Otherwise, everything would radiatively cool at the same rate as if it were surrounded by absolute zero. Because it cools more slowly, it's temperature is higher than it would be otherwise. I don't care if people call this "warming" or "less cooling", the result is the same-water temperature will slowly increase over time relative to what it would be otherwise. -Scott Reply Kristian says:  July 0, 0000 at 00:00 PM  