A Canada goose flew in and rested for a few hours last week. At midnight, the sun is about 10 degrees above the northern horizon. I find that I have a little trouble sleeping. This is all very interesting. Carbon dioxide is the cause, the trigger, that starts the warming.
Water vapor provides the positive feedback that amplifies the warming.
Clouds, from condensed water vapor, may have a warming or cooling effect. I can see where an increased cloud cover would lower the surface temperature, that make sense. Let me try again. Increased CO2 is expected to lead to warming. This leads to increased water vapor which will also result in warming.