In the late 1990s, as the idea of global warming began to attract widespread public attention and research funding, the claim that recent warming was unprecedented and dangerous was conflicted by extensive evidence of a preceding Little Ice Age (LIA) and, before that, a Medieval Warm Period (MWP) that was as warm or warmer than the present. As later revealed in the Climategate email leak, leading proponents of the warming threat privately discussed a need to get rid of the LIA and MWP. Soon thereafter this was achieved by publication of what became known as the Hockey Stick graph (Mann, Bradley & Hughes 1998), which purported to show no statistically significant trend in average global temperature over the previous millennium until a sudden steeply increasing rise over the 20th century. In the accompanying study the LIA and MWP were dismissed as only unimportant local fluctuations limited to north-western Europe.

The Hockey Stick was based primarily on estimates of temperature from variations in growth rings from a few dozen pine trees in two very localised and extreme environments. This data, presented as representing the global pattern, was analysed using a statistical treatment which has been shown to result in a hockey-stick shape even with random input data. In addition, a lack of any indication of ongoing warming in the 20th century part of the tree ring record was hidden by overwriting this portion with selected data from the instrument record. The whole hokey confection was published in a leading journal, received banner treatment by the news media and was subsequently adopted by the IPCC as the iconic image for their Third Assessment Report in 2001.

All this blatant chicanery has been thoroughly exposed, the infamous Hockey Stick graph being refuted by hundreds of peer reviewed studies, as well as numerous historical records which confirm the LIA and the MWP as having been real, distinct and global in scope. Even so, rather than just let the Hockey Stick graph die and be forgotten, the alarmists have chosen to make fools of themselves by vigorously, even viciously, defending it. They still argue for its validity, despite it having been no less discredited than Piltdown Man or phlogiston.

Now, having learned nothing from the Hockey Stick debacle, the alarmists are setting out to further their discredit by attempting to refute the so-called hiatus or pause in warming marked by no statistically significant trend in global temperatures for the past two decades. This new hokey hockey stick is being fabricated by “adjusting” the temperature record of the past century. It started with unannounced and unexplained “adjustments” to the records from weather stations. When noticed and questioned, the only explanation offered has been generic and hypothetical reasons for needing to make adjustments with no specific details as to what or why anything was done in any particular instance!

Although this approach has forestalled critical examination, an ongoing lack of warming is making it impossible to maintain any pretense of scientific credibility by continuing to adjust the temperature record from weather stations.

Desperate times require desperate measures, and with credibility running thin on changes to the weather station records, attention has been turned to the two-thirds of the planet covered by oceans. For most of the past century the ocean temperature record comes primarily from the cooling water intake of ships, and, then over the past two decades, a much more accurate measurement from a global network of instrumented buoys, both anchored and free floating. Adding to the complexity has been a further mix of records from satellites, expendable bathythermographs dropped from ships and earlier records using thermometers in buckets of water scooped from the surface. All these have their own differing errors and biases, making comparisons highly uncertain at the levels of accuracy required to assess climate trends.

In June, 2015, a group of NOAA researchers published a study (Karl et al., 2015) applying “adjustments” to the ocean surface temperature record with the result that the ocean data which previously had shown no statistically significant trend now exhibited an ongoing warming. This study has met with considerable criticism and controversy. Then on January 4, 2017, another group of researchers published still another study (Hausfather et al., 2017) reassessing the ocean data and making more adjustments which further increases the purported warming trend.

However, in addition to all of the uncertainties in measurements by the different methods there also exists a major variable in Sea Surface Temperature the existence of which appears to not even be recognised by the climate “experts” and which is the key point of this essay. In referring to the surface temperature of the ocean it is generally assumed to refer to the temperature of the upper hundred metres or thereabouts where mixing by wave action results in a more or less uniform temperature down to a thermocline, where the deep sea suddenly starts to become much colder. Although this is normally the case, in periods of extended calm another layering develops with major effects on both surface temperatures and their measurement as well as the whole ocean/atmosphere energy exchange.

In calm conditions, when wave-driven mixing ceases, a distinctly warmer layer forms at the surface. After a week or more of calm this layer can be a metre or two in depth and as much as 3-4ºC warmer than the water immediately underneath. When the wind comes up and wave-mixing resumes this layer disappears in a matter of hours. When it is present it not only enhances the ocean/atmosphere exchange it also blocks the heat flow into what is normally the much larger upper mixed layer and results in cooler than normal surface water when mixing resumes.

Normally, periods of extended calm are restricted to a relatively narrow, seasonally shifting equatorial zone known to meteorologists as the Inter Tropical Convergence Zone, or ITCZ, and to mariners as the Doldrums. However, when the trade winds weaken and El Niño conditions arise the doldrums expand in latitude and the region of extended calms can affect millions of square kilometres of ocean. The region primarily affected in this regard is the equatorial Pacific. This is also an area that in the past was outside the major shipping routes so the temperature record from ships is relatively sparse. In addition, the cooling water intakes of ships are normally 5 metres or more below the surface — well below the surface warm layer which results from calms. However, Sea Surface Temperatures from satellites and the more accurate recent data from buoys do sample this warm layer.

The result of this difference in sampling depth is that the recent SST data from buoys and satellites has been measuring the upper surface warm layer when it is present while the ship intake water data has been from the cooler water beneath. Averaged into the SST record this difference in sampling can account for most or all of the purported warming claimed to have been found in the reassessment of SST data.

All along, this particular 800 pound gorilla has been sitting all over the SST data. This has not just gone unnoticed but also has hopelessly polluted a large but indeterminate portion of the past temperature record. It is probably going to be impossible to determine and adjust for it with any reasonable certainty.

The only reliable SST trend must come from the much more recent satellite and buoy data which at this point shows no statistically significant direction. Unfortunately, another impossibility will almost certainly be in getting the “experts” to even admit this problem exists. We are probably going to be stuck with their latest shoddy confection until its credibility also collapses under the necessity of repeated adjustments to maintain a warming trend.

Although this important surface layering effect has been obscured by its short-term variability and the muddle of different sampling methods, it is strong, widespread and quite apparent in the real world, even if not so in the sampling record and entirely missing in the climate modelling. Continuing to claim “the science is settled” is going to require a rather daunting level of both ignorance and arrogance. However, having freed itself from the onerous constraints of scientific integrity, one can be confident the alarmist “settled science” community will be up to the challenge.

A marine biologist, Walter Starck has spent much of his career studying coral reef and marine fishery ecosystems