According to the Population Media Center, Woody Allen gave this speech to graduates in 1979, which was subsequently republished in the New York Times. I haven't been able to locate the original source. But it provides some helpful guidelines for thinking about population  issues:

More than at any other time in history, mankind faces a crossroads. One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.

I speak, by the way, not with any sense of futility, but with a panicky conviction of the absolute meaninglessness of existence which could easily be misinterpreted as pessimism.

It is not. It is merely a healthy concern for the predicament of modern man. (Modern man is here defined as any person born after Nietzsche’s edict that “God is dead,” but before the hit recording “I Wanna Hold Your Hand.”) This “predicament” can be stated one of two ways, though certain linguistic philosophers prefer to reduce it to a mathematical equation where it can be easily solved and even carried around in the wallet.

Put in its simplest form, the problem is: How is it possible to find meaning in a finite world given my waist and shirt size?...

Overpopulation will exacerbate problems to the breaking point. Figures tell us there are already more people on earth than we need to move even the heaviest piano. If we do not call a halt to breeding, by the year 2000 there will be no room to serve dinner unless one is willing to set the table on the heads of strangers. Then they must not move for an hour while we eat. Of course energy will be in short supply and each car owner will be allowed only enough gasoline to back up a few inches...

Summing up, it is clear the future holds great opportunities. It also holds pitfalls. The trick will be to avoid the pitfalls, seize the opportunities, and get back home by six o’clock.