Mass third-world immigration into Europe.
Couple that with their low birthrates, and the immigrants high birthrates, and you can project that most Europeans won't exist by the turn of the century. I suspect something similar is going to happen to Japan too, given the talk of their low birthrates.
The general term for all of this is globalism. This Chomsky quote says it in an interesting way:
"See, capitalism is not fundamentally racist -- it can exploit racism for its purposes, but racism isn't built into it. Capitalism basically wants people to be interchangable cogs, and differences among them, such as on the basis of race, usually are not functional. I mean, they may be functional for a period, like if you want a super exploited workforce or something, but those situations are kind of anomalous. Over the long term, you can expect capitalism to be anti-racist -- just because its anti-human. And race is in fact a human characterstic -- there's no reason why it should be a negative characteristic, but it is a human characteristic. So therefore identifications based on race interfere with the basic ideal that people should be available just as consumers and producers, interchangable cogs who will purchase all the junk that's produced -- that's their ultimate function, and any other properties they might have are kind of irrelevent, and usually a nuisance."
I don't look forward to a future where there aren't different cultures to appreciate, which is guaranteed to happen if things continue to progress as they have been.