[Aeium]

Isn't this just going to make the surface more alkaline by pumping the acid (co2 rich) surface layer deeper down?

Then the surface can in turn absorb more co2, but I think at the end of the day the ocean overall will have more dissolved co2 and it will become more acidic.

Am I misunderstanding something?

[stubish]

It is a 'temporary' solution really, giving time for emissions reductions and other CO2 sequestration to take effect. What gets pumped down will be released eventually (50% gone after 2000 years). And there is an upper limit to how much can be stored (1500 GtC, or 150 GtC from the atmosphere by 2100 without hopefully creating other problems).

[laserbeam]

In my general understanding, most life in the ocean livs at surface level, and you probably don't actually hurt much down below. Corals for example only live at shallow depth and they suffer from the acidity.

The abstract claims that acidity will rise in a few hundred years. So an overall acidity rise would happen 300 years from now.

It sounds like one of those "let's buy time" solutions. I'm ok with those. It also sounds expensive, and someone has to show that moving so much water below won't produce more co2 than it would save.

[ncmncm]

You also have to stop emitting CO2. Without, it is pointless, because the surface will just absorb more and acidify again.

[stubish]

Become carbon neutral, not stop emitting CO2. I very much want to continue breathing.

[ncmncm]

Stop emitting excess CO2. Breathing will remain permissible, for the present.

Come climate catastrophe, many will stop breathing as it consumes more calories than they have access to.