PLEA Network

4 July 2025, The Conversation: Mauna Loa Observatory captured the reality of climate change. The US plans to shut it down. The greenhouse effect was discovered more than 150 years ago and the first scientific paper linking carbon dioxide levels in the atmosphere with climate change was published in 1896. But it wasn’t until the 1950s that scientists could definitively detect the effect of human activities on the Earth’s atmosphere. In 1956, United States scientist Charles Keeling chose Hawaii’s Mauna Loa volcano for the site of a new atmospheric measuring station. It was ideal, located in the middle of the Pacific Ocean and at high altitude away from the confounding influence of population centres. Data collected by Mauna Loa from 1958 onward let us clearly see the evidence of climate change for the first time. The station samples the air and measures global CO₂ levels. Charles Keeling and his successors used this data to produce the famous Keeling curve – a graph showing carbon dioxide levels increasing year after year. But this precious record is in peril. US President Donald Trump has decided to defund the observatory recording the data, as well as the widespread US greenhouse gas monitoring network and other climate measuring sites. We can’t solve the existential problem of climate change if we can’t track the changes. Losing Mauna Loa would be a huge loss to climate science. If it shuts, other observatories such as Australia’s Kennaook/Cape Grim will become even more vital. Read more here