The Temperature Context

Screen Shot 2014-08-13 at 11.22.50 The graph above shows results from the UK Meteorological Office Central England Temperature record (CET) since the turn of the millennium up until 2013. This is a small part of the world’s longest running temperature record. It appears not to have been significantly tampered with as have so many other official temperature records.

It would also seem to be a relatively reliable proxy for European temperatures as a whole. Although Europe has seen a warmer wetter winter this year, 2013 -2014, North America has seen one of the coldest winters ever recorded.

From this it is clear that since the beginning of the millennium the UKMO CET decline has been about -0.89°C in 13 years. Perhaps more significant the winter season temperatures (December January February) have diminished even further by -1.55°C. This significant decline has resulted in loss of agricultural productivity throughout Europe. But these recent features of the Central England / European temperature record should be seen in a much longer term 500,000 year historic context. Screen Shot 2014-03-19 at 16.28.43 The more normal state of the earth in current geological times is full glaciation, with ice sheets covering much of the land outside the tropics. There have been five warmer interglacial periods in the last 500,000 years. The timing of glaciation and inter-glacials is driven by planetary mechanics.

Screen Shot 2014-09-12 at 12.32.32

The previous Eemian interglacial epoch was some 120,000 years ago. At its peak it was about 3°C warmer than our current Holocene interglacial: hippopotami thrived in the Rhine delta. The Eemian epoch also lasted about 10,000+ years.

Petit, J.R., et al., 2001. Vostok Ice Core Data for 420,000 Years. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series #2001-076. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

The Civilisation of Mankind has thrived and developed in the last 10,000+ years, the period of the current warm and benign Holocene interglacial. From past records, our current benign Holocene interglacial period should be drawing to its close. The temperature record of the Holocene epoch can be seen in the GRIP Greenland ice core data. Its information is replicated in several other similar long term ice core records.

The Holocene epoch started with a “climate optimum” with its highest temperature values. In spite of the notable Minoan, Roman and Medieval warm periods the overall temperatures have progressively diminished by about 1.5°C since 8000BC.

Screen Shot 2015-04-12 at 11.07.51

The most recent millennium 1000 – 2000 AD has been the coldest 1000 year period of the current, benign Holocene epoch .

The Central England Temperature record, (CET) has been maintained and supported by the UK Meteorological Office since 1659.

Although the CET record covers only a small part of the northern hemisphere, it has shown a consistent rise since the end of the little ice age in 1850 at a rate of about +0.45°C / century or about +0.77°C in the last 150 years. This rise accords well with other temperature records. Mankind’s industrialisation could not have had much impact on climate prior to 1850, when CO2 levels were ~280-300 ppmv. The CET shows a gain of about 0.76°C 1850 to 1999 and there was a particular spurt up to the end of the last century. Screen Shot 2014-09-12 at 12.33.12 This temperature spurt coincided with increasing CO2 levels and is attributed by the IPCC, Intergovernmental Panel on Climate Change and by Anthropogenic Climate Change advocates wholly to the growing industrial CO2 emissions of mankind. Screen Shot 2014-09-12 at 12.33.28 The temperature gains since 1970 coincided well with three active solar cycles 21 – 22 – 23. This period of high level solar activity matches the timing of the great Global Warming scare.

Since the year 2000 a change has occurred: the CET record shows a marked reduction from its high levels loosing all the gains that it has made since 1850, even though at the same time CO2 levels have escalated further to ~400ppmv. The current solar cycle 24

is very much weaker. Solar experts predict that weakness will continue at least into cycle 25 peaking in the 2020s or even further.

Solar activity levels are then likely to be back to the levels of the Little Ice Age, around 1800 or the Dalton minimum. Although the visible light output of the sun is remarkably constant, its other electromagnetic radiations can vary significantly. These other radiative effects, that are mapped by the sunspot number, may well have much more influence over world climate.

Between 1850 and 1999 UKMO CET gained about 0.7°C . But in the last 13 years of since 2000, the CET winter December – March temperatures have shown a significant loss ~ -1.5°C. Although the CET relates to a relatively small area of the Northern hemisphere this would seem to be a truly radical change over the last 13 years. At the same time for the last 17+ years there has been a standstill in world temperatures overall shown in the HADCRUT data sets. Screen Shot 2014-09-12 at 12.33.49 However recently a further more extreme, perhaps extraordinary, escalation of the temperature local UK decline has occurred. In the first half of 2013, January – June, CET temperatures were a full 1.89°C lower than the monthly averages of the previous 12 years. This cooling phenomenon has been seen widely throughout Europe and the remainder of the Northern Hemisphere.

The effect has been mirrored in the Southern hemisphere.

That decline has lead to significant crop failures and serious loss of agricultural productivity.

In their recent report the IPCC have reluctantly accepted that global temperatures have stopped increasing and as can be seen above they may already be falling radically.

But throughout this period CO2 levels have been increasing. Perhaps its the sun and planetary mechanics that control the world’s climate.  

The last millennium 1000 – 2000 AD was the coldest of the whole of our currently benign Holocene epoch. At about 10,000 years long, the Holocene is coming towards its end. Then there will be an inevitable slide into the next real ice age, whether this century, this millennium or the next.


One thought on “The Temperature Context

  1. Pingback: Ed Hoskins – a series of articles worth reading | Scottish Sceptic

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