The Pliocene as an analogue for near-future climate change?
In 1958, atmospheric scientist Charles David Keeling installed an instrument at the Mauna Loa Observatory, in Hawaii, designed to measure the average global concentration of carbon dioxide (CO 2 ) in the atmosphere. Little did he realise at the time that the results of this experiment, driven by a desire to characterise the composition of Earth’s atmosphere, would not only become one of the longest observational records in science , but would have important implications for humanity and life on Earth. As Keeling’s instruments continued to measure CO 2 over the decades, it became increasingly obvious that atmospheric CO 2 was rising, rapidly and apparently unabated. The cause of this long-term trend was debated early on, but general consensus was soon reached: anthropogenic activity, caused by deforestation and the burning of carbon-rich fossil fuels, was releasing this powerful greenhouse gas in quantities that fa...