Still crazy after all these years

Nearly 21 years ago on ‘Earth Day’ April 1998 the “Hockey Stick” temperature graph was presented to the world by Michael Mann.

It was not quite so dramatic, colourful and flash as the one above; in subsequent graphs the handle got extended and colour was added.

But for all that, it sure made an impact. It became part of the IPCC gospel and an article of faith for, and an icon to be worshipped by, the Global Warming religion.

Here’s the original 1998 version.

Original ?hockey stick? temperature graph in Nature, 1998. The Y axis shows the Northern hemisphere mean temperature, in degrees Celsius; the zero line corresponds to the 1902 ? 1980 mean. Credit: ?Global-scale Temperature Patterns and Climate Forcing over the Past Six Centuries,? by Michael E. Mann et al. in Nature, Vol. 392, April 23, 1998

To produce this dramatic graph showing how evil our ‘fossil’ fuel burning habits were, Mann had reconstructed the past temperatures from tree ring data (there was no one reading thermometers back then and recording the results) and then added on to the end of that series the ‘modern’ temperature data.

All pretty reasonable, one might think. But it wasn’t.

It is not good science to splice two different data sets together. Also, the subsequent Climategate email dump released information that the tree ring data was from just one tree on the Yamal peninsula in Siberia (YADO61). It also seems that this tree was not representative of the rest of the Bristlecone pines in the area. Other trees showed evidence of the Medieval Warm Period, which doesn’t sit well with the ‘fossil’-fuel-is-causing-it-all narrative — but that is another whole tale of deception.

It got worse when in 2003 a Canadian statistician, Steve McIntyre, and his colleague Professor Ross McKitrick, showed how the graph had been fabricated by a computer model that produced “hockey stick” graphs whatever random data were fed into it, but that is yet another whole tale of deception.

The first part of the deception in this graph is the fact that any data that did not agree with the output they wanted was simply truncated and discarded. This has recently been graphically illustrated by cartoonist Josh.

Michael Mann is on the left and the critical part is scenes 2 and 3 in the cartoon. Tree ring data, his historical “temperature” gauge, went down in the modern era when the measured temperatures were rising. An inconvenient truth which was therefore discarded.

The naughty data that went the wrong way and was thus deleted

Such has been the modus operandi of many of the climate doomsayers.

The really incredible thing is that on the twentieth anniversary of this graph, Mann was still defending it in Scientific American. quote.

Two decades ago this week a pair of colleagues and I published the original ?hockey stick? graph in Nature, which happened to coincide with the Earth Day 1998 observances. The graph showed Earth?s temperature, relatively stable for 500 years, had spiked upward during the 20th century. A year later we would extend the graph back in time to A.D. 1000, demonstrating this rise was unprecedented over at least the past millennium?as far back as we could go with the data we had. […]

Yet, in the 20 years since the original hockey stick publication, independent studies again and again have overwhelmingly reaffirmed our findings, including the key conclusion: recent warming is unprecedented over at least the past millennium. end quote.


This is just one instance of one graph in “the science is settled” world that our politicians inhabit.

  1. Cherry pick data from one tree only.
  2. Splice together two very different data sets.
  3. Use a model that produces a hockey stick with random data.
  4. Cut out and discard contrary data.
  5. Continue to preach it after the skeptics prove you wrong.