Amid all the brouhaha about Ted Cruz’s insistence that the globe isn’t warming, based on his using satellite data for the lower troposphere (not Earth’s surface), insisting that it’s “the best we’ve got” (it isn’t), and ignoring absolutely all the other evidence (which isn’t just powerful, it’s overwhelming), we haven’t paid enough attention to the fact that Cruz, and Monckton, and Christy, and Spencer, and Curry are cherry picking. Not just a little — they are cherry cherry cherry picking.
They all start their “no warming” plots with the giant el Niño in 1997-1998. They pick that time because it shows what they want it to show — which is the textbook definition of cherry-picking.
What does cherry-picking do for you? It enables you to distort the real trend by picking out a trend you like, whether it’s really there or not.
Allow me to demonstrate.
Let’s use the RSS data for TLT (lower-troposphere temperature) — the one Ted Cruz and the rest of the cherry gang like to use. We’ll ignore the fact that it doesn’t agree with balloon–borne thermometers, instead it shows a drift. We’ll ignore the fact that it’s not measuring conditions at Earth’s surface. We’ll ignore the fact that it doesn’t actually measure temperature. We’ll ignore the fact that there are more adjustments to the satellite data than to the surface data. We’ll just take it at face value.
It shows this:
This is the graph Cruz and the cherry gang don’t show, because it includes the entire time span. They’d rather you didn’t see the whole time span — that would interfere with their cherry-picking.
Notice that if you plot a straight line through the entire time span (which I’ve done), last year’s value is dead on the money. That kind of throws a monkey wrench into the idea that it stopped warming. In fact none of the values is outside the two-standard-deviations limits above and below the linear trend line — except 1998. The monster el Niño. Where the cherry gang likes to start.
Here are the residuals from the full linear fit:
If it stopped warming, those residuals can’t be following a flat line. But they sure look like they do. Even so, we should test that idea, to see whether or not we can find evidence that it stopped warming.
So … let’s cherry-pick.
We’ll start with 1998. We’ll fit a straight line to the residuals from the full-time-span straight line fit, to see whether or not the slope isn’t flat — if it stopped warming, the post-1998 slope of residuals can’t be flat, it has to be less than the whole slope. We get this:
The slope is downward! A statistical test shows a t-value of -2.3!! That’s statistically significant at 95% confidence!!! OMG!!!!!!!
But wait … there’s more.
If you allow yourself to cherry-pick, then the “usual” t-value doesn’t follow the same statistics. It can get a lot more extreme, for no reason other than randomness, because there are so many possible choices to start your cherry-pick. But how extreme can it get? Can it get to -2.3?
We can answer that question with a little game called “Monte Carlo.” It’s a workhorse of statistical analysis: you use a random-number generator to create test series with no change, and test to see how much change you can find by allowing yourself to cherry-pick. I insisted that the cherry-pick had to leave at least seven years’ data before and after, and I ran 1,000 of those Monte Carlo simulations to get a good handle on how extreme the t-value can get just from random fluctuation, with no “stopped warming.” I even looked only for extreme downward slopes — after all, that’s what the cherry gang wants.
Here’s how the observed cherry-picked t-value (in red) fits in with the Monte Carlo distribution of cherry-picked t-values:
Rigorous statistics shows clearly, that it’s ridiculously easy to get such extreme values when you allow yourself to cherry-pick. Done right, the statistics does not confirm “stopped warming” at the 95% confidence level. It doesn’t even make the 90% confidence level.
The only reason that Cruz, and Monckton, and Christy, and Spencer, and Curry are able to point at satellite data and say “no warming” is that they cherry-pick.
We should definitely call them what they are. That includes two things: “denier” and “the cherry gang.”
Cherry cherry cherry. LOL!
If you like what you see, feel free to donate at Peaseblossom’s Closet.
And I’ve yet to hear an answer from our assorted deniers, why they would consider the (derived) temperature several thousand meters above us more important than the (measured) temperatures on the ground, where we live.
I’m not kidding – every time I ask that in a forum there’s either crickets or a painstaking effort to evade the question…
Maybe because they are looking for the tropospheric hotspot?
Allen & Sherwood (2008) “Climate models and theoretical expectations have predicted that the upper troposphere should be warming faster than the surface. Surprisingly, direct temperature observations from radiosonde and satellite data have often not shown this expected trend.
Well – if only they would (a) say so and (b) explain how this one aspect could invalidate the complete rest of the evidence. Which is why I presume a simple case of “…la lala la la, I can’t hear you…”
That Sherwood paper actually does find a tropospheric hotspot.
They can’t answer. Steven Goddard banned me from commenting on his blog posts for asking that same question, among others.
welcome to the club
Ted Cruz actually used Steve Goddards (aka Tony Heller) blog graphic in the hearing Heller actually boasts about it on his blog. How embarrassing for a presidential candidate to be using a graphic from a conspiracy blog.
Thanks for the (indirect!) mention Reggie. Most amusing!
I’m (indirectly) returning the favour. Please see:
2015 Really Is “The Warmest Year in Modern Record”!
for more details of my current battle with the forces of darkness, which finds me quoting Tamino at length and Tweeting Senator Cruz at high frequency!
Damn you Jim,I can barely keep up,,, you are everywhere
I noticed that residents of #fake_science left reggie alone at HIS new thread. It has almost three years since #reggie was all the rage with goddard and then we punked heller. This time he is going down and going to be counted out
Reggie learned something today, even the most rabid troll can be trained if you feed them the right BS
The brainwashed are easily controlled if you push the right buttons and have patience.
That’s because denial feels no allegiance to logical consistency. Or, often, logic, period.
One of the answers I have heard, I believe from Cruz, although these memes get passed around like a case of the flu, is that a satellite can see the whole world at once. This is not quite true, since a satellite can’t possibly view more than half the world at any given time, however, we can give them a break here and take a look at more serious issues.
The idea behind their criticism is that one thermometer or another will see only a very small part of the world at any given time, and we have only so many thermometers in the world, so obviously a satellite will have much better coverage than an entire network of thermometers on the ground. Then they will pull out a laundry list of potential issues that may result in a thermometer returning values that aren’t really representative of its region. It may be too close to an air conditioner, over asphalt, in the sun, in a region subject to urban development, etc..
The problem with their criticism, as I see it, is that when we have a large network of thermometers, some of the thermometers will read high due to various issues, others low, but in terms of the the temperature anomaly trend itself, these errors will tend to cancel out. This isn’t the case with a single satellite or series of satellites. If the satellite is reading temperatures a few minutes later in the day each day then this is going to get applied to the whole globe. If the satellite’s orbit is decaying such that it is judging the brightness of objects that are getting closer but the closeness isn’t being taken into account (or in Christy’s case, the error due to closeness is being compounded by a formula meant to correct for it having a sign reversed), then this is going to be reflected throughout the data, not just for one region or another, but globally, with errors being of all the same sign.
With satellites, errors won’t tend to cancel out. Moreover, since historically there have been so few satellites returning the sort of data that is needed to establish a trend in global average temperature at any given time, it will be much more difficult to cross-check the data that is being returned. What they would have people take as the greatest advantage of satellite records over other means of measuring trends in temperature is actually their greatest weakness.
Well – even if we would assume that the data were ‘better’ that doesn’t actually answer why the data in that altitude would be ‘more important’.
As for coverage – I’m always trying to imagine how temperatures in uncovered areas would need to behave in the real world, so that they could really change the story. If there actually was a ‘blob’ of unusually hot or cold air in those uncovered areas that you could not be aware of, because their effects don’t spill out to the covered areas around – then why bother, to take the argument to the extreme…
Climate is the world we live in. We live next to roads, air conditioners, and in urban heat islands. The thermometers measure the world we live in.
Cruz was trained as a lawyer. He sounds like a lawyer defending someone that he knows is guilty. He knows the truth, but he feels bound to defend his clients.
This is not about the truth. It is about a paid professional, doing what he was paid to do. This about his team seeking an advantage, even when they know the facts are against them. They do not care about facts, or ethics.
We either have to move the game to our court, or we have to play by their rules.
They hate the satellites until they love them, only interested in the desired result, not that it is the most wrong, having just the qualities they claim belong to the proven and tested records they reject. Sometimes I think it’s just all about the hate. Not a good way to view the world, so warped. Words fail …
Exactly but does it even rise to the level of Derived when it’s only inferred ?
When I read a thermometer I am not measuring the temperature directly but measuring the height of a column of mercury, then there is the inference that the length varies according to a specific mathematical relationship with temperature. Same sort of principle applies to electronic thermometers, except they may be based on electrical resistance where there is the inference from current, to resistance to temperature. The distinction between what is instrumentally, directly observed and that which is only inferred from data that is interpreted through models (or by “retrieval algorithms) is largely a matter of what you are willing to take for granted.
@Timothy Chase: That muddles the water a bit too much for my taste. The distinction between observed and inferred data for me is, what can and does go wrong when producing that data…
Random, it is a well-known fact that our senses are subject to perceptual illusions involving the contextual nature of color or length perception, for example. Furthermore, there are long chains of inference that lie behind many of our scientific instruments, yet those instruments can be far more precise at measuring many of the things we directly observe than the senses themselves.
Furthermore, satellites can be quite accurate in some areas – when aided by high inference. Using a “method of vanishing partial derivatives”, the Atmospheric InfraRed Sounder aboard the Aqua satellite is able to reliably infer concentration levels of carbon dioxide to within 1.5 ppmv of airborne flask measurements, imaging the variation in concentrations due to sources and atmospheric circulation.
M.T. Chahine, et al. (2008) Satellite remote sounding of mid-tropospheric CO2, Geophysical Research Letters, Vol. 35, L1707,doi:10.1029/2008GL035022.
Olsen, E. T., Chahine, M. T., Chen, L. L., & Pagano, T. S. (2008, April). Retrieval of mid-tropospheric CO2 directly from AIRS measurements. In SPIE Defense and Security Symposium (pp. 696613-696613). International Society for Optics and Photonics..
I believe that in the sciences the division between observation and inference is largely without merit. As your comment suggests, what we should actually be focusing on is the accuracy and reliability of measurements. But these qualities lie along a continuum.
Too late. Spencer and Christy have already convinced me that there won’t be any problems if I just move a kilometer above the surface of the Earth.
Yeah, this whole discussion amazes me. I can look out my back window and see what the temperature is on my Swix ski wax thermometer so I know what wax to use on my XC skis. Can a satellite do that?
Where do satellites live? Where do most of us live? Not even to get into the weeds of he various corrections as Tamino has done. See also Sou’s post at Hotwhopper and the post over at ATTP, among others.
why they would consider the (derived) temperature several thousand meters above us more important than the (measured) temperatures on the ground, where we live.
My snarky line is “who do you know lives in a dirigible?”
Deniers have no answer because they aren’t given one. When a disinformation site gives them an answer, you’ll get one.
Why they would consider the (derived) temperature several thousand meters above us more important than the (measured) temperatures on the ground?
Perhaps they think they’re still in Laputa.
Just to confirm… the labels on the y-axis represent the number of cases falling under each t-value ‘bin’?
I feel like Horatio must have had, or I wish existed, a “Cherry, Cherry” ode to this type of behavior.
Thanks Tamino, educational as usual. My favourite moment of the hearing was when Curry objected to the use of the term ‘denier’, then immediately claimed it was a scandal that “the IPCC establishment science can’t explain the recovery of the Arctic since 2013”! If that ain’t denial, it sure ain’t science…
There’s one thing I don’t get about Christy’s presentation -when he showed his chart of models running hot compared to satellite temperature models, what is he actually comparing there? Is there a troposphere component to GCMs?
Yes, GCMs model the atmosphere and ocean in 3-dimensions. Including the troposphere and typically also including (the lower) stratosphere.
Thanks Victor. Just to be clear:
GCMs match the surface temps pretty well, and also the satellite-derived stratosphere temperature models.
The satellite temperature models for all 11 channels are consilient with the GCMs when we look at their overall trends since their inception, but the TLT and TMT channels are not consilient with GCMs since 1998…?
‘Tis the season to pick cherry
Fa la la la — La La La La.
While there doubtless are vocal deniers stupid enough to believe the propaganda, I’d suggest that the great majority of the politicians and ex-scientists pushing denial are not nearly that stupid. They know full well what they’re doing. The fact that they retain the support of a bit less than half of US republican/tea-party voters – who tend not to see the scientific refutations – shows how weak the deniers’ case is in practice.
Since the surge of web-based and media denial during 2009, it is scientists and activists who have put huge effort into countering it. To my mind this begs a series of questions.
– Apart from a very few fine exceptions, why are Democrat politicians effectively silent on this classic wedge issue ?
– Given the ~8% of US GDP provided by the fossil lobby, with say 67% provided by corporations with no inherent loyalty to fossil fuels but with their global supply chains ever more vulnerable to climate damages, again,apart from a very few fine exceptions, – why are general US corporations with their hugely superior financial, political and media clout effectively silent on the climate threat ?
– Is the upholding of a minority popular denialsm – that is nowhere near large enough to prevent the WH from choosing to launch effective programs of public education, of national decarbonization, of carbon recovery and of global re-orientation – really the primary goal of the organizers of denial ? Or is their role actually more mundane in simply providing the crucial political cover for grossly deficient action by the WH ?
– What exactly is the objective of the diverse, apparently bipartisan, efforts to postpone commensurate efforts for the mitigation of AGW ? Cui bono ?
– Consider; the deniers’ agenda is apparently of keeping a debate on whether or not AGW is happening, but in reality its effect is to undermine and largely silence the crucial debate on what is to be done about it.
– Consider: the many issues ‘neglected’ by the WH – such as for five years actively blocking the EPA from meeting its legal duty to regulate CO2 – remain a highly potent but unused list of denier propagandas showing how the WH ‘knows’ that AGW is a fraud.
– Consider: the Paris Outcome was the expression of “American leadership” on addressing climate destabilization, with its voluntary goal of “Net-zero emissions in the second half of the century.” Being devoid of any definition of valid offsets, or their proportion, or a target date, the goal is ambiguity cubed, and as such is ideal to serve as a central propaganda of the “denial of urgency.”
People surely need to start asking just what issues could be seen by the US establishment as having priority over dealing with the fundamental threat of climate destabilization.
(Clue as to one plausible answer: – what is now threatened that has been the basis of US corporations’ profitability since WW2 ?)
From where I stand the only denial that really matters is the denial of urgency.
What you are ignoring is that politics is the art of the possible, and the first rule of politics is that you have to stay in power to have any hope of maintaining momentum in policy.
Yes, the momentum toward acknowledgement of AGW as “real” has increased in the past 6 years from its nadir in 2009. However, recognition of urgency among the electorate is very limited. Very few voters acknowledge that this is a threat, let alone a top priority. It will not win a politician votes, and it will lose them both votes and money.
Politics is the art of counting–counting votes, counting donors, tallying support. Obama has proven to be quite good at counting. Paris is probably the best deal we could have gotten, precisely because it is voluntary and doesn’t have to go through the senate.
Thanks for your post.
I used the animation below in a discussion on a Dutch website in December, it resembles your first graph. It’s something I picked up from frequently visiting your blog. Thanks for that also.
> “who do you know lives in a dirigible?”
“Who do you get your information from — some guy supported by a gasbag?”
Nah, they’d never get it.
Satellite temperatures are for people with their heads in the clouds.
Gavin Schmidt has weighed in on this topic in the past, in response to this comment:
1. 9 Feb 2012 at 4:18 AM
“Given current indications of only mild La Niña conditions, 2012 will likely be a warmer year than 2011, so again another top 10 year, but not a record breaker – that will have to wait until the next El Niño”.
So, doesn´t this mean that you´ll be worried about the state of understanding, recalling your response to a similar question about trends vs. noise back in 2007?
The questions were:
(1) If 1998 is not exceeded in all global temperature indices by 2013, you’ll be worried about state of understanding
(2) In general, any year’s global temperature that is “on trend” should be exceeded within 5 years (when size of trend exceeds “weather noise”)
(3) Any ten-year period or more with no increasing trend in global average temperature is reason for worry about state of understandings
and you replied:
[Response: 1) yes, 2) probably, I’d need to do some checking, 3) No. There is no iron rule of climate that says that any ten year period must have a positive trend”.
While I´m well aware that temperatures are still rising, you appear to concede in the above statement that it´s now very likely that 1998 will not be beaten by 2013 in all global temperature indices. Does this indicate re your 2007 admission that the trend of warming might be overstated? Just curious.
[Response: Well, since 2010 was warmer than 1998 in GISTEMP, NCDC and in the forthcoming HadCRUT4, I don’t think I need to worry too much. – gavin]
It’s important you point out it’s actually a TRIPLE cherry pick trick they do (or maybe that’s what you meant by cherry cherry cherry ;) Firstly, out of all the evidence they choose the one with the highest statistical fluctuations i.e. surface air temperature, then they cherry pick the temperature data set that shows the least warming and the highest 1998 el-nino peak, i.e. satellite data, AND then finally still have to cherry pick the exact time frame within the data set and Voila!, no warming … lol
Going back to Tamino’s earlier discussion of sea level rise: if RSS were accurate, should we have seen a slowing or stop in sea level rise since 1998? Or is 18 years not enough time given that post-1998 RSS temps are warmer than pre-1998 RSS temps?
I suppose I should check the comments in that old post….
Senator Sheldon Whitehouse used Tamino’s graph in Congress:
Time to Wake Up: Climate Change in Texas
https://www.youtube.com/watch?v=WMdIqTE_YrI (from 8:00)