The message of winter-time air pollution and the need to limit driving, reduce wood burning, etc., now is one with which most Denver area residents are familiar.
(The message of winter-time air pollution and the need; is; one with which most Denver area residents are familiar; T:now) (most Denver area residents; are; familiar)
The message of winter-time air pollution and the need most Denver area residents
is are
one with which most Denver area residents are familiar T:now
familiar