re-5: global warming – The official NOAA ice core data


Richard Moore

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Corresponding newslog article:

The NOAA website:


In the above newslog article there are some charts, allegedly derived from Greenland ice cores. Not wanting to trust the source, I went to the official NOAA government site, and downloaded the raw data from the ice cores into Excel. I used Excel’s charting feature, and compared it to the graphs. They are accurate. This is the official temperature history from the ice cores, the most reliable long-term indicator we have for global temperatures.
If we look at temperatures since 1400, we see the familiar IPCC hockey stick:
However, if we go back to 800 AD, we see a very significant Medieval Warm Period:

And when we go back to 3,000 BC, which basically covers the history of civilization, we see we are currently at a relatively low temperature, and that our current upward spike is not at all unusual. If we are entering a new warm period, it is likely to be less than the Medieval Period, as the peaks have been steadily declining:

When we go back to 9,000 BC, which is basically since agriculture was developed, we again see that temperatures have been gradually declining, since we recovered from the last ice age:

When we go back to 11,000 BC, we see how we’re still on a relative plateau from the last ice age:

Going bak to 50,000 BC, we see a lot of temperature variation during the ice age:

Going back to 400,000 BC, we see a very clear cyclical pattern, and we see that we’re beginning the decline into the next ice age:

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