Bryan Leyland: Things you know that ain't so - 2015 was the hottest year ever

“Things you know that ain't so - 2015 was the hottest year ever”

The mainstream media has inundated us with reports that 2015 was the hottest year ever. But was it?

Of course not. Many reliable records show that it was warmer in the mediaeval warm period, the Roman warm period and the bronze age warm period.

Was it the warmest since we had reasonably accurate records? It all depends on where you look and how you interpret the data. An excellent place to start looking is climate4you.com where Prof Humlum reproduces data from a number of reputable sources.

There are five internationally recognised temperature records. The most accurate are the satellite records (a few years ago NASA suggested that they should be the sole record as they were most accurate) followed by the surface temperature record from the Hadley Centre in the UK and then two records from the USA (NASA/GISS and NCDC) that are generally regarded as being the least accurate.

One of Prof Humlum's charts plots all five records on a single sheet that shows the running averages of the satellite temperatures and the surface temperatures. The remarkable thing about this chart is that it shows the two records tracking each other quite accurately from 1979 when satellite observations started until about 2008. But from then on the surface temperature records diverge and now the surface temperature records are about 0.25° warmer than the satellite records.

If we believe the more accurate satellite records, 2015 was 0.2 degrees cooler than 1998. If we believe NASA/GISS, 2015 was warmer than the previous record by 0.13°. Confused?

If we take +/- 0.1 error margin into account, NASA/GISS shows that 2015 may or may not have been the warmest year: according to the satellites, it was not.

So why have many climate scientists and the mainstream media focussed only on the NASA/GISS surface temperature record and failed to tell us about the error margin and the other records? The simple answer is that there are a large number of people in the world whose scientific reputation, political future, career and/or income depend on persuading the public that man-made global warming is real and dangerous. They don't have to conspire together: it is obvious to all of them that they will be rewarded for sustaining the myth.

Why have the surface temperature records diverged above the satellite records over the last few years? The answer seems to lie in recent adjustments to the surface temperature records. A few months ago the NASA/GISS adjusted past sea surface temperatures downwards because, they claimed, there had been errors in the original measurements. While it is true that temperature records do need adjusting for number of good reasons, it is seriously odd that, in all the surface temperature records, virtually all of the adjustments result in past temperatures being pushed downwards and recent temperatures being pushed upwards. (This has also happened in New Zealand.) Common sense would suggest that the adjustments should go both ways and, to a large extent, average out.

But there is something else much more important in the climate debate that has received no publicity at all. The whole scenario of carbon dioxide causing dangerous warming is based on the output of computer models that have never been properly validated and never made accurate predictions. According to the IPCC, 111 out of 114 model runs predicted temperatures much higher than actually occurred.

Nobody bothers to tell us that according to the computer predictions the world should be 0.4° warmer than it is now. In any other branch of science, models that yielded such inaccurate results would be abandoned. In climate science, It seems, they believe the models and massage the data.

In a world that has hardly warmed and carbon dioxide levels have steadily risen, hapless taxpayers have paid trillions of dollars to climate scientists, politicians and carbon traders. Electricity consumers have seen huge increases in power prices to fund massive subsidies for expensive and useless wind and solar power and to pay for the generators that are needed when the wind doesn't blow and the sun doesn't shine.

The truth is that the increased carbon dioxide has promoted plant growth, reduced desertification been a huge benefit to agriculture worldwide. It might have warmed the world by a tiny and beneficial amount.

When will we see a return to reason?