The Trenberth article contains so many glaring errors and biased assumptions, it’s hard to know where to start.
First of all, the difference between theory and hypothesis:
The problem is not with dueling hypotheses, it is with dueling theories regarding the processes resulting in observed global warming. One theory states: Observed global warming is the result of human greenhouse gas emissions. Another theory states: Observed global warming is not caused by human greenhouse gas emissions, but is a result of natural geophysical processes.
The statement, “Global warming is the result of human greenhouse gas emissions” is not an hypothesis, it is a proposition, or at best, a simple theory. A theory is an explanation of process based on a body of observation.
Hypotheses, on the other hand, are predictive “if…then” statements used to test a small subset of a theory as an adequate explanation of observations, thus either strengthening or weakening the theory. The results of an individual hypothesis never disprove a theory. A theory can only be weakened and eventually replaced by the accumulation of a body of evidence that contradicts the theories explanation of observations, and the formulation of a new theory that provides a more adequate explanation.
We can test the theory of anthropogenic global warming with the hypothesis: If observed global warming is caused by human greenhouse gas emissions, then we should find a positive correlation between the amount and rate of greenhouse gas production and global average temperature rise. This is weak test of the theory, since, if we find such a positive correlation, we merely confirm the existing theory. No new information is gained. If we fail to find the positive causal correlation, it may be because we just have not looked hard enough yet, or haven’t looked in the right places. The truth is still out there!
The null hypothesis would be stated as: If observed global warming is caused by human greenhouse gas emissions, then we should not find a negative correlation between the amount and rate of greenhouse gas production and global average temperature rise. This is a much stronger test of the hypothesis, since it only takes one instance of negative correlation to negate the hypothesis and weaken the theory as an explanation of observations.
This is the process of Science, the Hypothetico-deductive Method of Theory Confirmation.
Secondly, Trenberth repeatedly fails to make a distinction between Global Warming and Anthropogenic Global Warming. There is no question that the average global surface temperature of the Earth has been increasing steadily over the past 20,000 years or so, else, we would still be skirting glaciers on our daily commute. The question is: What is the contribution of anthropogenic greenhouse gases to this warming, and, what effect will reduction of anthropogenic greenhouse gases have on this on-going global warming, if any?
Since we do not yet fully understand the natural geophysical processes that result in observed climate variations over geologic time periods, it is very difficult, if not impossible, for us to fully understand the contribution to global climate variation resulting from anthropogenic greenhouse gases. Wild predictions of future catastrophic weather events are simply science fiction prognostications with as much scientific validity as a Star Wars movie.
The periodic reports by the IPCC are not scientific documents, they are produced to give policy-makers estimations of the relevant probabilities of various climate scenarios, as an aid in preparation of national and international policies dealing with climate variation. These statements of probability have been inflated by the world press and by politicians anxious to make a name (and fortune) for themselves. Probability has been turned on its head into certainty and is being used by all manner of organizations and individuals to forward their individual agendae. Hyperinflated scare stories of sea level rise, catastrophic flooding, heat waves and droughts have been used to justify continued human growth and development in the face of dwindling natural resources and increasing air, water and soil pollution, all in the name of environmental justice.
At some point, increasing evidence of negative correlations between global average atmospheric CO2 concentrations and global average surface temperature will falsify the null hypothesis and greatly reduce the adequacy of the anthropogenic global warming theory as an explanation of observed global average surface temperature increase. Environmental organizations, politicians and science policy organizations will find they’ve hitched their wagons to a black hole. Their unceasing drum-beat for Anthropogenic Global Warming will ultimately discredit their otherwise worthwhile and necessary programs to reduce human pollution as a result of unrestricted human population and economic growth.
@ur momisugly Mike Haseler says:
January 16, 2011 at 5:04 am
Perhaps you would find this useful. This is a on-line preprint, the full book is available thru Amazon ( where else 🙂 ):
PROBABILITY THEORY:
THE LOGIC OF SCIENCE
by
E. T. Jaynes (deceased )
Wayman Crow Professor of Physics
Washington University
St. Louis, MO 63130, U.S.A.
http://omega.albany.edu:8008/JaynesBook.html
Some are looking at the precession of the earth’s rotational axis and how it results in changes in the earth’s climate. That of course along with the sun and moon would be difficult to tax and a poor reason to turn corn into fuel and drive electric cars.
If you ask me and no one has, it seems instead of predicting global disaster from climate which they can’t prove we should be thankful that we live in a time of relative good weather and take advantage of it. Of course you could not tax good weather to save the planet. Then at some time if and when there is proof of impending climate disaster the problem can be look at with calm deliberation rather than hysterical fanaticism.
By hysterical fanaticism I am referring to politicians who are willing to destroy our economy and way of life based on claims not proven. Don’t get me wrong, research in climate is important and should continue but with the wheat separated from the chaff.
As complex as weather and climate are nailing it to one thing such as CO2 resulting from man and the modern world seems to be a bit too convenient and too easy to tax.
There are other equally relevant null hypothesis in the AGW debate such as “High cosmic rays does not cause increased low cloudiness in the tropics” or “Rising CO2 in the atmosphere is not amplified by positive feedbacks. These null hypothesis are actually currently being tested. Also the statement “There is no question that the average global surface temperature of the Earth has been increasing steadily over the past 20,000 years or so, else, we would still be skirting glaciers on our daily commute.” is rather simplistic. The Greenland ice cores and multiple paleoclimatologic records show a slow, irregular cooling since the Holocene Optimum about 5,000 th 2,500 BC with good evidence that the “Minoan” Warm period”, Roman Warm Period, and Medieval Warm Period were warmer than the present. Some time in the future we may well be skirting glaciers.
Picky, picky, time…..
“agendae” is a “false plural”. “Agenda” is already plural, the plural of “agendum”. There is more information than you really want to know about this at http://en.wiktionary.org/wiki/agendum
I was remote from being a scholar in Latin, but some things stick in my mind.
IanM
Just a thought, but rather than trying to measure our possible contribution to GW in a percentage of CO2 concentration, compared to an unknown natural CO2 concentration, is there a way of estimating the human contribution in terms of waste heat generated, compared to natural heat generators? If all of human society in the last several thousand years could only generate the equivalent heat of say one volcano, then the entire argument would seem to be over. Am I just looking at the problem simplistically?
Peter O’Brien says:
January 16, 2011 at 4:22 am
“One day, in my Internet perambulations, I noticed another ‘hockey stick’ graph. This was one graph that I believed. It showed human population growth, and looked remarkably like the IPCC graphs – indeed you could superimpose it seamlessly. What it showed is that, in 1950, world population was 1.5 billion people. Today, we are nearly 7 billion – more than FOUR times in ONLY SIXTY years.”
========================================================
Peter, I can’t help you with what direct effect our heat generation has on the global temps, but I think its rather transient and insignificant. A better perspective might be, in terms of global population, to understand that if we placed everybody in the world shoulder to shoulder, we’d all fit in the state of Texas with room left over. It is every bit as relevant as graphing CO2 in ppm.
Peter, you’ve ambled across the pertinent graph in the whole CAGW discussion. You can indeed superimpose population graphs with hockeystick temp graphs. This isn’t accidental. From Ehrlich to Mann, the message is the same. Indeed, before Ehrlich, Malthus. And a litany of other characters before and aft. The underlying recurrent theme is that humanity is destructive and evil and harms the rest of the world. That, instead of being part of nature, we are an aberration of nature. Further, the solutions to the humanity difficulty is always destructive and harmful to humanity. It is always to control and regulate the very nature of mankind that is seen as a remedy for these perceived difficulties.
Indeed, a recent speaker inadvertently let the cat out of the bag when he stated, “But there’s another kind of doubt that doesn’t rely on the vagaries of Mother Nature. It is manufactured by man, specifically by a small group of influential libertarians in the U.S. who have led a decades-long ideological fight, first against the communists and then the health community and now environmentalism.”
They are all cut from the same cloth. They all seek the same thing. This is why your graphs are identical.
http://www.edmontonjournal.com/health/Climate+change+deniers+skilfully+fuel+doubt/4114099/story.html
Curiousgeorge says: @ur momisugly Mike Haseler says:
Perhaps you would find this useful. This is a on-line preprint, the full book is available thru Amazon ( where else 🙂 ):
PROBABILITY THEORY:
THE LOGIC OF SCIENCE
Curiousgeorge, thanks, but that’s just a tad too simplistic for the problem I’m looking at. What you’ve got to consider is that there are many ways to derive knowledge or truth. When you have a problem suitable for the scientific method, then clearly the scientific method is to be recommended, but if the problem has more nebulous information and particularly when you need to use your experience as a human, you clearly have to use methodology from other areas such as the social “sciences” and/or politics. Take for example relationships — do you really think an approach of insisting on null hypothesis regarding your spouses new hair is going to “solve” the problem of a marriage?
Where many people make a mistake (and climate “scientists” are notable for this) is to assume that science is ALWAYS the answer.
Now there are subjects like archaeology, economics and perhaps social “sciences” which are close enough to real science to use many of the ideas of science to derive data etc., but are far enough into the more nebulous areas to have to combine the scientific technique with other tools for assessing validity of ideas – and that is my problem, how to meaningful combine the two without do the climate “science” trick of pretending to be science without doing real science.
The problem I highlighted were areas like climate “science” and “experimental” archaeology which make some kind of claim to be “scientific” without fully endorsing the scientific method. All too often what you find is people calling what they do “science” — but when you check (as e.g. Trenberth reversal of the null hypothesis), you find they call what they do “science” but really they pay no head to the accepted methodology.
Perhaps, what we need is to divide climate “science” into different areas: Climate measurement – the scientific measurement of climate; “climate forecasting” – the use of models to forecast climate – and the testing of the validity of models by their ability to forecast, and climate “policy” – which would be a less rigorous subject which allowed people to express their non-scientific views using the standards of politics and other akin subjects and would be an ideal place for people like Trenberth.
The article states:
“The null hypothesis would be stated as: If observed global warming is caused by human greenhouse gas emissions, then we should not find a negative correlation between the amount and rate of greenhouse gas production and global average temperature rise. This is a much stronger test of the hypothesis, since it only takes one instance of negative correlation to negate the hypothesis and weaken the theory as an explanation of observations.”
That is not the null hypothesis. But it could be a theory weakening evidence. It does not even differentiate between coordination and cause. My alarm clock rings every day close to the rise of the sun. There is a correlation that can be found. But the alarm clock is not the cause of the sun rising. There is a huge difference between correlation and causes.
— Mats —
Since one of the hypothesis of AGW is more heat waves, does this mean that the theory has been weakened?
http://cdnsurfacetemps.wordpress.com/2011/01/09/more-heat-waves-expected/
Dramatic Ocean Circulation Changes Caused a Colder Europe in the Past
http://www.sciencedaily.com/releases/2011/01/110114155336.htm
“Dr Thornalley said: “These insights highlight just how dynamic and sensitive ocean circulation can be. Whilst the circulation of the modern ocean is probably much more stable than it was at the end of the last Ice Age, and therefore much less likely to undergo such dramatic changes, it is important that we keep developing our understanding of the climate system and how it responds when given a push.”
I suppose that is the cookie thrown to the Warmists. But the story confirms otherwise.
“… as a result of unrestricted human population and economic growth. ”
Surely you do not mean to say that these things should be restricted.
Excuse me for nit picking but the earth has not “been continuously warming for the last 20,000 years”. We had a very sharp warming ca 12,000 years ago, a sudden cooling (the Younger Dryas) and then a renewed warming to a max. ca 8000 years ago, and then a long cooling trend. COOLING for 8,000 or so years, punctuated with shorter warming/cooling cycles.
If we compare the Holocene with the Eemian (the previous interglacial), we see that the Younger Dryas event blew a hole in what might have been an earlier and higher warming peak. Warming early, and then a long cooling until things tip into the next glacial period.
While I agree over all with the article, there is some confusion regarding the terms “theory” and “hypothesis.”
In general, a theory makes testable predictions, as in the theory of relativity. A hypothesis is a testable conjecture. This article explains the diferences between a law, a theory, a hypothesis and a conjecture.
Also, Mats Bengtsson is right. There is some confusion regarding the null hypothesis. The definition of a null hypothesis is “the statistical hypothesis that states that there are no differences between observed and expected data.”
In another thread, Richard Courtney gave a good example of the null hypothesis, and why it is relevant:
Trenberth’s problem is that the planet’s temperature, the rate of change, trends, etc., are all well within the same parameters that existed throughout the Holocene.
CO2 is like a placebo: some folks truly believe that it makes a difference – but there is no measurable difference compared to the climate prior to the industrial revolution. All the CO2 that has been added amounts to .o1% of the atmosphere. It’s not surprising that there has been no detectable difference with such a minuscule change.
A common thread in the catastrophic AGW crowd is that they ignore the scientific method. Since Trenberth cannot falsify the null hypothesis, he now proposes to replace it with his own alternate hypothesis. But since there can be many alternate hypotheses to the null, Trenberth is simply engaging in scientific charlatanism.
@Peter O’Brien
I have had similar thoughts.
If you just think about the amount of electrical energy delivered every second of every day, a fraction of that goes into doing some form of work, moving something from here to there, shuffling electrons around inside computers etc. But the vast majority ends up as heat. Also consider that the generators themselves are only 50% (or so efficient), and an equal amount of heat is generated there (that’s why they have those huge cooling towers), then thee is the 30% or so “lost” in transmission … lost being a euphemism for turned into heat.
Then we can start thinking about transport. Again, only a tiny proportion of the energy used goes into moving lumps of matter from A to B.
Then there is the biological component. Every human being on the planet consumes food. The processing of the food generates heat. Ever notice how warm a room gets when filled with people and there is no AC?
If someone had access to all the relevant data, I think we would find that heat islands are not just caused by the roads and buildings holding the day’s heat, but by the huge amounts of energy dumped into them by electricity, vehicles and people.
This would only be the case if one were suggesting that the warming over the past century were solely caused by human activity, but no one is suggesting that. The IPCC said most of the warming over the last 50 years is very likely due to human activity. There are of course other drivers of our planet’s climate, and these have been studied at length by climate scientists. They recognize that human activity (greenhouse gas emissions + changes in land use such as deforestation) is one of a number of drivers of temperature, though most climate scientists are of the opinion that human activity is the main driver of the recent warming due to the preponderance of evidence supporting this view.
James Barker
It’s not our direct production of heat that’s the problem, rather it’s our production of heat-trapping greenhouse gases such as CO2 and methane. Through estimates of the ratiative forcings of these compounds we can calculate the warming effect of our emissions.
@ur momisugly Mike Haseler says:
January 16, 2011 at 8:38 am
Mike, in the context of your post, Jaynes book may not be suitable re your area of interest, but I’d hardly call his work simplistic. Are you familiar with his work?
A nice summation of the position apart from the last paragraph which is, in itself, an opinion, not an argument.
Mark Haseler sed :
“- if archaeologists did use the “beyond all reasonable doubt” test of science, then most of history would consist of statements of this or that artefact having been discovered and no concept of how they were actually used less what society looked like.”
I would expect sociologists and anthropologists, not archeologists, to explain such things as what purpose has the red box and iron implements therein that was found in an underground chamber next to an apparently self-propelled chain-driven two-wheeled vehicle.
I expect archeologists to map the locations of the findings and endeavor to place them on an historical timeline, and to associate them with other similar finds. Is that a wrong notion?
I have similar old world views of climate science and climate scientists. They should tell us, in unbiased clarity, what they know, not what they believe, not what their models predict, and let society’s elected representatives work out a response.
John Johnston
You appear to be misunderstanding Phil Jones’s use of the term “statistical significance”.
In my essay “The Art of Controversy” (http://retreadresources.com/blog/?p=670) just posted on 15th I talk about Art Schopenhaur’s 19th century essay call The Art of Controversy. In it he list 38 ways or tricks (his words) to win an argument. We have all seen them before and many were learned in debating and speech perpetration course work. It is the art of sophistry and propaganda. We should not be the least bit surprised when an advocate for any side of any argument uses these techniques almost all going back to the invention of discourse. It is interesting to notice that believers seem not to notice when facts or reality is obfuscated, while nonbelievers pick every subtle point.
The only true test is does the speaker remain true to his philosophical principals? Given the principals underlying the philosophy of science are being decimated, this fellow fails the test.
Interesting post, and it seems readers would do well to keep the these terms in mind:
Conjecture, Hypothesis, Theory, Model:
Conjecture: Simply an educated “guess” about the something. The key word is EDUCATED. It means the person or persons has the background of experience, education, and knowledge to make the conjecture. Many famous conjectures were based on intuition, and turned out to be true.
Example: You CONJECTURE that your two new work associates, Bill and Sue, who are both single and like to ski, will end up dating.
Hypothesis: An explanation of observable events based on measurement and data.
Example: You see Bill & Sue (from the example above) at a bar in a dark corner laughing and having drinks and you make the HYPOTHESIS that they are dating.
Theory: A explanation of a general phenomenon that has been throughly tested through observation, experiement and analysis and is ususally accepted by the majority of experts.
Example: You see Bill & Sue kissing passionately in the parking lot and then she gives him and quick swat on the butt before winking and getting into her car and driving away so you THEORIZE that they are likely dating. You discuss this with other co-workers and they add their similar observations to yours and so the THEORY that Bill and Sue are dating is created. One co-worker had never seen the two of them together in a romantic way and disagrees with your THEORY.
Model: A mathemetical or physical construct that represents the dynamics of some phenomenon or group of phenomenon. Models are based on established prinicipals, laws and observations. Models of non-chaotic systems will tend to be more reliable and accurate than models of chaotic systems, or systems existing on the edge of chaos, such as the climate. Models are constantly being refined with new observations.
Example: One could create a mathmatical MODEL of Bill and Sue’s relationship, giving various values to variables such as attractiveness to each other, common interests, values, etc. and predict the liklihood that they would get together and how their relationship might progress. Similar kinds of MODELS actually exist, and are the basis of such web services such as match.com and eharmony.com.
In general, a CONJECTURE can become a HYPOTHESIS, which can then become a THEORY. MODELS are independent of all of these and can exist at any stage, but tend to come in at the hypothesis stage and develop and change constantly.
Let’s look at the history of the AGW Theory (at least some could argue it is now a theory)
______
1859 – Tyndall first CONJECTURES that changes in GHG’s could bring about climate change.
1896 – Arrhenius CONJECTURES that anthropogenic emissions of CO2 could warm the planet and publishes the first calculation for this effect.
1897 – Chamberlin produces the first MODEL for global carbon exchange
1938 – Callendar, using collected DATA, makes the first HYPOTHESIS that AGW is underway and is being caused by CO2.
1956 – Phillips produces the first computer MODEL of the global atmosphere.
1956 – Plass uses a MODEL to calculate that adding CO2 to the atmosphere will have signficant effects on the radiation balance.
1958 – Keeling makes the first modern direct measurement of CO2 in the atmosphere at 315 ppm and begins making regular readings.
1963 – It is first CONJECTURED that feedback with water vapor could make the climate much more sensitive to CO2 increases.
1965 – Lorentz et. al., first CONJECTURE that the climate, being a chaotic system, could be subject to sudden shifts.
1967 – Manabe and Wetherald make a mathematical MODEL that doubling CO2 would raise world temperatures a couple of degrees.
1969 – Budyko and Sellers present MODELS of catastrophic ice-albedo feedbacks.
1975 – Manabe et. al. produce complex computer MODELS which show a temperature rise of several degrees for doubled CO2.
1979 – US National Academy of Sciences report finds the CONJECTURE that doubling CO2 will bring 1.5-4.5°C global warming to be highly credible.
1981 – Several scientists CONJECTURE that the greenhouse warming “signal” should be visible by about the year 2000.
1985 – Ramanathan and collaborators CONJECTURE that global warming may come twice as fast as expected, from rise of methane and other trace greenhouse gases.
1990 -First IPCC report makes the HYPOTHESIS that the world has been warming from CO2 and future warming seems likely.
1995 -Second IPCC report detects “signature” of human-caused greenhouse effect warming, declares and THEORIZES that serious warming is likely in the coming century.
2001 -Third IPCC report states that anthropogenic global warming, unprecedented since end of last ice age, is “very likely,” and THEORIZES possible severe surprises.
2002 -Studies find surprisingly strong “global dimming,” due to pollution, has retarded arrival of greenhouse warming, but dimming is now decreasing.
2007 -Fourth IPCC report warns that serious effects of warming have become evident; cost of reducing emissions would be far less than the damage they will cause.
2007 – Greenland and Antarctic ice sheets and Arctic Ocean sea-ice cover found to be shrinking faster than expected.
2009 – Many experts warn that global warming is arriving at a faster and more dangerous pace than anticipated just a few years earlier.
2009 – Level of CO2 in the atmosphere reaches 385 ppm.
2009 – End of the warmest decade on record.
2010 – Tied for warmest year on record, and is wettest year on record globally. Atmospheric water vapor continues to rise (a far more potent GH gas) as first conjectured to be a result of increased CO2 in 1963.
It would seem that the AGW conjecture first became a hypothesis in about the 1930’s and probably sometime in the 1990’s made the transition to become a theory. As such, as Trenberth clearly points out, the burden of proof would be on competing theories to explain the body of global climate phenomenon that AGW Theory does. A competing theory or theories would have to at the minimum explain the combined and simultaneous occurances of:
* Declining sea ice (seasonal and decade to decade)
* Increasing ocean heat content
* Increasing atmosphereic temperatures (decade to decade)
* Decreasing stratospheric temperatures (decade to decade)
* Melting permafrost
* Acclerations in the hydrologcial cycle
* Increasing atmospheric water vapor levels
* Increasing ocean acidity
Many competing hypothesis are out there, but they are mostly incomplete, and don’t explain the simultaneous occurance of all these phenomenon as the AGW Theory and related models do. It will be interesting to see if any ever can, and if one should arrise, and be accepted by a large body of qualified scientists then it would become a competing theory to AGW. I won’t be holding my breath on that one.
AGW assumes that increasing CO2 increases temperature and is responsible for the majority of the 20th Century warming.
That assumption fails the observed archeological record.
Anybody want to buy shares in a Lemon scheme?
robertvdl
Throughout human history the earth’s climate has been pretty stable. When temperatures were a lot hotter than they are now, that’s when dinosaurs ruled the earth and the only mammals were small rodents.
You also need to consider the rate at which the planet is warming. A gradual change, as most past climate changes have been, would give us and other species time to adapt to the new conditions, but the current rate of warming is, when compared with previous changes, very rapid, such that if we experience warming of more than a couple of degrees C before the end of this century the major adadptations our societies would have to make, particularly the agricultural sector, would be extremely difficult and would likely result in food shortages in some regions, particularly teh equatorial regions where subsistance farming is common.
For more info see the Skeptical Science page on this and the IPCC’s Working Group 2 report, Impacts, Adaptation and Vulnerability.
R Gates,
You obviously didn’t read this article explaining the differences between Conjecture, Hypothesis, Theory and Law. If you did read it, retaining what you read was like water sliding off a duck’s back.
You replaced “Law” with “Model” [Conjecture, Hypothesis, Theory, Model]. I suppose in your world that makes sense. In the real world, it is nonsense.
Your rambling misrepresentations are simply alarmist spin. A few examples: first, AGW was proposed as one alternate hypothesis to the null hypothesis. Now, you attempt to make it a theory. But AGW cannot make accurate predictions – one of the hallmarks of a theory; for example the Theory of Relativity, which makes numerous accurate predictions.
AGW [and the ridiculous CAGW] cannot be defined as theories. CAGW is nothing more than a failed conjecture, with no empirical, testable evidence to support it. The predictions it made have failed.
Models, upon which your conjectures depend, predicted the tropospheric hot spot as the “fingerprint” of AGW. The models were wrong. They failed to accurately predict.
Next, you mistakenly make the assumptions: “2009 – End of the warmest decade on record.” And: “2010 – Tied for warmest year on record…”
Nonsense.
Finally, it is no surprise that you implicitly agree with Trenberth that his CO2=CAGW conjecture should replace the null hypothesis. Your post shows desperation on Trenberth’s part, and a misuse of scientific terms on your part.
Spin, spin, spin.