posted on Jun, 26 2010 @ 08:21 AM
While i understand what your saying about the oil not being an extinction level event, the point is that your right. An oil spill/rupture is not an
extinction level event.
However the methane, which is being released in huge quantities as well, is
cause to worry about extinction.
there is algae-which turns light energy and water into oxygen-this is where a large percentage of earth's oxygen comes from.
there are also oil-eating microbes which break down oil into safer byproducts.
Methane depletes oxygen levels, something that both of these require to survive. Corexit is a toxic chemical which would most likely kill both of
these.
Crude Oil and related chemicals/gases are capable of killing the algae.
So, however you look at it- oil=less oxygen, corexit=less oxygen, methane=less oxygen. Which overall means the longer this continues unchecked the
more quickly the overall oxygen-producing capacity of the earth and her creatures is being depleted.
No methane is actually lighter than the air causing it to diffuse slowly upwards, but like you said it would rise more forcibly with heat, or the
ocean could just get saturated and then release it in a large "explosion" but it doesnt matter how it makes its way into the atmosphere the point is
it will, eventually. And once it makes it there, it has 21 times the heat trapping potential of co2.
A chain reaction of warming could easily be caused by this release of methane: methane released in significant quantities from rupture enters
atmospere, then traps significant amounts of heat, causing a significant rise in temperature, causing the sublimation of millions of tons of
methane-hydrates that are currently sitting on the sea floor.
There has always been large methane-hydrate fields on the seafloor, something disrupted them in the past- and the result was the Permian-Triassic
extinction event which killed off 95% of all life on earth. It took millions of years for earth's biodiversity levels to return to pre-extinction
level.
The following is an excerpt from an essay i wrote for Eng102(only 3 years ago lol)
“Ninety-six percent of all marine species and seventy percent of terrestrial vertebrae species [became extinct.]” Approximately 251 million years
ago, life on Earth came frighteningly close to extinction, during the event known as the Permian-Triassic extinction event, informally referred to as
the Great Dying. Hardest hit were the marine species, in which only four percent of existing aquatic life survived. Almost six-million years passed
before regular levels of biodiversity returned. While the exact cause remains in dispute, one widely accepted theory references “[t]he flood basalt
eruption which produced the Siberian Traps [and] was the largest known volcanic event on Earth and covered over 200,000 square kilometers (77,000
square miles) with lava.” These eruptions occurred in a coal rich area, the heating of which caused extremely large quantities of carbon dioxide
and methane to be released into the air, leading to extreme global warming of up to 5°-7°C. In turn, this warming was enough to “sublimate solid
methane hydrate[s]” that were present in millions of tonnes on the ocean floor(“Permian-Triassic extinction event”). Today, the warming
predicted by the Arctic Council would be sufficient to sublimate the nearly 400 gigatons of methane locked in clathrates (forms of methane and other
gases locked in ice formed by great pressure) in the arctic tundra. This could easily lead to a similar chain of events in the near future(Atcheson).
Atcheson , John. "Ticking Time Bomb." Baltimore Sun 15 Dec 2004 27 Feb 2007 .
"Permian-Triassic extinction event." Wikipedia. 24 Feb 2007. 27 Feb 2007 .