GEG 1302 Lecture Notes - Lecture 7: Centenarian, Birth Rate, Wheat
3 Feb 2017
School
Department
Course
Professor
Document Summary
World population: 7, 481, 277, 000 (approx. : as of 5pm on jan 31, 2017. Increasing by approximately 100 million/year: 1 birth every 8 seconds, 1 death every 11 seconds. Population will continue to grow, at least until mid-century. Today, attention focuses on capacity of the global environment to sustain a large population. In past, concern focused on famine, insufficient food production, disease. Components of population change: births, death, migration. Live births: crude birth rate (cbr, 8-55/1000 people for a given year, world cbr = 20 in 2011. Fertility: total fertility rate (tfr, world tfr = 2. 5 in 2011, replacement-level fertility: 2. 1-2. 5 children per woman. Doubling time: measure of how long it will take a population of a region (e. g. a country) to double in size. At a growth rate of 1. 8% per year, population doubles in about 40 years. Factors affecting fertility: biological, economic, social, cultural.
