• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

RealClimate

Climate science from climate scientists...

  • Start here
  • Model-Observation Comparisons
  • Miscellaneous Climate Graphics
  • Surface temperature graphics
You are here: Home / Extras / Glossary / Hockey Stick

Hockey Stick

28 Nov 2004 by group

Instrumental data describing large-scale surface temperature changes are only available for roughly the past 150 years. Estimates of surface temperature changes further back in time must therefore make use of the few long available instrumental records and natural archives or ‘climate proxy’ indicators, such as tree rings, corals, ice cores and lake sediments, and historical documents, to reconstruct patterns of past surface temperature change. Due to the paucity of data in the Southern Hemisphere, recent studies have emphasized the reconstruction of Northern Hemisphere (NH) mean, rather than global mean temperatures over roughly the past 1000 years.

The term “Hockey Stick” was coined by the former head of NOAA’s Geophysical Fluid Dynamics Laboratory, Jerry Mahlman, to describe the pattern common to numerous proxy and model-based estimates of Northern Hemisphere mean temperature changes over the past millennium. This pattern includes a long-term cooling trend from the so-called “Medieval Warm Period” (broadly speaking, the 10th-mid 14th centuries) through the “Little Ice Age” (broadly speaking, the mid 15th-19th centuries), followed by a rapid warming during the 20th century that culminates in anomalous late 20th century warmth (Figure 1). Numerous myths regarding the “hockey stick” can be found on various non-peer reviewed websites and other non-scientific venues.

Filed Under: Glossary

Primary Sidebar

Search

Search for:

Email Notification

get new posts sent to you automatically (free)
Loading

Recent Posts

  • “But you said the ice was going to disappear in 10 years!”
  • Time and Tide Gauges wait for no Voortman
  • Lil’ NAS Express
  • DOE CWG Report “Moot”?
  • Climate Scientists response to DOE report
  • Critique of Chapter 6 “Extreme Weather” in the DOE review

Our Books

Book covers
This list of books since 2005 (in reverse chronological order) that we have been involved in, accompanied by the publisher’s official description, and some comments of independent reviewers of the work.
All Books >>

Recent Comments

  • Susan Anderson on Unforced Variations: Sep 2025
  • Susan Anderson on “But you said the ice was going to disappear in 10 years!”
  • Steven Emmerson on Unforced Variations: Sep 2025
  • Mal Adapted on “But you said the ice was going to disappear in 10 years!”
  • Mal Adapted on “But you said the ice was going to disappear in 10 years!”
  • zebra on “But you said the ice was going to disappear in 10 years!”
  • Paul Pukite (@whut) on Unforced Variations: Sep 2025
  • Piotr on “But you said the ice was going to disappear in 10 years!”
  • Paul Pukite (@whut) on “But you said the ice was going to disappear in 10 years!”
  • Killian on Unforced Variations: Sep 2025
  • Atomsk’s Sanakan on “But you said the ice was going to disappear in 10 years!”
  • JCM on Unforced Variations: Sep 2025
  • Barry E Finch on “But you said the ice was going to disappear in 10 years!”
  • Barry E Finch on “But you said the ice was going to disappear in 10 years!”
  • Barry E Finch on Unforced Variations: Sep 2025
  • Killian on Unforced Variations: Sep 2025
  • jgnfld on Unforced Variations: Sep 2025
  • Thomas Fuller on “But you said the ice was going to disappear in 10 years!”
  • Mo Yunus on Unforced Variations: Sep 2025
  • Mo Yunus on Unforced Variations: Sep 2025
  • Mo Yunus on Unforced Variations: Sep 2025
  • Mo Yunus on Unforced Variations: Sep 2025
  • Pete best on “But you said the ice was going to disappear in 10 years!”
  • Mal Adapted on “But you said the ice was going to disappear in 10 years!”
  • Jim O'Hara on “But you said the ice was going to disappear in 10 years!”
  • b fagan on Time and Tide Gauges wait for no Voortman
  • Piotr on Unforced Variations: Sep 2025
  • Mo Yunus on “But you said the ice was going to disappear in 10 years!”
  • Mal Adapted on “But you said the ice was going to disappear in 10 years!”
  • Mo Hummus on Time and Tide Gauges wait for no Voortman

Footer

ABOUT

  • About
  • Translations
  • Privacy Policy
  • Contact Page
  • Login

DATA AND GRAPHICS

  • Data Sources
  • Model-Observation Comparisons
  • Surface temperature graphics
  • Miscellaneous Climate Graphics

INDEX

  • Acronym index
  • Index
  • Archives
  • Contributors

Realclimate Stats

1,382 posts

11 pages

247,040 comments

Copyright © 2025 · RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists.