Hugely contravertial.

you have a lake. algae is growing. there is a nice ballance - fish eating algae, algea feeding off fish waste.
There are no predators, the fish multiply. The fish eat all the algae. The fish die. This planet can only support so many life-forms.

the issues:
do we set the limit by the amount of food that can be grown on the earth's surface? this means rainforests will b cut down and turned into farmland.
If we become vegitarian we can support many times the population. Will our overpopulating trend force us into veganism?
If we go with aquaponics we can have greenhouses of multiple floors, now we can support huge populations.
Will we be happy when we live in little cubicles with food grown in laboritories? at least there will be lots of us!
Do we adapt to the stresses of our population and use its momentum as a driving force behind our technological advancements?
Or do we halt our nature and control our population consiously?
where do we draw the line?
Does a global Government have the right to enforce a population control?
Should we be colonizing other planets and exporting our excess population by means of economical encouragement to settlers of new worlds?

Who is the champion for natural environments? Who speaks for the beasts and plants with no voice?