The world’s longest continuous carbon dioxide (CO?) measurement series has been interrupted by an eruption of Mauna Loa, the largest active volcano on Earth. The Mauna Loa Observatory (MLO) in Hawaii, located at an altitude of 3,397 meters on the northern flank of the volcano, is one of the most important facilities for climate research. The long-term experiment of researcher Charles Keeling, installed in 1958, has been documenting the CO? content in the atmosphere ever since. The graphical representation of the CO? concentration trend, known as the “Keeling Curve,” is considered evidence of anthropogenic climate change. The measurement series is the longest continuous record of its kind. However, an eruption of Mauna Loa has now interrupted the series.
On Monday, lava flows erupted from several fissures of the world’s largest active volcano for the first time since 1984. The largest lava flow reached the access road to the Mauna Loa Observatory, cutting off the power supply to the measurement station. As a result, the measurements had to be discontinued, and the research facility is currently inaccessible. It is unclear when the MLO can resume operations. Fortunately, no employees were injured or killed in the incident, and the lava has not yet reached inhabited areas.
At present, the atmospheric CO? concentration is 415 parts per million (ppm), according to data from the National Oceanic and Atmospheric Administration (NOAA). Ralph Keeling, an atmospheric scientist and longtime director of the measurement station, stated in an interview with New Scientist that the CO? measurement will continue. However, since it could take several months to restore the power supply, the responsible parties are considering retrieving the measuring devices and relocating them to another location. The measurement series was interrupted only twice before, in the 1960s due to budget cuts and in 1984 due to an eruption of Mauna Loa. Charles Keeling chose the Mauna Loa volcano in Hawaii as the location for the measurement station in the 1950s because there were no continuous sources of interference such as industrial plants nearby. Occasional disruptions of the CO? measurement series due to volcanic activity can be easily filtered out.
