Sensing the Skies: Environmental Apprehension and the Instrumentation Revolution (Invited Presentation)

How have instruments changed the ways that we understand and respond to environmental change? Historians of science use the term “instrumentation revolution” to describe a transformative change in chemistry caused by the development of electronic, physics-based analytical instruments during the 1930s-1960s. This paper extends that insight into atmospheric science. New instruments transformed the way that scientists could apprehend the atmosphere, in the dual senses of catching it, and understanding it (Fleming 1998). This paper sketches key moments in that story. Scientists using oxidant recorders and ozonesondes discovered that smog was a photochemical product of automobiles and gasoline, rather than industrial soot. New instruments enabled scientists to measure the circulation of the atmosphere, from blunt measurements of air masses using radiosondes beginning in the 1930s, to the fine-grained measurement of acid rain causing pollutant dispersion using tracer gases detected through gas chromatography and the electron capture detector. This paper also connects instrumental measurements to a third meaning of apprehension: concern and anxiety. While Lester Machta’s use of an oxygen analyzer helped dispel the brief but intense anxiety about an oxygen depletion crisis in 1970 (Henderson and Turner 2018), Dave Keeling’s adaptation of a non-dispersive IR gas analyzer enabled one of the most iconic representations of today’s climate crisis (Howe 2015).