Bishop Hill Conveying truth 3
Jan 17, 2012 Climate: MetOffice Climate: Surface With nothing of any great import on the newswires today, I'm going to return to the subject of the Met Office's 2010 briefing to central government. The next statement I want address is this one:
Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius and that warming is accelerating.
This is supported by a figure (click for full size):
;)
The original caption reads:
Past, current and future changes in northern hemisphere temperatures relative to 2000.
I think the first part of the statement is supportable (although perhaps with caveats), but is there any evidence to support the second part? Surely the words above grossly misrepresent the temperature history of the last half century? Surely the graph lends no support to the statement made at all? I don't think my saying so is even controversial - some readers may have seen James Annan's recent observation that 'there is little sign of the acceleration in warming that most models had predicted'.
We've all let off steam about the quality of this briefing on the earlier threads, so I'd be grateful if readers could refrain here, and stick to considering how recent temperature history should be described?
Reader Comments (76)
Minor secular variation
A couple of points:
Where is the MWP? Is the earlier part of the graph based on the hockey stick? That bit looks rather odd.
Secondly it looks as if the recent temperatures are not shown on the graph. Perhaps some smoothing is used so that the current years don't show, but that would be unfortunate if we are talking about what is happening now. All in all it's a bit of a puzzle.
I guess it would be acceptable to write something like (sticking to four sentences again):
The graph is misleading in its handling of the past record. The label on the shaded region in the past is "envelope of IPCC analysis of paleo records." The region seems to have been derived from IPCC AR4 Figure 6.10(b), by considering the lowest and highest curves of various Northern Hemisphere reconstructions. First off, they've messed up the time axis; although the curves match, the left end of the IPCC figure corresponds to year 700 while the MO figure labels it as 1000. More importantly, though, the individual curves represent means, and each has an uncertainty associated with the reconstruction at any given year. For example, looking at the MO, one would suspect that we knew the average temperature in the year 1000 fairly exactly (well, a little past 1200 according to the MO labelling), because the reconstructions all happen to intersect (nearly) there. The picture which should have been provided is Figure 6.10(c), which indicates not only the uncertainty associated with the differences between the various reconstruction means, but also the inherent uncertainties due to reconstruction.
The claimed acceleration is the artefact of the false 'back radiation' concept. How these people were dumb enough to consider this breach of the 2nd Law of Thermodynamics possible is a serious indictment of the education they received.
No process engineer can accept they have got it right.. After all, we have to get the calculation of radiation problems right and 'Prevost Exchange energy' is drummed into us as the oldest of the Radiation laws [1791].
No professional physicist should ever have accepted it either, but it is clear some have. As for climate and environmental science courses, it's clear they teach fake physics either through ignorance or as propaganda: this needs rooting out [CRU/UEA first?]
A superposition of tricks, fixes and revealed truths.
0.7C change has no real physical context.
How should recent temperature history be described?
"Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius and that warming is decelerating."
"and that warming is accelerating" - Feb 2010
I wonder why the MO did not use their own 2009 "Decadal prediction" to illustrate the acceleration?
http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/decadal-prediction
Click to enlarge the chart, yellow and blue lines are the MO predictions, the black line is the actual. Which clearly shows the rate of acceleration - nil!
This has now been superseeded by "Decadal forecast" starting in Sept 2011 where there is more info:-
http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/long-range/decadal-fc
Not quite as easy to see the divergence due to the truncation of the relvant "model prediction" period 1985 to 2020. I wonder why it now goes back to 1950 and includes GISS and NCDC data? But it does show a clear acceleration in their forecast/prediction (thick blue line) especially over the first 2 years - Sept 11 to Aug 13, going to be interesting to watch.
"stick to considering how recent temperature history should be described?"
Tinkered, Tailored, Soldout,Sly
My brother is an Instrument Mechanic who has spent a good part of his career calibrating temperature gauges in the real world (Power Stations, Gas Rigs, Oil Rigs.) He laughs when he hears figures like 0.75 on a global temperature-.
So what is the realistic error bar? To me 0.75 it is just false accuracy.
Green Sand, I’ve actually saved a copy of that graph. I can’t believe they’re actually predicting around 0.5c rise over the rest of this decade and back smack bang on the modelled mean by 2015. Interesting is certainly the word.
Jiminy Cricket
I think your brother is being kind. I think he was talking about the instrument error of the typical thermometer, that is of a single thermometer. The errors are far more enormous than 0.75° C when you consider that these "measurements" where taken over a 100 year period, with thousands of different thermometers, which were made by hundreds of manufacturers each with their on standard of 0° and 100° (typically measured by the freezing point and boiling point of water at whatever altitude and barometric pressure may have been in place at the time, with whatever impurities that may have been in said water). And that is just the instrument inaccuracies.
Next we look at the procedural inaccuracies. At what time of day and year were the measurements made? At what altitude, weather conditions and locations relative to heat sources such as cities, industrial plants, etc.
None of this is controlled at all and we are told that they can somehow do this accurately?
Yes, your brother is being kind. The 0.75°C claim is far more than laughable -- it is an outright deception.
Do we know who is respoensible at the Met Offcie for signing off the comtents of briefings to government like this.
Perhaps a politie but public request, to clarify/justify this statement is warranted, and whether or not Met Office/Hadley Centre/Cru scientists would support this briefing to government
Don Pablo, and Jiminy, I think you are being too harsh. I wouldn't like to have to measure a single temperature to within 0.75 degrees (though come to think of it, as a parent of young children, I know that thermometers do reliably distinguish between 36.9 and 37.65 if you use them correctly). But unless there's a very weird pattern to the errors you make on every single measurement carried out at hundreds of places at hundreds of times, then getting some meaningful trends even at levels below 0.75 will be possible. Lets say one place is 15 degrees, and another is 15.8. And you measure the temperature in each 1000 times. There will be measurements reporting 16.5 at the first place, and 14.6 at the second - but there will also be many more 14.8's at the first place, and 15.9's at the second. The uncertainty on each of the averages is much smaller than the uncertainty on a single measurement.
I don't think it is useful for sceptics to doubt every single thing that the consensus claims. The increase over time of the urban heat island effect notwithstanding, I think the first part of the statement - "Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius" is much more likely to be true than false, if you interpret the "about" as meaning +/- 0.2 or 0.3 degrees. It is the second part of the statement which is clearly unsupported.
In addition to the "warming is accelerating" statement, the figure is cited by the briefing in the following bullet point (my emphasis below)
It seems that the presentation of the uncertainty in the past record was chosen to make that point visually; using the actual IPCC uncertainty regions (see above post at 1:42 PM) would have indicated that such is quite possibly the case, but it's plausibly not so.Is this a case of "hide the uncertainty"?
"and that warming is accelerating"
It depends over what period the acceleration is measured. If I look at a more reliable metric, such as UAH (NH, SH, TROPICS or GLOBAL), and cherry-pick a short period such as from the beginning of 2008 to the beginning of 2010, then yes there is an acceleration. But that would be a very deceptive thing to do. Nobody could look at the 30+ years of UAH and say there was an accelerating trend.
I was told by Richard Betts that I shouldn't say the Met Office was lying. But I can't see how else that statement can be interpreted (unless it was a mistake and whoever in the MO was responsible for checking the document also did not notice the mistake. I believe the Met Office does have QC procedures, so I presume it would be thoroughly checked and approved before going to Government).
How about "The rate of warming is not accelerating. This contradicts model projections."
Sorry Philip but I think you are heading into Dowager Duchess mode when you start throwing accusations of lying around. Why not stick to the simple statement that you think they are wrong. You might be mistaken, they might be mistaken, but if you start accusing others of lying then you just marginalise yourself. (And the rest of us, see these sceptics can't carry on a simple discussion without flying off the handle.)
Lets stick to the facts, that's all we need to do.
Accelerating? http://www.c3headlines.com/modern-temperatures-chartsgraphs.html
Unprecedented? http://www.c3headlines.com/temperature-charts-historical-proxies.html
0.75C change in global temp is a human construct.
Don't forget that an object in orbit, in what is commonly known as "free fall", is also constantly accelerating.
Perhaps that's was the sense of the word that they meant?
Well ...
I used to think that 1998 was the warmest year in recent times, now I hear that in the latest HADCRIT4 record 1998 has been overtaken by bnoth 2005 and 2010. This suggests hitherto unacknowledged acceleration of recent years.
mydogsgotnonose Jan 17, 2012 at 1:42 PM
Is there somewhere we could discuss this? (Or maybe point me to where this is explained.) I don't see how thermodynamics comes into it but I want to understand this viewpoint.
Long live Death!
a.n.ditchfield
On the eve of the Spanish Civil War, “Viva la muerte!” was the paradox shouted by fascist thugs who disrupted an appeal for peace at the University of Salamanca. They also chanted “Muera la inteligencia!”, a confession of the state of their minds. In spite of the unsavory origin, the death-wish of Viva la Muerte! has crept in as policy and behavior of Western societies.
Perpetuation of the species is the primordial urge that drives all living beings. Existence is a theme central to religious beliefs that hold that the purpose of adult men and women is to bring to life and rear the next generation. A countervailing force set in the 1970s. The liberalization of Western economies unleashed market forces which encouraged women to work, at a time when contraception and abortion gave them control over their own fertility. Given the erosion of religious values among secularized city dwellers, the average Western couple began to have fewer than 2 children; by 1999 the figure was 1.3. This far from what existed in 1900: buoyed by the Industrial Revolution, populations of European Union countries accounted for 14% of world population even while sending a large flow of immigrants to populate the New World. It is now 6% and trends to 4%. Europeans are bound to extinction by their own hands; fewer mouths to feed, but also fewer hands and brains to produce and breed. The median age of Greeks, Italians and Spaniards is projected to exceed 50 years by 2050 – this means that one in three people in these countries will be 65 years old or older. A tax burden of 75% on the income of adults in working years would then be needed, mainly for entitlements of the elderly. Retirement and subsidized health services will come to an end, be it for lack of people. Greece, Italy and Spain are now at the center of a Eurozone crisis because a Viva la muerte! culture is closing a full circle. Worse lies in store for the Chinese, with their one child per couple policy.
The vilification of mankind saw its beginnings more than two centuries ago, after Benjamin Franklin, resident in England, spoke about the American population growing at a rate of 3% a year. The number captured the mind of a Cambridge student, Thomas Malthus, a divinity student and also a mathematician. With compound interest arithmetic, he reckoned that population would double every 23.5 years; hence population size in successive periods would be proportional to the series: 1;2;4;8,16,32,64,128…. After seven generations, 128 persons would demand the food available for one person; unsustainable, since the land available for food production is fixed. Malthus concluded that universal penury would be the lot of future generations. Nature would restore the balance catastrophically, with famine, war and disease, unless public policy checked the trend to overcrowding. The Malthus book, An Essay on the Principle of Population attracted attention in the first decades of the 19th century, but interest waned when its predictions were discredited. Initially in Europe and North America, the Industrial Revolution brought growing prosperity to sustain an unprecedented population expansion, with healthy and well nourished people. The book underestimated the role of technology in expanding farm productivity and in shipping farm produce.
Contradicted by facts, Malthusian thought remained dormant until the 1960’s. At that time, the huge advances in medical science, the advent of antibiotics and the control of disease with better sanitation, combined to bring about a worldwide drop in mortality rates while birth rates remained the customary ones, needed to offset the early deaths of previous times. The unusual surge in world population growth in the middle of the 20th century ushered in a spate of alarmist books that made Malthusianism fashionable again. Population Bomb, of Paul Erlich, carried predictions of hundreds of million deaths by famine in Asia, and even the rise of mortality rates in America, in the 1980s, as the result of undernourishment. The pessimistic outlook was magnified by predictions of another influential book, Limits to Growth, of which 12 million copies were distributed. Its message is that a limited planet cannot support unlimited growth. It introduced the concept of a fixed stock of non-renewable resources depleted at an alarming rate, in an analogy with Malthus’ concept of limited availability of land.
The pessimists have three assumptions they accept with an act of faith:
• • We are running out of space. The world population is already excessive for a limited planet, and grows at exponential rates, with effects that will be disastrous.
• • We are running out of resources. Non-renewable resources of the planet are being depleted by ever increasing consumption, at a rate that renders further expansion of a global economy unsustainable.
• • We are running out of time, as tipping points are reached making vicious climate change irreversible. The carbon dioxide emitted by human activity brings global warming that will soon render the planet uninhabitable.
Many accept the three assumptions because Prince Charles believes, the Main Stream Media journalists believe, the UN Intergovernmental Panel on Climate Change believes, the scientists believe it is so. The daisy chain of acts of faith is too long to hold. Belief has no place in dealing with measurable physical phenomena. When issues are quantified, the contrast between true and false stands out clearly.
THERE IS PLENTY OF SPACE
Is overpopulation a serious problem? So it may seem to the city dweller of a congested metropolis living under local discomfort, but it is not something that can be generalized for the planet. The sum of U.S. urban areas amounts to 2% of the area of the country, and to 6% in densely populated countries like England or Holland. And there is plenty of green in urban areas. It is arguable that 7 billion people could live a comfortable urban life on 100 thousand square miles, the area of Wyoming, or less than 0.2% of a total terrestrial area of 148 million square kilometers. With about 99.8% of free space, the idea that the planet is overpopulated is an exaggeration. Demographic forecasts are uncertain, but the most accepted ones of the UN foresee stability of the global population to be reached in the 21st century. According to some, the world population will start to decrease at the end of this century; aging population is what emerges as the issue of concern. With so much available space it is untenable that the world population is excessive or has the possibility of becoming so.
RESOURCES ARE ADEQUATE
Although little is known of the content of the crust of the planet, the axiom is that, ultimately, a limited planet will not allow unlimited growth. It can also be counter-argued that, ultimately, that there are no non-renewable natural resources on a planet governed by the Law of Conservation of Mass, stated by Lavoisier in the 18th century. In popular form, it holds that "nothing is created, nothing is lost, everything changes." Human consumption never subtracted one gram from the mass of the planet and, in theory, all material used can be recycled. The feasibility of doing so depends on the availability of low cost energy. When fusion energy becomes operational it will be available in virtually unlimited quantities. The source is deuterium, an isotope of hydrogen found in water in a proportion of 0.03%. A cubic kilometer of seawater contains more energy than would be obtained from combustion of all known oil reserves in the world. Since the oceans contain 1400 million cubic kilometers of water is safe to assume that energy will last longer than the human species. Potable water need not be a limitation, as is sometimes said; innovative nanotube membranes hold the promise of reducing energy costs of desalination to a tenth of current costs, which would make feasible the use of desalinated water for irrigation along the coast continents (750,000 km).
There is no growing shortage of resources signaled by rising prices. Since the mid-19th century, The Economist periodical, has kept consistent records of prices of commodities in real terms; they fell over a century and a half, with technological progress. The decline has been benign. The cost of feeding a human being was eight times higher in 1850 than it is today. Even in 1950, less than half of the world population of 2 billion had a proper diet of more than 2000 calories per day; today, 80% and have it, while the world's population tripled.
No historical precedent backs the notion that human ingenuity is exhausted and that technology will henceforth remain stagnant at current levels. Two centuries ago, this idea led to the pessimistic Malthus prediction about the exhaustion of resources to feed a population thought to grow at exponential rates.
MANMADE GLOBAL WARMING IS UNCERTAIN
A scientific consensus is alleged on climate change issues, but the notion is unfounded. What is fair to say is that there is wide acceptance by European governments of ideas of a faction of climate researchers who believe that there is worrisome global warming, from carbon dioxide generated by human activity. Such researchers have downplayed uncertainties in a field rife with them, ultimately to their discredit.
There is no climate science with forecasting power comparable to that of astronomy and such power may never come into existence. Until recent times, no university offered a B.Sc. degree in climate science. Climate studies rely on a hundred fields such as mathematics, physics, chemistry, geology, botany, zoology, paleontology, fluid mechanics, thermodynamics etc…Climate has a chaotic behavior, in the mathematical sense, and is thus subject to a high degree of uncertainty, which will not be diminished by advances in scientific knowledge.
In fields where science is uncertain, different hypotheses contend to explain relationships of cause and effect. If a hypothesis is hijacked by a commercial interest to support its claims, the debate slides from the academic to the political plane, in which all gimmicks of propaganda and public relations are fair. Debate becomes polarized in two political camps, each with its own agenda. In climate forecasts over a century, one camp appeals to the authority of climate research professionals in support of an anti-industrial policy, admitted as painful but necessary, the other camp claims lack of scientific basis for such a policy, qualified as suicidal. At each pole there are interests that have turned the alleged manmade global warming into a political and a journalistic phenomenon, not a scientific one.
Suspect from the start is the haste with which restrictive measures are promoted to curtail fuel use on the grounds that we are reaching tipping points. There are political circles that use this unverifiable hypothesis in support of a grab for power of bureaucrats, or as a pretext to tax fuels to give governments colossal revenues, or to favor one form of energy generation over others. They put in the dock an Industrial Revolution, which has over the last two centuries redeemed much of humanity from extreme want. However, one quarter of humanity still has no access to electricity and suffers from all the evils arising from it.
It is fair to apply to the matter a maxim of Roman law, In dubio pro reu, which states that where there is doubt, justice should benefit the accused: an Industrial Revolution, propelled by growing and cheaper energy. The stance expresses the rigor of true science, skeptical of unproven links of cause and effect.
There are valid arguments to question the existence of a link between increased manmade carbon dioxide and global warming. Contrary to the expectation raised by computer models, there has been constancy or decline in temperature since 1995, after the temperature rise for the two previous decades that triggered environmental alarm. This shows that there are natural forces shaping the climate, of magnitude greater than the effect of carbon dioxide, whatever its origin. These include cyclical swings in ocean currents and temperatures, sunspot activity and the effect on cosmic rays of the sun's magnetic activity. These natural cycles are still partially understood, and their weight compared to the effect of manmade carbon dioxide is debatable. However, mankind can do nothing for or against natural forces of this magnitude. Sensible public measures are welcome to mitigate effects of climate change, if and when they occur and whatever the cause.
The allegation of misconduct in what became known as Climategate led to questioning the veracity of UN-IPCC studies contributed by professionals clearly wedded to political agendas. The claim of consensus of professionals is wrong. The refrain of propagandists of doom has been: The debate is over; the science is settled. This runs counter to science. In the scientific mind there is no place for Magister dixit, a Byzantine reference to Aristotle as final authority, because the master says so. This argument merits retort with the Royal Society's motto, Nullius in verba, according to which science rejects the word of authority above proof backed by verifiable experimental evidence and logical reasoning.
Lacking support in solid theory and empirical evidence, the mathematical models underpinning the UN-IPCC predictions are speculative thought that reflects assumptions fed into models to support interests of sponsors. These computer simulations provide no rational basis for public policies that inhibit economic activity "to save the planet." And carbon dioxide is not toxic or a pollutant. It is a plant nutrient in the photosynthesis that sustains the food chain of all living beings on the planet.
RECKLESS ALLEGATIONS OF ZEALOTS
In support of the manmade global warming speculation the stories of coming disaster are reported in strident tones, typical of the propaganda of totalitarian regimes that once incited masses duped by demagogues. Their tactics were described by H. L. Mencken:
“The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.”
Anything that happens on earth is quickly attributed to global warming: influenza pandemics; an earthquake in the Himalayas; the volcanic eruption in Iceland; the 2004 tsunami in the Indian Ocean; tribal wars in Africa; heat wave in Paris; plague of snails on the tiny Isle of Wight. In Australia: wildfires, dust storms in the dry season and floods in rainy season. In North America: recent severe winters, the collapse of a bridge in Minnesota, the hurricane season in the Gulf of Mexico; Evo Morales blames Americans for summer floods in Bolivia. Hugo Chaves speculated that capitalism may have killed an advanced civilization on Mars. Fidel Castro says earthquakes are induced by the current US boom in gas production. With friends like these do Green causes need enemies?
THE GREEN POLITICAL AGENDA
In the view of Professor Aaron Wildavsky global warming is the mother of all environmental scares. “Warming (and warming alone), through its primary antidote of withdrawing carbon from production and consumption, is capable of realizing the environmentalist's dream of an egalitarian society based on rejection of economic growth in favor of a smaller population's eating lower on the food chain, consuming a lot less, and sharing a much lower level of resources much more equally.” The fantasy of ageing hippies come true.
The Met Office stated "The Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius and that warming is accelerating."
"And that warming is accelerating." Lets not mince words. THIS PART OF THE MET OFFICE STATEMENT IS A LIE.
Don,
I agree, but I am not allowed to say it because I marginalise myself.
The claim is that the rate of change of the rate of change is increasing. If someone thinks they can measure this in a noisy signal I would say they are not lying. But they probably are bullshitting themselves (and others).
[Bullshit is not lying, though it is related. To lie, you have to know what you say is false. If you do not know whether or not what you are saying is true, you are bullshitting.
Note that the highest quality bullshit comes from those who have convinced themselves of the verity of what they are saying without in fact having firm evidence for its correctness. Tony Blair, I am sure, spoke of the existence of WMD with the utmost sincerity.]
It is hard enough to measure the rate of change of a noisy signal. This is because the frequency spectrum of most physical signals falls off with increasing frequency, whereas the frequency spectrum of white (uncorrelated) noise is flat. Taking the 1st difference of the sequence of noisy signal values, to estimate the rate of change, amplifies the high frequencies in the noise, so the signal-to-noise ratio falls drastically.
Taking a second 1st difference of the differenced sequence, to estimate the rate of change of the rate of change will generally leave any signal completely buried in noise. Unless the initial sequence has an extremely high signal-to-noise ratio and the differencing process is carefully tailored with shaping filters, you must assume that the second difference will be pure noise. Even with ideal conditions of high signal to noise and known frequency spectra to permit optimisation of the shaping filters, you'd need very convincing statistical evidence to place any reliance even on the sign of the second difference.
So someone stating "warming is accelerating" is probably bullshitting. They may well believe it but it is belief based on faith rather than evidence.
I submitted a comment that seems to have evaporated in which I discussed the frequency spectra of 2nd differences and the true nature of bullshit and the relation between the two. But my carefully crafted comment seems to have disappeared who knows where.
I believe that the statement is not a lie (which is a statement known by the utterer to be false) but bullshit which where they are saying something that may or may not be false and which the utterer may well believe (though without evidence) to be true.
On Bullshit
"On the eve of the Spanish Civil War...Perpetuation of the species is the primordial urge that drives all living beings...etc." --a.n.ditchfield
Very interesting, well written, albeit not very concise. Reminds me of Michener's Centennial in some ways. If I had an infinite amount of time, I'd read your fine comment in toto. Sorry.
On Bullshit
I don't think it is off-topic to point out that if every day The Met Office tells me it is NOW sunny/cloudy or wet/dry based purely on what their model says it is (not what you can see out of the window) and they do, then this is just another modelled outcome - should we be surprised??
Jeremy Harvey: "Don Pablo, and Jiminy, I think you are being too harsh."
They aren't being harsh they're using language that would lose them the debate. But let's look at what they're saying. They're telling the government that global tempetratures went up in the past century by 0.75C. If as you point out there were differences between the temperatures the anomaly would remain the same, and it would be a calumny to describe there assertion as a "lie". And you're right to say so. Now I don't know whether they've done anything about it or not in their assessment of the rise in global temperatures, but over the last century the temperature records were taken fro many more temperature stations and during the same period temperature stations were moved and adjusted locally, while huge numbers of weather stations were removed from the tempature records. So to say with any certainty that global temperatures have risen by 0.75C over the last century would require the researches to scrub all the unused weather station data out of the historical record, make adjustments for the adjustments and compare the behavior od moved stations. If they haven't done that and know they haven't then they aren't telling the truth, they're missing vital information from the message they're putting out deliberately. If, on the other hand, (God I should have been a judge!) they didn't know they had to do all this to compare apples with apples, they are incompetent. Personally I'd rather be a liar than incompetent.
"Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius and that warming is beneficial and welcome."
Taking the graph as is, without reference to anything else, it is interesting to see that in recent times the observed temperature record is outside of the IPCC paleo record envelope, by up to about 0.5°C. Something is amiss.
"The warming is accelerating" is, on it's own, totally meaningless. For the past decade and more the trend has been flatlining. If they want to say that temps are accelerating then they need to include more detail as to what they're talking about. They must be talking about the difference in trend during one period, to the trend in another period. Unless they specify which periods they are talking about, it is meaningless, surely. There are any number of trend lines that can be drawn.
On the subject of the accompanying graph, the graph that Green Sand keeps pointing to can't be beaten:
http://www.metoffice.gov.uk/media/image/s/n/decadal-prediction-global-average-temperature-lb.jpg
They have no idea what they're talking about. And unless they can persuade Mt Pinatubo to erupt again soon, they'll be fresh out of excuses.
I agree with Harold W that the envelop of IPCC reconstructions has nothing to do with the estimated uncertainty in this plot. In 1210, the uncertainty shown is <0.1 degC, better than climate scientist report for 1900, when we had thermometers reporting from hundreds of site from around the globe! Anyone with half a brain must realize this can't be right.
Furthermore, von Storch created artificial proxy data using climate models; added various amount of noise to the data, and showed that MBH methodology (and probably the methodology used in other AR4 reconstructions) suppressed (by a factor of 4?) the reconstructed natural variation in the artificial proxy data. Any plot which combines such reconstructed temperatures with observed temperatures exaggerates 20th century change vs reconstructed natural variation by a large factor.
I don't remember whether your book (or the NAS) had much to say about von Storch's contribution. Basically the flat handle of MBH 98 is an artifact of the reconstruction methodology. Mann's recent reconstructions, however, all utilize methodology which is capable of reproducing the dynamic range of artificial proxy data.)
Am I the only one who thinks that that graph looks ridiculous? I am pretty sure that it will look ridiculous in a hundred years time. Are these people seriously expecting us to believe that temps that have spelled out a more or less horizontal wavy line for a thousand years are suddenly going to go rocketing off into the statosphere?
They claim is that the rate of change of the rate of change is
increasingpositive.This graph was designed to meet a political not scientific purpose . therefore you need to consider that when reviewing its details. So in decided how to describe recent temperatures you first need to known why you want to do the process in the first place, for that controls the very words you use not the data .
Perhaps you should use the standards of the esteemed Bob Ward. In an article in the scholarly Guardian last October he said one must rely on "the most up-to-date results of scientific research". I would suggest that there are two distinct variations from this standard in their graph. The first in that the pre-twentieth century proxy data relies on an old study. The 2009 reconstruction of Mann et al (Science 326 (5957), 1256. [DOI: 10.1126/science.1177303].) indicates that the early 11th century experienced temperatures that were distinctly higher than any period until around 1980, and more than 0.5 degrees warmer than in the 17th century.
The second is that the actual data seems to stop at the turn of the twentieth century, prior to the climate model prediction being grafted on. If the actual data was carried on until 2010, one would find a distinct deceleration in the warming trend. Indeed, if the Met Office care to follow the link below, they will find that temperatures have been at a standstill this century. This is only conjecture, as the graph does not make a clear distinction between actual and forecast data. This should be amended at the earliest opportunity. (If the scientists at the Met Office have trouble doing this, I will give free and strictly confidential lessons in Excel, if they contact me through my site.)
I would also pass on a tip. When zooming in on a short period, for which one has more reliable data, it might also be worth referencing a more detailed graph. This will again aid greater clarity, and dispel the concerns of those who are prone to be a tad sceptical in these matters.
http://climateaudit.org/2009/11/27/yet-another-upside-down-mann-out/
http://www.metoffice.gov.uk/hadobs/hadcrut3/
@jeremy and geronimo
People seem to put words in my mouth :-)
What I am actually saying is simple. With an engineering eye, to come up with changes of temperature of less than 1 degree, and to give these to 2 decimal places based on the records is quite frankly b*llocks. :-)
Not very scientific I know, but as an engineer (and after speaking to my Big Hairy Instrument Mechanic Bruv) I can place my own degree of confidence on matters. It was drummed into us at University (combined Mechanical Aeronautical and Production course) not to create false accuracy, and not to forget the likely range of values. Lives are at risk.
I will be generous and give you +-0.5 C degree. Which on the chart above makes the curve little better than useless.
This is very much from the Fred Dibnor school of science ("Eye Lad that's the right size") but do not dismiss it out of hand.
Ps. the child's thermometer was a poor analogy for many reasons, not least because the reading mattered.
Martin A: the 'back radiation' idea is from Arrhenius who argued that thermalisation of IR energy absorbed by GHGs warmed the upper atmosphere and this was an energy source. Thus we have Trenberth and Kiehl's heat transport diagram which shows this 'back radiation' [50% of the absorbed IR energy] hitting the earth's surface and warming it. In turn through iteration this gives the positive feedback.
The oxymoronic 'climate sceantists' argue that this is real because when they point a radiometer upwards, they measure a signal. However, us grizzled process engineers know this is a basic mistake. If you shin up a radio mast for 800 feet at night, and measure Up-Down signal, it falls exponentially to zero, proof that the IR from the Earth's surface obeys the Beer-lambert law as it is 'absorbed'. This experiment has been done recently in Holland.
What is claimed is that a colder object can heat a warmer object: that is forbidden by the 2nd Law unless you provide external energy. This is absolute: no other branch of science makes this claim. The confusion comes because there is a downward signal: it's the bit of the radiated energy that links the IR density of states in the objects within line of sight but can do no thermodynamic work.
This is truly a major howler only supported by the peer review fraud. Arrhenius was wrong, full stop..
All I see in this is the Hockey Stick rides again. They've lost the MWP and the LIA.
"I'd be grateful if readers could refrain here, and stick to considering how recent temperature history should be described?"
There has been a 0.75C rise since (1890?) within a range of uncertainty. During this time there are discrepancies between the paleo records and the instrumental records. The rise has not been monotonic and it is not possible to ascribe it to any single factor with acceptable certainty. Significantly, there has been no rise in the last decade.
We do not have sufficient information to make useful predictions from such a short instrumental record and to do so would be to engage in baseless speculation.
Here goes...
There are many things about this policy guide that constitute DECEPTION. If you choose to call deception a form of lying then I can't disagree.
Look up deception in the dictionary and then tell me if you think omitting uncertainty boundaries, given information that you ought to know through your profession is not complete and claiming that warm and cold periods in the past were local without citing your evidence is not deception and therefore lying.
Martin A perhaps you could adress this issue.?
Jeremy Harvey:
"Don Pablo, and Jiminy, I think you are being too harsh."
What is this, a popularity contest? Consensus? Whose consensus?
It is utter bollocks that temperature measurements taken over 100 years, most of it with thermometers made of glass tubes and mercury by who knows who using who knows what techniques could possibly take measurements that can be compared to one another over that period of time with an accuracy of even a couple degrees, let alone with the precision needed to come up with the preposterous statement of 0.75 C.
Yes, I know about the medical thermometer you use on your kids, which typically have a range of 30° C to 40° C, as that is all that is of interest. However, when you consider thermometers used for weather information, their range has to be much larger -- at least -50° C to +80° C or 130° C. And true, you can find thermometers with that range with the required accuracy today, but 100 years ago? Or even 20 years ago?
And then how do you correlate the temperatures? That was pointed to as well.
No, I do not see that the data is at all valid. And I really don't care what consensus may be out there. I think for myself.
Don Pablo, Jiminy, the bit about the medical thermometer was an aside, and I agree it is pretty much irrelevant. The bit about the error on the mean being lower that the error on an individual measurement was not an aside.
Anyway, on another point, I hadn't paid attention to the figure being a multi-century hockey-stick, contrary to the text which is just about one century. That adds the implicit parenthesis to the statement "Over the last 100 years the Earth has warmed by about 0.75 degrees Celsius (after centuries of stability) and that warming is
accelerating." Silly.
Don Pablo,
If you have a population of thermometers, all accurate +/- 0.5C, you can make a statement such as the average temperature calculated from their readings has increased by 0.75C over 100 years.
However, such a statement isn't worth much unless you also point out that it's a probabalistic statement and give the uncertainty. There will be all sorts of factors apart from the limits of the instruments degrading the confidence, such as differing operator disciplines and the operator guessing because he overslept that morning, the fact that some thermometers aren't regularly calibrated etc.
For instance, if the thermometers were accurate to within +/- 10C you could still make the statement of a 0.75C but it wouldn't be worth much because the confidence bounds would be so broad.
At a first pass, the 0.75C statement gives the impression that we are dealing with thermometers good for +/- 0.05C or better and can have a high level of confidence.
mydogsgotnonose Jan 17, 2012 at 9:24 PM
Thank you. I agree fully with the above (if I did not, I would, justifiably, be certifiable).
But I have not managed to work out how the idea of back radiation contradicts this, since the direction of net heat flow is from hotter (earth's surface) to colder (cooler atmosphere).
[I can easily explain how, given a hot lump of copper and a cool lump of copper, I could build a machine where, though the overall flow of heat would be from hotter to colder, there would be a measurable smaller flow from colder to hotter.]
I'll think about it more and come back with more questions, if I may.
Martin A