then differencing of those samples and quantile estimates for the difference distribution), and obtained something like a >99.5% probability that 2015 will be warmer, using NASA's numbers. Of course, that means warmer than 2014. But the outcome of 2010 is the only other one close enough to have a non-negligible (>0.001) impact on that probability, so I'd myself place it closer to 99% probability.

    4. ==> "Deniers will most likely put up two protests. "

      Only two? How about UHI (and airport runways), "Fraudulent adjustments made to deliberately warm the temps," "Climategate," "But, Real Climate moderation," "Al Gore is fat," "But, plate tectonics," "One World Government," "They called me a denier," "McCarthy/Lysenko/Eugenicists," "DDT bans killed tens of millions," "without coal millions of poor children in Africa will starve," etc.?

    5. You're right, Joshua. Most of the WUWT comments are wails about "fudging" the data. How do they know? They read it on their favourite climate conspiracy blog. Utter nutters.

    6. There's also been renewed push for Cosmic Rays floating around the denier blogs:


    7. As so many others have noted, the Denialati's reflexive response is "El Niño!" But if they want to whittle something from the current El Niño global impact they need to go straight back to 1998 and do exactly the same thing to that cherished milestone of theirs, and suddenly they'll find themselves edging toward real analysis and discovering that there's a significant underlying trend... human-caused global warming.

      Truly, anyone who persists in attempting to deny the obvious is a mendacious and/or ignorant sociopath of the highest order.

      The good thing is that the planet's countries have agreed in Paris to do something about it. The bad thing is that there's still a world of wriggle room and vested-interest interference to be run, and no time with which to fiddle. I really hope that the time is imminent when science denialism in the face of objective logic becomes a pariah ideology, just as Nazism (hello Godwin) or sexism has.

    8. Bernard, climate conspiracy theorists don't let contradictory notions (or facts, or evidence) stand in the way of their denial. It's ingrained. (A lot of them aren't aware that sexism and racism are frowned upon in polite society. They can be excused since crude, rude and vulgar deniers are lowlifes who don't inhabit polite society.)

    9. The most useful thing to come out of the COP21 agreement - if it happens - would be the impetus for the big nations to implement a revenue-neutral carbon tax at source. Other countries would surely follow the lead.

      P.S. Getting the "I'm not a robot" tick-box every time now using OpenID. Wahey!

      Hansen is probably rightly skeptical that it won't happen. Hope for humanity's sake it does sooner rather than later though. But the brain-dead Rethuglicans will surely block it in the States, until we vote out those idiots in the pockets of the fossil fuel corporations.

  3. I sense some anomaly creep here, what with the become usual baseline 1951-1980. I thought the Paris try was for +1.5° C to +2° C at most compared to 'pre-industrial'. Even if we creep that to the year 1900, we'd be at +1.3° C or so presently.
    I'm gonna see those plus two years near my pensioning age, less than 20 years.

  4. Years of living in Western countries have inculcated us with the notion that a year must begin on 1 January and end on 31 December. That division of the yearly spin around the Sun is about 2000 years old and doesn't begin to capture the physics of the natural world. For example, the shortest day of the year is about 21 December. The same may be said about dividing the year into months with varying numbers of days. From a scientific point of view, the meteorological year begins about 1 December and ends on 30 November. From this perspective, the weather year 2015 is already in the can, so to speak. There's no need to wait until after 1 January to proclaim 2015 to be a record...

    1. >>the shortest day of the year is about 21 December

      The days are getting longer here :)

    2. More seriously, using GISTemp, the hottest meteorological years were 2010 and 2014, both with an anomaly of 0.73 °C. This past year (Dec - Nov) the anomaly was 0.84 °C. That's the hottest ever on record by 0.11 °C.

      To compare with the El Nino of 1997-98:

      1997 at 0.46 °C was the equal hottest on record with 1995.

      1998 at 0.64 °C was the hottest on record beating the 95 and 97 records by 0.18 °C.

      The question is, what will the second year of this El Nino bring? Will it also be much hotter, like 1998 was?

  5. Holland is building a December whose average minimum temp will come out above the record warmest December (regular, daily average temp) of 1974.
    This winter month will surpass a normal (today's normal) April. It will smash the old record with over two degrees C margin.

  6. "Holland is building a December whose average minimum temp will come out above the record warmest December (regular, daily average temp) of 1974.

    Just stop and think about that, people. Really, think about it.

    "This winter month will surpass a normal (today's normal) April. It will smash the old record with over two degrees C margin."

    Extreme weather records are rarely broken to this degree of difference, quite apart from the increasing frequency at which such records are broken.

    And still humans are unable to grok that they're in a saucepan of boiling water...

    That thing that's coming toward us very fast? It's natural selection, and it really doesn't want to be friends with us.

    On an evolutionary scale we have about two shakes of a lambs tail left during which to pull a species-level Macgyver trick from our hat.

    1. It's hard to fathom. Really. Even if you're inside it and it is actually happening.
      A number of trees won't blossom much coming spring, because they're doing it now.

      "Extreme weather records are rarely broken to this degree of difference.." - this is a crucial and imo hugely underestimate aspect of climate change. Wrt precip numbers even more relevant (some records in e.g. Texas got doubled).

    2. I believe my uncle has said that one of his trees (they live in the middle of Ohio) is blossoming right now. First thing I thought of was how likely it would be for the tree to die this winter from a late frost.

    3. We saw something similar in southern Oz. An unusually mild spell in late winter brought on new season growth on a backyard lemon tree, and a hard frost knocked it back (badly)

  7. Across the pond from holland, Eastern Canada has had a December where the coldest low is the 1980-2000 normal high, and it's staying that way ok month long. No snow within a day's drive of Montreal, except possibly on the highest mountain anywhere nearby (but even that's not for sure).

  8. Well, the denier tactic after their latest faux pause draws to end will be to claim that the increase actually took place over a couple of years only, and global temp was "constant" before and after.. So they then can sum all these eye balled "hiatuses" together to a very long pause..

    It does not matter for them that it is uter nonsense and does not pass any real statistical scrutiny.. Their current "pause" has been pretty similar case anyway, and has been accepted / endorsed by Curry and others who in principle should know that you cannot honestly analyze / describe a physical phenomenon by forgetting all older data and starting only from a point carefully cherry picked for producing flat line.. Utter nonsense..

  9. But why then is this El Niño so much warmer than any other recorded El Niño ?
    That's a bit hard to wiggle out of.

    1. Easy: It is those data cooking world domination seeking conspiratorial climate scientists.. Sold their souls to UN.. You know.. ;)

    2. El Niño criteria bases on temp anomalies.
      SST's get hotter with CC, therefore El Niños get hotter.
      Since 1998 there's been 17 years of additional warming. If you subtract this trend you may find this year's El Niño to be same or a little weaker than 1997-1998.

      It is not only El Niño that is making for record global warmth by the way. The 'Warm Blob' is an anomaly on El Niño conditions. CC itself was good enough to set 2014 #1 before El Niño kicked into this year.

  10. Adelaide swelters and the Australian Bureau of Meterology has no hesitation in acknowledging that it's a sign of global warming:


    1. It's been very warm for December here in Victoria as well. The heat wave in South Australia is heading east. I thought it was hot enough the last few days, but for the next three days it's forecast here to be from 39C to 41C - more typical of later in January and early February (these days).

    2. Well, of course it would. The ABM became part of the vast Agenda 21 global conspiracy years ago.

      To look at all those casually-dressed, modestly-paid apparently harmless and friendly geoscientists meeting in San Francisco this week you'd never guess they were our future ruthless overlords or their lackeys.

      It just goes to show how deep the conspiracy goes.

    3. Magma, magma, magma...that's just what they act like in the public portions. The REAL meetings take place down in the basement where the plots for world domination continue to be planned out in ever more significant detail.

    4. The best part is the barbecueing of kittens and the ritual sexual abuse of wildebeest.

    5. Tomorrow the Dec record for Adelaide should go. It is by then exactly two years old, so that was SOME hiatus...

    6. Meantime, middle of winter, Holland is working on its year average using temps belonging to the middle of May (modern times May).

  11. I wonder how long it will be before the people around me accept that they have to choose between their high carbon slob lifestyles and their children's futures. Or have they already chosen?

    1. I reckon we'd do better to show people that their "high carbon slob" lifestyles aren't really in much danger. Presuming that their slob lifestyle is the middle class style slob rather than the too-poor-to-change-much of their activities or purchases. Anyone with a couple of kids and a few large tvs and computers and appliances all over the place can support all of those things _without_changing_anything just by investing in enough solar panels. I realise that not everyone has the commercial contacts to imitate one of my relatives to instal a whole roof's worth of solar panels at a bargain price. However, they spent about $26000 on that and they used to have quarterly bills exceeding $1000 - not many, they freaked out when they saw the second one, following the first one that they thought was an aberration because they'd moved into a new house. However, ever since then they've had no bills at all and several substantial credits from the FIT. Getting $3000 to $4000 annual return on a $26000 investment is pretty good. The return would be even more if they moderated their behaviour but they don't see the need. I reckon their next big decision will be when they replace a car. They're over 200 kms from Adelaide so an EV might be a problem, but most of their travel is very local short distance stuff, much shorter and quicker than similar travel in the city and suburbs, so a hybrid would be a good option if they chose it.

      Recommending solar hot water, or solar PV or solar PV + rechargeable car shouldn't be too much for most people. No worries if people don't immediately agree with such suggestions.

      Sow seeds everywhere. Some wouldn't work in the best conditions. Others will respond gradually to such suggestions coming from a dozen different people or businesses or relatives. Your contribution might be the first which is dismissed, the first which strikes a now-receptive mind or the last which results in a definite yes - or any one of the many along that path.

      Note: Of course, you may or may not want to mention that, once you have solar PV, your attitude to power use can change. If you have a big enough installation, you start thinking in terms of reducing use, turning things off, as a way to increase your rebate if there's an FIT or to decrease your usage so that your bill is reduced enough to increase your ROI on the cost of panels. We get about $1000 per annum on our initial not quite $5000 outlay. There's no investment to compare. (We did quite well on a cheap offer and a fairly high FIT, but even without such a high return, we'd still be doing pretty well.)

    2. I should run numbers on a few ways to improve my own usage.

      I'm pretty sure the biggest thing would be a heat pump, replacing (or augmenting) resistive heat.

      Solar panels would take me forever to pay off at 45N with decent cloud cover, and I'd be displacing hydro. So I'll leave the panels for ye who still use coal.


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