The excellent Kevin Lewis points us to a new paper in Science by Patrick Gerland, et.al.:
The United Nations recently released population projections based on data until 2012 and a Bayesian probabilistic methodology. Analysis of these data reveals that, contrary to previous literature, world population is unlikely to stop growing this century. There is an 80% probability that world population, now 7.2 billion, will increase to between 9.6 and 12.3 billion in 2100. This uncertainty is much smaller than the range from the traditional UN high and low variants. Much of the increase is expected to happen in Africa, in part due to higher fertility and a recent slowdown in the pace of fertility decline. Also, the ratio of working age people to older people is likely to decline substantially in all countries, even those that currently have young populations.
The paper is here, gated for some of you. A variety of summaries and forms of coverage can be found here. That is good news for those who buy into Julian Simon, bad news for those worried about environmental sustainability.