But.... what of acidification?
Two pluses of this approach are:
1. Increasing Earth albedo (reflectivity) would more solar energy back to space, reducing what the boffins refer to as the "energy imbalance" and
2. A cooler ocean will store more carbon dioxide and will keep methane clathrates frozen, reducing the threat that warm oceans will release a lot of carbon dioxide and massive amounts of heat-trapping methane gas.
But storing even more CO2 in the oceans has another result:
The oceans will become more acidic.
Why does this matter?
Geological history shows that when CO2 concentrations rise to high levels, most shellfish and other invertebrates (lobsters, crabs, etc.), become extinct. Their shells are eaten away by the acidic waters faster than they can build them. This process goes on, leaving calcium carbonate (limestone) deposits on the ocean floor, until a new balance (equilibrium) is reached.
Not only will humans miss out on centuries if lobster and shrimp, many of the larger fish that dine on shellfish will not survive. The impact on the food chain humans depend on could be severely disrupted.
It's a worthy study, but don't be lulled into a false sense of comfort. The level of CO2 in the air almost certainly still needs to come down to between 280ppm and 350ppm.