Am I all wet here?
Short answer: somewhat damp.
In general I think we overfertilize the coastal areas (and maybe shipping lanes) and overharvest the food chain (defertilizing the open ocean?); both of which disrupt and lower the productivity overall.
That would make sense if the open oceans were ever fertile and bursting with life. They were not. The dearth of life over most of the abyssal plains was not caused by our fishing practices.
Whales used to eat a million tons a day of CO2 (in plankton). Now it is more like a thousand tons/day because there are so few whales. I think that'd be true across the board.
This is an interesting thought. You seem to be equating whales to trees as carbon sequestration sinks. Do whales keep growing throughout their lifetimes, continually adding carbon? What is the fate of the carbon in krill, now that fewer whales are available? Is it added to the biomass of other predators, or does it just rot and return to the atmosphere? I don't know the answers to these questions, myself.
I've been thinking about this for months and am still learning about the overall picture of climate influences. Overall I wonder if the increase in CO2 over the "industrial era" might be more tied to our depletion of the productivity of the oceans. The assumption being that healthy oceans would have been able to soak up the increasing CO2.
I don't know how the oceans fit into the the global carbon balance relative to other parts of the carbon cycle. Investigating the dynamics of the various carbon pools is pretty hot research in a number of the earth sciences right now. I can't say you're wrong.
The oceans may hold more carbon, but how dynamic is that pool? What is the capacity of the ocean for holding carbon, and how is that capacity influenced?
I guess I also feel that if the oceans aren't made into better carbon sinks, cutting down on our output of carbon by even 50% won't make much diffenece. Isn't the decrease in pH of the oceans an indication that they won't be absorbing much more CO2?
Ah, feelings. Without better knowledge of the global carbon balance, that's all the two of us can express on this topic. If the oceans are reaching their capacity for absorbing carbon, why wouldn't reduction in carbon emissions make a difference?
Dissolving CO2 in water certainly lowers its pH. Is that the reason the pH of the oceans are changing, and does it mean the limit of carbon absorption is at hand? I have no idea. I'm a dirt scientist.
Every thing I read about fertilizing the oceans ends with a paragraph saying that we can't recommend this because it'd probably have worse unintended consequences; but how is that any different from what we've been doing all along to the lands, rivers, lakes, and oceans?
I agree with what you've read. The difference between intentionally changing the chemistry of the oceans and accidentally changing it due to ignorance and short sightedness is moral, IMO. History is replete with disasterous consequences stemming from our intentional manipulation of natural systems. To do so on such a large scale is betting the lives of millions (or more) people, and populations of other creatures on a hypothesis.
