I'll start this one out by saying that if you're looking for your average, action/effects-heavy disaster movie rollercoaster, you will not get it here. The way I see it, writer, Chris Sparling ('Buried') and director, Ric Roman Waugh ('Angel Has Fallen') took into consideration the zombie apocalypse scenarios that are 'The Walking Dead' and 'The Last of Us', and asked "why have they never done this with disaster movies?"
Nine times out of ten, an average disaster movie is entertaining because of its effects-driven action, and its meant to be a sort of thrill ride with little bits of attempted drama thrown in. Sometimes they're awesome, sometimes they suck, sometimes they're a combination of both, but you check these movies out for a little dose of adrenaline with a laugh here and there. 'Greenland', however, was probably the first disaster movie I've ever seen that actually made me feel a sense empathetic of dread. This is due to the fact that they gave me characters I gave a damn about, and the story is much more about them than the disaster itself. Going back to the aforementioned zombie material, that's what it felt like to me - what's happening around them doesn't matter nearly as much as what's happening to them.
The film centralizes on a "family" of three; John Garrity (Gerard Butler), his estranged wife, Allison (Morena Baccarin), and their son, Nathan (Roger Dale Floyd). As small details about their relationship are revealed, in the meantime, a comet is said to be passing by the Earth named "Clark" (Possibly after Clark Kent?). Due to reassuring news reports and the like, the comet seems to be nothing to worry about. That is, until something changes its trajectory, and it starts heading towards Europe with plenty of big town-killing space rocks in tow.
While many smaller meteors and meteorites start landing, John is alerted by phone and TV that he and his family have been selected as part of a survival lottery. They are to report to a secret location in order to be flown to a secret bunker, far north (guess where), which will house any hopeful survivors of the disaster in order to rebuild. The catch is that they can't bring anyone in tow - no exceptions. This is all illustrated with a pretty emotional scene, but to the film's credit, that's exactly what it's out to do. This was just one part of the film that made me feel that genuine dread, and think to myself "this movie isn't messing around".
All goes pretty well until due to an admittedly stupid mistake, young Nathan's insulin gets left in the damn car. This sends John back for it, but while he's gone, the military in charge find out Nathan's diabetic and there are to be no illnesses on board the flight. One thing after another unfolds after that, and as I say, the film doesn't mess around and seemingly makes things very real-world, given the situation. Some examples of this include the fact that there are seemingly good-natured and terrible people wandering around. One particular looting scene illustrates this concept almost perfectly. We also see how good natured people can turn, and vise-versa, and the whole time, you're with this family, experiencing their respective experiences more than the film taking you to a variety of different groups and characters.
This may, however, be one of those cases where I give the film more praise than some. As mentioned earlier, this is not your average run of the mill disaster movie, and I think that's important to know before going in. If you are looking for a whole lot of awesome effects and a fun time, this isn't gonna be for you. Things do get dramatic here, and things honestly even get a little scary at times, often not having anything to do with the comet in question. I think this is one to approach if you want a good emotional ride as opposed to a good action-packed ride. Otherwise it may not quite be for you. If I'm honest, I kind of loved it, and at no point did I roll my eyes at it... except when I found out the military uses the same scanning gun I do at work.