As reported in New Scientist, revised United Nation population estimates see 800 million fewer people on Earth in 2050 than were predicted just a year ago. This reduction is equivalent to the entire current population of North America (United States, Mexico and Canada combined). There’s still gonna be a lotta folks, tho. The new UN estimates see a rise in Earth’s total population from its current 6.3 billion to 8.9 billion in just under fifty years from now. The drop in estimated population numbers is split equally between 400 million fewer births due to falling birthrates and 400 million due to skyrocketing HIV/AIDs infection rates. “HIV/AIDS is a disease of mass destruction,” said Joseph Chamie, the head of the U.N. Population Division in New York. So far, 20 million have died of AIDS and 40 million more are infected today. Chamie predicts AIDS will claim 278 million lives by mid-century and have prevented the birth of over 100 million more who would otherwise have been born to the victims of AIDS. Beyond 2050, “fertility rates will be below replacement levels in three-quarters of the world”, with industrialized countries seeing population drops from 15% down in Japan to 50% down in Russia from today’s census levels. Populations of the U.S. and U.K. are expected to grow primarily based on their current levels of immigration. The next five decades are also set to see a massive ageing of the world population. The number of people over 80 will rise fivefold. The median citizen – the one with half the world older than him or her and half younger – will be aged 37 in 2050, compared to 26 today.