Fossil giant sea snail reveals what European summers may look like in the distant future

A Belgian-Dutch study shows that 45 million years ago, Western Europe experienced a warm and humid climate with monsoon-like conditions, under the influence of high CO₂ concentrations. The findings in this study are relevant for improving our understanding of current and future climate change.

The Champagne region is a popular tourist destination for many Belgian people. Its present-day attractions – rolling hills and culinary delights – were nowhere to be found 45 million years ago. During the Eocene period, much of what is now northern France was submerged, and the climate resembled that of the Bahamas. 

A Belgian-Dutch research team, led by KU Leuven, has now shed new light on the climate in Western Europe 45 million years ago. The researchers analysed the fossil shell of the Campanile giganteum snail, discovered in the Champagne region. Campanile giganteum is an extinct giant sea snail that grew exceptionally fast, and with this fast growth, a highly detailed account of the climate was recorded in the snail’s shell. Measurements of the shell’s calcium carbonate reveal that Western Europe at the time experienced monsoon-like conditions: mild winters, hot and dry springs, and warm, particularly wet summers with intense rainfall.

‘Because this fossil sea snail grew so rapidly, its shell contains a wealth of information. The growth lines provide a detailed picture of the climate and weather patterns millions of years ago,’ explains first author Nick Van Horebeek, who studied the shell for his master’s thesis at KU Leuven. ‘We combined our analysis with climate models and found that the pronounced seasonal contrasts could be explained by shifting wind and ocean circulation patterns.’ 
 

The Eocene shows how the climate system responds to very high CO₂ concentrations

Palaeontologist Johan Vellekoop (KU Leuven, Institute of Natural Sciences)

Worst-case scenario

The Eocene period, from 56 to 33.9 million years ago, was marked by a distinctly warm and humid climate and exceptionally high CO₂ concentrations. A better understanding of the climate during that period may be of great value in assessing the effects of current and future climate change. ‘The Eocene serves as a natural experiment that shows how the climate system responds to very high CO₂ levels,’ says Johan Vellekoop, head of the research team and professor of geology at KU Leuven, affiliated with the Institute of Natural Sciences.

‘If we fail to curb climate change and allow greenhouse gas emissions to rise unchecked, Western Europe may find itself in an Eocene-like scenario within a few centuries. However, if we draw the right lessons from the past, such an outcome can still be avoided.’

The study is published in the journal Nature Communications.
 

[This article is the press release by KU Leuven]