One of the correlations, maybe the only one so far discovered, between CO2 concentrations in the atmosphere and temperature is that first the temperature rises, then 600 years later, the CO2 increases. That may be caused by the ocean absorbing large amounts of CO2 out of the air when it is cold, and then releasing it when the ocean warms up again.
If we are heading into a sharp cooling, the ocean will draw CO2 out of the atmosphere. In the last ice age, we went down to 180ppm, and today we are only at 400+ppm. Photosynthesis stops at about 150ppm. So if we don't want to gamble that the next minimum will take us below 150ppm, putting more CO2 into the atmosphere would be a good idea.
The climate is also affected by several cyclic variations in the earth’s orbit, changes in the intensity of volcanic activity, occasional meteorite impacts, and large-scale natural but poorly explained changes in climate such as the Younger Dryas and the 8.2 ka event.
Having to fly often to Malaysia on business I realized that the oceans are very big. We are very small.