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The Hockey Stick and Climate Change

The Hockey Stick and Climate Change

The climate change statistics war seems set to run until one side scores the final goal.

The hockey stick is the simple curve at the end of a straight line.
It can go left or right – but it will always head in the opposite direction to the original line.

Many years ago I read what seemed very considered piece on the looming issue of climate change and the connection with human-made carbon dioxide emissions.

It was very impressive – and very scary. Here was clear and incontrovertible proof that the central plank of climate change, CO2 emissions, had started as the industrial revolution had revved up and ballooned in volume since the start of the 20th century.

The increase in CO2 in our atmosphere had created and accelerated a temperature warming phase unprecedented in the history of mankind.

This was Michael Man’s famous ‘hockey stick’ and rarely has a scientific theory or hypothesis been accepted with such universal enthusiasm.

The Canadian government embraced the theory and sent hockey stick graphs to every high school – proclaiming the 1990’s to be the warmest decade of the millennium.

Al Gore’s ‘Inconvenient Truth’ was based substantially on the hockey stick theory and the U.K. government as so impressed it arranged for a copy of ‘Inconvenient Truth’ to be sent to every school in the country.

Doctor Mann was lauded as one of the great scientists or our time. However two Canadian researchers gained access to Mann’s papers and painstaking analysis revealed Mann had manipulated and weighted figures to give the resultant outcome a ‘hockey stick’ look.

This graph shows the comparison.



Mann supporters counter-attacked but there was enough disquiet to see a U.S. Senate Committee of Inquiry check out both Mann and his critics. The findings were damning.

“Our Committee believes the assessments that the decade of the 1990’s was the hottest decade in a millennium and that 1998 was the hottest year in a millennium cannot be supported by MBH98/99 ( The technical name for Mann’s original ‘hockey-stick paper). 

The Intergovernmental Panel on Climate Change has virtually ignored the findings of the U.S. inquiry and still uses ‘the hockey stick’ in campaigns about climate change.

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