50 years measuring the cleanest air

Summary

1 April 2026 News Release Australia marks 50 years of monitoring the worlds cleanest air in remote northwest Tasmania at Kennaook / Cape Grim Baseline Air Pollution Station, supporting global efforts to track human-driven changes to the atmosphere. Perched above cliff tops in north-west Tasmania, the station plays a critical role in measuring the composition of the atmosphere, including greenhouse gases such as carbon dioxide (CO₂), methane, as well as reactive gases and aerosols, and more than 80 polluting gases including ozone depleting substances such as chlorofluorocarbons (CFCs). Australia’s national science agency CSIRO uses the data to undertake research on the composition of the atmosphere, to track and understand how it’s changing. The Bureau of Meteorology funds and operates the facility. Measurements at the site began on April 1, 1976. The location was chosen due to its position facing the vast Southern Ocean that brings very clean ‘baseline air’ that has travelled thousands of kilometres uninterrupted by land or recent human influence. CSIRO Senior Principal Research Scientist Dr Melita Keywood said Kennaook / Cape Grim delivers vital data for Australia’s climate research, and internationally. “The long-term data we collect at Kennaook / Cape Grim is critical for understanding changes in the atmosphere over time and how to manage them in the future," Dr Keywood said. “For example, we have seen an ongoing increase in CO₂ over the last 50 years from human-induced activities. “However, we have also seen a decrease in the pollutant black carbon and ozone-depleting substances like CFC-11, showing us that international efforts to reduce pollution, like the Montreal Protocol, can be effective.” For 24 hours a day, air is drawn through several inlets—one located 80 metres up a tower—and analysed in real time to measure atmospheric compounds to track the drivers of climate change and ozone depletion. Each season, scientists collect air samples into air tanks that...