hockey stick graph, definition of

The hockey stick graph refers to the plot of temperature over the last 1000 years that shows a gradual temperature decline, until the early 20th century - then there is a 'ramp up' in temperature to a point not previously obtained in the proceeding 1000 years; hence demonstrating man's effect on the climate through industrialization. Made famous (or infamous) by its use in the 'Inconvenient Truth'.

The 'significance' of the graph as a true indicator of temperature (and especially the effective unprecedented temperature increases) has been a point of strong debate since it was published some ten years ago. Also the way the graph has been presented (smoothed/unsmoothed with or without error bands or indications of data sources and combinations there of) has lead to further controversy and heated discussions. Also the fact only 1000 years are presented, when we have proxies that go back many thousands of years is also a point of discussion.

For more background information see here .

• Mark Steyn ordered to pay $1 million to deter climate deniers from criticizing sacred scientists
  The “hockey stick” graph as published in IPCC TAR (Figure 2-20, 2001) By Jo Nova Climate deniers must be punished For newcomers: Michael Mann’s hockeystick graph was wildly different from hundreds of studies of other studies and instantly became...
• The Guardian wins Voodoo Bingo — little Ice Age caused by Volcanoes, White men and CO2
  The Wheels Slowly Turn on the Shifting Sands of The Narrative After years of saying the Little Ice Age was just a European, or Northern Hemisphere event, now apparently it was more global...
• Hockeysticks don’t die, they just get more corrupt
  “The IPCC remains addicted to hockeysticks”
• Finally Hockeystick secret science emails to be released
  The Hockeystick graph rewrote history and was used to justify billions of dollars of expenditure. The people who created it were public servants dedicated to science and writing businesslike emails to each other — which is why they fought tooth...
• Who needs to update the HockeyStick graph – it’s only the fate of the planet at stake?
  Two weeks ago on the HockeyStick Update post we discussed the miracle of how the Bristlecones used in HockeyStick graphs had finally (sort of) been updated...
• HockeyStick, finally updated with modern trees, collapses
  You’ll be shocked that after decades of studying 800 year old tree rings, someone has finally found some trees living as long ago as 2005. These rarest-of-rare tree rings have been difficult to find, compared to the rings circa Richard III. The...
• “Mike’s trick” to hide the decline — still shocking
  Jean S revisited “Black Tuesday” with a post on Climate Audit. Even though I’ve seen these graphs before. It is still so arresting:
• Mann’s trick to hide the decline — still shocking
  Jean S revisited “Black Tuesday” with a post on Climate Audit. Even though I’ve seen these graphs before. It is still so arresting:
• Matt Ridley on Tamiflu-gate. Hidden data, omitted trials, “like the Hockey Stick Graph”
  Matt Ridley looks at pharmaceutical research and finds problems of confirmation bias, lack of access to data, and lack of replication of results. He compares it to the hockey stick debacle which is rising in notoriety to become the new benchmark of bad...
• The Marcott Hockey-stick: smoothing the past and getting a spike from almost no data?
  The message to the world is unequivocal: “We are heading for somewhere that is far off from anything we have seen in the past 10,000 years – it’s through the roof...

Related Tags: climate change, global warming