Plotting the data

Now I've been defied to graph together Christchurch's temperature record with the Atmospheric CO2 content.

Well, that's a silly question, for two reasons.

  1. nobody ever said that temperature and CO2 are linearly related. Well, they roughly are on the scale of 1000 years or so, but basically there isn't enough data to see the kind of direct correlation being challenged for.
  2. it's about global mean average, any particular random spot might show quite some discrepancy between that and the global average.

But if you go ahead anyway, and compare it to the GISS record, you can see that it's not that unlike the average.

GISS record for Christchurch: 5 year rolling average

How I produced the above: first, I took a 60-month rolling average of the Christchurch temperature record. That's the blue line on the graph. Then I added the GISS anomalies, baselined to the 1951-1980 period (as the GISS record is). The Northern Hemisphere line is yellow, and the Southern Hemisphere is in Red. The green line in between is the global average.

Things to notice:

  1. While I haven't plotted a trend line, the overall upward trend is visible
  2. ChristChurch has many upward peaks at about the same time as the global data
  3. The assertion that Global Warming is a NH-only phenomenon is not what the data says