• 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 / Archives for Extras

Extras

Comment policy

9 Dec 2004 by group

  1. Comments are moderated. Comments are periodically reviewed, but especially at weekends, evenings and holidays, there may be some delay in approving otherwise non-contentious posts. Please be patient.
  2. Questions, clarifications and serious rebuttals and discussions are welcomed.
  3. Only comments that are germane to the post will be approved. Comments that are “off-topic” should be made on an open thread (usually entitled “Unforced Variations”), and we may move OT comments to those threads.
  4. Comments that contain links to inappropriate, irrelevant or commercial sites may be deleted.
  5. Discussion of non-scientific subjects is discouraged.
  6. No flames, profanity, ad hominem comments are allowed. This includes comments that (explicitly or implicitly) impugn the motives of others, or which otherwise try to personalize matters under discussion.
  7. We reserve the right to make spelling corrections, correct text format problems, etc.
  8. We use moderation to improve the “signal to noise” in the discussion. For this reason, we may choose to screen out comments that simply repeat points made in previous comments, make claims that have already been dealt with or that “muddy the water” by introducing erroneous, specious, or otherwise misleading assertions. These comments may be sent to “The Bore Hole“.
  9. We reserve the right to either reject comments that do not meet the above criteria, or in certain cases to edit them in a manner that brings them into accordance with our comments policy (e.g. by simply deleting inflammatory or ad hominem language from an otherwise worthy comment). In cases where we do this, it will be noted by an [edit].
  10. Given that RealClimate represents a volunteer effort by about 10 different contributors, each of whom are free to participate in queue moderation, the items indicated above only constitute the basic ground rules. We cannot insure uniform application of the various considerations listed above from one individual comment to the next.
  11. Quick responses to questions that don’t merit a full post will be placed in-line (with credits).
  12. All comments are assumed to be released into the public domain.
  13. Comments generally close after a month.
  14. Repeat violators of our comments policy (in particular, individuals demonstrating a pattern of “trolling”) may be barred from future access to the blog.

revised 01/06/11

Filed Under: Comment Policy

Weren’t temperatures warmer than today during the “Medieval Warm Period”?

8 Dec 2004 by mike

Translations: (Français)

This is one of a number of popular myths regarding temperature variations in past centuries. At hemispheric or global scales, surface temperatures are believed to have followed the “Hockey Stick” pattern, characterized by 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. The late 20th century warmth, at hemispheric or global scales, appears, from a number of recent peer-reviewed studies, to exceed the peak warmth of the “Medieval Warm Period”. Claims that global average temperatures during Medieval times were warmer than present-day are based on a number of false premises that a) confuse past evidence of drought/precipitation with temperature evidence, b) fail to disinguish regional from global-scale temperature variations, and c) use the entire “20th century” to describe “modern” conditions , fail to differentiate between relatively cool early 20th century conditions and the anomalously warm late 20th century conditions.

Filed Under: Climate Science, FAQ, Paleoclimate

OK, But we do know it was warmer than present 6000 years ago, don’t we?

8 Dec 2004 by mike

Translations: (Français)

This is yet another oft-repeated but problematic assertion based in this case on the mis-characterization of the so-called Mid-Holocene Climatic Optimum” or “Mid-Holocene Warm Period”. Paleoclimate experts now know that the mid-Holocene warmth centered roughly 8000 to 6000 years ago was probably restricted to high latitudes and certain seasons (summer in the Northern Hemisphere and winter in the southern hemisphere). Because much of the early paleoclimate evidence that was available (for example, fossil pollen assemblages) came from the Northern Hemisphere extratropics, and is largely reflective of summer conditions, decades ago some scientists believed that this was a time of globally warmer conditions. More abundant evidence now demonstrates, for example, that the tropical regions were cooler over much of the year.

[Read more…] about OK, But we do know it was warmer than present 6000 years ago, don’t we?

Filed Under: Climate Science, FAQ, Paleoclimate

Why does the stratosphere cool when the troposphere warms?

7 Dec 2004 by Gavin

Translations: (Français)

This post is obsolete and wrong in many respects. Please see this more recent post for links to the answer.

14/Jan/05: This post was updated in the light of my further education in radiation physics.
25/Feb/05: Groan…and again.

Recent discussions of climate change (MSU Temperature Record, ACIA) have highlighted the fact that the stratosphere is cooling while the lower atmosphere (troposphere) and surface appear to be warming. The stratosphere lies roughly 12 to 50 km above the surface and is marked by a temperature profile that increases with height. This is due to the absorbtion by ozone of the sun’s UV radiation and is in sharp contrast to the lower atmosphere. There it generally gets colder as you go higher due to the expansion of gases as the pressure decreases. Technically, the stratosphere has a negative ‘lapse rate’ (temperature increases with height), while the lower atmosphere’s lapse rate is positive.

[Read more…] about Why does the stratosphere cool when the troposphere warms?

Filed Under: Attic

Contributors

6 Dec 2004 by group

The current contributors to content on this site are:

  • Gavin Schmidt
  • Michael Mann
  • Rasmus Benestad
  • Stefan Rahmstorf
  • Eric Steig

William Connolley was a contributor, but has now left academia; Ray Bradley, David Archer, and Ray Pierrehumbert are no longer active; Jim Bouldin was a contributor from 2009 and Caspar Ammann and Thibault de Garidel were early supporters of the site. Group posts can be assumed to be the from the whole set of current contributers, or will be individually signed.

Filed Under: Contributor Bio's

Gavin A. Schmidt

6 Dec 2004 by Gavin

Gavin Schmidt is a climate modeller at the NASA Goddard Institute for Space Studies and Earth Institute at Columbia University in New York and is interested in modeling past, present and future climate. He works on developing and improving coupled climate models and, in particular, is interested in how their results can be compared to paleoclimatic proxy data. He has worked on assessing the climate response to multiple forcings, including solar irradiance, atmospheric chemistry, aerosols, and greenhouse gases.

He received a BA (Hons) in Mathematics from Oxford University, a PhD in Applied Mathematics from University College London and was a NOAA Postdoctoral Fellow in Climate and Global Change Research. He was cited by Scientific American as one of the 50 Research Leaders of 2004, and has worked on Education and Outreach with the American Museum of Natural History, the College de France and the New York Academy of Sciences. He has over 100 peer-reviewed publications and is the co-author with Josh Wolfe of “Climate Change: Picturing the Science” (W. W. Norton, 2009), a collaboration between climate scientists and photographers. He was awarded the inaugural AGU Climate Communications Prize and was the EarthSky Science communicator of the year in 2011. He tweets at @ClimateOfGavin.

More information about his research and publication record can be found here.

All posts by gavin.

Filed Under: Contributor Bio's, Extras

Michael E. Mann

6 Dec 2004 by mike

Dr. Michael E. Mann is Presidential Distinguished Professor in the Department of Earth and Environmental Science at the University of Pennsylvania, with a secondary appointment in the Annenberg School for Communication. He is director of the Penn Center for Science, Sustainability, and the Media (PCSSM).

Dr. Mann received his undergraduate degrees in Physics and Applied Math from the University of California at Berkeley, an M.S. degree in Physics from Yale University, and a Ph.D. in Geology & Geophysics from Yale University. His research involves the use of theoretical models and observational data to better understand Earth’s climate system.

Dr. Mann was a Lead Author on the Observed Climate Variability and Change chapter of the Intergovernmental Panel on Climate Change (IPCC) Third Scientific Assessment Report in 2001 and was organizing committee chair for the National Academy of Sciences Frontiers of Science in 2003. He has received a number of honors and awards including NOAA’s outstanding publication award in 2002 and selection by Scientific American as one of the fifty leading visionaries in science and technology in 2002. He contributed, with other IPCC authors, to the award of the 2007 Nobel Peace Prize. He was awarded the Hans Oeschger Medal of the European Geosciences Union in 2012 and was awarded the National Conservation Achievement Award for science by the National Wildlife Federation in 2013. He made Bloomberg News’ list of fifty most influential people in 2013. In 2014, he was named Highly Cited Researcher by the Institute for Scientific Information (ISI) and received the Friend of the Planet Award from the National Center for Science Education. He received the Stephen H. Schneider Award for Outstanding Climate Science Communication from Climate One in 2017, the Award for Public Engagement with Science from the American Association for the Advancement of Science in 2018 and the Climate Communication Prize from the American Geophysical Union in 2018. In 2019 he received the Tyler Prize for Environmental Achievement and in 2020 he received the World Sustainability Award of the MDPI Sustainability Foundation. He was elected to the U.S. National Academy of Sciences in 2020. He is a Fellow of the American Geophysical Union, the American Meteorological Society, the Geological Society of America, the American Association for the Advancement of Science, and the Committee for Skeptical Inquiry. He is also a co-founder of the award-winning science website RealClimate.org.

Dr. Mann is author of more than 200 peer-reviewed and edited publications, numerous op-eds and commentaries, and four books including Dire Predictions: Understanding Climate Change, The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, The Madhouse Effect, The Tantrum that Saved the World and The New Climate War; He is co-founder of RealClimate.

More information about his research and publication record can be found here.

All posts by mike.

Filed Under: Contributor Bio's

Caspar Ammann

6 Dec 2004 by group

Caspar Ammann is a climate scientist working at the National Center for Atmospheric Research (NCAR). Dr. Ammann is interested in the reconstruction of natural climate forcings, natural climate variability, coupled modeling of natural and anthropogenic climate change, and data/model intercomparison. Dr. Ammann got his B.S. from Gymnasium Koeniz (Switzerland), his M.S. from the University of Bern (Switzerland), and a Ph.D. from the Department of Geosciences at the University of Massachusetts.

Filed Under: Contributor Bio's

Rasmus E. Benestad

6 Dec 2004 by rasmus

I am a physicist by training and have affiliations with the Norwegian Meteorological Institute [My views here are personal and may not necessarily represent those of Met Norway]. I have a D.Phil in physics from Atmospheric, Oceanic & Planetary Physics at Oxford University in the United Kingdom.

Recent work involve a good deal of statistics (empirical-statistical downscaling, trend analysis, model validation, extremes and record values), but I have also had some experience with electronics, cloud micro-physics, ocean dynamics/air-sea processes and seasonal forecasting. In addition, I wrote the book ‘Solar Activity and Earth’s Climate’ (2002), published by Praxis-Springer, and together with two colleagues the text book ‘Empirical-Statistical Downscaling’ (2008; World Scientific Publishers). I have also written a number of R-packages for climate analysis posted http://cran.r-project.org.

I was a member of the council of the European Meteorological Society for the period (2004-2006), representing the Nordic countries and the Norwegian Meteorology Society, and have served as a member of CORDEX Task Force on Regional Climate Downscaling.

In my work, I often get questions from media and lay persons about climate change. I believe it is necessary to approach these questions with identifying what we really don’t know and what we are more sure about. I believe that some of Karl Popper ideas about falsification can be useful.

[Read more…] about Rasmus E. Benestad

Filed Under: Contributor Bio's

Raymond S. Bradley

6 Dec 2004 by Ray Bradley

Ray Bradley is Director of the Climate System Research Center (www.paleoclimate.org) at the University of Massachusetts, Amherst and a University Distinguished Professor in the Department of Geosciences. His interests are in climate variability and why climate changes, over a wide range of timescales. He did his graduate work at the Institute of Arctic and Alpine Research, University of Colorado, Boulder. He has written or edited ten books on climatic change, and authored more than 100 refereed articles on the subject. In 2004, he received a Doctor of Science (D.Sc) degree from Southampton University (U.K.) for his contributions to the field of paleoclimatology.

Ray Bradley has been an advisor to various government and international agencies, including the U.S., Swiss, Swedish, and U.K. National Science Foundations, the National Oceanic and Atmospheric Administration (NOAA), the U.S. National Research Council, the Inter-Governmental Panel on Climate Change (IPCC), the US-Russia Working Group on Environmental Protection, and the International Geosphere-Biosphere Program (IGBP), Stockholm.

More information about his research and publication record can be found here.

Filed Under: Contributor Bio's

  • « Go to Previous Page
  • Page 1
  • Interim pages omitted …
  • Page 8
  • Page 9
  • Page 10
  • Page 11
  • Page 12
  • Interim pages omitted …
  • Page 15
  • Go to Next Page »

Primary Sidebar

Search

Search for:

Email Notification

get new posts sent to you automatically (free)
Loading

Recent Posts

  • Unforced variations: Jun 2025
  • Predicted Arctic sea ice trends over time
  • The most recent climate status
  • Unforced variations: May 2025
  • Unforced Variations: Apr 2025
  • WMO: Update on 2023/4 Anomalies

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

  • Steven Emmerson on Predicted Arctic sea ice trends over time
  • Kevin McKinney on Unforced variations: Jun 2025
  • Kevin McKinney on The most recent climate status
  • Kevin McKinney on Unforced variations: Jun 2025
  • Kevin McKinney on Unforced variations: Jun 2025
  • Kevin McKinney on Unforced variations: Jun 2025
  • Susan Anderson on Unforced variations: Jun 2025
  • Susan Anderson on Unforced variations: Jun 2025
  • Barton Paul Levenson on Unforced variations: Jun 2025
  • Barton Paul Levenson on Unforced variations: Jun 2025
  • Barton Paul Levenson on Unforced variations: Jun 2025
  • Barton Paul Levenson on The most recent climate status
  • William on Unforced variations: Jun 2025
  • William on Unforced variations: Jun 2025
  • William on The most recent climate status
  • William on Predicted Arctic sea ice trends over time
  • William on Predicted Arctic sea ice trends over time
  • William on Predicted Arctic sea ice trends over time
  • Nigelj on Predicted Arctic sea ice trends over time
  • b fagan on Unforced variations: Jun 2025

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

1,367 posts

11 pages

243,551 comments

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