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A Sceptic’s Guide To Global Temperatures

Clive Best

So how accurately do we really know what the earth’s temperature really is? The answer would appear to be not very well  at all since it has been constantly changing since the last IPCC report.

Weather stations before 1900

Climate change may well turn out to be a benign problem rather than the severe problem or “emergency” it is claimed to be. This will eventually depend on just how much the earth’s climate is warming due to our  transient but relatively large increase in atmospheric CO2 levels. This is why it is so  important to accurately and impartially measure the earth’s average temperature rise since 1850.

It turns out that such a measurement is neither straightforward, independent nor easy.  For some  climate scientists there sometimes appears to be a slight temptation to exaggerate recent warming,  perhaps because their careers and status improve the higher temperatures rise. They are human like the rest of us. Similarly the green energy lobby welcome each scarier  temperature increase to push ever more funding for their unproven solutions, without ever really explaining how they could possibly work better than a rapid expansion in nuclear energy instead.

Despite over 30 years of strident warnings and the fairly successful efforts of G7 countries to actually reduce emissions, CO2 levels in the atmosphere are still stubbornly accelerating upwards. This is because simultaneously the developing world has strived to raise the wellbeing and living standards of their large populations through the use of ever more coal and oil, exactly as we did. This is our current dilemma. Should they somehow be stopped from burning fossil fuels, or maybe compensated financially  to ‘transition’ to so-called renewable energy instead? All this again depends on the speed of climate change, which simply translates to the slope of the temperature record.

The good news is that once global emissions start reducing, as they inevitably will, so the climate will rather quickly stabilise. Yet it may still take a thousand years or more for the earth to fully return to a supposedly “normal” pre-industrial climate. But is this actually what we want?

This idyllic  normal climate also includes regular ice ages, the last one of which reduced the  human population to just a few thousands of individuals struggling to survive outside of Africa. The earth’s climate has anyway been cooling by ~4C over the last 5 million years mainly due to land uplift caused by plate tectonics, which initiated violent natural swings in climate.  Human civilisation only developed within the current holocene interglacial (last 10,000 years).  Therefore it is in all our interests for the holocene to continue for as long as possible. Once we get through this temporary climate “transition” we will soon realise that controlling  the climate through some enhanced CO2 levels is a far better outcome for humanity than returning to a pre-industrial climate. A 2C colder climate is far worse than a 2C warmer climate.

So how accurately do we really know what the earth’s temperature really is? The answer would appear to be not very well  at all since it has been constantly changing since the last IPCC report. The most notable of these changes since 2012 is a  dramatic increase in what experts now say the global temperatures is compared to what those same experts  said it was 10 years ago. The hiatus as reported in the latest IPCC report has now completely vanished.  How is this possible? 

The Paris agreement proposed limiting temperature increases to 1.5C since pre-industrial times, but if you believe the most recent temperature results this limit was already breached in 2016, and will surely be exceeded with another major El Nino event. In this report I hope to explain how a combination of new temperature data, further adjustments to those data, and changes in the methods used for calculating global averages can explain why temperatures ended up being ~0.25C warmer than they were originally reported in 2012. Somehow each new version of any temperature series essentially rewrites climate history. Global warming always turns out to be  far worse than we feared it was a year previously. This ratcheting up of alarm is continuous.

A 7 year evolution in global temperatures.  Each new version of a temperature series rewrites climate history

Recent temperatures now apparently show a ~0.25C  warming  simply due to a continuous process of adding, merging and adjusting multiple short temperature records. But how is that possible?  To really answer that question we first need to understand what the term “global temperature” really means.

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