Look at Earth from space.
You see water, clouds and ice. The sun sees water, clouds and ice. The water vapor is also there but not visible. Water, in all of its states, is abundant on Earth.
Water, in all of its states, controls the temperature of earth. You do not build a massive cooling system with a trace of something. The temperature that sea ice does melt and freeze is the set point for Earth's thermostat.
In the long run, it will not matter. Oceans are warm and it is snowing more and earth will cool, beyond the point that it can be hidden. It may not be soon enough to prevent harmful measures being put in place to reduce CO2.
If you took away all the CO2, Earth temperature would possibly change a little, but water, in all its states, would still regulate the temperature in or near the same range. CO2 provides a small part of the total Greenhouse effect and provides nothing to account for the other properties of water in all of its states.
If you took away all the Water, in all of its states, you would have a planet more like Mars and temperature would get much hotter where the sun was shining and much colder where the sun was not shinning.
You do not control the temperature of a massive system with a trace of anything. You do control the temperature of a massive system with an abundant substance that changes state in the range that permits control. I learned this in Air Conditioning 101, back in the 1970's.