Tradu: this is amazing, just an hour ago I offered an english speaking friend to make "Save the Planet!" a multi-lingual forum. You officially started it: this topic is now officially in english,let's keep it that way, ok?
Overpopulation, then.
This issue was raised by Al Gore in his film "An Unconvenient Truth", and the solution is not terribly complexe, and doesn't necessarily raise any moral issues.
Think of the smoking tobacco issue: how is it being solved?
First campaign for decades about how overpopulation is bad and it's every one's responsability.
Then stop sponsering people for having kids, then tax them if they have kids, then.... make it illegal to make babies in public places!
See? Simple.
It's really too bad that I went for the joke (I like it, though!), because in fact I'm serious: I believe it's that simple (except we probably won't have to make it illegal) (let's hope).
A world comission could for instance establish how many people each country can sustain, and then it would be up to each country to try to reach that number. If they don't, they're taxed, if they do, they're sponsered, or awarded.
"Finland: ten points! Portugal: Disquallified!"
Sorry, can't help it...