I don't think overpopulation is such a big problem .. well it is if we keep starving the 3rd world, but if we actually helped them for once, by giving them better prices for their goods and speed up their development, then there would be plenty of food and they would have a better economy to fund their educational system and entire infrastructure etc..
there's plenty of land to plant forest on and set up preservations .. and with a better economy most of the tropical countries wouldn't need to cut down all their forests to make a living!
Economy is the biggest issue for me .. but not at the expense of the enviroment, CO