Cosmic rays & the late 20th century temperature data: a smoking gun?

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 derivation, 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 derivation 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 upjudting figures).

Here’s a list of graphs which may be relevant:

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11 Responses to Cosmic rays & the late 20th century temperature data: a smoking gun?

  1. futureboy says:

    One explanation, particularly for the breaking of the link between precipitation and the temperature figures is that the latter are false.

    However since that would imply a massive fraud for 32 years, which is not easily credible, there must be some other explanation.

    I have no idea what it could be.

  2. It could of course simply be that the early 1980s was when the CO2 induced warming already in the pipeline started to kick in,and that CO2 is a much bigger driver than cosmic rays. But that would be a dull explanation and wouldn’t allow the conspiracy theorists out to play.

    • That’s a worthy comment. The reason I think it is unlikely is because we seem to have a fairly sharp turn. If it was a delayed response, you would expect it to gradually build up … to be smoothed out. But I grant you, it could be a chance bit of natural variation which has given a general smoothed upward curve the appearance of suddenly taking off.

      The big worry, is that on its own this is quite a rapid & unexplained change – far be it from me to promote concern – but when you get significant anomalies like this it would be useful to get some level headed research on the subject … then one looks at the nutters who run climate now, and we all know that they are going to go off on some flight of fancy.

  3. Pingback: Another smoking gun | ScottishSceptic

  4. kim says:

    Do the temp and precip just flip on a 60 year cycle? What’s the curve look like now?

  5. kim says:

    Thanks. Opaque.

  6. lapogus says:

    Very interesting.

    Could be just a coincidence of course, but the late 1970s was also the turning point in the Chiefio’s ‘Great Dying of the Thermometers’:

    NikfromNYC’s graph also springs to mind, which does not appear to show any significant rise in temps in other historic temperature datasets since 1980, (except Geneva and the CET):

    So maybe it is only Europe which has been warming since the 1980s and it is not a global trend?

    It does seem that the removal of many northern and cold stations in Canada, and the loss of many SIberian stations after the fall of the USSR coincides rather well with the divergence. It couldn’t be that simple could it?

    No, I think there was a little warming in late 20th century, (or to qualify that we had some milder NH winters), but I am open to thinking that the big datasets have been statistically tortured / corrupted (mostly inadvertently rather than maliciously except for Hansen’s GISS perhaps). The satellite data is key here, but the fact that we only have 30 years of it doesn’t help much.

    Final thought – I have just remembered Prof Vincent Courtillot’s brilliant presentation at the EIKE 2010 conference – his analysis of regional temperature trends is from 5 minutes onwards, and identifies 1986 as the year the European temps suddenly rise, (and confirms that the 20th century trends for the US and Europe are incongruous, and not what the IPCC models suggest).

  7. I’m sure Lapogus is on to at least part of the issue.

    I’d say, it’s the thermometers first, middle, and last. First, as Lapogus says, there was a stupid abandonment of all the best rural records about this time. Middle, we know that UHI has not, repeat not, been dealt with properly, see my page. Last, since the satellite temperature sensors are calibrated by land data that is likely distorted, they too are suspect – in a way that few will even think to consider.

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