billy, decreased cloud cover = increased radiation. Clouds/water vapour is accepted as the predominate greenhouse gas. In recent times record frosts have been occurring. Whilst the nights have been dropping to these record low temperatures, as warm as the following day gets, the temperatures reached don't get anywhere near record temperatures. Cloud cover may have greater effect radiating off heat trying to escape than radiating off heat trying to get in. Afterall isn't that what is being claimed for CO2?
