"This world is sad."
Since "sad" can mean either "saddening (depressing)" or "unhappy", I think that this sentence I gave can mean either "This world is saddening." or "This world is unhappy.", am I right? If yes, how can I let the person who is listening to me understand which one I mean when I say that sentence? Is it understood by the context?
For example, let's say I received some bad news about some killings in a country. In this case, if I said "This world is sad", I think it would be understood as "This world is saddening".