This is certainly true, but amount matters. If its 300 years then we have a problem, if its 3000, maybe not so much. Articles like this do not help give perspective.
There are almost no positive feedback loops in nature, for the simple reason that they tend to get triggered by random variations and feedback on themself till they reach limit and convert to negative loops.
"The fact that the ice core records do not seem full of methane spikes due to high-latitude sources makes it seem like the real world is not as sensitive as we were able to set the model up to be."
Actually since ocean acidification provides a chemical power source for protozoa, we probably only have a year or two before one of the species adapts and brings it back to it's previous level by harvesting the energy in it. That will allow one of those species to rapidly spread, which is exactly what we want in this case.
Trying to fix it using any kind of non-self-replicating technology is, imho, a non-starter.
