Originally posted by Gh0stFT
Moray37,
what do you think about methane hydrate (solid form of water that contains a large amount of methane)
extremely large deposits of methane hydrate have been found under sediments on the ocean floors of Earth).
Could this be the reason we had at the end of the Paleocene (55.5 to 54.8 Mya)
it was marked by one of the most significant periods of global change during the Cenozoic Era. A sudden global climate change, the Paleocene-Eocene Thermal Maximum (PETM), upset oceanic and atmospheric circulation, leading to the extinction of numerous deep-sea benthic foraminifera and a major turnover in mammalian life on land that marked the emergence of mammalian lines recognizable today.
Tracking the ratio of carbon isotopes in marine calcium carbonate sediments, a sharp decrease was found in the amount of heavy carbon in 55-million-year-old marine fossils. A synchronous drop in carbon isotope ratios in many terrestrial environments has also been identified,
indicating that a gas with very low amounts of heavy C-13 appears to have flooded the atmosphere.
Looks like a sea surface temperatures rose between 5 and 8°C could be enough to restart PETM soon?
An alternative theory proposes that a comet impact triggered the PETM?
R
Gh0stFT
I think, honestly, it's the one thing we have to fear the most. It is the single worst "greenhouse gas". It's heavy, it tends to hold in thermal radiation in concentration, and it binds with very few compounds, which makes it very interesting in the free form. And, no, we're not talkin about flatulence release, which, I already know, someone will go flailing off on (see laz) saying we now have to hold in our farts. The methane locked up in hydrate form (bound with ice or permafrost) is of quantity much more than that of all the release of all the animals on the planet. Also, CH4 is very tough to bind with other compounds. It is a metabolic inhibitor, unless it used by a chemiosynthetic organism. Once released it pervades in a gaseous form for a lengthy period...until locked back in hydrate form.
For a long time, the PETM was a mystery, how it happened and raised the global mean so fast... until someone looked into the methane deposits sitting in permafrost and the seabed. Suddenly all the traces started making alot of sense. The most disturbing thing to me, is recent cores seem to indicate the last ice age was ended by a similar event of lesser magnitude, and that that event may have ended the ice age in as little as 20 years.
Good post. Nice to see someone thinking past CO2.