The simplest explanation is usually the correct explanation
Guest essay by Eric Worrall
Professor Keven Trenberth once campaigned for the scientific world to accept the alarmist view of climate change as the “null hypothesis”, the baseline theory against which all other theories must be measured.
http://wattsupwiththat.com/2011/11/03/trenberth-null-and-void/
The reason Trenberth faced an uphill battle to have his view accepted, and ultimately failed, is that the simplest explanation of contemporary climate change does not involve Anthropogenic CO2.
As Professor Phil Jones of the CRU once admitted in an interview with the BBC, the instrumental record contains periods of warming which are statistically indistinguishable from the 1990s warming – periods of warming which cannot have been driven by anthropogenic CO2, because they occurred before humans had made a significant changes to global CO2 levels.
Between 1860 and 1880, the world warmed for 21 years, at a similar rate to the 24 year period of warming which occurred between 1975 and 1998. There was simply not enough anthropogenic CO2 in the atmosphere to have driven the 1860s warming, so it must have been driven by natural variation.
So how does Occam’s Razor apply to this observation?
According to the definition in Wikipedia, the principle of Occam’s Razor states “that among competing hypotheses, the one with the fewest assumptions should be selected. Other, more complicated solutions may ultimately prove correct, but—in the absence of certainty—the fewer assumptions that are made, the better.”
From Wikipedia, the reason why Occam’s razor is important:
“To understand why, consider that, for each accepted explanation of a phenomenon, there is always an infinite number of possible, more complex, and ultimately incorrect alternatives. This is so because one can always burden failing explanations with ad hoc hypothesis. Ad hoc hypotheses are justifications that prevent theories from being falsified. Even other empirical criteria like consilience can never truly eliminate such explanations as competition. Each true explanation, then, may have had many alternatives that were simpler and false, but also an infinite number of alternatives that were more complex and false. However, if an alternate ad hoc hypothesis were indeed justifiable, its implicit conclusions would be empirically verifiable. On a commonly accepted repeatability principle, these alternate theories have never been observed and continue to not be observed. In addition, we do not say an explanation is true if it has not withstood this principle.
Put another way, any new, and even more complex theory can still possibly be true. For example: If an individual makes supernatural claims that Leprechauns were responsible for breaking a vase, the simpler explanation would be that he is mistaken, but ongoing ad hoc justifications (e.g. “And, that’s not me on film, they tampered with that too”) successfully prevent outright falsification. This endless supply of elaborate competing explanations, called saving hypotheses, cannot be ruled out—but by using Occam’s Razor.”
Source: http://en.wikipedia.org/wiki/Occam’s_razor
In other words, if we reject the principle of Occam’s Razor, we open the door to accepting theories of arbitrary, ultimately infinite complexity. A theory created by researchers who do not accept the principle of Occam’s Razor cannot be falsified, because the theory can always be tweaked in arbitrary ways to avoid falsification.
So why does applying the principle of Occam’s Razor force us to reject the theory that anthropogenic CO2 is the main driver of contemporary climate change? The reason is that nature has produced periods of warming similar to the recent warming, without any significant contribution from Anthropogenic CO2.
So we have two competing hypothesis for what is driving contemporary climate change:-
1. Observed natural variation, which has produced periods of warming statistically indistinguishable from the warming which ended in 1998.
2. Observed natural variation + an unproven assumption that Anthropogenic CO2 is now the main driver of Climate Change.
Clearly the second hypothesis fails the test of Occam’s Razor. In the absence of compelling evidence that anthropogenic CO2 has overridden natural variation, we have to accept hypothesis 1 – that observed climate change is the result of natural variation.
The climate is not hotter than it was in the past, periods such as the Holocene Optimum, or looking further back, the Eemian Interglacial. The warming which ended in 1998 was not faster, or of significantly longer duration, than similar natural warmings which occurred in the recent past.
Nothing about the current climate is outside the bounds of climatic conditions which could reasonably be produced by natural variation – therefore, according to the rules of science, we have to reject hypothesis which unnecessarily embrace additional unproven assumptions, unless or until such assumptions can be tested and verified, in a way which falsifies the theory that natural variation is still in the driver’s seat.
“bushbunny says:
March 23, 2014 at 1:17 am”
Indeed, YAD061.
“Eric Worrall says:
March 23, 2014 at 12:15 am
climateace
Where is your evidence that we are seeing anything other than natural variation?”
Climateace (LOL) beleives what the BoM and CSIRO models tell “him”. “He”, as clearly demonstrated over the last several months, has no grasp on reality.
“bushbunny says:
March 23, 2014 at 1:17 am”
I have read several post by you recently about DNA and genetics etc, I agree. And also, you appear to be very learned in that space. Is that due to your African experience?
rgbatduke: “CO_2 increase should produce a locally linear (globally logarithmic) response in terms of average temperature from some very simple physics.”
Presumably a great number of people who refer to a “logarithmic” response of temperature to concentration know what they mean, but maybe I have company in not knowing what the meaning is. Specifically, if the concentration approached zero, a logarithmic relationship would suggest implausible cold.
Perhaps someone give a rough derivation of that logarithmic relationship?
bushbunny says:
March 22, 2014 at 9:48 pm
“Just remember 75% of our air we breathe is nitrogen, 21% Oxygen, 3 % CO2, and 1% is trace gases.”
bushbunny, I can’t believe you believe that!!
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
3% co2 would suffocate you.
bushbunny says:
March 22, 2014 at 9:48 pm
“Just remember 75% of our air we breathe is nitrogen, 21% Oxygen, 3 % CO2, and 1% is trace gases.”
bushbunny, I can’t believe you believe that!!
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
3% co2 would suffocate you.
“tom says:
March 23, 2014 at 4:09 am
3% co2 would suffocate you.”
Given CO2 is heavier than usual air, anything that can displace O2, or lighter than CO2, will result in same. So what is your point?
Patrick says:
March 23, 2014 at 4:12 am
So what is your point?
My point was to enlighten bushbunny to her error.
I used to work in dry ice distribution so I appreciate the fact that c02 so heavy. It made it possible to slice hundreds of blocks of dry ice on a bandsaw and to shovel thousands of pounds of pellets from 3000 lb. containers to 300 lb. containers.
Since the Holocene Optimum the earth’s climate has been on a slow glide path down to the next Ice Age. Each warming peak has been lower and the world has benefited from its slight thaw from the recent little ice age. Our sun was its most active in the past 8000 years during cycles 21-23 and it warmed and now is cycle 24 it is its least active in 170 years and it has cooled sine 2002. I do fear the coming cycle 25’s potential crop failures. Solar variations of solar wind, UV and Cosmic Rays cloud formation variation by Forbush effect are my favorite suspects.
I agree entirely with Worrall’s piece. For a simple, transparent forecast of the timing and amount of the coming cooling based on the obvious 60 and 1000 year quasi- periodicities in the temperature data and the use of the neutron count as the best proxy for trends in solar “activity”
see several posts at
http://climatesense-norpag.blogspot.com
The abandonment of the Ockham’s Razor principle is the fundamental error which vitiates and invalidates establishment climate science.
The near identical temperature rises for the periods 1910 – 1940 and 1976 – 1998 are interesting in that they allow us to reference the loadings on the planet from what are apparently two completely different sources.
I understand that most if not all opinion / science is quite happy to ascribe the 1910 – 1940 warming to natural causes, this being the case, if the 1976 – 1998 rise is ascribed to human CO2 pollution we must consider carefully what we are actually saying.
When we say that CO2 caused the warming of the second half of the 20th century we are saying that the output of our global society (co2) resulting from the uncoordinated and unforeseen day to day activities of 5 to 7,000,000,000 people on earth, their various inventions, the computer, the jet aeroplane, the car, types of heating and cooling systems in their buildings, the economic up turns and down turns, the wars, the collapse or rise whole nations ( Russia – China – India) all resulted in a CO2 output (Forcing factor) that exactly or near as damn it exactly matched the natural forcing factor that resulted in the 1910 – 1940 temperature rise !!!!!!!.
Personally I would find it easier to believe in miracles than to believe that we exactly matched the forcing factors in the 1976 – 1998 heating period to that which drove the 1910 – 1940 heating period. ( heat in = temp signal out.)
If someone could explain how this was achieved and /or what guiding hand controlled the late 20th century events to bring about this immensely impressive control process I would be forever grateful.
At present I am more inclined to believe that the ultimate answer really is 42
K.I.S.S.!
This thread is a fun read, except for the usual sprinkling of insults, which are tiresome.
However, real data observations tend to trump theory, however well-established.
For anyone who thinks he/she understands the science under discussion, even a little bit, please ponder the following, excerpted from an earlier post:
http://wattsupwiththat.com/2014/03/06/more-reax-to-lewis-and-crok-what-the-ipcc-knew-but-didnt-tell-us/#comment-1584866
Excerpt:
Unsurprisingly, there has been a lot of recent scientific research aimed at gaining a better understanding of what the climate sensitivity [ECS] may be. We have detailed much of this research in our ongoing series of articles highlighting new findings on the topic. Collectively, the new research indicates an ECS value a bit below 2°C.
My comment:
“A bit below 2°C” is still much too high.
If [incremental] ECS exists at all, it is below 1°C and probably below 0.2°C.
And [incremental] ECS may not exist at all in the practical sense, since atmospheric CO2 LAGS temperature at all measured time scales, and the future cannot cause the past.
Alternatively, as Richard Courtney said some years ago, “Show me your time machine.”
Regards to all, Allan
“which was clearly caused by Anthropogenic CO2 seeing that natural influences during that period had a cooling effect!” This makes about as much sense as saying, “because a twig was broken it was clearly caused by a bigfoot”.
Satellites measure more radiation entering the globe than leaving it.
Citations, please? While I agree that satellites measure TOA spectra locally with great accuracy, and that satellites with specialized IR sensors measure e.g. tropospheric temperatures, it is my understanding that we have neither the coverage nor the precision to measure a global radiation imbalance. If you have specific papers that assert otherwise, I’d very much like to read them.
I believe you mean that GCMs predict that more radiation is entering the globe than leaving it.
As for the rest of your list, I agree with quite a lot of it, but:
* Global warming has been going on since the Little Ice Age, which was approximately the coldest single stretch of the Holocene in over 9000 years, all the way back to the end of the Younger Dryas.
* We do not know why the Medieval Warm Period (comparable in warmth to today within the precision of the temperature estimates) occurred or ended. We do not know why the LIA began or ended. We do know why the Earth’s temperature erratically recovered over roughly two and a half centuries. What we do know is that the thermal pattern of recovery did not change character from the first half of the 20th century, when anthropogenic CO_2 was clearly irrelevant, to the second half, when it is clearly relevant. In other words, the natural variation of the climate is clearly capable of explaining 100% of our climate observations without the inclusion of CO_2 at all.
* Our understanding of CO_2 forcing in a dynamical nonlinear system is unbelievably poor. Our implementation of “micro”scopic computational solutions to the coupled Navier-Stokes system that is the climate sucks — it is difficult to list all of its — really their, as there are many GCMs — inadequacies. As a consequence there is quite a long list of places where the GCMs are failing to predict the actual climate. The statistical treatment of the GCM results in selling catastrophe in the ARs is shameful and inexcusable. The deviation of the GCMs from the actual climate has gotten so large that the entire Box 9.2 in AR5 is apologia for “The Hiatus” — the simple fact that the climate system deviated from the simple exponential growth rate of temperature all of the climate models agree on almost from the minute that they were released, that the climate models fail to reproduce any of the climate record outside of the reference interval (training set) used to “validate” them, that individually the most of the climate models would fail a simple hypothesis test based on their perturbed parameter ensemble results and yet are still included in the indefensible and statistically meaningless MultiModel Ensemble mean that is used to convince both politicians and the public that there is an emergency that is worth spending trillions of dollars and tens or hundreds of millions of human lives to solve.
Because make no mistake about this — every dollar diverted towards studying, measuring, computing the climate comes from money that could be spent studying, measuring, or computing other things with a higher marginal rate of return on the investment. Every dollar spent treating CO_2 as a “pollutant” that is forcing the Earth towards an inevitable catastrophe comes at the expense of other ways to spend that dollar that might (just for example) feed the hungry, heal the sick, build energy wealth in developing countries, develop global education, bring about world peace, or just simply stay in our pockets to make us wealthier and more comfortable and more secure in our quotidian existences. Every year several million people die because of energy poverty, perhaps 3/4 of them children. If we diverted one tenth of what is being wasted every year demonizing Carbon Dioxide without sufficient evidence that it is, in fact, a demon, we could easily cut that number by 90% or more. If we diverted another tenth to curing global poverty (I’m talking ten billion dollar ANNUAL chunks here — serious money) we would be making huge inroads there as well. In a decade we could reshape the entire global economy in positive ways.
So sadly, I have to reject your statement that the onus of proof is on skeptics to show that CO_2 is harmless. The null hypothesis here is that CO_2, an essential part of the biological cycle of life, is harmless. At this precise moment, there is almost no actual data that by itself suggest otherwise. All there is is failing general circulation models that were built and tuned by people that already were convinced of the conclusion they were supposed to test and predict, initialized across the single 15 year interval in the latter half of the 20th century when significant warming occurred, that utterly fail to hindcast the late 19th century cooling or early 20th century warming that almost precisely matches the late 20th century warming, right down to the flat turnover at the end. The models also fail in detail to predict tropospheric warming, global rainfall variation or distribution, and much more. Chapter 8 in AR5 details many of their individual and collective failures while taking care to couch them in language that obscures the problem.
Right now the fundamental problem with climate science, which is pretty much entirely the GCMs as we still have a horrendously sparse and trouble plagued system of measuring the current climate (a.k.a. weather) on a sufficiently precise global basis to be able to say with any certainty what the global climate state of the planet is right now, is that all of its claims of ongoing disaster are failing. Seriously. Get this one straight. Not one single claim made by Hansen (who admittedly has made some entirely egregious claims in public venues in his time) has come true. Not a single GCM has predicted the last 15+ years of the evolution of the climate — they haven’t even come close. The absolute closest that any part of the world has come to “disaster” is that the Arctic has reduced sea ice, much as it did back in the 1930’s (where of course it could not be as fully documented as it is today). At the same time, however, the Antarctic has record setting levels of sea ice (again with the problem that the “record” involved is even more paltry in its extent as the Antarctic is still largely terra incognita). There has been no statistically resolvable change in the frequency or violence of storms, and even the IPCC is hastily backpedalling on any assertion otherwise as they recognize that this is a petard they might well be hoist upon. One in a long list. There is no discernible warming, and hasn’t been for an interval as long as the entire interval of warming in the late 20th century, which almost all occurred between 1983 and 1998. Sea level is rising — at almost exactly the rate it has been rising across the entire instrumental record, an entirely non-catastrophic 2-3 mm/year, order of a foot a century. This rate of SLR is not unprecedented — it is clearly visible in multiple segments of the instrumental record over decades where CO_2 was not an issue. Glaciers are retreating — just as they have been since the end of their period of growth during the LIA, which many of us would consider a fortuitous thing as living in the glacial era of an ice age sucks, and the advent of the next round of Pliestocene glaciation (or just a small LIA bobble) would very likely directly kill several billion people and precipitate numerous wars on a timescale of decades.
The most likely venue for some sort of catastrophe is not even thermal — it is chemical. Changes in the pH of the ocean are at least moderately alarming, and very likely are linked to increases in atmospheric CO_2. Most of the life of the ocean can very likely cope with the gradual decrease in pH (it has in the past) and it is not yet clear how the ocean itself will respond to the change in terms of increased biological activity or sequestration processes but there are very likely niches that will be affected. Catastrophically affected? Hard to say.
rgb
Don’t mean to nitpick but…a better statement of Occam’s Razor is “The preferred explanation is the one with the fewest number of assumptions that still explains all observations.” This is not always the ‘simplest’ explanation. We should seek simplicity and distrust it.
rgbatduke says on March 23, 2014 at 8:11 am
“The null hypothesis here is that CO2, an essential part of the biological cycle of life, is harmless.”
Agreed as stated, but furthermore:
Earth is CO2–deficient at this time and additional CO2 (from whatever source) is beneficial.
The classical example is Galieo’s and Copernicus’ ellipses with the sun as a major point, rather than the epicycles of the Greeks. You can get there with epicycles, but the math is a lot simpler with elliptical orbits. All you are doing is effecting a transformation between co-ordinate bases from anthropcentric to heliocentric – a fact that the Church understood and Galileo did not.
His insistence on the truth content of his theories was what got him into trouble, and rightly so.
While I agree with much of what you say, this particular part of your otherwise admirable essay is piffle. You should stick with the “classical example” part of the assertion. Ptolemy’s model as you say worked. It nevertheless suffered from several problems, only one of which was causality per se. The bigger problem was that it was impossible to build a meaningful causal model from the explanatory model. It was basically an amplification of Plato’s “ideal” causal mechanisms, motion in invisible spheres that formed some sort of firmament, but every time a new observation was made — e.g. moons of Jupiter — a new set of “spheres” and epicycles had to be added to what was supposedly (as always with philosophers) a “perfect” system. Ptolemy’s model fails multiple tests for knowledge in the modern sense and is an excellent example of the dangers of creating unfounded mathematical models of physical phenomena. There I think we agree.
However, you do Galileo a serious disservice when you allege that Galileo had no reason to think that his (really the Copernican) model was superior to Ptolemy’s geocentric epicycle model. Note that neither of them was a theory as that would have to wait for confirmatory evidence from the observations of Brahe and mathematical treatment of Kepler and and explanatory physical model that required the invention of physics itself by — Galileo and Newton (and various others).
Note that Galileo had already made personal observations that deduced the existence of the gravitational force, had determined that the gravitational force was proportional to the mass, and that it produced identical acceleration of distinct masses (all from observations of the oscillations of candelabra in a library as their candles burned down, timed with his own pulse). He lacked only two things needed to complete the invention of physics well before Newton — Descartes’ analytic geometry (that formed the basis of calculus) and the work of Brahe and Kepler that was proceeding in the background even as his persecution by the church proceeded and ultimately made the entire argument moot long before Newton. There is no reason at all to imagine that he did not understand gravitation well enough to have postulated that it was the cause of heliocentric orbits, although he was of course unable to prove this.
What Galileo might have achieved, or published, if it were not for the inquisition prosecuted by Cardinal Saint Bellarmine and his subsequent muzzling under house arrest, a broken man, we will never know. What we do know is Bellarmine’s agenda, as it is beautifully preserved in his letter to Galileo. Basically, the church’s official position was that the Earth was the center because the Bible Says So, and any demonstration to the contrary was a demonstration of the fallibility of not only the Bible, but every one of the supposedly divinely inspired saints and holy fathers that agreed with the mistake!
It was, in other words, a conceptual clash that opened the door to disbelief. If the Bible is fallible in one place, why is it infallible somewhere else? If our belief that it is divinely inspired truth fails in one place where we can actually check it, how can we trust it elsewhere where it cannot be so easily checked? Bellarmine was right to fear Galileo’s assertions. They were the beginning of the ongoing end of hegemony of the Catholic Church as a dominant political force in Europe and the world. It forced the church to successively narrow its assertions of infallibility to where they are now so narrow that they can never again be falsified by evidence — they are pure statements of myth and magic or events that supposedly occurred in the remote past and were documented decades to centuries later that no one can ever test.
There is nothing, in other words, noble about the Church’s stance in this. Under no circumstances is it a good thing to use direct force and the threat of mortal sanction to interdict the honest assertion of or search for the most reasonable set of personal beliefs. The Church wasn’t defending “truth” — it was defending its position of political and economic power, a position that it had only because it had established itself as the sole judge of metaphysical and physical truth via a document true, as Bellarmine noted ad litteram, not as some sort of metaphor, a document that could be contradicted only at the cost of losing the entire game, yielding all of this authority and power, for the rest of human history.
There are frightening parallels between this entire controversy and the modern controversy over the climate. The GCMs have taken on the role of the Bible — CAGW is the prediction of the infallible “physics based” models, a kind of punishment for the sin of being wealthy and enjoying the many benefits of electricity and easy, cheap transportation. The prescription of the church of CAGW for the sins of mankind is a return to austerity, a time when individual per capita consumption of energy was a tiny fraction of what it is today, simply because there are no plausible substitutes capable of providing sufficient energy to maintain the standard of living across the globe (let alone improve it) that are currently technologically feasible. That or a massive human die-off, which some warmists have shockingly enough actually asserted as a good thing (as long as the die-off doesn’t include them, of course, but so far being a warmist doesn’t seem to involve giving up driving or airplane flight or electric lights or heat or the internet or imported clothing or modern medicine serviced by all kinds of electrical equipment dispensing drugs synthesized with mined raw materials and energy or the right to have children. At least not involve them giving these things up.
rgb
We should also take the razor to the complex assumptions used to justify the many homogenization and adjustments that build the warming trend from raw data that doesn’t support it.
How exactly would one test and potentially falsify the theory that “Natural Variability” explains recent climate?
@MarkB
Take a random sample and do the work, as explained here
http://blogs.24.com/henryp/2013/02/21/henrys-pool-tables-on-global-warmingcooling/
Joe Born says:
March 23, 2014 at 3:33 am
The logarithmic response of global T to increased atmospheric CO2 means that most of the warming effect occurs in the first 100 ppm. Each subsequent doubling raises the temperature less & less, with diminishing returns. A doubling from “preindustrial” 280 ppm to 560 would produce warming of about 1.2 degree C (& maybe less in nature than in the lab), without assuming feedback effects not in evidence.
As MIT’s Dr. Lindzen has explained, adding more CO2 beyond the minimum required for life is like painting a white wall with more white paint. The degree of whitening of the wall diminishes with each extra coat.
Leo Smith says:
March 22, 2014 at 9:42 pm
You’ve got Galileo & Copernicus wrong, hence your erroneous conclusion about the Church.
Neither Galileo nor Copernicus argued for elliptical orbits. That was Kepler, who discovered the elliptical orbit of Mars by analyzing Tycho’s naked eye observations. Both Galileo & Copernicus still believed in perfectly circular orbits, as of course did the Church, relying upon Ptolemy. The Copernican system as formulated by him thus still required epicycles. Where Galileo & Copernicus were right & the Church wrong was in saying that the earth moved, rotating & wobbling on its axis while revolving around the sun, contrary to the stationary earth advocated by the Church, based upon the Bible.
milodonharlani: “The logarithmic response of global T to increased atmospheric CO2 means that most of the warming effect occurs in the first 100 ppm. Each subsequent doubling raises the temperature less & less, with diminishing returns.”
Thanks for the response. But, limited as my mathematics is, I do know what is meant by “logarithmic.” What I don’t know is how it was arrived at in this case, particularly since the logarithm of zero is negative infinity. I admit I’m no scientist, but my guess is that eliminating all CO2 would not give us a temperature below absolute zero, and no one thinks it would, so there must be some nuances I’ve missed in what they mean by a “logarithmic” relationship.
Joe Born says:
March 23, 2014 at 12:52 pm
Maybe this will help illustrate what is meant by a logarithmic relationship:
http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/