"Significant" has a very personal context. Things that affects significance to me are things like: proximity to my home/work, my hobbies, my age, my financial situation, etc.
For example, if my neighbourhood's crime rate had gone up by 100%, I'd want to see that amongst the top news of the day.
I don't like the word "top" because even on the most uneventful day there's going to be something that qualifies as top (because of the lack of competition).
So proper term would probably be "globally significant news" or "news significant to humanity as a whole".