Thursday, January 03, 2008

2008: like 55 million years ago...

Every once in awhile it is an encouraging thought to know that things can get even worse than they already are. That was the case tonight as I sat back down after the Christmas break (a good two days worth) to look at what stories had appeared in my feeds.

It appears that some 55 million years ago in the period which has now been enthusiastically named the Paleocene-Eocene thermal maximum (PETM), the planet suffered a global warming increase as a direct result of a rise in carbon dioxide levels.

The PETM phase was studied using sediments that had collected on the ocean floor, in what is now New Jersey. The new study published in the December edition of Nature shows that a large portion of the greenhouse gasses that warmed the planet were released suddenly as a result of a chain-reaction of events.

The most likely explanation is that carbon dioxide levels increased as a result of volcanic activity. As a result of those increased emissions heightening the greenhouse effect, submarine methane hydrates (ice-like structures in which massive amounts of methane are stored) melted, subsequently releasing large amounts of methane.

The study, which shows the chain-reaction amplification of global warming temperatures, is the first of its kind to be published.

But more importantly to us is the “analogous” story that is being told.

The new research shows and confirms that global warming can indeed set off a chain-reaction of events that further release stored carbon in to the atmosphere. Thus, current and future warming may very well see similar effects.

The group of researchers have also previously shown that tropical algae migrated north in to the Arctic during the PETM. When temperatures rose to 24oC, the research showed that the Arctic was home to crocodiles and palm trees; obviously items that are not conducive to a successful freezing of the oceans. Current climate models are incapable of simulating such high temperatures in the arctic, which have serious repercussions for future models predicting our climate future.

The journal article was entitled Environmental precursors to rapid light carbon injection at the Palaeocene/Eocene boundary and was written by Appy Sluijs, Henk Brinkhuis, Stefan Schouten, Steven M. Bohaty, Cédric M. John, James C. Zachos, Gert-Jan Reichart, Jaap S. Sinninghe Damsté, Erica M. Crouch & Gerald R. Dickens.

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