Mongabay: By 2100, over 13 billion people could be walking the planet. That's the conclusion of a new study published today in Science, which employed UN data to explore the probability of various population scenarios. The new study further demolishes the long-held theory that human population growth will quit growing by mid-century and then fall. "Analysis of these data reveals that, contrary to previous literature, world population is unlikely to stop growing this century," reads the paper. It's worth...