I'll be presenting 'Sea Level: A History' at the Greenhouse Book Talks on January 27 at 16:00 CET. Join me to discover how our main geodetic baseline was created and how reference systems serve as powerful environing tools, starting with the conceptual history of mean sea level. More information at: https://newnatures.org/greenhouse/events/booktalk/online-book-talk-graf-von-hardenberg-sea-level/ #envhist #histsci