World population lesson (Statistics)

NCTM Illuminations
NCTM Illuminations

Is it feeling a little crowded in here, or is it just us? In November 2011, the UN predicted the world population had reached 7 billion.

In "The Next Billion," students try to predict when we will surpass 8 billion. Throughout the lesson, students discuss the reliability of their predictions, compare them to past trends and discuss social factors that affect population growth.

See http://illuminations.nctm.org/LessonDetail.aspx?id=L715 for the full lesson from NCTM's Illuminations Site.

Also, see an article in the Grand Island Independent: http://www.theindependent.com/opinion/columnists/george_ayoub/after-milestone-occupancy-rate-a-consideration/article_10b49f40-6cae-5467-8bc3-2c2f0cf39a21.html

According to this article, each minute, 255 people are born and 106 die. Using these numbers, how does your estimate for the population reaching 8 billion change? What assumptions must one make in predicting future populations?