[News] Climatic Chain Reaction Caused Runaway Greenhouse Effect 55 Million Years Ago

[Moontanman]

Climatic Chain Reaction Caused Runaway Greenhouse Effect 55 Million Years Ago

ScienceDaily (Dec. 27, 2007) — There are new findings regarding a phase of rapid global greenhouse warming that took place 55 million years ago. This period of climate change is regarded as the best fossil analogue to current and future greenhouse warming.

 

Climatic Chain Reaction Caused Runaway Greenhouse Effect 55 Million Years Ago

[Eclipse Now]

The wiki introduces this as:

 

The Paleocene/Eocene boundary, 55.8 million years ago, was marked by the most rapid and significant climatic disturbance of the Cenozoic Era. A sudden global warming event, leading to the Paleocene–Eocene Thermal Maximum (PETM, alternatively "Eocene thermal maximum 1" (ETM1), and formerly known as the "Initial Eocene" or "Late Paleocene Thermal Maximum",[1] (IETM/LPTM)), is associated with changes in oceanic and atmospheric circulation, the extinction of numerous deep-sea benthic foraminifera, and a major turnover in mammalian life on land which is coincident with the emergence of many of today's major mammalian orders.

 

The event saw global temperatures rise by around 6°C (11°F) over 20,000 years, with a corresponding rise in sea level as the whole of the oceans warmed.[2] Atmospheric carbon dioxide (CO2) concentrations rose, causing a shallowing of the lysocline. Regional deep water anoxia may have played a part in marine extinctions. The event is linked to a negative excursion in the δ13C isotope record, which occurs in two short (~1,000 year) pulses. These probably represent degassing of clathrates ("methane ice" deposits), which accentuated a pre-existing warming trend. The release of these clathrates, and ultimately the event itself, may have been triggered by a range of causes. However, an alternative mechanism has also been proposed.[3]

Paleocene–Eocene Thermal Maximum - Wikipedia, the free encyclopedia

 

However, my favourite journey into this story is from the ABC's "Crude".

Crude - the incredible journey of oil - Broadband edition - ABC Science

 

It's free online viewing. 90 minutes in 3 half hour parts. Get a coffee, and enjoy. It covers the geology of how oil is made in part 1, peak oil in part 2, and then a very frightening 'super-greenhouse' theory in part 3 which explores the anoxic oceans hypothesis.

 

VERY worth watching! Bookmark it, and watch half an hour with a coffee, and come back to it over the next few days. Or better yet, ask your local library to buy a copy off the ABC, and then people browsing at your local library can take it home and watch it on their big fat energy hungry Plasma TV's, and get the fright of their lives as they realise "global warming" has some very serious scenarios, and also a mean little brother called "peak oil".

 

Cheers all.