In terms of total global heat content sure. In terms of surface ocean temp, I'm not so sure you have a point. It's a pretty indirect path for greenhouse gasse

In terms of total global heat content sure. In terms of surface ocean temp, I'm not so sure you have a point. It's a pretty indirect path for greenhouse gasses to heat the ocean, and they can't push the water above the temp of their air. Less shade however can cause solar heating well above air temperatures.