The central climate fallacy is that the unknowns are known

By Christopher Monckton of Brenchley

What is science for? Its end and object is to stretch out a fumbling hand for the truth by a humble and eternally-unsatisfied attempt to constrain uncertainties.

The scientific method is hungry curiosity, followed by acute observation, followed by careful measurement, followed by the meticulous application of pre-existing theory to the results, followed by the detailed drafting and reviewed publication of a hypothesis, followed by other scientists’ attempts to overturn the hypothesis, which is either discarded or slowly accorded credence to the extent that it has survived the process of error elimination.

In the physical sciences, absolute proof – which mathematicians call demonstration – is very seldom available. In mathematics, the art that is the language and the queen of the sciences, demonstration is more often available, particularly in number theory, the branch of discrete mathematics that concerns itself chiefly with the integers. Die ganze Zahl schuf der liebe Gott, said Kronecker. Alles übrige ist Menschenwerk.

One of the reasons why the Thermageddonite superstition has been so successful until recently is that just about the only formal demonstration that nine-tenths of the population recall – and even then hazily – is that in the Euclidean and hyperbolic planes the square (or semicircle) on the hypotenuse of a right triangle is equal to the sum of the squares (or semicircles) on the other two sides.

Now, the problem with the theorem of Pythagoras is that it is unquestionably true. For those who agree with the philosopher Schopenhauer that Euclid’s demonstration is “a triumph of perversity”, here is the admirably clear proof by dissection attributed to the fifth-century Hindu mathematican Aryabhatta.

However one looks at the theorem, the wretched thing is objectively true. There are hundreds of distinct demonstrations of it. It is true whether or not you or I or anyone else wants it to be true or believes it to be true or knows it to be true. In the language of theology, it is intrinsice honestum. It is right in itself.

I submit that it is the theorem of Pythagoras that has allowed the Thermageddonites to succeed when, scientifically speaking, they should simply have been laughed at.

For the truth of that venerable theorem has misled generations who have been given some acquaintance with the sciences but little or none with the philosophy of science into believing that every scientific finding is definitive, unalterable, unchallengeable and unquestionable.

Yes, liberating greenhouse gases by combustion will cause some warming – all other things being equal. Yes, we are liberating greenhouse gases by combustion. These things have been established beyond reasonable doubt. But what has not been established is the crucial quantitative question how much warming we may cause.

That simple fact has been relentlessly and artfully concealed from the population, who have been sedulously deluded into believing that “the science is certain” and that anyone who questions how much warming we may cause is by implication also challenging the well-established experimental results showing that greenhouse gases cause warming.

It is worth briefly considering the how much question – or, as the climate scientists call it, the question of climate sensitivity.

In response to my recent posting pointing out that on the RSS satellite record there has been no global warming for 17 years 10 months, a commenter, one Stacey, asked:

“Please could you … demonstrate the actual climate sensitivity in respect of the last 30 years due the increase in CO2 in the atmosphere? My guess is that it’s zero. :-)”

“Stacey” is adopting a sound, scientific approach, beginning with that vital first step: curiosity. Socrates used to say that the first step on the road to knowledge was an awareness of one’s own ignorance. And what is curiosity, the wellspring of the sciences, if not an awareness of one’s own ignorance coupled with a determination to do something about it?

“Stacey” offers the hypothesis, that climate sensitivity to CO2 over the past 30 years has been zero, and asks whether she is right.

So let us examine the hypothesis. We begin with the observation that in the climate there appear to be quasi-periodicities of about 60 years in global temperature – roughly 30 years’ tendency to warm followed by 30 years’ tendency to cool – and that these cycles are tied to, and may be caused by, the great ocean oscillations, of which the most influential seems to be the Pacific Decadal Oscillation.

Therefore, in order to cancel these naturally-occurring cycles, it is necessary either to take periods that are multiples of 60 years in length or to take periods that straddle a phase-transition from one 30-year phase of the PDO to another.

Usefully, the most recent phase-transition in the PDO was in about the year 2000, so that the past 30 years will have been about equally influenced first by a warming phase of the PDO and then by a cooling phase. That removes the most obvious potential natural distortion of our attempt to determine climate sensitivity from what has actually occurred.

Next, measurement. How much global warming was there in the past 30 years? For this, we shall take the mean of the global mean surface temperature anomalies on all five principal datasets – GISS, HadCRUT4, NCDC, RSS, and UAH.

We now make the assumption, for the sake of beginning somewhere, that all of the global warming over this 30-year period was attributable to us.

As the CO2 record on the chart shows, CO2 concentration rose by 54 ppmv over the 30-year period. We shall assume that all that increase in concentration was anthropogenic. If so, official theory suggests it caused 0.78 Watts per square meter of radiative forcing.

We shall also assume that over the period CO2 represented 70% of all anthropogenic forcings, so that the total anthropogenic forcing was 1.11 Watts per square meter. This assumption is derived from the IPCC’s Fifth Assessment Report.

We shall further assume that none of the warming was committed but unrealized warming from before 1984, or that, if there was some, it was approximately balanced by uncommitted warming generated over the 30-year period but not yet apparent in the temperature record.

Now we can divide the measured temperature change of 0.48 Cº by the total anthropogenic forcing of 1.11 Watts per square meter to obtain the transient-sensitivity parameter λ_t where t = 30 years, which is 0.43 Cº per Watt per square meter.

However, the instantaneous, Planck or zero-feedback sensitivity parameter λ₀, which is the mean of the first derivatives across all latitudes of the fundamental equation of radiative transfer at the characteristic-emission altitude, where incoming and outgoing radiative fluxes balance, is just 0.31 Cº per Watt per square meter (IPCC, 2007, p. 631 fn.).

Next, some handy equations, that you will not find in most textbooks, will help us to determine the system gain G_t, the closed-loop feedback gain g_t, and the feedback-sum f_t directly from the Planck sensitivity parameter λ₀ and the transient-sensitivity parameter λ_t:

The transient system gain G_t, which is the factor by which the direct warming from anthropogenic forcings is multiplied to allow for the action of feedbacks over the 30-year period, is simply 0.43 / 0.31, or 1.39, showing that short-acting feedbacks have increased the direct warming by almost two-fifths.

The loop gain g_t, which is the product of the sum of the short-acting feedbacks and the Planck parameter, is 1 – 0.31/0.43, or 0.28.

Then the feedback sum f_t, the sum of all short-acting feedbacks over the period, is 1/0.31 – 1/0.43, or 0.9 Watts per square meter per Celsius degree of warming over the period.

The IPCC’s current central estimate is that at equilibrium, when all short-acting and long-acting feedbacks have acted, the feedback sum is just 1.5 Watts per square meter per Cº (IPCC, 2013, table 9.43, red dot at top right). This is a substantial reduction from the 2.1 Watts per square meter per Cº (blue dot at top right) central estimate implicit in IPCC (2007).

From that current estimate of the equilibrium feedback-sum f_∞, which is the sum of all feedbacks acting over the thousands of years till the climate has established a new equilibrium following perturbation by a forcing, the equilibrium system gain G_∞ may be determined, using the Bode system-gain equation:

From the Bode equation, the equilibrium system gain G_∞ is [1 – 0.31(1.5)]^–1, or 1.87. In short, the IPCC’s current implicit central estimate is that feedbacks increase the direct forcing-driven warming by seven-eighths.

The central estimate of Charney sensitivity implicit in the IPCC’s current central estimate of the feedback sum is given by

Thus, the IPCC’s current central estimate of Charney sensitivity to a doubling of CO2 concentration ought to be (5.35 ln 2)(0.31)(1.87), or 2.1 Cº. So the 3.2 Cº that is the current central estimate of the CMIP5 model ensemble is too big by at least half.

The eventual warming as a result of the anthropogenic forcings of the past 30 years will be (1.11)(0.31)(1.87) = 0.64 Cº, of which 0.48 Cº, or three-quarters, has already occurred, leaving just 0.16 Cº warming committed but unrealized over the period. Yet the IPCC says there is about four times that amount of committed but unrealized warming in the pipeline.

Now, all that is set out above is mainstream climate science. It is possible that we caused some of the warming of the past 30 years. It is possible, though by no means certain, that we caused at least half of it.

Why, then, can we not be more precise in deriving a climate-sensitivity estimate from the temperature change and CO2 concentration change we have seen over the past 20 years?

The answer – though you will very seldom hear it from the Church of Thermageddon – is that there are far too many unknowns. The biggest outright lie in the IPCC’s 2013, 2007, and 2001 reports is the notion that we can determine with any confidence the fraction of global warming over recent decades that is attributable to us.

In 2001 the IPCC said it was 66% confident we had caused most of the warming since 1950; in 2001, 90% confident; in 2013, 95-99% confident. All of these confidence values are direct lies. For there is no dataset from whose values any such supposed confidence levels can be determined by any recognizable statistical process.

It is a measure of the contempt in which today’s scientific elite holds the rest of the population that the IPCC, as the elite’s soi-disant spokesman on climate change, could have made and persisted in and doubled down upon these particular lies. It knows it can get away with them, for scientists have abdicated, forfeiting their high priesthood to far-left politicians and profiteering environmental protection rackets.

We do not know enough about the climate to say in what direction, let alone by how much, the climate would be changing in the absence of any anthropogenic influence. We do not know the forcing from CO2 or any other greenhouse gas to a sufficient precision. The official value of the CO2 forcing was cut by a massive 15% in 2001.

We do not know the value of the Planck parameter to any great precision. We thought we did: then the actual mean surface temperature of the Moon was measured, and was found to be 40% adrift from the official value that had been determined on the basis of the lunar sensitivity parameter, and had been confidently published on official government websites.

We do not know what fraction of manmade warming is attributable to each of the greenhouse gases. We do not know the magnitude or even the sign of the forcing from our emissions of soot to the atmosphere.

We certainly do not know the values of the individual temperature feedbacks to anything like the narrow error bars falsely claimed by the IPCC. We do not even know the sign of the cloud feedback, and the IPCC has recently been forced to reduce the value of that feedback drastically.

Then there are the major non-radiative transports: evaporation and convection up, advection across, and precipitation and subsidence down.

We cannot predict the behavior of the oceans – indeed, we cannot even measure changes in their heat content with sufficient resolution to give a meaningful result.

We cannot predict el Niño and la Niña events. Look how many enviro-left news media predicted a record-busting event this year. They predicted it because they wanted it.

They needed it, desperately, to bring the Great Pause to an end and reduce the humiliation that the less dishonest among them are beginning to feel now that the laymen like me at whom they have viciously snapped and sneered for so long are – so far, at any rate – closer to the mark than they and their expensive but useless models.

For it would take only a very small reduction in each of the assumed values on the basis of which the IPCC makes its predictions to reach a climate sensitivity far less than the models’ currently-claimed central estimate of 3.2 Cº per CO2 doubling. And there are powerful theoretical reasons why some of those values must have been greatly overstated, though there is no space to consider them here.

My own best estimate, for what little it is worth, is that a doubling of CO2 concentration would warm the world by about 1 Cº, if that. The IPCC is heading – albeit far too slowly – towards the same answer. It has cut the CO2 forcing; it has accepted that the next-biggest anthropogenic forcing, from methane, has been vastly overestimated; it has slashed the feedback-sum and consequently the equilibrium system gain; it has all but halved its near-term predictions of global warming.

However, the honest answer to Stacey’s question about what climate sensitivity is indicated by the temperature record of the past 30 years is, “We do not know”.

But you will never hear that honesty on the lips of the Thermageddonites, as they furtively and profitably cement in place the last of the thousand interlinked supranational bureaucracies that are the silent sinews of what – if they get their way in Paris in December next year – will be an all-powerful world government founded upon the greatest lie ever told, the lie of certainty in a cloud of unknowing, elected by none, loved by few, feared by all, and answerable only to itself.