http://www.economist.com/news/international/21619986-un-study-sparks-fears-population-explosion-alarm-misplaced-dont-panic
actually somewhat more than I remembered, so my apologies, but still well within carrying capacity for the planet, as it stands currently. I'm afraid however, the actual population in 2050 will be under 1 billion, as climate change renders a lot of very heavily populated land uninhabitable (India, Egypt/Sudan/Kenya, south east asia), and submerges some bits. Which I guess will solve the population pressure problem, in a hideous fashion.