Because this time a glacier that broke off from Greenland could sink a ship! Since that's never happened before, or well it has happened, but that just proves global warming, we need to panic. I don't mind the science behind climate change. I have no doubt that the technology and industry humanity immersed itself in over the last couple hundred years hasn't been good for the environment. That's, of course, why I tend to be hesitant about turning the keys over to science to solve all of our problems.
But the not-too-subtle subtext of this story, that this is yet another reason to fear MMGW, when the story has to stop to refer to that other famous example from almost a hundred years ago, is the problem that seems to permeate all modern discussion of the phenomenon. When I see more predictions come true, and hear some scientists admit there could be things that disprove MMGW but here's why they aren't happening - as opposed to saying whatever happens in the climate world proves MMGW - then I'll be more inclined to listen.
Also it wouldn't hurt if MMGW didn't sound the 'we're going to die' mantra that dominates modern science, mixed with the teaching that humanity, being nothing more than a festering malignant blight on mother earth, might need to be exterminated from existence for the greater good.