Key Points
Climate depends on radiation from sun
Surface and lower atmosphere cool by infrared radiation to space from upper troposphere (ERL= effective radiating level, such that total CO2 above is fixed)
Increased concentration of atmospheric CO2 raises ERL, reducing outgoing IR, until troposphere has warmed to compensate
Ocean heat storage in ocean takes decades to come to new balance
For given CO2 concentration, low clouds cool , high clouds warm