I'd say (if the volcanoes are any indication), although that doesn't mean adapting to the cold isn't worthwhile (since all non-cold-adapted species are currently experiencing population decline), and the icecaps will stick around even after that.
Depends on who you are. A small plant might profit from a forest fire destroying the larger plants that used to overshadow them, which would enrich the soil and remove competition for light, for example.
For a more extreme example, I don't see any mammals complaining about the K-T extinction.
EDIT: If the question was about events that are exclusively positive, I don't know if those exist in nature.