Are ocean currents in danger of slowing down or stopping and not circulating oxygen to the bottom of the oceans?

Neh

yes, it has happened several times in the history of the earth. one time was so heavy, that just the oceans surface had oxygen and the lower levels were acidicly full of sulfuric compounds. it was one of the larger species vipe outs. in this time the climate was very hot and the polar caps were very small or didnt exist at all.

Awkwardly right now, the ocean is sucking up so much, the acid levels have increased like 10% (dont quote me) And is starting to kill off the bottom dweller fishies.

By the time we even get down there, we'll kill everything off.

I think it's thought that water circulation is a result of temperature variance, so change the temperature of the water and - ya it will probably change and not for the better. Thats not as bad as whats down there that we should be very afraid of is the massive amount of methane, that will spice things up quite a bit and the fact that where changing the structure of water itself to not be able to hold oxygen at all to sustain life by using detergents and phosphates, thats called a dead zone.
Its actually really depressing stuff when you think about it.


http://en.wikipedia.org/wiki/Ocean_current

http://en.wikipedia.org/wiki/Dead_zone_(ecology)