A global food disaster.

Sid Perkins reminds us in "Disaster Goes Global" (SN: 8/30/08, p. 16) that in some regions we humans are already consuming close to two-thirds of the land's biomass. A couple of years ago, a study warned us that at current fishing rates we'll deplete the ocean's seafood stocks by 2050 ("Worthless waters," SN: 11/4/06, p. 291). Yet unless we make efforts to slow the growth of the world population, our numbers will increase by 40 percent in that same time frame. Is my math wrong, or are we going to run out of food?

Patricia Leitner, Oakland, Calif.