I don't think you can quantify the scale of a news just by numbers. Natural disaster happens on a regular basis, and brings widespread damage without discrimination: versus odd ball incidents that show a glimpse of trouble inflicted by our supposed civilization and higher believes, the value of these news is almost incomparable.
In fact, even the same piece of news looked at different perspective can yield very different values, if you look at the victim you get a personal battle against odds, but if you look at the suspect you get a cross section of the religious conflict that is shaping world politics on a greater scale. - One perspective will mean more then another depending on what the viewer is after.
Femine , imo is often disregarded because the situation is often a stalemate, with no real progress and change in sight, and people's attention will go away, massive number of deaths will interest the public only for so long, when they realize what they are looking is pretty much a status quo, they get use to it and sometimes, even trivialize it. It's just how human nature are more interested in a state of transition and new discovery - and it makes sense since NEWS is about the current and happening.
Here's a thought, how many people die of old age per day? and why isn't there a mass mourning about it?