The climate after 450 PPM: ‘Detectives’ investigating past climate prepare us for the future

Published 23-12-2023

An insight into the Miocene can help us to be better prepared for future climate change.

Photo: Underground Channel.

There has been a large increase in the CO2 content of the atmosphere – from about 280 ppm (parts per million) in the pre-industrial era to almost 420 ppm today. The last time Earth experienced similar atmospheric CO2 concentrations was millions of years ago, during the Miocene epoch.

Kasia Śliwinska, Senior Researcher at the Geological Survey of Denmark and Greenland (GEUS), is a kind of ‘climate detective’. Kasia Śliwińska studies what the climate was like during the Miocene, and her research can be used to tell us about the climate changes that we can expect in the very near future.

The study of the Miocene is particularly important for understanding the effects of climate change as the CO2 values increase. The remarkably warm period 14-17 million years ago, known as the Miocene Climatic Optimum, is the most recent period in Earth’s history with CO2 levels corresponding to the values that we can expect in the coming decades (i.e. around 400-600 ppm).

“Of course, our data from the Miocene are not as comprehensive as those that have been measured in modern times. But our data from the Miocene are based on fossil pollen, spores, plankton and biomarkers that can tell us about e.g. temperature, precipitation and changes in the vegetation, which gives us a very clear picture of what the climate was like back then,” says Kasia Śliwinska.

Therefore, it is an obvious choice to study this period in order to make more qualified predictions about how the climate will change when the CO2 levels are high.

Kasia Śliwinska talks about her research in this film by Underground Channel:

Life Beyond 450 PPM - Underground Channel.

Kasia Sliwinska
Senior Researcher
Geo-energy and Storage
Malene David Jensen-Juul
Communications Officer
Press and Communication