I am going to post this on my bulletin board over my desk. I am working on kicking a killer (literally, if I let it...) soda habit and over the last two or three days found myself falling back into old ways. Coke isn't my poison of choice, but the point is well made and certainly applies to other soda brands as well.
I think overconsumption is the bigger issue. As previous posters have pointed out, it is the wealthy and developed nations of the world contributing the most to many global ecological crises, not the rapidly growing nations of the developing world. The "disposable" cultural practices we live with here in the USA cause ecological damage on a far greater scale than our population alone would suggest, and the world cannot support even a fraction of its current population if this is the standard of living to which the world aspires.