Albert A. Bartlett is Professor Emeritus of Physics at the University of Colorado in Boulder. He has long been an outspoken critic of population growth. His latest work, urging the United States to begin reducing population immediately, is here.

Parts one and two of this article, from Canadian soil scientist Peter Salonius, clearly show how our current food production practices are unsustainable.

Here is an excellent article from Brishen Hoff debunking the myths surrounding population growth and its economic impact.