Everyone swears the IPCC have proof, but still nothing from the AR5

The IPCC don’t have no evidence!

(All right, all right! Leave off with the double negative put-downs already!)

common arguments • interesting rebuttals • startling absence of proof

Reader:

Looking at the recent geological (let’s say prehistoric) record then the exogenous inputs (mainly from volcanism) seem to have been low relative to historic exogenous inputs (mainly from agricultural soil organic matter breakdown and fossil fuel burning), which means that the two eras are not comparable and so conclusions drawn from one cannot be applied to the other.

Yet the IPCC does exactly that. They rip an isolated fact from its primeval context and claim it applies today. But it flies in the face of copious evidence and asserts that the global mean surface temperature (GMST) is determined by only a single factor: the trace gas carbon dioxide. For instance, on p. 50, the AR5 Technical Summary harks back 52 million years to inform us:

Reader:

In several periods characterized by high atmospheric CO₂ concentrations, there is medium confidence that global mean temperature was significantly above pre-industrial level. During the mid-Pliocene (3.3 to 3.0 Ma [mega-annum, million years ago]), atmospheric CO₂ concentration between 350 ppm and 450 ppm (medium confidence) occurred when GMST was 1.9°C to 3.6°C warmer (medium confidence) than for pre-industrial climate. During the Early Eocene (52 to 48 Ma), atmospheric CO₂ concentration exceeded about 1000 ppm when GMST was 9°C to 14°C higher (medium confidence) than for pre-industrial conditions.

We are to deduce that 1) high CO₂ levels caused great warming in the past and 2) therefore they’ll do the same today. But no causal connection is described for 1), so deducing 2) is illogical. In addition, we hear four times in three sentences that the IPCC have “medium confidence” in this thesis, which demonstrates no confidence at all and emphasises the lack of causation. Overall, not a powerful prelude to demanding trillions of our tax dollars to battle the weather.

Preposterous narrative

Reader:

Are you saying that the evidence of the past hundred years or so is unreliable that raised levels of atmospheric CO₂ cause increased atmospheric temperature?

Yes, since the evidence indicates the exact opposite: the data clearly show that increased temperatures occurred before atmospheric carbon dioxide rose. This perhaps happened largely through outgassing from the ocean. The IPCC have not demonstrated a causal connection between atmospheric CO₂ and warming, nor can they produce such evidence when asked. Temperatures have not consistently risen over the last 100 years and show much variation, though CO₂ levels have risen almost monotonically. Early records are sparse but a narrative that ignores any temperature decline and claims in defiance of observation that CO₂ rises before temperature does is preposterous and fraudulent.

Three plain atmospheric facts show clearly that CO₂ does not dominate the surface temperature.

First

Mankind has of course contributed some of the airborne CO₂, but how much, exactly? There are many studies, but two are in the same ball park: Dr Ed Berry, a consulting meteorologist with a PhD in physics, and the AR5 from IPCC (summarising other PhDs).

Dr Berry shows anthropogenic CO₂ is 18 ppmv (4.4% of the atmosphere, or 0.141 × 10¹² tons CO₂). A paper, Human CO₂ Emissions Have Little Effect on Atmospheric CO₂ (pdf, 670 KB), was published last year in the International Journal of Atmospheric and Oceanic Sciences, concluding:

Human CO₂ is insignificant to the increase of CO₂ in the atmosphere.

The IPCC AR5 suggests an increase of about 113 ppmv in atmospheric CO₂, stating that 240 GtC have accumulated in the atmosphere from 1750 to 2011 (AR5 SPM, p. 12). So 240 billion tonnes of carbon × 3.667 = 880.08 Gt CO₂, or 0.880 × 10¹² tons (trillion tonnes) — not terribly far from Dr Berry’s 0.141 trillion tons.

Even if carbon dioxide significantly raises the temperature, our responsibility for weather events is practically imperceptible and the IPCC can offer no more certainty of human influence than a sheer guess, as revealed in this summary from the AR5:

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.  – (AR5 SPM, p. 17)

How warped, perverted and wicked that we find at the heart of the IPCC narrative of man-made warming an empty, meaningless paradox. The first sentence thinks it extremely likely that man-made warming was about 50% of the observed warming, but that’s immediately refuted by the second sentence opining that man-made warming was the whole amount of the observed warming. This frankly brainless logic offers a clarity of mind arising only in intellects needing prolonged, intensive pedagogy.

We have been assiduous during more than 15 years, yet wherever we look for the evidence that everyone else says the IPCC has written in its reports, we find nothing.

Second

Radiation transmitted by the atmosphere, with wavelengths increasing from left to right. The red line shows where incoming shortwave radiation (left) gives way to outgoing longwave radiation (right). Click for the complete diagram.

At concentrations varying from about 10,000 ppmv to over 40,000 ppmv, and at 25 times to 100 times more abundant, water vapour’s influence towers over CO₂, which at present is about 408 ppmv. By mass, there are 12.7 trillion tonnes of airborne H₂O as both vapour and liquid, dwarfing the 3.2 billion tonnes of CO₂. CO₂ is only a quarter the mass of water and responsive to only a small fraction of outgoing radiation. In the diagram at right showing absorption by various gases at a range of wavelengths, where the grey bands in different rows overlap, then in the troposphere water absorbs the lion’s share of radiation. In total, CO₂ stands little chance of intercepting photons before water gets them, and in the few wavelengths where it does stand a chance, there’s little energy available to be absorbed.

Third

It’s not the atmospheric trace gases that dominate the world’s surface temperature, it’s water vapour—the IPCC say so. At different times, H₂O is 500 to 2000 times more abundant than the man-made portion of CO₂ and a molecule of water vapour absorbs more than 10 times the amount of incoming solar energy and outgoing long-wave energy than a molecule of CO₂. This diagram shows the relative abundances of water vapour and carbon dioxide — both natural and anthropogenic. H₂O outclasses CO₂ in all departments.

The troposphere contains 99% of the H₂O and around 80% of total atmospheric mass, which means it has 80% of the CO₂. It seems highly unlikely that water vapour would be overwhelmed by the meagre quantity and puny radiative effects of CO₂.

Click to enlarge.

The diagram shows the relative atmospheric abundances by mass of three gases: oxygen, water and the two interesting kinds of carbon dioxide, natural and man-made, in four disks. Our red oxygen disk at this scale is over a metre in diameter so we see only a portion. Oxygen in turn would be surrounded by nitrogen at about 4.4 metres in diameter, 3.7 times more massive than oxygen, and the whole atmosphere (5.1 m), over four times more massive than oxygen.

An arrow points to man-made carbon dioxide accumulated since 1750 — the teeny dot beside the green CO₂ disk. I’ll shortly add argon to the picture and polish the arrangement, but at least now you can see it (I’ve been working on this erratically for months).

Still no evidence — incredible

The only evidence that higher levels of CO₂ cause increased atmospheric temperatures comes from unverified climate models which are completely unreliable — not to mention that they don’t derive the warming from first principles, they’re told what warming to calculate. Actually, most sceptics say the models are false to the point of fraud. So do I. For the last twenty years the models have predicted rapidly rising temperatures and have always been wrong. The IPCC have reduced their projections further with each new Assessment Report.

Local variations in humidity over mere minutes can cause changes in forcing that far outweigh CO₂ increases of the order of 120 ppmv over a century, while anthropogenic changes amount to less than 10 ppmv over 100 years.

The GMST is not controlled by a single gaseous factor but multiple complex systems. In the words of the IPCC (Third Assessment Report, TAR, ):

The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future exact climate states is not possible.

A statement of good science missing from more recent reports. See more extracts from the TAR.

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