The graph on the left shows cosmic ray flux (dark line) and reconstructed climate. (dotted) from 1850 to 2003. It does show an upward trend for most of the time with a reasonable correlation between ups and downs on cosmic rays and global temperature until, the early 1980s when the two take a sharp dislike to each other.
It’s well known (amongst archaeologists) that C14 used to date artefacts is created by cosmic rays … but there’s another source nuclear testing, so this was my first thought: could the level of “manmade cosmic rays” have any relationship with the deviation. Looking at the graph below, we can see the estimated manmade contribution to C14 due to nuclear testing. What this shows is that the level of “manmade” cosmic rays reached a peak in 1965 and then decayed. These were due to the above-ground nuclear tests that occurred in several countries between 1955 and 1980 ; after the tests ended the atmospheric concentration of the isotope began to decrease.
However, despite some dispute as to how to calibrate C14 i.e. how much of this is manmade and how much is natural (sounds familiar), it doesn’t seem to explain the deviation, although it does add to the uncertainty.
But looking more closely at the post 1950 period of direct measurements of cosmic rays, there is a good correlation during the period of direct measurement until the early 1980s … which strangely is when the global warming concern raised its head!
So, as I’d just been looking at a graph of global precipitation (cloud form rain droplets, so rainfall should indicate cloud cover, or that was the thinking)
This is interesting as the global temperature anomaly (shown in blue above) and global precipitation move along together until, suddenly up goes temperature. Now as precipitation is a proxy for temperature this needs quite a bit of explanation. (for more see Bob Tisdale) Temperature and precipitation aren’t the same thing, but it does represent the heat in the system. So, why is there just a dramatic deviation between temperature and precipitation … FROM THE EARLY 1980s, precisely when the cosmic ray/temperature deviation comes in.
Then I remember the Central England Temperature anomaly, versus the Met Office data:
Again we get the same “mysterious” variation starting in the early 1980s. This is starting to look very suspicious. There is a remarkable similarity between all these: temperature data is showing a sharp change from other temperature series, climate proxies and cosmic rays, all at the same time and as far as I can see, all with the same general trend.
There’s no doubt about it. There is something really odd going on here.
Following a comment, I began thinking about what could possibly have happened that wasn’t intentional corruption (it does seem far fetched to think of someone at the Met upjusting figures).
Here’s a list of graphs which may be relevant: