 In 2017 the UN predicted a decline of global population growth rate from +1.0% in 2020 to +0.5% in 2050 and to +0.1% in 2100.Jørgen Randers, one of the authors of the seminal 1972 long-term simulations in "The Limits to Growth", offered an alternative scenario in a 2012 book, arguing that traditional projections insufficiently take into account the downward impact of global urbanization on fertility.Randers' "most likely scenario" predicts a peak in the world population in the early 2040s at about 8.1 billion people, followed by decline.