This video looks at the scientific research to answer three basic questions: 1) Was the Medieval Warm Period global? 2) Was it warmer than today? 3) And what does this all mean anyway? I examine the internet feud over the hockey stick and the various myths and misinterpretations about the Medieval Warm Period that seem to be rife on the Internet. My sources for the myths are blogs and videos; my sources for the facts are scientific papers.


  1. #1 sailor
    July 28, 2012

    There are stories of viking ships getting damaged by marine borers in UK waters. When I left the UK in the 70’s the only place the water in the UK was warm enough for this to be a problem was near the outlets of atomic power plants. The water might have warmer back in Viking days, or the stories might be innaccurate.

  2. #2 Greg Laden
    July 28, 2012

    Or, given the way Viking stories go, the “UK” could have been “Italy” or something.

  3. #3 anthrosciguy
    July 28, 2012

    In a quick internet search I only found a mention of Viking ships infested with shipworms after a trip from Vinland to Greenland. This suggests either that these shipworms did alright enough in cold similar to that found around the UK, or a misdiagnosis, or???.

  4. #4 Amoeba
    July 28, 2012

    Teredo distribution map

    Native range: China, Faeoe Islands, Iceland, Japan, Korea Republic, Norway, Taiwan

    Google Scholar turns up a number of hits for Viking and Teredo, but the ones I looked at were hidden behind a paywall so that was that.
    Apparently there aren’t any Teredo in the Baltic.

  5. #5 Alan
    July 29, 2012

    For those of you who haven’t seen one before, Peter Sinclair is what an investigative journalist looks like. His “climate crock of the week” series on youtube is an outstanding example of genuine skepticisim.

  6. #6 Alan
    July 29, 2012

    Opps, I meant Peter Hadfield. o_0