Although positive feedbacks between sea ice and the Arctic circulation exist, we find that these are small during summer. Instead, circulation variations over the Arctic have been a significant factor in driving sea-ice variability since 1979, and have had a non-trivial contribution to the total surface temperature trend over Greenland and northeastern Canada39 . The potentially large contribution of internal variability to sea-ice loss over the next 40 years reinforces the importance of natural contributions to sea-ice trends over the past several decades. The similarity of high-latitude circulation variability associated with sea-ice loss to the teleconnections with the tropical Pacific suggests a contribution of sea-ice losses from SST trends across the tropical Pacific Ocean. Decadal trends in the hemispheric circulation are an important driver of Arctic climate change, and therefore a significant source of uncertainty in projections of sea ice. Better understanding of these teleconnections and their representation in global models under increasing greenhouse gases may help increase predictability on seasonal to decadal timescales.
As you may already be able to imagine, this paper (PDF as submitted) is already the source of considerable controversy! Firstly let’s take a look at an overview of the paper from the University of Washington, entitled “Rapid decline of Arctic sea ice a combination of climate change and natural variability”:
“The idea that natural or internal variability has contributed substantially to the Arctic sea ice loss is not entirely new,” said second author Axel Schweiger, a University of Washington polar scientist who tracks Arctic sea ice. “This study provides the mechanism, and uses a new approach to illuminate the processes that are responsible for these changes.”
[First author Qinghua] Ding designed a new sea ice model experiment that combines forcing due to climate change with observed weather in recent decades. The model shows that a shift in wind patterns is responsible for about 60 percent of sea ice loss in the Arctic Ocean since 1979. Some of this shift is related to climate change, but the study finds that 30-50 percent of the observed sea ice loss since 1979 is due to natural variations in this large-scale atmospheric pattern.
Now let’s take a look at another overview of the paper, this time from Roz Pidcock at Carbon Brief and entitled “Humans causing up to two-thirds of Arctic summer sea ice loss, study confirms”:
Rising greenhouse gas emissions are responsible for at least half, possibly up to two-thirds, of the drop in summer sea ice in the Arctic since the late 1970s, according to new research. The remaining contribution is the result of natural fluctuations, say the authors.
The paper, published today in Nature Climate Change, confirms previous studies which show how random variations in the climate have acted to enhance ice loss caused by rising CO2.
Importantly, the authors state clearly in the paper that their work does not absolve human activity as a driver of Arctic sea ice loss. A News and Views article that accompanies the paper, by Dr Neil Swart from Environment and Climate Change Canada, adds:
“The results of Ding et al. do not call into question whether human-induced warming has led to Arctic sea-ice decline — a wide range of evidence shows that it has.”
There has already been much debate about the paper on Twitter! Here’s the “scientific” edition:
FILE PHOTO: An undated NASA illustration shows Arctic sea ice at a record low wintertime maximum extent for the second straight year, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA. NASA/Goddard’s Scientific Visualization Studio/C. Starr/Handout via Reuters/File Photo
Natural swings in the Arctic climate have caused up to half the precipitous losses of sea ice around the North Pole in recent decades, with the rest driven by man-made global warming, scientists said on Monday.
The study indicates that an ice-free Arctic Ocean, often feared to be just years away, in one of the starkest signs of man-made global warming, could be delayed if nature swings back to a cooler mode.
Natural variations in the Arctic climate “may be responsible for about 30–50 percent of the overall decline in September sea ice since 1979,” the U.S.-based team of scientists wrote in the journal Nature Climate Change.
David embellished his article with some “humorous” asides such as:
“This is the worst of the worst catastrophes in the world! Oh, it’s crashing … Oh, the humanity! Honest, I can hardly breathe. I’m going to step inside where I cannot see it.”
Please say it ain’t so!!!
“The melt of the Arctic is disrupting the livelihoods of indigenous peoples and damaging wildlife such as polar bears and seals while opening the region to more oil and gas and shipping.”
Eskimos, seals and polar bears!!! Oh My!!! And more oil and gas shipping!!! Aiiieeee!!!!
which some of us took exception to:
David – An Arctic indigenous person of my acquaintance asks me to tell you to “go f(r)@ck yourself”!
What should I reply on your behalf?
No answer has yet been received to that (im)pertinent question!
All this excitement in the Twittosphere and elsewhere leads one to wonder whether Ding, Schweiger et al. saw (or should have seen?) all this coming, and if so what might have been done differently? In any event this story is set to run and run and run and……
38,000 results. We’re number 4. If you repeat the exercise please feel free to experiment with the search phrase(s) you employ. Make sure to only click on the link that leads you back here!
Without being able to pick any obvious holes I feel somewhat uncomfortable with that; the idea that September ice depends just on JJA circulation doesn’t feel at all right. Having decided that, though, they then run a variety of model experiments, for example “nudging” the circulation back to re-analysis, with and without an ocean-ice model underneath. And the result seems to be that it is mostly the circulation forcing the sea ice, rather than the sea ice changes forcing the atmosphere. This kinda-fits the “information flow” meme from way back so I should be prepared to accept that mostly. Having done that they then convince themselves that most of the circulation changes that matter to the ice are not GW forced, and so must be natural variability; and hence the conclusion. If you took all of this at face value then they’d have solved one of the puzzles, that on the whole models show much less ice decline that reality. But of course if the decline is substantially a freak of variation, not forced, that would fit.
The flaw in this overall, without looking at the details, is that it’s hard to see a near-40-year trend and being so much natural variability. That seems to be asking for an awful lot of one-way variation.
Prof. Andrew Shepherd, Director of the Centre for Polar Observation and Modelling at the University of Leeds, said:
“According to this new research, the dramatic decline in Arctic sea ice that we have witnessed over recent decades is primarily due to anthropogenic (man-made) climate warming.
“Although this finding may not come as a surprise, being able to separate this from the effects of natural climate variability is an important step forwards, and paves the way for an improved understanding of what we should expect in future decades.”
Dr Ed Hawkins, Climate research scientist at the University of Reading, said:
“Recent summer Arctic sea ice extents have all been amongst the lowest on record but this is not necessarily all due to warming global temperatures – part of the sea ice decline is also because of changes in the atmospheric circulation.
“It is challenging to determine how much of the change in the circulation is itself due to warming temperatures, but this study suggests that a substantial fraction is due to natural fluctuations.
“Looking ahead, it is still a matter of when, rather than if, the Arctic will become ice-free in summer, but we expect to see periods where the ice melts rapidly and other times where it retreats less fast.”
The Arctic icecap is shrinking – but it’s not all our fault, a major study of the polar region has found. At least half of the disappearance is down to natural processes, and not the fault of man made warming.
Part of the decline in ice cover is due to ‘random’ and ‘chaotic’ natural changes in air currents, researchers said.
The rest has been driven by man-made global warming, scientists said.
The research means that although it is widely feared that the Arctic could soon be free of ice, this could be delayed if nature swings back to a cooler cycle.
Colin Fernandez’ Daily Mail article reproduced at Mark Morano’s “Climate Depot”
Study in journal Nature: HALF of Arctic ice loss driven by natural swings — not ‘global warming’
The five earliest years of data plot near +2 standard deviations. The five most recent full years of data plot near or just outside of -2 standard deviations. Ding et al., 2017 conclude that up to half of the difference is due to the NAO and other natural climate fluctuations.
Astonishingly though, the study makes no mention of the Atlantic Multidecadal Oscillation, which also has a significant effect on Arctic sea ice extent.
Since the late 1970s, the AMO has moved from the coldest point of its cycle to its highest, coinciding with a decline in Arctic sea ice coverage.
Considering that the climate models are already performing poorly as it is, the new finding means that they are actually faring even worse than has been generally realized. And accounting for this strengthens the case for a lukewarming future from greenhouse gas emissions.
Ring up another strike against the climate models, and another reason why basing government policy on their output is a bad idea.
The article itself is of course straight off the GWPF’s porky pie production line, but in the small print at the bottom there is this “Shock News!”:
Finally, we must correct a mistake. In February a scientist involved in the production of the HadCRUT4 global surface temperature data set told us what January’s figure was before its official publication. It turns out they were wrong, and we have corrected the graphs accordingly. Here is HadCRUT4, with its pause and recent El Nino peak.
When the HadCRUT4 data for 2016 was complete the MET Office estimated that 0.2°C was due to the El Nino. So here is that difference.
A scientist involved in the production of the HadCRUT4 global surface temperature data set told us that once again David Whitehouse is mistaken:
The February 2017 PIOMAS Arctic sea ice volume numbers are out. It’s no longer surprising to report that they are the lowest ever for the month of February in records going back to 1979:
Here’s the PIOMAS gridded thickness map for February 28th:
There does seem to be a small patch of slightly thicker ice in the East Siberian Sea off Chaunskaya Bay, but there’s still a much larger area of sub 0.5 meter thick ice in the Laptev and Kara Seas.
The Danish Meteorological Institute’s temperatures for the “Arctic area north of the 80th northern parallel” graph shows somewhat more “normal” readings in February 2017, but still without falling below the ERA40 climatology this year or in 2016:
The graph of cumulative Freezing Degree Days (FDD for short) is still far below all previous years in DMI’s records going back to 1958:
Finally, for the moment at least, here’s the high resolution AMSR2 Arctic sea ice area and extent:
I’m going to have to eat some humble pie, or crow pie as I gather it’s usually referred to across the Atlantic, following my tentative “2017 maximum prediction” a couple of weeks ago. Both area and extent posted new highs for the year yesterday, with area creeping above 13 million square kilometers for the first time this year.
[Edit – March 7th]
Commenter Michael Olsen suggests that “thicker ice being pushed into the Alaskan and Russian parts of the Arctic Ocean”. Here’s some evidence:
The United States’ National Weather Service current sea ice stage of development map for Alaskan waters:
This week’s Canadian Ice Service sea ice stage of development map is expected later today, so for now here’s last week’s:
Especially for Michael, a visual image of all the “thicker ice [that’s been] pushed into the Russian parts of the Arctic Ocean” courtesy of the nice folks at NASA:
NASA Worldview “true-color” image of the Chukchi Sea on March 10th 2017, derived from the MODIS sensor on the Aqua satellite
[Edit – March 12th]
Yet another strong Arctic cyclone has been battering the sea ice in the Arctic Basin. According to Environment Canada this one bottomed out at 971 hPa at 06:00 UTC today.
Has drawn on official sources.. to uncover what is actually happening [in the Arctic]
Have we got news for you Christopher? That’s not how it works in the cryodenialosphere! Mr. Homewood’s article about Mr. Booker’s article about Mr. Homewood’s previous article(s) is littered with factual errors. This is what happens should you be foolish enough to attempt to correct such errors.
Here is what we typed into the comment section of Mr. Homewood’s blog:
Of course if Mr. Booker were to have considered Arctic sea ice volume he might have thought twice about his “there is even more of it today than in February 2006, and it is also significantly thicker.” remark?
In 2017 Antarctic sea ice extent is beating all the records. All flavours of the metric are already below the minimum of all previous years in the satellite record, and it looks like there’s still some more melting left to go. Here’s the NSIDC’s 5 day averaged extent:
It seems highly likely that the 2017 Antarctic sea ice minimum extent has now been reached. Here’s the NSIDC 5 day averaged extent graph:
The minimum extent of 2.106 million square kilometers was reached on March 3rd. Here’s the University of Bremen’s Antarctic sea ice concentration map for March 3rd:
David Rose is mercifully quiet this weekend, but there’s no rest for the wicked! Christopher Booker in the Sunday Telegraph leads a bunch of the usual Alt-facts suspects in a barrage of fake news about our dearly beloved Arctic sea ice. According to Mr. Booker in the “Arctic Myths” section of his column today:
As the fake science of global warming continues to crumble, one scare story the zealots are determined to hold on to at all costs is their claim that ice in the Arctic is dangerously vanishing. Yet again lately we have been treated to a barrage of such headlines as “Hottest Arctic on record triggers massive ice melt”.
The nearest we got to such a headline here at the Great White Con was “Arctic Sea Ice News from AGU” in which article we showed images which said things like:
That’s because last year was the *hottest year on record in the Arctic! Undeterred by mere facts Mr. Booker continues:
But that ever-diligent blogger Paul Homewood has drawn on official sources such as the US National Snow and Ice Data Center to uncover what is actually happening. Under “Arctic Fake News”, on NotALotOfPeopleKnowThat, he posted a graph showing that last week the extent of sea ice was much the same as it has been at this date ever since 2001. Indeed, according to the Danish Meteorological Institute, there is even more of it today than in February 2006, and it is also significantly thicker. Back in 2008 much of the ice was only a metre thick. Today that has risen to two metres, and in some places four.
Mr. Booker appears to be more than somewhat confused, since this is what the DMI Arctic sea ice extent graph he links to reveals:
In addition the DMI thickness maps he refers to aren’t available at any of the places he mentions! Not a lot of people know that he was probably thinking of another recent article by Paul Homewood entitled “Arctic Ice Fake News“, which includes these two DMI thickness maps:
Even without considering other sources of Arctic thickness and/or volume data it is quite clear from the two volume graphs that according to the Danish Meteorological Institue Arctic sea ice volume is significantly lower this year than it was in 2008. If Arctic sea ice extent is greater this year and the volume is lower then the laws of physics (which not even the combined talents of Messrs Homewood and Booker can change) dictate that its average thickness must be LESS this year than in 2008!
Mr Booker blunders on:
The DMI data also show that the Greenland ice sheet, which we are told is melting at horrendous speed, is actually growing this year at a record rate, to a size way above its average for the past 26 years. And the most authoritative record of Northern Hemisphere snow cover shows this year’s ranking as one of the six highest since 1967.
He seems blissfully unaware that the “DMI data” to which he refers is the output of a DMI climate model that attempts to determine the “surface mass balance” of the Greenland ice sheet. He seems to think it’s a measurement of the mass of the Greenland ice sheet, which it isn’t. However this is, courtesy of NASA:
In his bubble of astounding Arctic ignorance Mr. Booker continues:
The Deplorable Climate Science blog, run by US expert Tony Heller, gleefully reproduces a 2007 headline: “Scientists: ‘Arctic is screaming’, global warming may have passed tipping point”. As Heller comments: “The Arctic is indeed screaming at climate scientists – to shut up.”
Now as luck would have it I have been (vainly!) attempting to persuade Mr. Heller “to shut up” on the very article Mr. Booker references! Let’s take a quick look at a couple of highlights shall we?
It seems safe to assume that Mr. Booker wasn’t reading Mr Heller’s blog on or after February 22nd does it not? Otherwise he would surely have had second thoughts about writing such a ludicrous phrase as “there is even more of it today than in February 2006”?
Then of course there’s the burning question of the “Hottest Arctic on record”
You seem to have forgotten about spring Gail? Here’s April:
Here’s the May graph from “the most authoritative record of Northern Hemisphere snow cover” for good measure:
To summarise, Messrs Booker and Homewood could have confined their due diligence on their assorted Arctic articles to reading my comments on Mr. Heller’s blog. Having done so it would quickly have become apparent to them that every single point they made was in actual fact a “fake fact”.
The inevitable conclusion is that they have no interest whatsoever in establishing the actual facts about the Arctic. All they are interested in is propagating “fake news” about the Arctic as far and as wide as possible in pursuit of a common “agenda”. As is David Rose.
It’s far too early to be sure about this yet, but it’s not beyond the bounds of possibility that the 2017 maximum is already in place. Here’s our favourite high resolution extent graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:
The current maximum Arctic sea ice extent for 2017 is 13.49 million square kilometers on February 19th. Here’s Arctic sea ice area for good measure:
The current maximum area for 2017 is 12.88 million square kilometers on February 20th. Here also is the NSIDC’s 5 day averaged extent:
This reveals a current maximum extent for 2017 of 14.302 million square kilometers on February 20th.
[Edit – March 1st]
Here are the high resolution AMSR2 area and extent graphs for the end of February:
With each day that passes the highs of February 19th/20th look more likely to have been this years maximum. Nonetheless past experience suggests it’s still far to soon to be sure about that.
[Edit – March 10th]
Arctic sea ice area and extent are declining again, having reached new heights for the year on March 3rd:
However the 2013/14 winter showed a late surge is still possible.
[Edit – March 18th]
A “late surge” is looking increasingly unlikely. That being the case, here is our provisional long term graph of NSIDC daily Arctic sea ice extent:
Subject to an unanticipated “surge” the 2017 maximum of 14.447 million square kilometers occurred on March 5th.
JAXA extent has dropped steeply over the last couple of days, and it is now once again “lowest for the date since records began”:
The 2017 JAXA maximum of 13.878 million square kilometers occurred on March 6th.
In the continuing absence of updates to Cryosphere Today area, here’s the high resolution Arctic sea ice area graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:
The maximum for that particular metric was 13.03 million square kilometers on March 3rd.
In the wake of the 2015/16 El Niño, recent weeks have seen the denialoblogosphere inundated with assorted attempts to proclaim yet again that there have been “19 years without warming”. In another of his intermittent articles Great White Con guest author Bill the Frog once again proves beyond any shadow of a doubt that all the would be emperors are in actual fact wearing no clothes. Without further preamble:
Ho-hum! So here we go again. The claim has just been made that the UAH data now shows no warming for about 19 years. A couple of recently Tweeted comments on Snow White’s Great White Con blog read as follows…
For the nth time, nearly 19 years with no significant warming. Not at all what was predicted!!
and
Just calculated UAH using jan: R^2 = 0.019 It’s PROVABLE NO DISCERNIBLE TREND. You’re talking complete bollocks!!!
Before one can properly examine this “no warming in 19 years” claim, not only is it necessary to establish the actual dataset upon which the claim is based, but one must also establish the actual period in question. A reasonable starting point within the various UAH datasets would be the Lower Troposphere product (TLT), as most of us do live in the lower troposphere – particularly at the very bottom of the lower troposphere.
However, one also has to consider which version of the TLT product is being considered. The formally released variant is Version 5.6, but Version 6 Beta 5 is the one that self-styled “climate change sceptics” have instantly and uncritically taken to their hearts.
The formally released variant (Ver 5.6) is the one currently used by NOAA’s National Centers for Environmental Information (NCEI) on their Microwave Sounding Unit climate monitoring page. As can be seen from the chart and the partial table (sorted on UAH values), the warmest seven years in the data include each of the four most recent years…
The above chart clearly doesn’t fit the bill for the “no warming in 19 years claim”, so, instead we must look to the Version 6 Beta 5 data. Before doing so, a comparison of the two versions can be quite revealing…
In terms of its impact on trend over the last 19 years or so, an obvious feature of the version change is that it boosts global temperatures in 1998 by just over 0.06° C, whilst lowering current temperatures by just over 0.08° C. Therefore, the net effect is to raise 1998 temperatures by about 0.15° C relative to today’s values. That is why some people refer to a mere 0.02° C difference between 1998 and 2016, whereas, NOAA NCEI shows this as 0.17° C.
(It is not difficult to imagine the hue and cry that would have gone up if one of the other datasets, such as NASA Gistemp, NOAA’s own Global Land & Ocean anomalies or the UK’s HadCRUT, had had a similar adjustment, but in the opposite direction.)
Anyway, it seemed pretty obvious which variant would have been used, so the task was merely to establish the exact start point. It transpires that if one ignores all the data before January 1998, and then superimposes a linear trend line, one does indeed get an R² value of ~ 0.019, as mentioned in one of the Tweets above. (The meaning of an R² value, as well as its use and misuse, will be discussed later in this piece.) In the interim, here is the chart…
Those with some skill in dealing with such charts will recognise the gradient in the equation of the linear trend line,
Y = 0.0004X + 0.1119
As the data series is in terms of monthly anomalies, this value needs to be multiplied by 120 in order to convert it to the more familiar decadal trend form of +0.048° C/decade. Whilst this is certainly less than the trend using the full set of data, namely +0.123° C/decade, it is most assuredly non-zero.
The full dataset (shown below) gives a far more complete picture, as well as demonstrating just how egregious the selection of the start point had been. Additionally, this also highlights just how much of an outlier the 1998 spike represents. Compare the size of the upward 1998 spike with the less impressive downward excursion shown around 1991/92. This downward excursion was caused by the spectacular Mt Pinatubo eruption(s) in June 1991. The Pinatubo eruption(s) did indeed have a temporary effect upon the planet’s energy imbalance, owing, in no small measure, to the increase in planetary albedo caused by the ~ 20 million tons of sulphur dioxide blasted into the stratosphere. On the other hand, the 1997/98 El Nino was more of an energy-redistribution between the ocean and the atmosphere. (The distinction between these types of event is sadly lost on some.)
The approach whereby inconvenient chunks of a dataset are conveniently ignored is a cherry-picking technique known as “end point selection”. It can also be used to actually identify those areas of the data which are most in line with the “climate change is a hoax” narrative. Once again, it is extremely easy to identify such regions of the data. A simple technique is to calculate the trend from every single starting date up until the present, and to then only focus on those which match the narrative. Doing this for the above dataset gives the following chart…
It can clearly be seen that the trend value becomes increasingly stable (at ~ +0.12° C/decade) as one utilises more and more of the available data. The trend also clearly reaches a low point – albeit briefly – at 1998. This is entirely due to the impact that the massive 1997/98 El Nino had on global temperatures – in particular on satellite derived temperatures.
The observant reader will have undoubtedly noticed that the above chart ends at ~ 2006. The reason is simply because trend measurements become increasingly unstable as the length of the measurement period shortens. Not only do “short” trend values become extreme and meaningless, they also serve to compress the scale in areas of genuine interest. To demonstrate, here is the remainder of the data. Note the difference in the scale of the Y-axis…
Now, what about this thing referred to as the R² value? It is also known as the Coefficient of Determination, and can be a trap for the unwary. First of all, what does it actually mean? One description reads as follows…
It is a statistic used in the context of statistical models whose main purpose is either the prediction of future outcomes or the testing of hypotheses, on the basis of other related information. It provides a measure of how well observed outcomes are replicated by the model, based on the proportion of total variation of outcomes explained by the model.
Unfortunately, the coefficient of determination r² and the correlation coefficient r have to be the most often misused and misunderstood measures in the field of statistics.
…
The coefficient of determination r² and the correlation coefficient r quantify the strength of a linear relationship. It is possible that r² = 0% and r = 0, suggesting there is no linear relation between x and y, and yet a perfect curved (or “curvilinear” relationship) exists.
Here is an example of what that means. Consider a data series in which the dependent variable is comprised of two distinct signals. The first of these is a pure Sine-wave and the second is a slowly rising perfectly linear function.
The formula I used to create such a beast was simply… Y = SinX + 0.00005X (where x is simply angular degrees)
The chart, with its accompanying R² value, is shown below, and, coincidentally, does indeed bear quite a striking resemblance to the Keeling Curve…
The function displayed is 100% predictable in its nature, and therefore it would be easy to project this further along the X-axis with 100% certainty of the prediction. If one were to select ANY point on the curve, moving one complete cycle to the right would result in the Y-value incrementing by EXACTLY +0.018 (360 degrees x 0.00005 = 0.018 per cycle). A similar single-cycle displacement to the left would result in a -0.018 change in the Y-value. In other words, the pattern is entirely deterministic. Despite this, the R² value is only 0.0139 – considerably less than the value of 0.0196 derived from the UAH data.
(NB There is a subtlety in the gradient which might require explanation. Although the generating formula clearly adds 0.00005 for each degree, the graph shows this as 0.00004 – or, more accurately as 0.000038. The reason is because the Sine function itself introduces a slight negative bias. Even after 21 full cycles, this bias is still -0.000012. Intuitively, one can visualise this as being due to the fact that the Sine function is positive over the 0 – 180 degree range, but then goes negative for the second half of each cycle. As the number of complete cycles rises, this bias tends towards zero. However, when one is working with such functions in earnest, this “seasonal” bias would have to be removed.)
Summing this up, trying to fit a linear trend to the simple (sine + ramp) function is certain to produce an extremely low R² value, as, except for the two crossover points each cycle, the difference between the actual value and the trend leaves large unaccounted-for residuals. To be in any way surprised by such an outcome is roughly akin to being surprised that London has more daylight hours in June than it does in December.
So what is the paradox with the low R² value for the UAH data? There isn’t one. Just as it would be daft to expect a linear trend line to map onto the future outcomes on the simple (sine + ramp) graph above, it would be equally daft to expect a linear trend line to be in any way an accurate predictor for the UAH monthly anomalies over the months and years to come.
Nevertheless, even although a linear trend produces such a low R² value when applied to the (sine + ramp), how does it fare as regards calculating the actual trend? Once the “seasonal” bias introduced by the presence of the sine function is removed, the calculated trend is EXACTLY equal to the actual trend embedded in the generating function.
Anyway, even if the period from January 1998 until January 2017 did indeed comprise the entirety of the available data, why would anyone try to use a linear trend line? If someone genuinely believed that the mere fact of a relatively higher R² value provided a better predictor, then surely that person might play around with some of the other types of trend line instantly available to anyone with Excel? (Indeed, any application possessing even rudimentary charting features would be suitable.) For example, a far better fit to the data is obtained by using a 5th order polynomial trend line, as shown below…
Although this is something of a “curve fitting” exercise, it seems difficult to argue with the case that this polynomial trend line looks a far better “fit” to the data than the simplistic linear trend. So, when someone strenuously claims that a linear trend line applied to a noisy dataset producing an R² value of 0.0196 means there had been no warming, then there are some questions which need to be asked and adequately answered:
Does that person genuinely not know what they’re talking about, or is their intention to deliberately mislead? (NB It should be obvious that these two options are not mutually exclusive, and therefore both could apply.)
Given that measurements of surface temperature, oceanic heat content, sea level rise, glacial mass balance, ice-sheet mass balance, sea ice coverage and multiple studies from the field of phenology all confirm global warming, why, one wonders, would somebody concentrate on an egregiously selected subset of a single carefully selected variant of a single carefully selected dataset?
Our regular reader(s) will be all too familiar with the 2015 and 2016 editions of our annual Great White Con “New Einstein” Award. The jury has now finished its deliberations on the 2016 award in a smoke filled igloo just outside the Great White Con Ivory Towers, not far from Santa’s swimming pool. I am pleased to be able to announce that the first prize of the loan of a polar bear suit kindly donated by the Daily Telegraph plus a battered big board from Cotty’s quiver has been awarded to none other than Ben Pile (AKA @clim8resistance) with this extremely witty remark way back when in March 2016:
Here are the initial entrants for the 2017 competition:
1) Mike Haseler, whose Twitter profile tells us that his heart’s greatest desire is a “Scotland free from the EU”. We’ll forgive Mike his minor typo and give him lots of credit for his imaginative use of a cryptic computer programming language to impart a similar message to Ben Pile’s award winning entry last year:
Go forth and multiple or is that Forth> : go multiple And ;
— Mike MPE (Planetary Engineer) #Endlockup #NoMuzzle (@scotpolitik) February 17, 2017
2) AndyG55, who is another expert emitter of ad homs in a long line of such creatures on the blog of Tony Heller (AKA “Steve Goddard”).
Over at “Steve’s” recently renamed “Deplorable Climate Science” blog I had the temerity to point out that the deplorable emperor was somewhat scantily clad, having claimed “Over the past nine years, there has been a huge increase in the area of thick Arctic sea ice”:
Balderdash Tony!
Need I say more?
To which Andy wittily responded:
2017 extent above 2016 for this day.
Need I say more.!
You are starting to look even more STUPID and IGNORANT than usual Jimbo.
Off you trot and get some info on long term Arctic sea ice history from your Exeter bum-chums.
Or are you going to continue to be CLIMATE CHANGE DENIER #1.
3) Gator69, who is another denizen of “Deplorable Climate Science” and a regular entrant in our “New Einstein” contests. In response to my PIOMAS post above, Gator fired back with a by now familiar theme:
Starvation Jim! How many times must I rub your nose in your genocide before you get it?
Please feel free to provide feedback to our 2017 jury in the space provided below.
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