A picture’s worth the right words

The October 2020 issue of Physics Today included an item (page 26 ) by David Kramer entitled “The Great Lakes are filled to their brims, with no signs of receding.” Kramer writes, “Water levels have always fluctuated on the Great Lakes, but the recent extreme seesawing, particularly on the upper lakes—Superior, Michigan, and Huron—is unprecedented in the century that records have been kept…. Michigan and Huron, which are linked and share the same level, stood at record highs in August, 84 cm above their historic average.”

The article is interesting, and I do not dispute its general theme. However, the above quoted statement is misleading in that it is not a sound interpretation of the accompanying charts. They clearly show that the “record high” in August 2020 was matched by a similar high around 1987, and fluctuations do not appear significantly greater in recent years than those over the century since 1918. In fact, in 2000–2014, the levels were consistently below the long-term average.

Data presented in a scientific report should be seen to support the arguments and conclusions made. That is particularly important now, when the reliability of “the science” is under sharp scrutiny in disputes about such matters as climate change and epidemiology.