Temperatures were 2ºC warmer 5000 years ago according to archaeological and geological evidence from Skara Brae in Orkneys, Scotland
Professor Ian Stewart presented the series Making Scotland’s Landscape, one program focused on historic climate.
I produced the following chart from 3 separate charts shown on the program, the original charts are shown lower down.
It is clear
- current temperatures are not unusual
- there have been a number of changes in temperature over the millenia
Here is the section which presents the archaeological and geological evidence temperatures were 2ºC higher around 3000BC and have cycled since then.
Here are the 3 individual charts I spliced together
For whatever reason the scale on this chart was different to the previous two, so I had to guess (err I mean estimate) rescaling to fit on one chart.
It is interesting to compare the temperatures from Making Scotland’s Landscape with these 3 charts which come from page 202 of Working Group 1 of IPCC AR1, the first IPCC report issued in 1990. Whilst they not exactly identical they show the same pattern of falling and rising temperatures and more or less the same times.
It seems to me as these records show past temperatures being higher than at present
- If CO2 is responsible for higher temperatures then CO2 was higher in the past and this higher level could not be caused by humans.
- Some mechanism other than CO2 was reponsible for previous higher temperatures, so how do we know current warming is solely due to CO2, in fact how do we know CO2 makes any appreciable difference?
- As there has been cooling of several degrees in the past some mechanism must have caused this, how do we know it will not cause more cooling in the future?
Which ever way you look at it the past temperature record seems to show there is no reason to believe either
- Human emissions of CO2 are solely responsible for current temperature
- Temperatures will not fall at some time in the future.
If this is true all the measures being taken to avoid raising CO2 (and hence temperatures) are a waste of money, e.g.
- Closing coal fire power stations
- Burning wood from USA in UK power stations
- Trying to stop using fossil fuels
- Knocking down sea walls in face of rising sea levels
What do you think?