Let me try to explain it this way. Let's start with the

wiki carbon cycle model:

Please note it starts with 750 GtC in the atmosphere and 39120 GtC in the ocean. This totals 39870 GtC. 1.88% of it is in the atmosphere and 98.12% is in the ocean. This is a 52.16:1 ratio.

Next year, we add 8 GtC and the ocean absorbs 2 of it. We Now have 39878 GtC with 1.90% of it in the atmosphere (756 GtC) and 98.10% in the ocean (39112 GtC). This is a 51.75:1 ratio.

Another year, we add 8 GtC and the ocean absorbs 2 of it. We Now have 39886 GtC with 1.91% of it in the atmosphere (762 GtC) and 98.09% in the ocean (39124 GtC) . This is a 51.34:1 ratio.

Another year, we add 8 GtC and the ocean absorbs 2 of it. We Now have 39894 GtC with 1.93% of it in the atmosphere (768 GtC) and 98.07% in the ocean (39126 GtC). This is a 50.95:1 ratio.

See, as the temperature increases, the ocean holds less and less, percentage wise. If man did not add any CO2 at all, the percentages would still change with temperature. CO2 would change as follows:

Start 39870 GtC, 750 (1.88%) in the air, 39120 (98.12%) in the ocean,

First year, 39870 GtC, 755.8 (1.90%) in the air, 39114.2 (98.10%) in the ocean

Next year, 39870 GtC, 761.7 (1.91%) in the air, 39108.3 (98.09%) in the ocean

Next year, 39870 GtC, 767.5 (1.93%) in the air, 39102.5 (98.07%) in the ocean

Please note that the ratios also change like the first four examples and the ocean is now a net source, of 6 GtC annual. That's what warming does.

Look at it as quantity and ratios. Not simple addition and subtraction. Solubility of CO2 increases as water cools and decreases as water warms.