Global Cooling is occurring since the blooms are earlier. This phenomenon has nothing to do with CO2 concentrations but the recovery of the plankton populations after decades of atomic weapon testing. if there are no further tests or oil spills than the fish stocks will also recover. It is obvious that if you destroy the phytoplankton by bombing than the bacteria will take over and suppress the phytoplankton. It takes a long time to recover. if it had not happened the ocean would die and we would go back to precambrian times with little Oxygen to breathe and water would also evaporate leaving a Martian landscape.
Actually the phytoplankton bloom has a lot more to do with cosmic ray flux which is greater in the arctic regions and at this time with low sunspot numbers. A greater cosmic ray flux is devastating to zooplankton which have no calcium carbonate shell to protect against the short wave radiation. So they migrate downward as the phytoplankton go upward in their diatom shells and the population booms. At night the zooplankton feed but the bacteria population is also down so more DMS that is released from feeding escapes to the atmos to form clouds and thus the Cooling commences. that is it in a nutshell, of course the full explanation is much more complex which includes cavitation, ecology, water temperatures, seasonal variations, currents etc.
