Start with this:

http://carto.eu.org/article2481.html

A +10 C change in temperature goes with a +100 ppm (parts per million by volume) change in CO2 concentration. Kirsten asks how much CO2 would be released from the ocean if the world warmed up by 1 C. The solubility of CO2 in water decreases with temperature.

http://jcbmac.chem.brown.edu/myl/hen/CO2Water.gif

The average ocean temperature is around 14 C. At that temperature, water can hold up to 0.2 g CO2 / 100 ml, and if saturated with carbon dioxide, releases 0.05 g CO2 / 100 ml / C. That's 50 g / m3 / C (m3 is one cubic meter).

The density of CO2 at atmospheric pressure is 2 kg / m3. So one cubic meter of water releases 0.025 m3 when it warms up by 1 C.

Consider a square meter of ocean and the atmosphere above it. The ocean is almost all at 4 C. There is a surface layer that changes temperature.

http://www.windows.ucar.edu/tour/link=/earth/Water/temp.html&edu=high

The surface layer appears is "100 to 400 meters" thick. Let's say 200 m. Lets assum that if the average annual surface temperature of the world rises by 1 C, this surface layer warms up by 1 C also. It releases 200 * 0.025 = 5 m3 of carbon dioxide.

The column of air above our cubic meter of ocean is at atmospheric pressure at the water surface. Its pressure halves every 6000 m you go up.

http://en.wikipedia.org/wiki/Barometric_formula

As far as the amount of air is concerned, this column of air is approximately equal in mass to a 6000-m column of uniform pressure 1 atmospher. We can approximate the column with 6000 m3 of air at atmospheric pressure.

When we mix 5 m3 of CO2 with 6000 m3 of air, we get a 1,700 ppm increase in CO2 concentration. The earth is only 3/4 ocean, so for the earth's atmosphere as a whole, let's say roughly +1000 ppm / C.

If the oceans are saturated with carbon dioxide, a 1 C rise in global temperature would release enough CO2 from the ocean to raise the concentration of CO2 by 1000 ppm. We observe only a 100 ppm / C effect.

That's because the oceans are far from being saturated by carbon dioxide. Instead, they are in some kind of equilibrium with the atmosphere. From what we read, this equilibrium is complex, involving carbolic acid and other compounds, as described here:

http://www.john-daly.com/oceanco2/oceanco2.htm