As for the ad itself, I'm not sure what was going through the director's mind and it's probably a deep-seated metaphor on how we enjoy watching people getting people blown up in an explosion of blood and gore.
//blows up people in CoD4 Multiplayer
If it's an actual ad for cutting carbon emissions, it's essentially a death threat. If it's a jab at those who are pushing for cutting carbon emissions, it's too direct. Either way, it was pretty ill-conceived.