Overpopulation is not a global crisis since overpopulation is a myth.
The belief that the world is overpopulated is a simple myth. There are many areas of the world that have little or no human habitation. The entire population of the world could be fit in a space significantly smaller than the United States of America. Even when you add the extra space required for growing food and other resources there is still plenty of global land mass that would stand fallow.