Roland Emmerich is actually a german. In an interview on german television, he stated that this movie connects his faible for big disaster-films and his wish to incite a discussion and second thoughts about the excessive 'american way of life' that creates pollution and depletes natural resources at a rapid rate and neglects all the possible consequences of such a life-style.

The only thing that makes me doubt his motivations is, that his films usually have a very american flavored happy end. Such an ending would be counter-productive to his goal to provoke a public discussion about the environmental consequences of the irresponsibility in common lifestyles in 'modern' industry nations.

Films like 'Independence Day' and his remake of 'Godzilla' were successful worldwide, so I wouldn't say the phenomenom of people being attracted to disaster films is only present within the borders of the United States.