This is the distinction between feedback and forcing (see the Real Climate article cited above). (illconsidered.blogspot.ru)
When a major science journal publishes a major climate article led by our top climate scientist — and is wise enough to make it an open access article — you MUST read it. (thinkprogress.org)
I've tried to explain the same thing numerous times in the comments sections of many climate articles. (skepticalscience.com)