Have we factored in carbon sequestration as bones and shells of larger creatures?
Intuitively, there wouldn’t be enough to make a significant difference. Even shells and bone are often degraded if not buried quickly and contain little carbon to begin with. It took eons for enough shells to form chalk to accumulate. It is doubtful this occurs fast enough to make a major difference in the short term. Also, bravozulu is outright lying. Increasing the CO2 concentration does not give you massive increases in carbon fixation. Very rarely is CO2 the limiting nutrient. Algae won’t magically start fixing more carbon unless you start dumping huge quantities of ammonia and phosphorus in the North Atlantic as well. Not to mention the fact iron would do absolutely nothing. The only form of iron usable by life is reduced iron. This can’t exist with oxygen, which rapidly makes the oxidized form of iron, which happens to be insoluble (organisms uptake the very limited oxidized iron still in solution and reduce it). Iron is a limiting nutrient only because it is insoluble in the env
