NEW research suggests that an extreme global warming event 56 million years ago was driven by massive CO2 emissions from volcanoes during the formation of the North Atlantic.

The study was led by the University of Southampton and involved a team of international scientists.

It used novel global climate modelling to show that the Palaeocene-Eocene Thermal Maximum (PETM) was associated with a geologically rapid doubling of atmospheric CO2 in less than 25,000 years – with volcanoes squarely to blame.

The PETM is the most rapid and extreme natural global warming event of the last 66 million years. It lasted for around 150,000 years and global temperatures increased by at least 5C – a rise comparable with projections of modern climate beyond the end of this century.

While it has long been suggested that the PETM event was caused by the injection of carbon into the ocean and atmosphere; the source of this carbon and the amount released, have up to now remained elusive.

To identify the source of carbon scientists measured changes in the balance of isotopes of the element boron in ancient marine fossils called foraminifera.

Southampton is one of few locations in the world where this kind of work can be carried out.

Professor Gavin Foster from the University of Southampton said: “How the ancient Earth system responded to this carbon injection at the PETM can tell us a great deal about how it might respond in the future to man-made climate change.”