— Ch. 1 · The Observatory On The Volcano —
Keeling Curve.
~3 min read · Ch. 1 of 6
In 1958, Charles David Keeling installed infrared gas analyzers on the slopes of Mauna Loa. This remote location sat far from continents and lacked vegetation to ensure clean data. The International Geophysical Year provided funding for this ambitious project. Scientists needed a place where local pollution would not skew their readings. They chose the volcano specifically because it stood above the thermal inversion layer. Incoming ocean breezes carried air that represented the free atmosphere over the Northern Hemisphere. Keeling measured samples taken during these specific wind patterns to avoid volcanic vent contamination. He normalized all data to remove any remaining influence from local sources. This careful selection process laid the foundation for decades of continuous monitoring.
From Pen Traces To Laser Sensors
John Tyndall invented the first instrument for measuring carbon dioxide in 1864. Early devices recorded results as pen traces on strip chart recorders. These machines were originally called capnographs and used infrared spectrophotometers. Modern operations at Scripps now run laser-based sensors alongside the original technology. NOAA measurements at Mauna Loa still rely on nondispersive infrared sensors today. Calibration uses World Meteorological Organization standards to maintain accuracy across time. The evolution from simple ink lines to complex digital lasers reflects fifty years of technological progress. Each new sensor type improved precision while keeping the core measurement method intact. Scientists continue to add new tools to run concurrently with older systems.